Top Line: Achieving a R0 resection for sarcoma in the retroperitoneal space is difficult.
The Study: Enter radiation as a common sense strategy to maximize success. With the majority of related morbidity and mortality occurring due to local progression, pushing the limits of neoadjuvant radiation is worthwhile. This retrospective study compared outcomes between patients receiving neoadjuvant conventionally-fractionated radiation of 45-50 Gy over typically 25 fractions with (n=34) or without (n=69) a dose-escalated simultaneous boost for localized, resectable retroperitoneal sarcoma. The boost was delivered to the posterior portion of the target volume that is both most at risk for an involved margin as well as furthest from dose-limiting organs at risk such as bowel. The median boost dose was 57.5 Gy. Interestingly, while there was no difference in rates of subsequent resection (81-82%) or involved margin (50-53.5%), there was a significant improvement at 5 years in local control (70 → 96%) and disease-free survival (36 → 60%) with the addition of an integrated boost. The numbers are small, but there was even a trend towards improved survival (68 → 90%). FInally, grade 3+ toxicity was, if anything, less likely with an integrated boost (3%) than without (22%) perhaps due to most concurrent larger volumes receiving only 45 versus 50 Gy when a boost was included.
TBL Adding an integrated boost to the at-risk posterior margin during neoadjuvant radiation for resectable retroperitoneal sarcoma improves cancer outcomes without adding appreciable toxicity.. | Liveringhouse, Int J Radiat Oncol Biol Phys 2023
The Study: Enter radiation as a common sense strategy to maximize success. With the majority of related morbidity and mortality occurring due to local progression, pushing the limits of neoadjuvant radiation is worthwhile. This retrospective study compared outcomes between patients receiving neoadjuvant conventionally-fractionated radiation of 45-50 Gy over typically 25 fractions with (n=34) or without (n=69) a dose-escalated simultaneous boost for localized, resectable retroperitoneal sarcoma. The boost was delivered to the posterior portion of the target volume that is both most at risk for an involved margin as well as furthest from dose-limiting organs at risk such as bowel. The median boost dose was 57.5 Gy. Interestingly, while there was no difference in rates of subsequent resection (81-82%) or involved margin (50-53.5%), there was a significant improvement at 5 years in local control (70 → 96%) and disease-free survival (36 → 60%) with the addition of an integrated boost. The numbers are small, but there was even a trend towards improved survival (68 → 90%). FInally, grade 3+ toxicity was, if anything, less likely with an integrated boost (3%) than without (22%) perhaps due to most concurrent larger volumes receiving only 45 versus 50 Gy when a boost was included.
TBL Adding an integrated boost to the at-risk posterior margin during neoadjuvant radiation for resectable retroperitoneal sarcoma improves cancer outcomes without adding appreciable toxicity.. | Liveringhouse, Int J Radiat Oncol Biol Phys 2023