ESTRO 2021 Abstract Book

S824

ESTRO 2021

Conclusion Despite elderly and locally advanced disease at presentation, preliminary results showed good treatment tolerance and response after CRT for HNSCC. Low muscle quality seemed to worsen survival outcomes and male patients may be at higher risk for such negative impact. The analyses completion of all the recruited patients will clarify our promising findings. PO-0992 Outcomes and toxicities of curative reirradiation for head and neck carcinomas A. Beddok 1 , C. Saint-Martin 2 , C. Ala Eddine 3 , L. Champion 4 , S. Krhili 5 , A. Chilles 6 , L. Catteau 1 , F. Goudjil 1 , S. Sefkili 1 , M. Amessis 1 , D. Peurien 1 , O. Choussy 7 , C. Le Tourneau 8 , R. Dendale 9 , I. Buvat 10 , G. Créhange 1 , V. Calugaru 1 1 Institut Curie, Radiation Oncology, Paris, France; 2 Institut Curie, Satistics, Paris, France; 3 Institut Curie, Radiology, Paris, France; 4 Institut Curie, Nuclear Medicine, Saint-Cloud, France; 5 Institut Curie, Radiation Oncology, Paris , France; 6 Insitut Curie, Radiation Oncology, Paris, France; 7 Institut Curie, Head and Neck surgery, Paris, France; 8 Institut Curie, Medical Oncology, Paris, France; 9 Institut Curie, Radiation Oncology, Orsay, France; 10 Institut Curie, LITO, Orsay, France Purpose or Objective Despite the constant improvement of techniques, locoregional recurrences (LR) after radiation therapy (RT) for head and neck cancer (HNC) remain frequent. In a curative context, in case of inoperability or incomplete resection, reirradiation (reRT) can be discussed. The objective of this study was to retrospectively analyze the outcomes and toxicities of patients treated with curative reRT (either by intensity-modulated radiation therapy [IMRT], or by proton therapy [PT]) for recurrent HNC. Materials and Methods This is a retrospective review of patients who underwent curative-intent reRT for nonresectable recurrent or second primary HNC from 30/08/2012 to 08/04/2019. All patients included received curative reRT for HNC LR. CTCAEv5 was used to assess acute and late toxicities. Follow-up was considered as the time between the end of reRT and the date of last follow-up. Survival times were defined between date of the end of reRT and the event date. Patient free of event have been censored to their last known contact date. Results Twenty-three patients were re-irradiated (47.8% with IMRT and 52.2% with PT) with curative intent for advanced HNC. The patients were mostly men (73.9%) and WHO 0 (87%). Locations at the time of reRT were mainly the nasopharynx, cervical nodes, oropharynx, nasal fossae and maxillary sinus. Nine patients underwent surgery prior to reRT, seven had neoadjuvant chemotherapy, and six had concomitant chemoradiotherapy. The median interval time between the two irradiations was: 23.9 months (IQR: 15.3–37.2 months). The median maximum dose prescribed to the CTV was: 66 Gy EBR (55.8-70.2 Gy), median overall treatment time: 54 days (45-66 days), median CTV and PTV volumes: 49.8 cc (IQR: 32.4–88.8 cc) and 124.3 cc