7th ICHNO Abstract book

7th ICHNO 7 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 14 – 16 March 2019 Barcelona, Spain __________________________________________________________________________________________ page 25

Compared to the standard conventional dose CCRT, slightly dose escalated accelerated hypofractionated VMAT regimen, has comparable efficacy and less acute and late side effects, and has the advantage of avoidance of chemotherapy related toxicities in LA-HNC patients. It can be an option for treating LA-HNC especially in patients who cannot receive chemotherapy. However, it needs to be more evaluated in larger prospective multi-centric randomized trials with longer follow up duration. PO-049 Management SCC unknown primary with contemporary diagnostic and radiotherapy techniques C.Paterson 1 , R. Crosbie 2 , P. McLoone 1 , D. Grose 1 , A. James 1 , C. Lamb 1 , M. Rizwanullah 1 , S. Schipani 1 , C. Wilson 1 , F. Campbell 1 , F. Easton 1 , M. Thomson 1 1 Beatson WoSCC, Clinical Oncology, Glasgow, United Kingdom; 2 NHS Greater Glasgow & Clyde, Ent, Glasgow, United Kingdom Purpose or Objective No randomised evidence exists to guide treatment of SCC of unknown primary (SCCUP) of the head and neck. Two main approaches with RT exist – treating involved neck only (INO) or the addition of an elective dose to potential primary sites and contralateral neck (MUC) to reduce the likelihood of the primary tumour emerging. If the frequency of mucosal primary emergence remains low without elective irradiation, we may be able to spare our patients toxicity. The purpose of our study was to evaluate disease related outcomes and doses to organs at risk in a contemporary cohort of patients investigated, diagnosed This was a retrospective cohort study; patients with histologically confirmed SCCUP with unilateral neck disease staged with FDG PET-CT scan were eligible. Patients were identified from the radiotherapy database and electronic case records reviewed Results 26 patients with unilateral neck disease from SCCUP were treated between August 2012 and April 2016. All patients underwent investigation with FDG PET-CT and EUA.All patients underwent radiotherapy with volumetric modulated arc therapy (VMAT). Patients receiving radiotherapy as primary treatment received 65Gy/30# to areas of gross disease and entirety of that involved nodal level and 54Gy/30# to areas considered at risk of harbouring microscopic disease. Patients who received adjuvant RT following neck dissection received either 65Gy/30# (if ECS) or 60Gy/30# to involved nodal levels (if no ECS) and 54Gy/30# to areas at risk of microscopic disease.16 patients received INO RT, 10 patients received MUC RT. 37.5% patients receiving INO RT had HPV/p16 positive disease. 50% patients receiving MUC RT had HPV/p16 positive disease. 56.3% patients in INO group received concurrent cisplatin, 50% in the MUC cohort. Median follow up is 35 months (range 30-46mths). No mucosal primaries in either group have emerged. 1 patient in the MUC group relapsed in contralateral neck in the elective dose volume. 2 year OS is 81.3% in INO group, 80% in MUC group. and treated for SCCUP. Material and Methods

Recent data from KEYNOTE-048 study show that pembrolizumab single agent improves overall survival in comparison to platinum-5FU-cetuximab (EXTREME) not only in patients with tumors expressing PD-L1 by combined positive score (CPS) ≥ 20 (44% of population), but also in patients with CPS ≥ 1 reaching 85% of the general population. Moreover, response rate in first line ranges 19- 23% and median duration of response is by far longer that that obtained with EXTREME (20.9 months versus 4.2-4.5 months respectively). Finally, PD-1 inhibitors display a much better safety profile, severe grade 3-5 adverse events rate being lower than that observed with chemotherapy (16.7% versus 69% in first line, 13.1-13.4% versus 35.1-36.3% in second line) and are associated with less deterioration of quality of life in the vulnerable population of patients with advanced head and neck cancers. PO-048 Hypofractionated dose escalated VMAT; comparable efficacy and less toxicity than standard CCRT in HNC E. Saad 1 , E. Abdel Hadi 1 , R. Hani Radwan 1 , M. Abdulla 1 1 Cairo University, Department of Clinical Oncology and nuclear medicine, Cairo, Egypt Purpose or Objective The standard Concurrent chemo-radiation therapy (CCRT) for locally advanced head and neck cancers (LA-HNC) can’t be applied to all patients’ categories. Both dose escalation and acceleration are supposed to improve tumor control rates with uncertain role of addition of concurrent chemotherapy. We aimed at developing a radiotherapy protocol for patients not eligible to receive the standard chemotherapy concurrently with conventional radiotherapy with little toxicity profile. To the best of our knowledge, no randomized trials were done to compare the dose-escalated hypo-fractionated regimen without chemotherapy with the conventional CCRT regimen Material and Methods 63 LA-HNC patients were randomized to receive either: 70Gy in 35fx in 7wks at 2Gy/fx concurrently with weekly cisplatin 40mg/m 2 (Arm A) or 74Gy in 33 fractions (fx) in 6.5 weeks at 2.24Gy/fx (Arm B). Volumetric Modulated Arc Therapy (VMAT) plans were created for both treatment arms. Biologically effective dose (BED) and Equivalent dose in 2 Gy/fx (EQD2) were calculated for the tumor, acute and late tissues in the investigational arm to be comparable with the conventional CCRT arm. Results There were 33 patients in arm A versus 30 patients in arm B with median follow up 24.2 months. No significant differences in disease LC, PFS, OS and QOL assessment between the two arms with comparable relapse pattern. Patients who developed CR were 54.5% and 63.3% in arm A and arm B respectively. The 2-year PFS and OS were 50% and 66.4% in arm A versus 58.8% and 61.5% for arm B respectively, but not statistically significant. Median PFS was 19.5 months in arm A and was not reached in arm B. The median OS wasn’t reached in either arm. Arm B had statistically significant less toxicity including: chemotherapy related toxicity (nausea, vomiting, hematological toxicities and KFTs elevation), acute and late toxicities (all grades of mucositis, dysphagia, fatigue and xerostomia) compared to arm A. Conclusion Poster: Multidisciplinary management

Dose to organs at risk are as below:

INO

RT

MUC RT(n=10)

(n=16)

Mean dose contralateral parotid

1217cGy 3336cGy p<0.01