Intraoperative radiation therapy for locally advanced gynecological malignancies

Purpose: Evaluate disease control and survival in patients with locally advanced gynecological malignancies who received intraoperative radiation therapy with electrons (IOERT) as a component of treatment. Methods and Materials: Between March 1983 and June 1995, 63 patients (pts) with locally advanced primary (9 pts) or recurrent (54 pts) gynecological malignancies received IOERT as a component of attempted curative therapy. The site of origin was uterine cervix in 40 pts, uterine corpus in 16 pts, vagina in 5 pts, and ovary in 2 pts. Thirty-eight patients with recurrent disease had been previously irradiated (median prior RT dose 5040 cGy, range 900-8400). External beam radiotherapy (EBRT) was given to 43 of 63 pts either before or after IOERT (900-6570 cGy, median 4960 cGy). Chemotherapy was given to 21 pts prior to IOERT and following IOERT in 2 pts. IOERT doses ranged from 800 cGy to 2500 cGy with a median of 1750 cGy. The median IOERT dose was 2000 cGy in 20 patients with gross residual disease and 1500 cGy in 43 patients with microscopic residual disease. Endpoints included central control within the IOERT cone, local control, distant failure, disease free survival and overall survival. Variables evaluated for impact on disease outcome included tumor grade, primary site, prior RT, IOERT dose, EBRT dose, residual disease at time of IOERT, and use of chemotherapy. Results: Survival and disease control data are presented in the table below. There was no impact of any disease or treatment related variable on local or central failure. Pts with microscopic residual disease at the time of IOERT had significantly fewer distant metastases than pts with gross residual (5 yr 31% vs. 77%, p = 0.001) and improved survival (5 yr 37% vs. 10%, p = 0.02). Patients with recurrent disease after previous RT had survival and disease control rates which were similar to those seen in pts without priot RT. Toxicity ≥ grade 3 due to IOERT was observed in 11 pts (17%). Conclusion: A significant minority of carefully selected pts with locally advanced gynecological malignancies can achieve long term disease control with aggressive multimodality treatment which includes IOERT. Disease control and survival is best in pts in whom a gross total resection is accomplished. Pts with local or regional relapse after previous RT appear to fare as well as previously unirradiated pts