Clinical Outcomes of Intensity Modulated Proton Therapy Reirradiation for Gynecologic Malignancies

Ariel E Pollock; Hunter Risher; Melanie Berger; Dana M Roque; Gautam Rao; Elizabeth M Nichols; Pranshu Mohindra

doi:10.1016/j.adro.2023.101191

Clinical Outcomes of Intensity Modulated Proton Therapy Reirradiation for Gynecologic Malignancies

Adv Radiat Oncol. 2023 Feb 25;8(4):101191. doi: 10.1016/j.adro.2023.101191. eCollection 2023 Jul-Aug.

Authors

Ariel E Pollock¹, Hunter Risher², Melanie Berger², Dana M Roque³, Gautam Rao³, Elizabeth M Nichols^{2

4}, Pranshu Mohindra^{2

4}

Affiliations

¹ Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, Maryland.
² Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland.
³ Division of Gynecology Oncology, University of Maryland School of Medicine, Baltimore, Maryland.
⁴ Maryland Proton Treatment Center, Baltimore, Maryland.

Abstract

Purpose: Pelvic reirradiation (re-RT) for patients with gynecologic cancers remains a challenge because of toxicity concerns. Given the dosimetric advantages of proton therapy, we aimed to assess oncologic and toxicity outcomes of patients with re-RT to the pelvis/abdomen with intensity modulated proton therapy (IMPT) for gynecologic cancers.

Methods and materials: We performed a retrospective analysis of all patients with gynecologic cancer treated at a single institution between 2015 and 2021 with IMPT re-RT. Patients were included for analysis if the IMPT plan had at least partial overlap with the treated volume of a previous radiation treatment.

Results: A total of 29 patients were included for analysis, with 30 total courses of re-RT. The majority of patients had been treated previously with conventional fractionation to a median dose of 49.2 Gy (30-61.6 Gy). With a median follow-up of 23 months, 1-year local control was 83.5% and overall survival was 65.7%. Three patients (10%) developed acute and late grade 3 toxicity. One-year freedom from late grade 3+ toxicity was 96.3%.

Conclusions: This is the first complete analysis of clinical outcomes for re-RT with IMPT for gynecologic malignancies. We demonstrate excellent local control and acceptable acute and late toxicity. IMPT should strongly be considered for treatments requiring re-RT for gynecologic malignancies.