ESTRO 2024 - Abstract Book

S1180

Clinical - Head & neck

ESTRO 2024

Keywords: JJCOG1008, Secondary analysis, hypothyroidism

62

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A phase II prospective trial of SBRT reirradiation for recurrent or 2 nd primary head & neck cancers

Sally S. Fouda 1 , Tarek H. Shouman 1 , Ashraf H. Hassouna 1 , Ayman A. Amin 2 , Maha Hassan 3 , Shaimaa Abdelgeleel 4 , May G. Ashour 1 1 National Cancer Institute, Cairo University, Radiation Oncology, Cairo, Egypt. 2 National Cancer Institute, Cairo University, Surgical Oncology, Cairo, Egypt. 3 National Cancer Institute, Cairo University, Medical Physics, Cairo, Egypt. 4 National Cancer Institute, Cairo University, Statistics department, Cairo, Egypt

Purpose/Objective:

To assess the toxicity (acute and late) and outcomes (Local control (LC), regional control, distant control, overall survival (OS), and progression free survival (PFS)) associated with stereotactic body radiation therapy (SBRT) reirradiation of head and neck (H&N) loco-regional recurrences or second primary malignancies (SPM).

Material/Methods:

From August 1st 2018 till April 1st 2022, 30 patients (with 31 sites) received SBRT reirradiation to their loco-regional recurrences (N=29), or SPMs (N=2). Median dose was 40 Gy in 5 fractions (30 - 50 Gy). SBRT reirradiation was used alone in 21 recurrences or SPMs. Ten patients received SBRT in the postoperative setting. SBRT planning was done using inverse intensity modulated radiation therapy (IMRT), and treatment was given using Linac. Toxicity assessment was done according to RTOG scoring criteria for acute and late effects.

Results:

Median follow-up was 18.2 months (2.7-55 months). In patients treated with SBRT reirradiation alone (N=21), at 3 months post-treatment, complete response (CR) was achieved in 13 patients (61.9%), and partial response (PR) in 7 patients (33.3%). While at 6 months post-treatment, CR was recorded in 16 patients (76.2%), and PR in 4 patients (19%). In patients treated with adjuvant SBRT reirradiation after surgery (N=10), at 3 months post-treatment, no recurrence was observed in 6 patients (60%). Median survival (MS) was 29.8 months (15.2 - 44.3 months). At 1 year, LC, regional control, distant control, OS, and PFS were 62.7%, 79.7%, 88.4%, 66.2%, and 45.8%, respectively. At 2 years, these outcomes were 54.8%, 73.6%, 82.9%, 54.2 %, and 32.1 %, respectively. Grade (G) 3+ acute toxicity was recorded in 5 patients (16.1%), with 1 patient (3.2%) having G3 dermatitis, and 4 (12.9%) having G3 mucositis. G3+ late toxicity was recorded in 9 patients (29%),