Radiotherapy of orbital metastases: a systematic review of management and treatment outcomes on behalf of palliative care study group of Italian association of radiotherapy and clinical oncology (AIRO)

Objectives: We search the current literature on data regarding the role of RT in OM treatment, focusing on the improvement of symptoms and patient quality of life. Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) recommendations. Results: From 340 citations, 60 papers were finally selected: 45 case reports and 15 case series. The case reports accounted for 47 patients. In 37/39 cases (95%), EBRT was done. Patients were mainly treated with 3DCRT, IMRT, and with SBRT. The most used RT regimens were 30 Gy in 10 fractions (23%) and 20-25 Gy in 5 fx (13%). No sever toxicity was reported. A median LC of 11 months (range 1-54 months) and a median OS of 12 months (range 1-54 months) were registered. Among the case series, a total of 457 patients were examined, 227 of whom underwent RT. The main used techniques were 3DCRT, CK, GK, SBRT, and BRT. RT doses could vary from 30 Gy/10 fractions to 60 Gy/30 fractions, 50 Gy/5 fractions, or 16.5-21 Gy in single fraction. No toxicity above G2 was reported. ORR could vary between 75 and 100%. Only two study provided information on response duration: a mean LC time of 22.8 months and a mean time to local progression of 5 months (range: 3-7). Regarding OS, the data were heterogeneous, ranging between 1 and 54 months. Conclusions: RT for OM seems to be a safe and feasible option. More information on the RT ideal techniques and dose are still needed. Advances in knowledge: This paper tried to sum up the few and fragmented data on the use of radiotherapy for orbital metastases: the possible option ranged from 3D and 2D CRT to SBRT, CK, and GK, with different possible fractionations (30Gy in 10 fractions, 60 Gy/30 fractions, 20-50 Gy/5 fractions, or 16.5-21 Gy in single fraction). Regardless of the chosen approach, almost all treated patients experienced a benefit after RT in terms of OMrelated symptom intensity reduction and a good acute and late toxicity profile.