P-223 - The first experience in Intraoperative Radiation Therapy for locally advanced or recurrent rectal cancer

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Rectal Cancer
Surgery and/or Radiotherapy of Cancer
Presenter S. Potemin
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors S. Potemin, I. Uvarov, I. Vasilenko
  • Krasnodar Oncology Center, Krasnodar/RU

Abstract

Introduction

Patients with locally advanced or recurrent rectal cancer often require multimodal treatment. Intraoperative radiation therapy (IORT) is a focal approach which aims to improve local control.

Methods

From December 2012 to December 2014 we retrospectively reviewed 68 patients (pts.) treated with IORT Intrabeam Photon Radiosurgery System (PRS) following definitive resection of a locally advanced or recurrent rectal cancer (RRC). Gender distribution was 41 male and 27 female aged from 33 to 82 years (median 67). Stage II primary rectal cancer (PRC) was in 47 pts., stage III in 21 pts., and RRC was in 9 pts., Wanebo staging Tr3 – 6 pts., Tr4 – 2, and Tr5 – 1 pt. A dose of 5.07 Gy was prescribed to a depth of 1 cm (surface dose range was 9.4-17.0, median 14.8 Gy). Median duration of IORT was 31.9 minutes (range 15–36). Spherical applicator of 5 cm. in diameter was used in 61 cases and in 7 pts. 4.5 cm. Overall survival and disease free survival rate evaluated by Kaplan-Mayer method.

Results

Of 68 patients, 18 (26.4%) had tumors fixed to the sidewall. Margins were positive in 7 patients (10.3%). Median follow-up after IORT was 11.4 months (range 0.9 – 20.1 month). The 20 month overall survival rate was 90.1%. Local recurrence rate was 5% (S.E. = 4.9). The 20 month distant metastasis was evaluable in 8 patients, of whom 1 hepatic and 1 lungs, rate was 11.8%. No intraoperative complications were attributed to IORT. Median discharge time after surgery was 17.7 days (range: 9–25). No cases of hydronephrosis or ureter fibrosis after IORT were documented.

Conclusion

Fist experience suggests that Intrabeam PRS appears to be a safe technique for delivering IORT in rectal cancer patients. IORT with Intrabeam PRS marginally increased operative time, and did not appear to prolong hospitalization. Our rates of long-term toxicity, local recurrence, and survival rates compare favorably with published reports of IORT delivery with other methods.