ICHNO-ECHNO 2022 - Abstract Book

3-5March2022 ONSITEINBRUSSELS,BELGIUM&ONLINE

Radiotherapy &Oncology Journal of the European SocieTy for Radiotherapy and Oncology

Volume 168 Supplement 1 (2022)

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ICHNO-ECHNO 2022 3-5 March 2022 ONSITE IN BRUSSELS, BELGIUM & ONLINE

Table of contents

THURSDAY 3 MARCH 2022 Keynote Lecture

The good and bad of TNM8...................................................................................................................................... Abs. 0001 Biomarker guided treatment and monitoring for head and neck cancers.......................................................... Abs. 0002 Symposium AI in head and neck oncology. ....................................................................................................................... Abs. 0003-0005 Proffered Papers Innovative highlights 1.................................................................................................................................... Abs. 0006-0011 New data from randomised trials.................................................................................................................. Abs. 0012-0017 Symposium Modern management of unknown primary H&N tumours. ....................................................................... Abs. 0018-0021

FRIDAY 4 MARCH 2022 Keynote Lecture

New concepts in the management of oligmetastatic disease. ............................................................................. Abs. 0022 Intraoperative margin analysis. ............................................................................................................................... Abs. 0023 Proffered papers Innovative highlights 2.................................................................................................................................... Abs. 0024-0029 Symposium The role of IO in the curative setting............................................................................................................. Abs. 0030-0032 Proffered papers Innovative highlights 3.................................................................................................................................... Abs. 0033-0038 Symposium How to manage frail patients in the localised setting. ................................................................................ Abs. 0039-0041 SATURDAY 5 MARCH 2022 Keynote lecture Update on the role of de-escalation in HPV driven disease.................................................................................. Abs. 0042 Symposium Innovative techniques to improve functional outcomes............................................................................. Abs. 0043-0045 Debate This house believes that follow-up should be symptom based. ................................................................ Abs. 0044-0053

DIGITAL POSTERS Epidemiology and prevention......................................................................................................................... Abs.0054-0058 Imaging, radiomics and artificial intelligence. .............................................................................................. Abs. 0059-0068 HPV or EBV related cancers............................................................................................................................ Abs. 0069-0083 Innovative treatments..................................................................................................................................... Abs. 0084-0097 Minimal invasive and reconstructive surgery................................................................................................ Abs. 0098-0112 Multidisciplinary management. ..................................................................................................................... Abs. 0113-0130 Biology and molecular targeting.................................................................................................................... Abs. 0131-0139 Immuno-oncology. ........................................................................................................................................... Abs. 0140-0153 Supportive care, quality of life, rehabilitation. ............................................................................................. Abs. 0154-0169 Salivary gland, skull base, skin and thyroid cancers..................................................................................... Abs. 0170-0177 Management of elderly or frail patients. ...................................................................................................... Abs. 0178-0185 COVID-19.......................................................................................................................................................... Abs. 0186-0188

ABSTRACTS

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Keynote lecture: The good and bad of TNM8

SP-0001 The good and bad of TNM8 Brian O’Sullivan Canada

Abstract not available

Keynote lecture: Biomarker guided treatment and monitoring for head and neck cancers

SP-0002 Biomarker guided treatment and monitoring for head and neck cancers

R. Brakenhoff 1

1 Amsterdam UMC, Department of Otolaryngology -Head and Neck Surgery, Amsterdam, The Netherlands

Abstract Text Head and neck squamous cell carcinomas (HNSCC) develop in the mucosal lining of the upper aerodigestive tract. At present two separate disease entities are distinguished: HNSCCs caused by human papillomavirus (HPV) infection and those that do not contain HPV. These tumors are distinguished based on p16 immunostaining as surrogate biomarker, often combined with a HPV DNA and/or RNA assay. The presence of p16 immunostaining or HPV DNA are a most well accepted biomarkers for tumor classification. Staging has been adapted for HPV-positive tumors in the TNM 8th edition, but remarkably treatment not. According to the National Cancer Institute, a biomarker is “a biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease,” such as cancer. Biomarkers can be applied for diagnosis, response prediction or treatment-guidance, and patient monitoring. Focus in this presentation are biomarkers associated with treatment response and disease monitoring. There are several trials in recurrent/metastatic disease to tailor treatment to mutations in the tumor, but results are far from optimal. Although the high-throughput genomics of head and neck cancer revealed intriguing new insights, these studies did not provide a wide array of novel therapeutic leads to be exploited on basis of the concept of oncogene addition. More complex synthetic and collateral lethality concepts have to be exploited, and recently an intriguing synthetic lethal interaction with the FAT1 tumor suppressor gene has been identified. Vice versa, for several routinely applied treatments such as cisplatin-based chemoradiotherapy, cetuximab-based bioradiotherapy, and anti-PD-(L)1 immune checkpoint inhibition biomarkers for response are urgently awaited, but are still lacking. Finally, a few disease monitoring approaches will be discussed. Most promising option is circulating tumor DNA analysis in blood and other liquid biopsies, but specifically early detection of recurrent disease is complex. Small tumor deposits are hard to detect, not only by imaging, but also by biomarkers. However techniques improve, and exciting new developments are underway.

Symposium: AI in head and neck oncology

SP-0003 AI guided pathological diagnosis Frederick Klauschen

Abstract not available

SP-0004 AI for better diagnosis and surgical treatment of head and neck cancer Cesare Piazza

Abstract not available

SP-0005 AI for head and neck radiation oncology

J. Bibault 1

1 Hôpital Européen Georges Pompidou, Radiation Oncology Department, Paris, France

Abstract Text Artificial Intelligence (AI) and Machine Learning (ML) have promising applications in radiation oncology. ML algorithms include data from many different sources that can be clinical, biological, radiologic, genomic and dosimetrics. They can be used to enhance the radiation oncology workflow management with automation of treatment planning steps such as automatic delineation or adaptive radiotherapy. They are also actively being explored as prognostic and predictive tools, correlated with histologic and genomic characteristics in several cancer types. In this presentation, each of these aspects will discussed: 1- Radiation Oncology Treatment Planning Radiotherapy treatment planning encompasses time consuming tasks such as delineation, dosimetric planification, and adaptive radiotherapy. Increasing automation of these tasks is a promising prospective. AI can also be used for Adaptive Radiation Therapy (ART) to take into account tumor shrinkage and patient emaciation during treatment. Benefits and

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feasibility of ART has been assessed by exploratory studies. ART is not routinely used, as a consequence of limited resources, its time consuming character, and unreliable automatic contouring. 2 - Normal Tissue Complication Probability Assessment NTCP models are usually based on dose–volume histograms (DVHs), which are not ideal representations of 3D doses and assume that all the regions of an OAR have an equal functional importance, thus discarding organ specific spatial information. Models taking into account more data such as 3D dose distribution in OARs, dependencies between the dose delivered at other OARs may enhance toxicity prediction. Models using machine learning might be well-suited since the bigger amount of interdependent data to take into account. 3 - Tumor Control Probability Assessment Improving the tumor control probability assessment before treatment is a promising way to adapt the treatment strategy. Head and Neck tumor treatment strategy mainly depend on the TNM stage. AI and radiomics could also be used to improve prognosis classification, determine HPV Status and extra nodal extension.

Proffered papers: Innovative highlights 1

OC-0006 Early detection of head and neck squamous cell carcinoma using RNA-seq on tumor-educated platelets

N. Wondergem 1 , J.B. Poell 1 , S.G. in 't Veld 2 , E. Post 2 , S.W. Mes 1 , M.G. Best 2,3 , E. Bloemena 3,4 , C.R. Leemans 1 , T. Würdinger 2 , R.H. Brakenhoff 1 1 Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Otolaryngology / Head & Neck Surgery, Amsterdam, The Netherlands; 2 Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Neurosurgery, Amsterdam, The Netherlands; 3 Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Pathology, Amsterdam, The Netherlands; 4 Academic Centre for Dentistry Amsterdam (ACTA), Maxillofacial Surgery/Oral Pathology, Amsterdam, The Netherlands Purpose or Objective Head and neck squamous cell carcinomas (HNSCC) arise in the mucosal lining of the upper aerodigestive tract, and are caused by carcinogen exposure or infection with human papillomavirus (HPV). The major determinant of prognosis is the occurrence of locoregional recurrence. Recurrences can be treated curatively, but late detection hampers clinical management. Tumor-educated platelets (TEPs) have been shown to hold promise as a diagnostic tool for several malignancies. The objective of this study is to provide proof of concept that TEPs might be well suited for early detection of (recurrent) HNSCC. Materials and Methods Platelet mRNA was isolated and sequenced from 101 HNSCC patients and 101 non-cancer controls. Non-cancer controls were matched for age, tobacco smoking and alcohol use. Patients and matched control pairs were randomly divided over training, evaluation and validation series (40/30/30%, respectively) to ensure equal distribution of matched variables among series. A particle swarm optimized (PSO) support vector machine (SVM) learning classifier was trained and re-trained iteratively using the training series to optimize classification performance of the evaluation series. Performance of the best classifier was subsequently evaluated using the independent validation series. Parallel classic statistical appoaches were employed for data analysis. Results 5,464 spliced mRNAs were detected. Those most contributive to the SVM algorithm were selected by ANOVA differential expression analysis, using PSO to determine the optimal FDR threshold. The resulting 200 gene classifier reached an AUC of 0.85 (95% CI, 0.75-0.95) and accuracy of 80% in the independent validation set for the detection of HNSCC, irrespective of HPV-status. Conclusion We show that a classifier of 200 TEP derived differentially expressed genes is able to identify HNSCC patients with an AUC of 0.85 and accuracy of 80%.

OC-0007 Intra-tumoral genetic heterogeneity in head and neck cancer

A. Pierik 1 , A. Brink 1 , J. Poell 1 , T. Poli 2 , R. Leemans 1 , R. Brakenhoff 1

1 Amsterdam UMC, Otolaryngology/Head and Neck Surgery, Amsterdam, The Netherlands; 2 University Hospital of Parma, Maxillofacial Surgery Unit, Parma, Italy Purpose or Objective Advanced stage head and neck squamous cell carcinomas (HNSCC) outside the oral cavity are often treated by definitive chemoradiotherapy, but locoregional recurrences still occur in 30–40%. In a previous study, low-coverage whole genome sequencing (lcWGS) for copy number alterations (CNAs) and target-enrichment deep sequencing for mutations were applied to paired tumors and local recurrences (LRs). Remarkably, half of the LRs did not show any identical mutation in the important head and neck cancer driver genes when compared to the corresponding primary tumors. This might be explained by intratumor genetic heterogeneity and treatment resistance of minor subclones. Here we analyzed the occurrence of intratumor genetic heterogeneity by analyzing CNAs and mutations in multiple biopsies of resected specimen.

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Materials and Methods We collected 32 spatially distinct biopsies from 13 resected primary oral cavity tumors (median 3 biopsies/tumor). The biopsies were snap-frozen at Amsterdam UMC (the Netherlands) or at the University Hospital Parma (Italy). None of the patients received treatment before surgery. On the DNA from all 32 biopsies, we performed lcWGS for copy number alterations (CNAs) and target-enrichment sequencing using a panel of 35 cancer genes which are frequently altered in HNSCC. Results Data from lcWGS demonstrated minor variations in all CNA profiles. The results of the target enrichment sequencing showed that all biopsies from each patient shared most somatic mutations. However, different mutations were observed in the biopsies of 5 out of 11 tumors. In these apparent heterogeneous tumors, extra mutations were observed in 1 to 3 genes with variant allele frequencies between 0.02 and 0.27. Conclusion By analyzing multiple spatially distinct biopsies from 11 oral cavity tumors we confirmed the presence of intratumor genetic heterogeneity with lcWGS and target enrichment sequencing. It remains to be determined whether this indeed explains the discordancy between mutational profiles between paired primary tumors and LRs after chemoradiotherapy. 1 Beatson West of Scotland Cancer Centre, Clinical Oncology, Glasgow, United Kingdom; 2 University of Glasgow, Institute of Cancer Sciences, Glasgow, United Kingdom; 3 Beatson West of Scotland Cancer Centre, Therapy Radiography, Glasgow, United Kingdom; 4 Glasgow Experimental Cancer Medicine Centre, Clinical Research Facility, Glasgow, United Kingdom; 5 University of Glasgow, Institute of Cancer Sciences , Glasgow, United Kingdom; 6 University of Glasgow, CRUK Clinical Trials Unit, Glasgow, United Kingdom; 7 University of Glasgow, Institute of Cancer Sciences, Glasgow, United Kingdom Purpose or Objective Poorer loco-regional control drives survival differences between good and poor prognosis oropharyngeal squamous cell cancer (OPSCC), suggesting radio-resistance is a significant factor. There are no established biomarkers which identify resistant tumours at baseline or during radiotherapy (RT) which would then allow stratification into alternative or intensified treatment strategies. Amino acid metabolism plays a central role in the response of tumours to RT and underpins radioresistance mechanisms. Radiation generates reactive oxygen species (ROS) which damages DNA and triggers cell death. Cancer cells use metabolism in two key ways to combat and survive radiation, firstly, by using amino acids to synthesise antioxidants (e.g. glutathione) to detoxify ROS. Secondly, by using amino acids and other nutrients to make nucleotides to repair damaged DNA, allowing tumour cells to survive. The aim of this study was to assess the feasibility of measuring baseline circulating metabolites in patients with poor prognosis OPSCC and to correlate these with response to RT. Materials and Methods Patients with intermediate and high risk OPSCC scheduled for radical (chemo) RT were recruited to this study. Disease control at 2 years and pattern of any relapse were noted. Patients who were alive and disease free were classed as responders to RT, those who had relapsed disease, non-responders. Whole blood samples were collected at baseline (i.e. pre-treatment). Polar metabolites were extracted and analysed on a high-performance liquid Chromatography mass spectrometry (LCMS) system. Peak area data was used for relative quantification and comparative analysis between responders and non-responders. Results Forty patients with a minimum of 2 years follow up were included. Multivariate statistical analyses were performed on the LCMS data to identify a metabolic signature in radio-resistant individuals. The data were examined by non-supervised principal components analysis (PCA) and partial least squares-discrimination analysis (PLS-DA). The results of multivariate statistical analysis were visualized and integrated with volcano plots to identify metabolites with significant difference between the survivors and deceased groups. A total of 152 metabolites showed significantly different abundance between responder and non-responder groups, see figure 1 for examples. OC-0008 Predicting radiotherapy resistance using circulating metabolites in poor prognosis OPSCC C. Paterson 1 , A. Huerta Uribe 2 , L. Hay 3 , A. Duffton 3 , L. Devlin 3 , M. MacLeod 4 , J. Evans 5 , E. Soulis 6 , O. Maddocks 7

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Conclusion Unbiased global metabolomics profiling is a promising strategy in the discovery of biomarkers. Our present work shows that there are significant differences in the metabolome of individuals that do not respond to radiotherapy. More work is underway to validate these initial test set results and to identify the metabolites that could lead to a metabolic signature able to detect radio-resistant tumours.

OC-0009 Real-life data on the lenvatinib activity in relapsed/metastatic adenoid cystic carcinoma of salivary glands.

F. Caspani 1 , S. Cavalieri 2 , E. Orlandi 3 , C. Bergamini 2 , C. Resteghini 4 , E. Colombo 4 , A. Ottini 4 , I. Nuzzolese 4 , S. Alfieri 5 , A. Mirabile 6 , A. Cassano 7 , P. Bossi 8 , T. Ibrahim 9 , M. Ghiani 10 , F. Bertolini 11 , R. Ingargiola 12 , L. Licitra 4 , L. Locati 13 1 IRCCS Istituto Nazionale dei Tumori, Head and Neck Medical oncology, Milano, Italy; 2 IRCCS Istituto Nazionale dei Tumori, Head and Neck Medical Oncology, Milan, Italy; 3 Fondazione CNAO - Centro Nazionale di Adroterapia Oncologica, Radiotherapy, Pavia, Italy; 4 IRCCS Istituto Nazionale dei Tumori , Head and Neck Medical Oncology, Milan, Italy; 5 CRO IRCCS, Head and neck medical oncology, Aviano, Italy; 6 San Raffaele Hospital, Medical Oncology, Milan, Italy; 7 Gemelli Hospital, Medical Oncology, Rome, Italy; 8 ASST Spedali Civili , Medical Oncology, Brescia, Italy; 9 Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori , Medical Oncology, Meldola, Italy; 10 Ospedale Oncologico Businco , Medical Oncology, Cagliari, Italy; 11 Azienda Ospedaliera - Universitaria di Modena , Medical Oncology, Modena, Italy; 12 Fondazione CNAO - Centro Nazionale di Adroterapia Oncologica , Radiotherapy, Pavia, Italy; 13 IRCCS Istituto Nazionale dei Tumori , Head and Neck Medical Oncology, Milan, Italy Purpose or Objective Recurrent or metastatic ACC (R/M ACC) might be managed by watchful waiting, reserving active treatment for progressing tumors. Lenvatinib, a potent anti-angiogenic agent, demonstrated a promising activity in two phase 2 studies, leading to its recommendation as first line treatment in the recent ASCO guidelines. Lenvatinib has been approved in Italy in July 2020 (law 648/1996). Our purpose was to evaluate the activity and toxicity of lenvatinib in R/M ACC patients 1 year after its approval in Italy. Materials and Methods This is a multicenter, retrospective study. Patients (pts) with ECOG PS ≤ 2, age ≥ 18 years and diagnosis of R/M ACC were eligible. Any prior lines of systemic therapies, except lenvatinib, were allowed and progression was not mandatory at study entry. Tumor characteristics, previous treatment (surgery, radiation therapy RT, systemic therapies ST), timing of treatments, initial dose, dose reduction and duration of lenvatinib, have been analyzed. Radiological response was assessed by RECIST 1.1 and treatment-related adverse events (TRAEs) were reported according to the CTCAE v5.0. Results From August 2020 to August 2021, 44 pts were included within 16 Italian sites. Female gender was prevalent (68%) with a median age of 56 years (range 35-83) at treatment initiation and 32% of pts ≥ 65 years. Major salivary glands were the most common primary site (55%). Forty-one pts (93%) received surgery alone (19%) or with RT (photons or heavy ions HI). HI were delivered in 10 pts: 6 received carbon ions (5) or protons (1) as post-operative treatment for R1/R2 disease; 4 pts with local relapse were re-irradiated with HI. Sixteen pts (36%) received ST, 2 out 16 (12%) received more than one line of treatment. Evaluable for response were 37 pts out of 44 (84%) while 3 pts were not evaluated at time of analyses or discontinued lenvatinib before radiological control because of toxicity, patient’s will and drug unrelated decline in clinical condition or

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cognitive decay one patient each. PR and SD was observed in 6 pts (16%) and 21 (57%), respectively, with a 73% disease control rate (PR+SD). Ten pts (27%) experienced a disease progression. All 44 pts were evaluable for toxicity. At least one TRAE of any grade was recorded in 100% of pts. The most frequent TRAEs > G3 were hypertension (27%), stomatitis (21%), fatigue (18%). No G5 TRAEs were reported. Sixteen out of 44 pts (36.4%) received lenvatinib 24 mg/daily as starting dose and 28 patients (64%) required at least one dose reductions for side effects. The median follow-up from the start of lenvatinib was 5.8 months (95% CI: 4.6-8.3). PFS rate at 6-month was 79% and at last follow-up date, 14 pts (32%) were still on lenvatinib. Conclusion Our data, coming from the largest real-world, unselected pts’ population series confirmed the activity and the safety of lenvatinib in R/M ACC. Side effects were consistent with the drug profile, except for the high rate of stomatitis > G3. P. Rondi 1 , D. Smussi 2 , A. Esposito 2 , V. Rampinelli 3 , M. Ferrari 4 , T. Tartaro 5 , P. Castelnuovo 6 , M. Turri Zanoni 6 , B. Vischioni 7 , G. Calareso 8 , N. Facchinetti 9 , N.A. Iacovelli 10 , E. Orlandi 9 , L. Licitra 11 , C. Resteghini 11 , P. Nicolai 12 , P. Bossi 13 , R. Maroldi 14 , D. Farina 14 , M. Ravanelli 14 1 University of Brescia - Spedali Civili, Radiology, Brescia, Italy; 2 Università degli studi di Brescia - Spedali Civili, Medical Oncology, Brescia, Italy; 3 Spedali Civili, Otorhinolaryngology, Brescia, Italy; 4 Università di Padova, Otorhinolaryngology, Padova, Italy; 5 Ospedale di Circolo e Fondazione Macchi, Medical Oncology, Varese, Italy; 6 Università degli studi dell'Insubria, Otorhinolaryngology, Varese, Italy; 7 Fondazione CNAO, Medical Oncology, Pavia, Italy; 8 Fondazione IRCSS Istituto Nazionale Tumori, Radiology, Milano, Italy; 9 Fondazione CNAO, Radiation Oncology, Pavia, Italy; 10 Fondazione IRCSS Istituto Nazionale Tumori, Radiation Oncology, Milano, Italy; 11 Fondazione IRCSS Istituto Nazionale Tumori, Medical Oncology, Milano, Italy; 12 Università degli studi di Padova, Otorhinolaryngology, Padova, Italy; 13 Università di Brescia - Spedali Civili, Medical Oncology, Brescia, Italy; 14 Università di Brescia - Spedali Civili, Radiology, Brescia, Italy Purpose or Objective The aim of this study is to assess the value of volumetric analysis in predicting outcome of patients with sinonasal epithelial cancers treated by neoadjuvant chemotherapy (NAC) followed by surgery or chemo-radiotherapy within the prospective clinical trials SINTART-1 and SINTART-2. Materials and Methods Fifty patients treated within the SINTART-1 and -2 clinical trials (NAC followed by locoregional treatment in locally advanced sinonasal epithelial cancers) with pre-treatment, after 1 cycle of NAC, and at the best response (BR) magnetic resonance (MR) were selected. Tumors were measured uni-dimensionally (along three orthogonal vectors) and volumetrically (V). Unidimensional measurements were prospectively used to assess treatment response according to RECIST 1.1. Measurements were repeated by two radiologists to assess the interobserver variability. Furthermore, in order to test the possibility of speeding up the segmentation of V, an additional volumetric measurement using interpolation (Vi) between non-contiguous slices (maximum of 5 slices manually segmented) was used. The percentage changes in tumor metrics were used in the survival analysis (overall survival, OS; disease-free survival, DFS). Results Volume was the most repeatable measure in pre-treatment studies and in terms of percentage variation during treatment. Correlation between manual V and Vi was excellent. Differently from RECIST 1.1 and uni-dimensional measures, which did not provide any prognostic correlation, V change of more than 50% after 1 cycle of NAC (HR 0.33 and 0.31, p 0.02 and p 0.01, respectively) and at the BR (HR 0.33 and 0.41, p 0.01 and p 0.04, respectively) correlated with OS and DFS. Conclusion Volumetric assessment seems to be the most valuable tool to track response to NAC and to predict the outcome, outperforming RECIST 1.1. Tumor segmentation can be significantly speeded up by using interpolation methods. S. Zhou 1 , C. Chan 2 , H. Dyab 3 , R. Rulach 1 , F. Hendry 3 , M.F. Dempsey 4 , C. Maxfield 3 , A. James 1 , C. Lamb 1 , D. Grose 1 , S. Schipani 1 , C. Wilson 1 , Y.C. Lau 5 , C. Paterson 1 1 Beatson West of Scotland Cancer Centre, Clinical Oncology, Glasgow, United Kingdom; 2 University Hospital Ayr, General Medicine, Glasgow, United Kingdom; 3 NHS Greater Glasgow and Clyde, Radiology, Glasgow, United Kingdom; 4 West of Scotland PET Centre, Radiology, Glasgow, United Kingdom; 5 Royal Alexandra Hospital, Medicine, Glasgow, United Kingdom Purpose or Objective The PET-NECK study demonstrated non-inferiority of PET-CT surveillance compared to planned neck dissection (ND) in patients who achieve a complete response (CR) to primary chemoradiation. An immediate ND (IND) was mandated for those achieving less than a CR. It is now accepted that HPV-related tumours can take more than 12 weeks to involute completely and that 12-week PET-CT has low positive predictive value for residual disease in this group. An extended period of surveillance was shown to be a safe alternative to IND with acceptable short-term survival. However, late relapses are well recognised in HPV-positive disease and should also be assessed. The aim of this study was to evaluate the long-term safety of the omission of IND in patients with HPV-positive OPSCC achieving less than CR on 12-week PET-CT. OC-0010 Volumetry to assess response to neoadjuvant chemotherapy in 2 prospective trials in sinonasal cancer OC-0011 Long term safety of further surveillance in HPV+ OPSCC with equivocal response on 12-week PET-CT

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Materials and Methods Patients with HPV-positive, node positive OPSCC HNSCC treated with radical radiotherapy (RT) between January 2013 and July 2019 were identified from the PET-CT database. PET-CT responses were classified as CR, incomplete (ICR) or equivocal (EQR), as defined by the PET-Neck study, by 2 radionucleotide radiologist. Patient demographics and clinical outcomes were obtained from electronic patient records. Results 310 patients were identified, patient and tumour characteristics are detailed in Table 1 . The median time from end of radiotherapy to PET scan was 93 days (IQR 87-101). Median follow-up was 46.7 (IQR, 34.9-63.0) months. 61.3% (190/310) achieved a CR, 24.5% (76/310) EQR, 14.2% (44/310) ICR nodal response. Within the EQR group, 5.3% (4/76) had an IND, 2 (50%) were pathologically positive. Median time from end of RT to IND was 4.8 (4.2-5.8) months. 9 (of 76, 11.8%) patients had a delayed ND, median time 9.3 (7.1 – 28.9) months post RT. 5 of 9 (55.6%) were pathologically positive. 63/76 in the EQR group did not have a ND at any timepoint and 61/63 are alive and disease free. Overall, of the 76 patients with an EQR on 12-week PET-CT, 66 (86.8%) had no residual disease during follow up (either no subsequent relapse or pathologically negative ND). Median survival of the EQR and CR groups were not reached with no statistically significant differences in overall survival (OS) between the groups, p=1.0, Figure 1 . Median survival of ICR was not reached. However, OS for ICR group was significantly worse than that of CR, and EQR, p<0.001 and p=0.001 respectively, Figure 1.

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Conclusion Despite the omission of immediate neck dissections in 95% of those who achieved an EQR nodal response, there was no difference in late survival between the EQR and CR groups. This validates the safety of extended surveillance in HPV- positive patients who achieve an EQR.

Proffered papers: New data from randomised trials

OC-0012 Hypofractionated vs standard radiotherapy in elderly unfit patients with HN cancer: ELAN-RT trial

C. ORTHOLAN 1 , A. Aupérin 2 , X. Sun 3 , Y. Tao 4 , S. Renard-Oldrini 5 , C. Lafond 6 , B. Guillaume 7 , P. Boisselier 8 , K. Bénézéry 9 , S. Racadot 10 , F. Huguet 11 , M. Bollet 12 , A. Braccini 13 , C. Khoury 14 , J. Stéphane 15 , J. Villa 16 , L. Martin 17 , D. Belemsagha 18 , W. Nadia 19 , A. Goineau 20 , N. Cheurfa 2 , C. Mertens 21 , H. Le Caer 22 , J. Bourhis 23 , J. Bourrhis 24 , J. Guigay 25,26 1 Centre Hospitalier Princesse Grace, Radiation oncology, Monaco, Monaco; 2 Institut Gustave Roussy, Biostatistics, Villejuif, France; 3 Hôpital Nord Franche-Comté, Radiation Oncology, Montbéliard, France; 4 Institut Gustave Roussy, Radiation Oncology, Villejuif, France; 5 Institut de Cancérologie de Lorraine, Radiation Oncology, Vandœuvre-lès-Nancy, France; 6 Clinique Victor Hugo, Radiation Oncology, Le Mans, France; 7 Groupe Hospitalier Bretagne Sud, Radiation Oncology, Lorient, France; 8 Institut du Cancer Montpellier, Radiation Oncology, Montpellier, France; 9 Centre Antoine Lacassagne, Radiation Oncology, Nice, France; 10 Centre Léon Bérard, Radiation Oncology, Lyon, France; 11 Hôpital Tenon, Radiation Oncology, Paris, France; 12 Institut Hartmann, Radiation Oncology, Levallois-Perret, France; 13 Centre Azuréen de Cancérologie, Radiation Oncology, Mougins, France; 14 Centre de Radiothérapie Saint-Louis Croix Rouge Française, Radiation Oncology, Toulon, France; 15 Centre de Cancérologie du Grand Montpellier, Radiation Oncology, Montpellier, France; 16 CHU Grenoble Alpes, Radiation Oncology, Grenoble, France; 17 Centre Guillaume le Conquérant, Radiation Oncology, Le Havre, France; 18 Hôpital Forcilles Fondation, Radiation Oncology, Forcilles, France; 19 Institut de Cancérologie de l' Ouest, Radiation Oncology, Nantes, France; 20 Institut de Cancérologie de l'Ouest, Radiation Oncology, Angers, France; 21 Institut Bergognié, Geriatric Oncology, Bordeaux, France; 22 Centre hospitalier de la Dracênie, Oncology, Draguignan, France; 23 Centre Hospitalier Universitaire Vaudois, Radiation Oncology, Lausanne, Switzerland; 24 GORTEC (Groupe d'Oncologie Radiothérapie Tête Et Cou), Radiation Oncology, Tours, France; 25 Centre Antoine Lacassagne, Oncology, Nice, France; 26 GORTEC (Groupe d'Oncologie Radiothérapie Tête Et Cou), Oncology, Tours, France Purpose or Objective Standard treatment for elderly patients (pts) with localized head neck squamous cell carcinoma (HNSCC) not suitable for surgery is standard fractionated radiotherapy (SF-RT) 70 Gy/35 fractions (fct). In routine practice, high toxicity and multiple fractions of SFR-RT lead physicians to often deliver adapted hypofractionated split course radiotherapy (HSC-RT) for frail pts. The ELAN (ELderly heAd and Neck cancer) RT trial is the first phase III comparing SF-RT to HSC-RT in elderly unfit pts (NCT01864850). Materials and Methods Pts with stage II-IV HNCSCC aged ≥ 70 were first enrolled in ELAN-ONCOVAL study classifying pts in fit/unfit using a geriatric evaluation. Unfit pts in curative situation were eligible to the multicentric non-inferiority ELAN-RT trial, comparing SF-RT (70Gy, 35 fct over 7 weeks) and HSC-RT (55 Gy in 20 fct over 6 weeks: 10 fct/2 weeks-2 weeks stop-10 fct/2 weeks). Primary endpoint was rate of pts alive without residual locoregional disease at 6 months, with a non-inferiority margin of 16%. Efficacy analyses were performed in intention-to-treat (ITT) and per protocol (PP). Results 201 pts were randomized from 10/2013 to 09/2018: 100 in the SF-RT arm and 101 in the HSC-RT arm. 28% were male. Mean age was 81.6 years (range 71-97), 64% pts were ≥ 80 years, 76% pts were PS 0-1, 24% PS 2, 92% pts had G8 score ≤ 14. 44% of tumors were in oropharynx (49% p16+), 22% in larynx, 17% in hypopharynx and 16% in oral cavity. Stage II, III and IV were 27%, 33% and 40% in SF-RT arm and 28%, 26% and 47% in HSC-arm. Three pts in each arm did not receive RT. 85 pts completed the 35 fct in the SF-RT arm and 87 pts completed 20 fct in the HSC-RT arm. Among pts who received all expected fcts, the overall treatment time was increased of > 7 days in 31% of pts in the SF-RT arm and 16% in the HSC-RT arm. Grade 3-4 acute toxicities were 45% in the SF-RT arm and 34% in the HSC-RT arm (p=0.12). Acute skin toxicity grade 2 or over was 31% in SF-RT arm and 13% in the HSC-RT arm (p=0.003). In ITT analysis, HSC-RT was non-inferior to SF-RT for the primary endpoint with 35 patients (34%; 95%CI 24%-44%) alive without residual locoregional disease at 6 months in the SF-RT arm versus 34 (35%; 95%CI 25%-45%) in the HSC-RT arm (rejection of inferiority hypothesis p=0.01). Median progression-free survival was 7.9 months (95%CI 5.2-11.1) in the HSC- RT arm versus 11.1 months (95%CI 8.1-17.5) in the SF-RT arm with HR=1.30 (95%CI 0.93-1.82). The median overall survival (OS) was 12.8 months (95%CI 9.8-17.0) in the HSC-RT arm versus 19.3 months (95%CI 14.3-29.9) in the SF-RT arm with HR=1.42 (IC95% 1.00-2.02). Results were similar in PP analysis. Conclusion Conclusion: Considering the primary endpoint, HSC-RT is not inferior to SF-RT. HSC-RT could be an option for unfit patients, but, due to the observed survival results, it should be offered only to patients not suitable for SF-RT. Careful geriatric assessment and proper patients selection is mandatory.

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OC-0014 Results from CompARE phase III RCT: Dose Escalated Chemoradiation vs control in oropharyngeal cancer

P. Sanghera 1 , W. Liu 2 , P. Gaunt 2 , C. Firth 2 , I. Humphreys 2 , A. Hartley 1 , M. Sen 3 , A. Kong 4 , D. Srinivasan 5 , R. Moleron 6 , K. Geropantas 7 , A. Chan 8 , L. O'Toole 9 , H. Booz 10 , M. Sivaremalingam 11 , J. Lester 12 , B. Foran 13 , C. Fong 1 , T. Roques 14 , R. Simoes 15 , Z. Nabi 15 , H. Mehanna 16 1 University Hospitals Birmingham NHS Trust, Oncology, Birmingham, United Kingdom; 2 Institute of Cancer and Genomic Sciences, University of Birmingham, Cancer Research Clinical Trials Unit, Birmingham, United Kingdom; 3 St. James's Institute of Oncology, Clinical Oncology, Leeds, United Kingdom; 4 Kings College London, Comprehensive Cancer Centre, London, United Kingdom; 5 Edinburgh Cancer Centre, Clinical Oncology, Edinburgh, United Kingdom; 6 Aberdeen Royal Infirmary, Clinical Oncology, Aberdeen, United Kingdom; 7 Norfolk & Norwich University Hospitals NHS FT, Oncology, Norwich, United Kingdom; 8 University Hospitals Coventry and Warwickshire, Arden Cancer Centre, Coventry, United Kingdom; 9 Queen’s Centre for Oncology, Clinical Oncology, Cottingham, Hull, United Kingdom; 10 University Hospitals Bristol NHS Foundation Trust, Oncology, Bristol, United Kingdom; 11 Royal Preston Hospital, Oncology, Preston, United Kingdom; 12 Weston Park Hospital, Sheffield Teaching Hospital NHS Foundation Trust, Clinical Oncology, Sheffield , United Kingdom; 13 Weston Park Hospital, Sheffield Teaching Hospital NHS Foundation Trust, Clinical Oncology, Sheffield, United Kingdom; 14 Norfolk & Norwich University Hospitals NHS FT, Clinical Oncology, Norwich, United Kingdom; 15 National Radiotherapy Trials Quality Assurance Group (RTTQA), Radiotherapy Physics, Mount Vernon Cancer Centre, Middlesex, United Kingdom; 16 Institute of Cancer and Genomic Sciences, University of Birmingham, Institute of Head and Neck Studies and Education, Birmingham, United Kingdom Purpose or Objective CompARE is a phase III randomised controlled trial using an adaptive, multi-arm multi-stage design to evaluate alternative regimes for escalating treatment of intermediate and high risk oropharyngeal cancer (OPC). This paper presents the first results of the investigational arm evaluating biological effective dose escalated accelerated hypofractionated chemoradiation. Materials and Methods Patients with Intermediate-risk OPC (HPV positive N2b or above disease and greater than 10 pack year history of smoking), or high-risk OPC (HPV negative), aged 16-70 years with ECOG PS 0-1 and suitability for concurrent chemoradiotherapy were randomised (2:1) to standard therapy in arm 1 using 70Gy in 35 fractions with concurrent cisplatin or one of several experimental arms. Arm 3 reported here evaluated 64Gy in 25 fractions with concurrent cisplatin delivered over 5 weeks. All centres participated in a central radiotherapy quality assurance programme and all patients had central HPV evaluation. Primary outcome was overall survival (OS) with an interim outcome of event free survival (EFS). 72 control arm events are required to perform the first interim analysis. Secondary outcome measures included toxicity (CTCAEv4.0), QoL, swallowing using MDADI questionnaire and gastrostomy dependence. Analysis was by intention to treat. Results 257 patients (172 in Arm 1 and 85 in Arm 3) were recruited across 27 centres and eligible for this analysis. Recruitment was suspended to this comparator arm in advance of planned interim analyses due to a SAE. Baseline characteristics were well balanced between the arms with 80% of patients having intermediate risk OPC and 20% with high risk. 97% patients received radiotherapy as planned for each arm. Overall median length of follow up was 36.7 months (95% CI. 27.6, 37.5). Three-year EFS rate was 72% (95%CI 64-78%) in arm 1 and 68% (95% CI 56-78%) in arm 3, (p=0.98). Adjusted hazard ratio for arm 3 versus 1 was 1.00 (95/% CI 0.62, 1.62). Three-year OS rate was 79% (95%CI 71-86%) in arm 1 and 74% (95%CI 62-83%) in arm 3, (p=0.59). Adjusted hazard ratio for arm 3 versus 1 was 1.17 (95% CI 0.66, 2.05). The proportional-hazards model was not violated. Rates of gastrostomy tube use at 2 years were 5% and 9% in arms 1 and 3 respectively (p=0.35). Conclusion Biological effective dose escalated chemoradiation did not appear to demonstrate any benefit over standard therapy in patients with intermediate and high risk OPC. The CompARE trial continues to recruit and evaluate other regimes. S. Ghosh Laskar 1 , D. Chaukar 2 , A. Chatterjee 3 , S. Chakraborty 4 , J.P. Agarwal 3 , P. Chaturvedi 2 , M. Deshpande 5 , T. Gupta 6 , V. Murthy 6 , A. Budrukkar 3 , P. Pai 2 , G. Pantvaidya 2 , A. Deshmukh 2 , D. Nair 7 , S. Nair 7 , K. Prabhash 8 , A. Joshi 9 , A.K. DCruz 10 1 Tata Memorial Hospital, Radiation Oncology, Mumbai, India; 2 Tata Memorial Hospital, Head and Neck Surgical Oncology, Parel Mumbai, India; 3 Tata Memorial Hospital, Radiation Oncology, Parel Mumbai, India; 4 Tata Medical Centre, Radiation Oncology, Kolkata, India; 5 Kokilaben Dhirubhai Ambani Hospital, Surgical Oncology, Mumbai, India; 6 Advanced Centre for Treatment Research and Education in Cancer, Radiation Oncology, Mumbai, India; 7 Advanced Centre for Treatment Research and Education in Cancer, Head and Neck Surgical Oncology, Mumbai, India; 8 Tata Memorial Hospital, Medical Oncology, Parel Mumbai, India; 9 Advanced Centre for Treatment Research and Education in Cancer, Medical Oncology, Parel Mumbai, India; 10 Apollo Cancer Hospital, Surgical Oncology, Mumbai, India Purpose or Objective Locally advanced Oral Cavity Squamous Carcinoma (OCSCC) is associated with poor outcomes and warrant some form of adjuvant treatment intensification even after complete resection. This Phase III Randomized Controlled Trial (NCT00193843) (OCAT) endeavoured to test the intensification of adjuvant therapy either by accelerating radiotherapy (6D- RT) or by adding concurrent chemotherapy (CTRT) in optimally resected locally advanced OCSCC. Reporting of the outcomes of harms and quality of life are the subject of a separate abstract to this meeting. OC-0016 Intensifying adjuvant therapy in advanced Oral Cavity Carcinoma: Results of a randomized study.

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Materials and Methods Medically fit patients aged 18-65 years with AJCC Stage (2005) –III/IV resected OCSCC with one or more adverse histopathological features{Extracapsular Extension (ECE), involvement of >2 regional lymph nodes, margins of resection involved by invasive cancer, extensive soft tissue and/or skin infiltration requiring major reconstructive procedure, perineural invasion(PNI) or lymphovascular embolisation (LVE)} were randomized 1:1:1 to Conventional 5D –RT (Arm A), CTRT with concurrent weekly Cisplatin (Arm B) and 6D-RT (Arm C). The primary endpoint was Locoregional Control (LRC) and the secondary endpoint was Overall Survival (OS). Results Between June 2005 and March 2013, nine hundred patients were accrued . Advanced gingivobuccal complex cancers comprised 65-72% of all cases. 90% of patients presented with T3-T4 primaries and nearly half had advanced neck nodal disease (N2-N3). Extracapsular extension was present in 55% of cases. Bone infiltration, skin infiltration, extensive soft tissue infiltration, LVE and PNI were present in 36.8%-42.7%,14.3%-18.6%,85.3%-87%,2.3-3.7% and 24.7%-28.4% patients, respectively. Microscopic positive margins were present in 0.3%,0.7% and 0.3% of patients in the 5D-RT, CTRT and 6D-RT arms, respectively. At a median follow up of surviving patients of 95.9 months (Interquartile Range -76.1-122.4 months), the 10 year actuarial estimates of LRC and OS in arms A, B and C were 57.3% (95%CI, 51%-64.5%), 62.3% (95% CI, 56.3%-68.8%,) and 59.6% (95% CI, 53.3%-66.7%) and 40.7% (95% CI-34.8%-47.6%), 40.4% (95% CI-34%-47.9%) and 46.4% (95% CI-40.5%-53.4%), respectively with no benefit seen for treatment intensification in the overall trial population. Patients harbouring a high-risk profile (with simultaneous ECE, T3-T4 primary and N2-N3 nodal disease) (n=311) were found to derive benefit from treatment intensification in OS (p=0.001, Arm B vs Arm A HR =0.58, 95% CI-0.42-0.81, Arm C vs Arm A HR =0.60, 95% CI-0.43-0.84). The increase in Grade 3 toxicity was minimal but statistically significant for treatment intensification and easily managed with no consequential increase in the late toxicity. Conclusion All locally advanced OCSCC do not warrant intensification of adjuvant treatment after complete resection. Treatment intensification is justified only in those patients harbouring multiple adverse factors simultaneously on histopathology and is achieved with manageable rates of severe toxicity.

Symposium: Modern management of unknown primary H&N tumours

SP-0018 What have we learned from TORS mucosectomy in management of unknown primary Vin Paleri United Kingdom

Abstract not available

SP-0019 Advances in pathology for unknown primary Senada Koljenovic The Netherlands Abstract not available

SP-0020 Evolving radiation oncology practice for the management of unknown primary cancers Vincent Grégoire France Abstract not available

Keynote lecture: New concepts in the management of oligmetastatic disease

SP-0022 New concepts in the management of oligometastatic disease

P. Szturz 1

1 University of Lausanne (UNIL) and Lausanne University Hospital (CHUV), Department of Oncology, Lausanne, Switzerland

Abstract Text The term oligometastatic refers to an uncommon pattern of malignant dissemination to distant organs which can be safely treated with local approaches with the intent of improving overall survival. Although typically characterized by the number of metastases not surpassing 3 – 5 lesions, emerging evidence suggests that a diagnosis based on a single snapshot imaging does not sufficiently provide for an accurate detection of a true oligometastatic disease. In fact, in order to be amenable to successful local treatment, even aiming for cure, the following criteria have to be met. First, the disease progression has to be very slow, including tumour growth rate and formation of new metastases (probably less than 0.6 new metastases per year as shown in lung cancer). Moreover, implying the presence of only few lesions in limited organ sites, the overall tumour burden has to be low to enable safe ablation using local interventions. Last but not the least, there should be no occult metastases. Obviously, not all of these criteria can be checked easily, but the probability of an oligometastatic presentation increases when dealing with a metachronous (versus synchronous) manifestation with a long disease-free interval after primary treatment, and a series of follow-up imaging studies shows corresponding tumour growth kinetics. In addition, using complementary nuclear medicine and radiological imaging techniques and evaluating relevant laboratory parameters, such as circulating markers in some cancers, help us lower the detection threshold for subclinical disease.

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However, it has become clear that further improvement can only be accomplished by implementing biological classifiers. In this respect, promising data have recently been reported in relation to genetic determinants (e.g., SMAD4 loss in pancreatic cancer, PBRM1 mutation in renal cancer), epigenetic modifiers (e.g., 14q23-encoded microRNAs), and tumour- host interactions (immune response). In head and neck cancer, the most prognostically favourable group comprises patients presenting with an oligorecurrence of human papillomavirus (HPV)-positive oropharyngeal cancer in the lungs. Of note, oligorecurrence represents a state of metachronous dissemination in which oligometastases develop in patients with a controlled local or locoregional disease who are at least 3 – 6 months after the primary diagnosis. Therefore, post-treatment follow-up has a decisive role, and although current guidelines do not recommend routine radiological examinations in all head and neck cancer survivors, they can be justified in those potentially presenting with curable oligometastases. Besides that, in patients receiving systemic therapy for polymetastatic cancer, there are further clinical scenarios sharing some of the hallmarks of oligometastases. They include oligoprogression if few distant lesions evade disease control and start growing and oligopersistence if a complete response is achieved except for few persisting lesions which are either stable or partially decrease in size. Importantly, the same local techniques, typically surgical resection, stereotactic body radiotherapy, or radiofrequency ablation, can be employed in these settings, albeit not with a curative intent but rather to prolong survival or delay a change or reinitiation of systemic treatment. Taken together, despite providing intriguing options to improve patient care, the concept of oligometastatic disease is still far from being fully understood and furnishes thus ample research opportunities in the areas of disease biology, workup, and treatment. Gaining a better insight into the biological basis of an oligometastatic phenotype together with finetuning its clinical determinants will be indispensable for developing reliable composite prognostic models and proper patient selection. This will probably not be possible without simultaneous advances in imaging modalities, such as using molecular imaging with novel positron emission tomography (PET) tracers, or introducing liquid biopsy to clinical practice as part of residual disease monitoring and early recurrence detection. Finally, investigational treatment strategies seek to address various issues encompassing development of new drugs (e.g., epigenetic modifiers reversing polymetastatic to oligometastatic phenotype), technologies (e.g., improvements in external and internal radiotherapy), combinations of local and systemic therapies (especially with immune checkpoint inhibitors), treatment sequencing, innovative approaches to clinical trial design (e.g., adjusted endpoints, patient-reported outcomes), and other. Importantly, some of these new concepts hold the promise of becoming site-agnostic tools, thus of interest also to the head and neck cancer field, while other are more specific such as circulating Epstein-Barr virus (EBV) DNA monitoring in metastatic nasopharyngeal cancer or still experimental measurements of cell-free plasma HPV DNA in oropharyngeal cancer.

Keynote lecture: Intraoperative margin analysis

SP-0023 Intraoperative margin analysis

R.J. Baatenburg de Jong 1

1 Erasmus Medical Center, Dept. of Otorhionolaryngology, Rotterdam , The Netherlands

Abstract Text The goal of head and neck oncological surgery is complete tumor resection with adequate resection margins while preserving acceptable function and appearance. For oral cavity squamous cell carcinoma (OCSCC), different studies showed that only 15%-26% of all resections are adequate. A major reason for the low number of adequate resections is the lack of information during surgery; the margin status is only available after the final histopathologic assessment, days after surgery. The surgeons and pathologists at the Erasmus MC University Medical Center in Rotterdam started the implementation of specimen-driven intraoperative assessment of resection margins (IOARM) in 2013, which became the standard of care in 2015. This method enables the surgeon to turn an inadequate resection into an adequate resection by performing an additional resection during the initial surgery. Intraoperative assessment is supported by a relocation method procedure that allows accurate identification of inadequate margins (found on the specimen) in the wound bed. The implementation of this protocol resulted in an improvement of adequate resections from 15%-40%. The protocol for specimen-driven IOARM and the relocation method will be presented in detail, supplemented with data on disease free and overall survival, as well as the decrease in need for postoperative radiation.

Proffered papers: Innovative highlights 2

OC-0024 Pre-treatment lymphocyte count predicts cisplatin benefit with radiotherapy in oropharynx cancer

J. Price 1 , H. Mistry 2 , G. Betts 3 , E. Cheadle 4 , L. Dixon 1 , K. Garcez 1 , T. Illidge 1 , Z. Iyizoba-Ebozue 5 , L. Lee 1 , A. McPartlin 1 , S. Papageorgiou 4 , R. Prestwich 5 , D. Pritchard 5 , A. Sykes 1 , C. West 4 , D. Thomson 1 1 The Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom; 2 The University of Manchester, Division of Cancer Sciences, MANCHESTER, United Kingdom; 3 Manchester Foundation Trust, Histopathology, MANCHESTER, United Kingdom; 4 The University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom; 5 Leeds Cancer Centre, Clinical Oncology, Leeds, United Kingdom Purpose or Objective There is a need to refine the selection of patients with oropharynx squamous cell carcinoma (OPSCC) for treatment de- escalation. We investigated whether pre-treatment absolute lymphocyte count (ALC) predicted overall survival benefit from the addition of concurrent cisplatin to radiotherapy.