SIDE EFFECTS OF EXTERNAL RADIOTHERAPY AND HDR BRACHYTHERAPY COMBINATION IN CERVIX CARCINOMA

Between August 1991 and December 1995, eighty six patients who were referred to DEGOG (Dokuz Eylül Gynecologic Oncology Group) were treated with the combination of external radiotherapy and HDR brachytherapy. Forty five of these patients were treated post-operatively, 41 patients received radiotherapy with curative intent. FIGO stage distribution were as follows; stage IB, 38 (44%); stage IIA, 4 (5%); MB, 22 (26%); IIIA, 1 (1%); NIB, 15 (17%); IVA, 6 (7%). Median age was 51 (30-79). External radiotherapy was given at a dose of 52.4 Gy (BED=83.9 Gy3). Midline blocking was performed at a median dose of 42.86 Gy (BED=70.3 Gy3) in postoperative patients and 44.6 Gy (BED= 71.6 Gy3) in patients who were treated with curative intent. Anteroposterior/posteroanterior (AP/PA) isocentric fields was used in 43 (50%) of patients and lateral portals were added (box technique) in 43 (50%) patients. The energies used were 23 MVX in 63 (73%) patients, 6 MVX in 6 (7%) patients, Co-60 in 17 (20%) patients. Brachytherapy was performed in 1-5 fractions and the median dose at point A was 69.1 Gy (BED=178.2 Gy3) while it was 69.9 Gy (BED=174.1 Gy3) at vaginal mucosa. Concomitant chemoradiotherapy was given to 19 (22%) patients. Chemotherapy schedules consisted of 20 mg/m2 cisplatinum weekly and 1000 mg/m2/day 5-FU during the last 3 days of radiotherapy in 12 patients, while it was only weekly cisplatinum at the above mentioned dose in 7 patients. Early and late side effects were evaluated during a median follow-up period of 22 months (3-52) according to RTOG morbidity scoring system. Urinary and gastrointestinal early side effects were grade I-II in 66% and grade III in 5% patients. Late side effects regarding these sites could only be evaluated in 62 patients who experienced grade I-II side effects in 47% and grade III-IV in 6% patients. Chi-square test was used to test the differences. The effects of isocenter depth, number of fields, field size, total dose, energies being used, presence of prior surgical operation, concomitant chemotherapy, total dose were analysed for early and brachytherapy fraction dose, BED of rectum and bladder for late effects; among these factors only the dose of brachytherapy being 10 Gy or more was statistically significant (p=0.019). As a result, we can conclude that, the dose of fraction should be below 10 Gy, however randomized trials are needed in this subject.