Outcome of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy +/- intraoperative radiation therapy in the management of peritoneal sarcomatosis: Real world experience.

e23581 Background: Sarcomas are aggressive malignancy,30-40% of them originate from retroperitoneal space. which makes adequate free surgical margin after surgical debulking mostly not achievable. The addition of Hyperthermic intraperitoneal chemotherapy (HIPEC)+/- Intraoperative radiation therapy (IORT) may overcome local failure with an overall survival benefit. we studied the outcome of cytoreductive surgery (CRS)+ HIPEC +/- IORT on patients with peritoneal sarcomatosis,at our institute. Methods: Patients with peritoneal sarcomatosis treated with CRS+ HIPEC +/- IORT, in the period between 2011-2016 were included. Results: 24 patients identified;15(62.5%) were males. Median age was 58(31-77). Liposarcoma was the most frequent diagnosis in 50% of them. Neoadjuvant chemotherapy was received in 5 patients, while neoadjuvant radiation therapy was received in 3 patients. Cytoreduction completeness score (CC-0/1) was achieved in 19(79.17%), with median peritoneal cancer index (PCI) of 11 (3–28). Melphalan was the most commonly used agent for HIPEC chemotherapy, it was used in 16(66.67%) patients. IORT was given in 16(66.67%) patients. 8 patients developed grade III-IV Clavien-Dindo (CD) complications, with one died 5 days post operatively due to pulmonary embolism. Adjuvant chemotherapy was received in 9 patients. After a median follow up of 21 months, the mean, 2 years and estimated 4 years progression free survival was 19.6 months, 30.6% and 15.3% respectively, 13(54.2%) patients developed systemic progression, lung was the most affected site at time of progression in 8/13(61.5%) patients. Local progression occurred in two patients, while both systemic and local progression occurred in one patient. The 3 cases progressed locally underwent redo CRS and HIPEC with average 18 months between the first and redo surgery. The mean, 2 years and estimated 4 years overall survival was 21.2 months, 75.7% and 75.7% respective. In univariate analysis only CC score correlate with PFS, the mean PFS for those patients with CC (0-1) vs (2-3) was 13.7 vs 11.5 months ( p = 0.036). Conclusions: Addition of HIPEC+IORT to surgical debulking in the management of peritoneal sarcomatosis; seems to be safe and may improve local control rate with a questionable survival benefit, a larger cohort with a multicentric study is needed for further evaluation.