Significant decreased complications, based on individualized post-radical hysterectomy irradiation for carcinoma cervix - FIGO stage IB with unfavorable prognostic factors

Abstract

Purpose: To evaluate long term cancer control and treatment complications of vaginal intracavitary brachytherapy in conjunction with reduced external beam RT tailored to individual unfavorable pathologic findings in patients with FIGO Stage IB cancer cervix. Materials and Methods: Between 1980 and 1995, 64 patients post-radical hysterectomy with positive pelvic nodal metastases or any of the following risk factors: > 1cm. stromal invasion, capillary lymphatic space involvement, and large clinical tumor diameter(>3 cm.) received postoperative adjuvant radiation therapy. The histological findings include: 46 squamous carcinoma, 16 adenocarcinoma, 1 adenosquamous and 1glassy cell carcinoma. 16 patients had pelvic nodal metastases. None of the patients received adjuvant chemotherapy. Fourteen patients were treated on GOG-92 protocol that delivers 5000 cGy external beam radiation, post radical hysterectomy for women with poor prognostic factors. The remaining 50 patients were treated with individualized adjuvant radiotherapy and are the basis for this paper. External beam radiotherapy consisted of whole pelvic treatment of 45Gy/25 fractions /5 weeks using a 4-field technique. Pelvic node positive patients received an additional 5.4 Gy pelvic boost using a 4 cm. midline block. Both groups, node positive and negative then received 25 Gy vaginal intacavitary LDR brachytherapy(mucosal dose); to increase the dose to the vaginal apex, an area considered to be at high-risk for local recurrence. Median follow-up was 82 months; all survivors were followed for a minimum 3 years - with periods ranging from 36 to 220 months. Two patients were lost to follow-up before completing the 3-year period. Results: The actuarial recurrence-free survival (local or distant) for the vaginal boost group (node negative and positive) was 88 % at 5 years. Of the 8 patients who failed; there was 1 vaginal cuff recurrence(2%), two pelvic recurrences(4%) and 5 with distant metastases (10%) . A subgroup of 27 patients that conformed to the risk criteria combination used in the GOG-92 study was analysed. The actuarial recurrence - free survival for this group was 87.5 % at 5 years, slightly better than 82.5% for the GOG study. There was an 11.1% rate of locoregional recurrences. (2 pelvic and 1 vaginal cuff), which corresponded to the GOG failure rate of 13.1%. Grade 3 and 4 side effects were non-existent. In contrast GOG-92 reported a 9 % incidence of grade 3-4 effects with one Grade 5 mortality. The 16 node positive patients showed a 75% 5 year Recurrence - free survival with a 0% local recurrence. Conclusion: The individualized use of adjuvant radiation therapy based on unfavorable pathological features used in this series was very effective in achieving loco-regional control, without Grade 3 and 4 complications. The application of adjuvant vaginal brachytherapy to increase vaginal apex dose, enabled a reduction in external beam pelvic dose .These results show the advantages for post-radical hysterectomy irradiation in patients with Stage IB carcinoma of the uterine cervix with poor prognostic features. The high incidence of grade 3 and 4 complications in GOG-92 questioned the use of adjuvant irradiation despite statistical benefits of control of disease. This paper shows such an argument is without merit with a small change in technique.