Abstract
BACKGROUND: Childhood cancer treatment has increasingly achieved favorable long-term survival rates, shifting focus toward reducing long-term comorbidities. Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue tumor, and radiation therapy is essential for its treatment. Proton beam therapy (PBT) is currently utilized due to its potential to reduce long-term complications; however, data on its impact on tumor prognosis remain limited. METHODS: We conducted a meta-analysis to evaluate whether differences in tumor prognosis exist based on radiation therapy modalities, such as photon radiotherapy (photon RT) and PBT, for pediatric parameningial RMS-only study (Group 2) and other pediatric RMS (Group 1). Studies published between 1990 and 2022 were included if they were written in English, included more than 10 cases, and reported outcomes such as overall survival (OS) and local control rates (LC). RESULTS: A total of 37 results (photon RT: 23, PBT: 14) were analyzed using random-effects meta-analyses. No significant differences were observed between treatment modalities in 1- to 5-year OS (photon RT vs. PBT) in Group 1. Early (1- and 3-year) inferior LC rates were observed with PBT in Group 2. DISCUSSION AND CONCLUSION: Overall survival or LC rates don't differ significantly between cases treated with photon RT and those treated with PBT. The inferior early LC rates in cases of parameningeal-only RMS study treated with PBT may be attributed to the limited number of studies describing PBT, many of which were single-center reports. Unbiased clinical trial data are needed to clarify differences in early local relapses in parameningeal RMS.