Hypofractionated Radiotherapy Combined with Weekly Chemotherapy in Patients with Unresectable or Recurrent Thymic Epithelial Tumor: A Prospective, Single-arm Phase II Study (GASTO-1042)
Mené entre 2018 et 2020 sur 50 patients présentant une tumeur épithéliale thymique non résécable ou récidivante, cet essai de phase II évalue l'efficacité, du point de vue de la survie sans progression, et la toxicité d'un traitement combinant une radiothérapie hypofractionnée et une chimiothérapie hebdomadaire concomitante
Purpose: This prospective phase 2 study aimed to evaluate the efficacy and safety of hypofractionated radiotherapy (HRT) combined with concurrent weekly chemotherapy in patients with unresectable or recurrent thymic epithelial tumors (TETs). Methods and Materials: Patients with unresectable or recurrent intrathoracic TETs which could be encompassed within the radiation fields were enrolled. HRT using intensity-modulated radiation therapy (IMRT) technique was administered with 3 different levels of radiation doses (51Gy/17fx, 48Gy/12fx and 45Gy/9fx; biologically effective dose of 66.3-67.5Gy), combined with weekly docetaxel (25mg/m2) and nedaplatin (25mg/m2). Weekly thymosin α1 (1.6 mg) was administered from the start to 2 months after radiotherapy. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), health-related quality of life (QOL) and toxicity were recorded. Results: Fifty eligible patients enrolled from August 1, 2018 to July 1, 2020 were analyzed. Most patients (82.0%) had stage IVB tumors. Patients had IMRT-HRT (36-51Gy in 9-17 fractions, median BED 67.2 Gy) and concurrent weekly docetaxel/nedaplatin (2-4 cycles). During a median follow-up of 25.0 months (14.0-40.0), the ORR was 83.7%, the 2-year PFS was 59.1% and the 2-year OS was 90.0%. There was one (2.0%) in-field recurrence while 19 (38.0%) patients developed out-of-field recurrence. Grade 3 pneumonitis was observed in one patient (2.0%). The ORR, 2-year PFS, 2-year OS and toxicity were similar among 3 dose levels. Fourteen (28.0%) patients had 2-4 courses of radiotherapy because of recurrent diseases. Only one suffered from grade 1 pulmonary fibrosis during follow-up. Most patients (88%) maintained a stable QOL within 1 year after radiotherapy. Conclusions: IMRT-HRT and concurrent weekly docetaxel/nedaplatin was effective and well-tolerated in unresectable or recurrent TETs. Considering the common out-of-field recurrence, this combined regimen could be an option for repeated radiotherapy. Thymosin α1 might help lower the incidence of pneumonitis and maintain the QOL.
International Journal of Radiation Oncology, Biology, Physics 2022