Posters— Surgical Treatment of Sarcomas

COMBINED THERAPY FOR RETROPERITONEAL SOFT TISSUE SARCOMAS: PREOPERATIVE RADIATION AND SURGERY

Gronchi A, Azzarelli A, Baratti D, Lombardi F, Gandola L, Navarria P, Bertulli R, Casali PG, Pennacchioli E, Rasponi A, Dileo P, Pilotti S, (Istituto Nazionale Turnori, Milan, Italy)

Intervention: Surgery is the standard treatment of retroperitoneal soft tissue sarcomas (RSTS), but is affected by an high failure rate. Adjuvant radiation may improve local control and possibly survival. We report the results of a phase I-II study on radiation therapy (RT) delivered in a preoperative setting, to determine the treatment feasibility and its possible benefit on surgical quality.

Patients and methods: From September ’96 to December ’99 41 patients affected by RSTS were referred to our institution. Twenty-one of them, affected by primary or recurrent disease, were eligible for the combined therapy. As regards to the histology, 14 were liposarcoma, 5 were leiomiosarcoma, 1 rhabdomiosarcoma and 1 abdominal gastro- intestinal stromal tumor. Seventeen were low grade and 4 high grade. A CT-based computerized treatment plan was obtained in all patients to determine treatment volume. Personalized shields were realized to conform dose distribution. The scheduled dose was 50 Gy. Surgery was then planned between the 30th and the 60th day after the end of RT.

Results: One patient received only 32 Gy for gastro-intestinal intolerance. All the other patients completed the treatment without significant toxicity. One patient progressed soon after RT and was not operated. All the other 20 patients underwent surgery 32-46 days after the end of RT. A complete removal of the tumor was possible in 15 cases: resection was extended to viscera with 10 nephrectomies, 7 colectomies, 2 distal pancreatectomies, 1 splenectomy, 1 gastric resection and 1 resection of the inferior vena cava. No major surgical difficulties were encountered. In the remaining 5 cases not completely resected a sarcomatosis was found at laparotomy. One patient died 3 months later due to related abdominal complications. One patients died 12 months later due to local abdominal recurrence and two 22 and 32 months later respectively due to distant metastasis. The remaining 11 patients are all alive with a median follow-up of 25 months (range 6-40), 8 of whom free of disease.

Conclusions: Preoperative radiation is feasible and safe. A controlled study with strict inclusion criteria is now recommended to investigate the possible benefit of the combined treatment on survival.