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 7

international guidelines (CTVn-IG). A radical identical dose was prescribed to the primary tumor. Both real and virtual treatments were calculated with RapidArc software by Varian®. Dosimetric data to the different organs-at-risk (OAR) were compared between the two plans. Response was evaluated at 3 months by PET/CT. Follow-up neck CT scans were performed at 6, 12, 18 and 24 months. Results Lymphatic migration was observed in all of the 44 patients. Four patients (9%) presented a unpredicted lymphatic drainage and 21 patients (48%) had only a unilateral drainage. The volumes of CTVn-LS and PTVn-LS (median volumes of 91.8 cc and 219.1 cc, respectively) were systematically smaller than CTVn-LS and PTVn-IG (median volumes of 188.3 cc and 405.3 cc, respectively). This led to a significant dose decrease in identified OAR, particularly to the controlateral parotid gland, controlateral submandibular gland, inferior constrictor muscle for oral/oropharynx tumors and superior constrictor muscle for larynx/hypopharynx tumors (Table 1). At a median follow-up of 42 months, 3 patients experienced a regional relapse: 2 in an irradiated area (4.5%) and 1 in a non-irradiated area (2.3%). Currently, 4 patients had a local reccurence and 6 patients died (2 patients from geriatric degradation and 4 patients experienced fatal local relapse).

Material and Methods ARTSCAN 2, an open multicentre randomised controlled comparative phase III study aimed to evaluate loco- regional tumour control (LRC), overall survival (OS) and QoL in patients with oral cancer with combined modality treatment, started to enroll 2007. Patients were randomized 1:1 between the two trial arms: AF RT (68 Gy in 4.5 weeks) prior to surgery vs. surgical resection followed by CF RT (60 Gy to histopathological low risk patients and 66 Gy+ weekly cisplatin to high risk patients). Results A total of 250 patients were randomized, whereof 240 were eligible for analysis; 120 in each arm. Median follow up was 4.7 years. LRC at two years was 83% for preop. AF RT and 79% for postop. CF RT (p=0.80; logrank). OS at 2 years was 73 % for preop AF RT and 78 % for post op CF RT (p=0.12; logrank). Asexpected acute mucosal side-effects were more pronounced in patients with preop AF RT compared to patients treated with postop CF RT. Late side-effects were slightly worse for some QoL parameters in patients treated with preoperative AF RT. Conclusion This study does not support that preop AF improves outcome in oral cavity cancer compared with the ”gold standard”, postoperative CF RT. The intense treatment schedule and the higher dose increased the severity of acute and possibly late side effects. In the choice between treatment options not only survival, but also QoL and health economics must be considered. OC-006 Individualized prophylactic irradiation based on sentinel lymph node(s) identification in cN0 HNSCC E. Longton 1 , G. Lawson 2 , B. Bihin 3 , S. Deheneffe 1 , I. Mathieu 4 , F. Hanin 4 , T. Vander Borght 5 , M. Laloux 6 , J. Daisne 1 1 CHU UCL Namur-site Sainte-Elisabeth, Radiation oncology, Namur, Belgium; 2 CHU UCL Namur- site Godinne-, Head and Neck Surgery, Yvoir, Belgium; 3 Namur Research Institute for Life Sciences Narilis, Unit of Biostatistics, Namur, Belgium; 4 CHU UCL Namur- site Sainte-Elisabeth, Nuclear Medicine, Namur,Belgium; 5 CHU UCL Namur- site Godinne-, Nuclear medicine, Yvoir, Belgium; 6 CHU UCL Namur- site Sainte- Elisabeth, Maxillofacial Surgery, Namur, Belgium Purpose or Objective Due to a risk of occult nodal metastases in clinically node- negative (CN0) head and neck squamous cell carcinoma (HNSCC) patients, prophylactic and often bilateral neck irradiation is mandatory. However, it leads to a large irradiation of healthy tissue and could miss unexpected nodal basins drained by the tumor. This prospective, non- randomized, interventional phase II study investigated how sentinel lymph node (SLN) mapping by SPECT/CT may help to individualize prophylactic neck irradiation and its potential impact on radiation-related toxicities and tumor control. The final results are presented. Material and Methods Forty-four patients with newly diagnosed cN0 squamous cell carcinoma of the oral cavity, oropharynx, larynx or hypopharynx were included and treated with upfront (chemo)radiotherapy with a curative intent. After simulation, all patients were imaged in treatment position with SPECT/CT after 99m Tc nanocolloid injection around the tumor. The neck levels containing up to four hottest SLN were selected for prophylactic irradiation (CTVn-LS). A comparative virtual planning was performed by including the levels selected on the basis of the current

Conclusion SLN mapping using SPECT/CT allowed to significantly reduce the prophylactically irradiated neck volumes in cN0 HNSCC patients. This resulted in a significant dose decrease in OAR, especially in patients presenting a unilateral lymphatic drainage, while uncompromising the oncological outcome. OC-007 Radiologic extranodal extension portends worse outcome in TNM-8 cT1-T2N1 HPV+ oropharyngeal cancer S.H.S.Huang 1 , E. Yu 2 , A. Billfalk-Kelly 3 , J. Su 4 , J. Waldron 3 , E. Bartlett 2 , A. Bayley 3 , S. Bratman 3 , J. Cho 3 , M. Giuliani 3 , A. Hope 3 , A. Hosni 3 , J. Kim 3 , J. Ringash 3 , A. Hansen 5 , J. De Almeida 6 , L. Tong 3 , W. Xu 4 , B. O'Sullivan 3 1 Princess Margaret Cancer Centre, 2B-Radiation Therapy, Toronto, Canada; 2 Princess Margaret Cancer Centre, Department of Medical Imaging, Toronto, Canada; 3 Princess Margaret Cancer Centre, Department of Radiation Oncology, Toronto, Canada; 4 Princess Margaret