Particle-Beam Radiation Therapy for Gynecologic Cancers- A Scoping Review and Expert Opinion by the Particle Therapy Cooperative Group – Gynecologic Subcommittee

Amelia Barcellini  et al.

This scoping review by the Particle Therapy Cooperative Group (PTCOG) Gynecologic Subcommittee, published in the International Journal of Radiation Oncology, Biology, Physics (2026), maps the clinical evidence on particle-beam radiation therapy in gynecologic cancers. Following PRISMA-ScR guidelines, the authors searched four databases through June 2025. Of 414 unique records, 41 studies were included; most came from Japanese centers, and most were cohort studies or case series, with 12 phase 1/2 trials.

Carbon-ion radiotherapy (CIRT) was the most frequently used modality, mainly for radioresistant tumors: locally advanced cervical cancer (especially adenocarcinoma), mucosal melanomas, and inoperable endometrial cancer. It showed promising local control with acceptable toxicity, although rectal invasion is a contraindication for definitive-dose CIRT because of severe gastrointestinal toxicity. Early data also suggest ablative CIRT may benefit selected patients with oligometastatic ovarian disease. Proton therapy was applied mainly in postoperative and recurrent settings, showing potential gastrointestinal-toxicity advantages over IMRT.

In conclusions, the evidence supports CIRT for radioresistant malignancies and unresectable recurrences, and proton therapy as adjuvant and reirradiation treatment. The authors call for standardized protocols, centralization of these rare cancers within the PTCOG network, and adequately powered prospective studies. Limitations include heterogeneous, largely retrospective data and differing RBE models.

Published by International Journal of Radiation Oncology Biology Physics.

http://doi.org/10.1016/j.ijrobp.2026.08.005