Recurrences of rectal cancers: results of a multimodal approach with intraoperative radiation therapy. French Group of IORT. Intraoperative Radiation Therapy.

Purpose: Prognosis of recurrent rectal cancer remains poor, mainly because of the difficulties of achieving a satisfactory local control. Intraoperative radiation therapy (IORT) allows for the delivery of a complementary single dose to the tumor residues or to the tumor bed and could be useful jn a multimodal treatment. In an attempt to evaluate this interest, a retrospective analysis of patients treated with IORT in six French hospitals has been performed.
Methods and Materials: Data have been collected in 73 patients (41 men), with a mean age of 62 years, treated with IORT. Initial rectal tumors were large (mean diameter: 45 mm), partially or totally fixed to the contiguous structures in 39%, and with nodal involvement in 50% of the cases. Initial surgery had been a sphincter-sparing surgery in 67%; external radiation therapy had been delivered in 52%, and a chemotherapy had been given in 10% of the patients. Recurrences were isolated (without metastases) in 86%, and were posterior or posterolateral in 55% of the cases. Surgery allowed for a complete macroscopical resection in 57%, a partial resection with gross residual disease in 29%, and no resection in 14% of the recurrences. Intraoperative radiation therapy was delivered in a dose of 10 to 25 Gy (mean 18.5) through localizators of a mean diameter of 75 mm (60 to 110). External radiation therapy, either preoperative or postoperatively was given to 30 patients without prior radiation therapy. Ten patients received additional chemotherapy with 5-fluorouracil.
Results: Four postoperative deaths occurred. Postoperative morbidity occurred in 16 patients and some complications were probably related to the IORT procedure. Four long-term complications were observed. Overall actuarial survival occurred in 72.4% of the patients at 1 year, in 44.6% at 2 years, and in 30.6% at 3 years. Twenty-one local failures have been observed. Actuarial local control occurred in 71.3% of the patients at 1 year, 47.7% at 2 years, and 31.3% at 3 years.
Conclusion: Intraoperative radiation therapy is a complementary treatment for recurrences of rectal cancer. It provides encouraging results, particularly in some selected situations, when patients have not previously been treated with external radiation therapy. Further studies of multimodal treatments are necessary.