Pulsed low dose rate brachytherapy for uterine cervix carcinoma

To analyze the outcome and complication rates for patients treated with curative-intent pulsed low dose rate (PLDR) brachytherapy and external beam radiation therapy (EBRT) for uterine cervical carcinoma.

Fifty-two patients have been treated, of whom 6 were excluded from analysis due to limited follow-up. Six patients were stage Ib, 3 were IIa, 11 IIb, 3 IIIa, 14 IIIb, 1 IVa, and 9 were treated for local recurrences following primary surgery for stage Ib disease. Thirty-six patients had squamous cell carcinoma, 8 adenocarcinoma, 1 adenosquamous, and 1 carcinosarcoma. Thirty-one had a staging laparotomy prior to radiation therapy. Brachytherapy was interstitial in 18 patients, and intracavity in 28. The median EBRT central pelvis dose was 45 Gy in 25 fractions. Median total prescribed doses (EBRT plus PLDR) were 75.8 Gy to the implant volume with interstitial, and 84.1 Gy to the A points with intracavitary, at a median dose rate of 0.55 Gy per pulse per hour. Six patients had laparotomy-documented periaortic node involvement, and received EBRT to this site, 45 Gy in 25 fractions. Thirty patients received concomitant weekly cisplatin chemotherapy (40 mg/m2).

With a median follow-up of 25 months (range 6 to 55 months) actuarial 4-year disease-free survival (DFS) rates are 66% for the entire group: stage Ib 100%, stage II 69%, stage III/IVa 68%, and 43% in patients treated for recurrences after surgery for initial stage Ib disease. Pelvic nodes contained tumor in 13 of the 31 patients (41.9%) who underwent laparotomy, as did periaortic nodes in 6 (19.4%). Patients with negative pelvic nodes had a 4-year actuarial DFS of 75% versus 59% with positive pelvic (and negative periaortic) nodes, and 50% with positive periaortic nodes. Using the RTOG late radiation morbidity scoring criteria, there were no grade V complications. Grade IV complications occurred in 2 patients (4.3%). One was a rectovaginal fistula and the other a vesicovaginal fistula, each occurring subsequent to a biopsy revealing benign tissue. One patient (2.2%) had a grade III complication (frequent hematuria), and 5 (10.9%) had grade II complications.

PLDR brachytherapy is a safe and effective brachytherapy method in the treatment of cervix carcinoma. It combines the physics benefits of dose optimization and the radiobiologic advantages of low dose rate brachytherapy. It eliminates radiation exposure to staff and visitors as well as the need for a source inventory. Although further follow-up will be required, it appears to provide outcome which compares favorably to other methods of brachytherapy delivery, and results in a low rate of complications.