EFFECT OF RADIOTHERAPEUTIC TECHNIQUE ON LOCAL-CONTROL IN PRIMARY VAGINAL-CARCINOMA

A retrospective analysis of 73 patients treated for primary vaginal ca rcinoma with radiation therapy was performed to evaluate the effect of radiotherapeutic technique on local control. Local control was achiev ed in five of 22 patients (23%) treated with pelvic external beam ther apy alone, three of four patients (75%) treated with intracavitary cyl inder or Bloedorn applicator alone, and 30 of 47 patients (64%) treate d with combination of external beam and brachytherapy. Radiation thera py complications requiring hospitalization occurred in six patients (8 %). A statistically significant difference in local control was achiev ed only when patients receiving external beam and brachytherapy were c ompared with patients receiving external beam therapy alone (P<0.005). Total mid-tumor dose was defined as the sum of midplane tumor dose fr om external beam therapy, mid-tumour dose from interstitial radium nee dles, and the vaginal surface dose from intracavitary radium systems. Total mid-tumor doses ranged from 16 to 121.7 Gy. Only two of 16 patie nts receiving less than 55 Gy total mid-tumor dose achieved local cont rol. As a result, dividing doses of 45, 55, 65 and 75 Gy produced a st atistically significant superior local control rate in the patients re ceiving the higher dose (P<0.01). None of the 16 patients receiving le ss than 55 Gy total mid-tumor dose had received brachytherapy. We conc lude that the combination of external beam therapy and brachytherapy i s essential to achieve optimal control of primary vaginal carcinoma.