A COMPARISON OF INTRACAVITARY VERSUS INTERSTITIAL IRRADIATION IN THE TREATMENT OF CERVICAL-CANCER

Objective, Management of locally advanced cervical cancer consists pri marily of combination external and internal radiation, In order to inv estigate the impact of intracavitary brachytherapy versus interstitial brachytherapy on local tumor control, survival, and complications, we retrospectively reviewed the concomitant experience of two institutio ns, each of which practice exclusively one of these radiotherapeutic t echniques. Methods. Between 1979 and 1989, 61 patients with bulky stag e II, III, or TVA cervical cancer were treated using a combination of teletherapy and intracavitary brachytherapy at one institution, while 70 similar patients were treated with teletherapy and interstitial bra chytherapy at another institution, Patients in both groups were simila r with respect to age, FIGO stage, tumor size, surgical stage, and his tologic subtype, Patients treated with intracavitary therapy received a mean cumulative dose of 7706 cGy to point A and 5523 cGy to point B using standard Fletcher-Suit techniques, Those who received interstiti al irradiation were treated with a mean external dose of 5050 cGy and 2 interstitial implants using a transperineal Syed-Neblett template wi th a mean tumor dose of 2239 and 1,942 cGy with each application, resp ectively, Patients treated with chemoradiation were excluded from this review. Results. Although initial rates of local control were not dif ferent, prolonged 5-year disease-free survival(50% vs 21%, P = 0.01) a nd improved 5-year local control (61% vs 32%, P = 0.01) were observed among patients with stage II disease treated with intracavitary irradi ation, No statistical differences in survival could be detected among stage III and IVA patients. Women treated with intracavitary irradiati on received a larger dose of brachytherapy than those treated with int erstitial therapy (4608 vs 3504 radium milligram hours equivalent, P < 0.0001) because a tandem was only used in 17 (24%) interstitial impla nts. Major complications occurred in 21% of patients in each group. Co nclusion. When a tandem is infrequently used during interstitial brach ytherapy, the toxicity is similar to that of intracavitary techniques, However, more relapses are observed among patients with stage II lesi ons treated with interstitial irradiation. (C) 1997 Academic Press.