RESUMO
Objective To discuss the dosimetric advantage of computed tomography-guided interstitial brachytherapy compared with the conventional intracavitary brachytherapy for locally advanced cervical cancer,offering a more advantageous clinical treatment approach. Methods Twenty-eight locally advanced cervical cancer patients with bulky tumors ( tumor size>5 cm) after external beam radiotherapy received computed tomography-guided interstitial brachytherapy. Dosimetric outcomes of the current study, including the total dose ( external beam radiotherapy+ brachytherapy ) D90 for the HR-CTV and D2cc for the bladder,rectum, and sigmoid, were compared with a former patient group consisting of 30 patients who received the conventional intracavitary brachytherapy ( uterine tandem+ ovoid pairs ) . Results The mean D90 value for HR-CTV in the intracavitary brachytherapy group and interstitial brachytherapy group were (76.9±5. 7) and ( 88.1± 3. 3) Gy, respectively. The D2cc for the bladder, rectum, and sigmoid in the intracavitary brachytherapy group and interstitial brachytherapy group were (84.7±6. 8) Gy,(69.2±4. 2) Gy,(67.8±4. 5) Gy and (81.8±6. 5) Gy,(6.8±4. 0) Gy,(64.8±4. 1) Gy,respectively.1-year local tumor control rate in the intracavitary brachytherapy group and interstitial brachytherapy group were 59. 3％ and 85. 2％, respectively. Conclusions CT-guided interstitial brachytherapy shows a significant dosimetric advantage compared with the conventional intracavitary brachytherapy, and is, thereby, clinically possible feasible. However,the long term curative effect and toxicity need to be further investigated.