Analysis of dosimetry and clinical efficacy of intracavitary/interstitial brachytherapy in locally advanced cervical cancer

Objective To study the dosimetric differences and short-term efficacy between intracavitary/interstitial brachytherapy (IC/ISBT) and conventional intracavitary brachytherapy (ICBT). Methods Forty-five patients with locally advanced cervical cancer were treated with IC/ISBT and ICBT. Points A (A1,A2), D90%, D100%, organs at risk, and the doses of bladder, colon, rectum and small intestine were calculated and the short-term efficacy was observed between two groups. Results Point A dose was significantly improved in IC/ISBT compared with ICBT (P<0.05). The D90% and D100% in IC/ISBT were significantly higher than those in ICBT (both P<0.05). After brachytherapy, IC/ISBT could obtain a significantly larger increase in target dose when residual tumor diameter was ≥3 cm compared with ICBT (P<0.05). The D2cm³ and D0.1cm³ of bladder, rectum, colon and small intestine did not significantly differ between IC/ISBT and ICBT (all P>0.05). The 1-,3-and 6-month clinical efficacy did not significantly differ between two technologies (all P>0.05). Conclusion During brachytherapy for locally advanced cervical cancer (residual tumor diameter ≥3 cm), IC/ISBT significantly increases the doses of target area and point A without increasing the dose of organs at risk or lowering the short-term clinical efficacy, which has significant dosimetric advantages.