Dosimetric analysis of CT-guided salvage interstitial brachytherapy for recurrent cervical cancer

Objective To analyze the dosimetric advantages of CT-guided interstitial brachytherapy for recurrent cervical cancer. Methods A total of 16 patients with recurrent cervical cancer after radical surgery and adjuvant external beam radiotherapy received interstitial brachytherapy with CT-guided implantation of metal needles. The high-risk clinical target volume (HR-CTV) was given 36 Gy in 6 fractions. D90 for HR-CTV in the brachytherapy and the cumulative D2 cm3 values for the bladder, rectum, and sigmoid colon in the previous external beam radiotherapy and the brachytherapy were analyzed. Results The mean D90 value for HR-CTV was 52.5±3.3 Gy. The cumulative D2 cm3 values for the bladder, rectum, and sigmoid colon were 85.6±5.8 Gy, 71.6±6.4 Gy, and 69.6±5.9 Gy, respectively. The mean number of metal needles was 6.1±1.5 in each brachytherapy. The actual 1-year overall survival and local control were 81% and 69%, respectively. Conclusions CT-guided interstitial brachytherapy for recurrent cervical cancer shows good dose-volume histogram parameters and few complications, so it may be clinically feasible. However, its long-term clinical efficacy needs further observation. Key words: Cervical neoplasms/interstitial brachytherapy; Dosimetry