ESTRO 2022 - Abstract Book

S959

Abstract book

ESTRO 2022

From Dec 2017 to May 2021, 9 pts (4m, 5f), mean age 42 (18-56) with AVMs were treated with CK. AVMs were located within cerebellum (3), temporal lobe (3), parietal lobe (2) and frontal lobe (1). 6 pts had previously undergone endovascular embolization. Median GTV was 3,65 cc (0,09-11,99) and median marginal dose was 19 Gy (18-21) with median isodose prescription of 80% (74-85). PTV median coverage was 99,76% (97,54-100) with median PTV CI of 1,6 (1,16-2,14). 6 pts completed the RT course, 1 pt had asymptomatic brain radionecrosis 19 months after the RT, 5 pts had > 1-year angiographic follow-up: 4 had stable disease and 1 AVM obliteration

Conclusion A specialized team approach is necessary for CK treatment of AVMs, including an SRS expert radiation oncologist and medical physicist, and an interventional neuroradiologist. CK is safe and effective for AVMs treatment, but long-term data are needed

PO-1129 Post-operative Proton Beam Therapy in cervical chordoma

K. Holub 1 , S. Froelich 2 , J.P. Guichard 3 , T. Passeri 2 , M. Polivka 4 , A. Carpentier 5 , H. Adle-Biassette 4 , L. Feuvret 6 , G. Lot 7 , S. Bolle 8 , A. Beddok 9 , R. El Ayachy 9 , F. Goudji 9 , I. Pasquie 9 , V. Calugaru 9 , R. Dendale 9 , H. Mammar 9 1 Institut Curie, Department of Radiation Oncology, SEOR-CRIS Foundation, Paris, France; 2 Hôpital Lariboisière , Department of Neurosurgery, Paris, France; 3 Hôpital Lariboisière , Department of Radiology, Paris, France; 4 Hôpital Lariboisière , Department of Pathology, Paris, France; 5 Hôpital La Pitié Salpêtrière , Department of Neurosurgery, Paris, France; 6 Hôpital La Pitié Salpêtrière , Department of Radiation Oncology, Paris, France; 7 Fondation Rothschild, Department of Neurosurgery, Paris, France; 8 Gustave Roussy, Department of Radiation Oncology, Villejuif, France; 9 Institut Curie, Department of Radiation Oncology, University Paris-Saclay, Paris, France Purpose or Objective To present outcomes of postsurgical proton-based RT in patients with cervical chordomas treated between 2014-2018 in the Centre of Protontherapy in Orsay, France. Materials and Methods A total of 9 consecutive patients with cervical chordoma with median age was 55.7 years old (range 38.8-72.3) at the time of RT were treated with postsurgical adjutant proton-based RT, at a median dose 73.8GyE (70.2-73.8). Only PT was administered to 5 patients (55.6%) and 4 (44.4%) were treated with a combination of photons (median dose 44.1 Gy, range 23.4-52.2) and PT GyE (median dose 29.7 Gy, range 18.0-50.4). Female/male ratio was 4/5. Histological subtypes were classic in 7 cases, chordoid in 1 patient and mixt classic-chordoid in 1 patient. Complete resection was achieved in 2 patients. The median time from surgery to PT: 7.6 months (4.6-38.0). Three patients were treated with 2nd surgery and four patients presented post-surgical squeals: 3 sensorial (hypoesthesia of left cervico-occipital territory, sensory deficit in three left fingers due to median nerve alteration, right latero-cervical hypoesthesia) and 1 motor (left arm motor deficit + XII pc). Results After a median follow up of 44.2 months (range 11.0-70.8, mean 41.6 months), 3 patients presented local and 1 distant progression. As 2 patients died (one due to chordoma progression), the overall survival rate was 73.8% and overall chordoma- related survival rate: 85.7%. Post-PT toxicity was described in 5 patients, all CTCAE grade 1-2 (hear loss unilateral, mild facial hypoesthesia, mild dysphagia, insomnia, mild cervical pain, asthenia, paraesthesia right arm). One patient presented asymptomatic radionecrosis resolved with corticoids.

Table 1. Characteristics of patients with cervical chordoma treated with PT