Outcomes of orbital malignancies treated with eye-sparing surgery and adjuvant particle radiotherapy: a retrospective study

BACKGROUND: To report the clinical experience of eye sparing surgery (ESS) and adjuvant carbon-ion or proton radiotherapy (CIRT or PRT) for orbital malignancies. METHODS: An analysis of the retrospective data registry from the Shanghai Proton and Heavy Ion Center for patients with orbital tumors was conducted. The 2-year local progression-free, regional recurrence-free, distant metastasis-free, progression-free, and overall survival (LPFS, RRFS, DMFS, PFS, OS) rates as well as associated prognostic indicators were analyzed. Radiotherapy-induced acute and late toxicities were summarized. RESULTS: Between 7/2014 to 5/2018, 22 patients with orbital malignancies of various pathologies received ESS followed by CIRT (18), PRT (1), or PRT + CIRT boost (3). With a median follow-up of 20.25 (range 3.8–38.8) months, the 2-year OS, PFS, LPFS, RRFS, and DMFS rates were 100, 57.9, 92.9, 93.3, and 72.8%, respectively. No acute severe (i.e., ≥grade 3) toxicity was observed. Two patients experienced severe visual impairment as late toxicities. CONCLUSION: With few observed acute and late toxicities, particle radiotherapy following ESS provided effective local control with infrequent severe toxicities for patients with orbital malignancies.