ESTRO 36 Abstract Book

S569 ESTRO 36 2017 _______________________________________________________________________________________________

We have the objective to study the incidence of chronic RAD in these head and neck recurrent tumors, previously irradiated, including patients over 70 years old (y) Material and Methods We evaluated 69 patients with recurrent disease, between 2005 to 2015. 33 larynx, 7 nasopharynx, 15 oropharynx, 6 hypopharynx and 8 oral cavity. The initial dose received 50- 70 Gy(2-2.2Gy/fraction), 30/69 received radical radiotherapy,21/69 radical chemoradiation; other adjuvant radiotherapy, of which 10/ 69 was combined with chemotherapy. In 29/69 nodal recurrence (N1-N2), local 22/69 (T2-T4), 7/69 local+nodal recurrence, 11/69 seconds tumor, median age 59 year (range 42–79) . Reirradiation with external 3D conformal/IMRT techniques/ and dose: 50-70 Gy bjective to study the incidence of chronic RAD in these head and neck recurrent tumors, previously irradiated, including patients over 70 years old (y) Results The acute grade 2–4 RTOG dysphagia in week 6 (RTOG G2– 4) was 75.4% (G2: 32/69, G3: 20/69). Of 69 patients, 21 (29.8%) had chronic-RAD at 12 months (G2: 17/69, G3: 3/69 G4: 1/69). All of these patients had acute toxicity G2-G3. After calculation of the TDRS, nine patients ( 3 patients <62 years old/ 6p ≥ 62 y (3p ≥ 70 y)), were classified in the low-risk group (TDRS 0–9); 15 patients ( 5 patients <62 years old/ 10 p ≥ 62 y (4p ≥ 70 y)),in the intermediate-risk group (TDRS10–18) and 45 patients ( 16 patients <62 years old/ 29p ≥ 62 y (14p ≥ 70 y)),in the high-risk group (TDRS > 18). MHM V69 was ≥ 79.5% in all patients with chronic-RAD at 12 months, with median age 59, 68% ≥ 62 years (31.5% ≥ 70 years old) Conclusion Aggressive treatment of this disease recurring, allowing long survival, even in extensive disease is superior to best supportive care. We have not seen a high incidence of severe damage in healthy tissues. TDRS can be used to predict chronic-RAD at 12 months (Grade ≥2), but also other relevant endpoints such as acute dysphagia during RT and MHM V69. In our series patients older than 70 years did not suffer more chronic toxicity dysphagia type EP-1038 Intraoperative electron beam radiotherapy for locoregionally recurrent head and neck cancer P. Wald 1 , J. Grecula 1 , A. Bhatt 1 , V. Diavolitsis 1 , T. Teknos 2 , M. Old 2 , J. Rocco 2 , A. Agarwal 2 , E. Ozer 2 , R. Carrau 2 , D. Blakaj 1 1 OSU Medical Center -James Cancer Hospital, Radiation Oncology, Columbus, USA 2 OSU Medical Center -James Cancer Hospital, Otolaryngology, Columbus, USA Purpose or Objective When feasible, standard of care for locoregionally recurrent head and neck cancer is salv age surgery. However, locoregional control (LRC) is unacceptably low with surgery alone. Adjuvant chemoradiation was shown to improve LRC and progression free survival (PFS) in a randomized controlled trial, but LRC at one year was still only about 60%. The role for intraoperative radiotherapy (IORT) in the salvage setting remains unclear due to limited data and variable patient selection criteria between institutions. We report our institutional outcomes using IORT for recurrent head and neck cancer. Material and Methods Between 2004 and 2015, 61 patients underwent salvage surgery and IORT for recurrent head and neck cancer at our institution. IORT was delivered using a mobile electron unit. A single fraction was delivered to a median dose of 12.5 Gy (range, 10 – 17.5 Gy). We retrospectively evaluated LRC, PFS, and overall survival (OS) for the entire group. We then evaluated the squamous cell carcinoma patients alone. Univariate analysis was performed using log-rank tests to correlate clinical outcomes with histology

(squamous cell carcinoma vs. others), surgical margin status (positive vs. negative), and adjuvant therapy received. LRC, PFS, and OS curves were generated using the Kaplan-Meier method. Results Median follow up for surviving patients was 15.9 months (range, 4.9 - 74.4). Forty-one patients (67%) were treated to the primary site and 20 (33%) to a neck recurrence. Forty-five patients (74%) had squamous cell histology (SCC). Fifty-seven patients (93%) had previously received external beam radiotherapy (EBRT) as a component of their definitive therapy (median dose 66 Gy). The median time interval between prior EBRT and IORT was 16.4 months (range, 1 – 227 months). Final surgical margins were positive in 28 patients (46%), negative in 27 patients (44%), and unknown in 6 patients (10%). Twenty-three patients (38%) received a course of post-operative EBRT (median dose 45 Gy, range 25 – 66 Gy) with a median time interval between IORT and completion of post-operative EBRT of 78 days (range, 52 – 131). Nine patients (15%) received post-operative chemotherapy. There was one grade 5 toxicity which resulted from carotid rupture 18 days after surgery/IORT. Conclusion The use of IORT for recurrent head and neck cancer at our institution has shown effective locoregional control and overall survival, despite only 38% of our patients receiving post-operative EBRT. OS was significantly better for non- SCC histologies compared to SCC. For SCC patients, there is a trend toward improved PFS (p = 0.09) and OS (p = 0.06) associated with negative surgical margins. IORT in the re- irradiation setting has shown acceptably low rates of severe toxicity. We plan to initiate a prospective trial to investigate the safety and efficacy of IORT in combination with post-operative chemoradiation for recurrent head and neck cancer in the near future. EP-1039 CTV growth evaluation for involved site neck lymphoma RT if pre-chemo RT position PET-CT is absent D. Bird 1 , C. Patel 2 , A. Scarsbrook 2 , V. Cosgrove 1 , E. Thomas 3 , D. Gilson 3 , R. Prestwich 3 1 Leeds Teaching Hospitals Trust, Medical Physics and Engineering, Leeds, United Kingdom 2 Leeds Teaching Hospitals Trust, Radiology and Nuclear Medicine, Leeds, United Kingdom 3 Leeds Teaching Hospitals Trust, Clinical Oncology, Leeds, United Kingdom Purpose or Objective A pre-chemotherapy PET-CT acquired in the radiotherapy treatment position has not been widely implemented in the management of lymphoma. An involved site radiotherapy (ISRT) CTV requires an expansion to account for the absence of optimal pre-chemotherapy imaging. The aim of this prospective imaging study is to determine the size of the expansion required for neck radiotherapy. Material and Methods 10 patients with Hodgkin lymphoma and diffuse large B cell lymphoma were identified from a prospective single centre imaging study who had undergone a pre- chemotherapy PET-CT in both the diagnostic and