Comparison of 1 vs 2 or more intracavitary brachytherapy applications in the management of carcinoma of the cervix, with irradiation alone.
Four hundred ninety-eight patients treated in the USA in 1978 for cancer of the cervix by external beam and intracavitary irradiation have been studied to determine the effect of using a single intracavitary (IC) application versus more than one. Most of the patients (46%) underwent intracavitary (IC) treatment after external radiation therapy (RT), 40% during external RT, and 14% prior to external RT. Five-year actuarial survival for all stages was 66% for greater than or equal to 2 applications versus 59% for 1 application, p less than .01. When survival was analyzed by stage, there was a trend toward improved survival with greater than or equal to 2 applications in Stage II (p .10). The rate of infield recurrence for all stages was higher in the 1 IC group (30% vs 17%, p less than .01). These were more frequent in the 1 IC group (53% vs 34%, p less than .05), in Stage III patients, but no significant difference was noted in the other stages. Distant metastases were more frequent in the 1 IC group (19% vs 11%, p .01). The incidence of major complications was the same in both groups. An analysis of patient characteristics and other variables that would explain the difference in results revealed that older patients (p .03), worse Karnofsky (p .056), and more parametrial involvement (p less than .01) accrued more in the 1 IC group. Higher paracentral point doses were administered when greater than or equal to 2 IC applications were used (p less than 0.01); this group also received higher bladder and rectal doses and lower whole pelvic doses. The use of two or more intracavitary insertions affords an opportunity to administer higher paracentral point doses, which appear to be related to higher pelvic tumor control, lower rate of distant metastasis, and better survival.