A critical narrative review of radiotherapy for retroperitoneal soft tissue sarcoma.

Retroperitoneal sarcomas (RPSs) are rare diseases, and the 5-year overall survival rate remains low. Management of RPSs is challenging, and the quality of treatment strategy is a crucial prognostic factor. Treatment decisions and the treatment department to which the patients is referred must be centralized. Overall survival rate is positively correlated with the number of patients treated in the centers. En bloc surgery is the standard of care for effective treatment and potential for cure, whereas perioperative chemotherapy or radiotherapy has not yet been validated. Pre- or postoperative radiotherapy was considered controversial, but the STRASS trial publication illustrated that preoperative radiation could be useful in some conditions. Retroperitoneal liposarcoma might become a future target of prospective trials. Furthermore, some retrospective studies have shown that preoperative radiotherapy increases the rate of R0-R1 resections. This article reviews the role of external beam radiotherapy in the management of RPS and highlights the optimal volumes, doses, and radiotherapy techniques for the treatment of RPS. As accurately predicting prognosis in patients with RPS is challenging, we also emphasize the utility of nomograms in the field of radiotherapy. However, these nomograms do not include radiotherapy as a predictive factor. Although some authors could conclude that use of radiotherapy should be avoided based on the results of the STRASS trial, some data argue that radiotherapy still has utility in select cases.