@article {Liu768, author = {Zhong-Shan Liu and Jie Guo and Yang-Zhi Zhao and Xia Lin and Bing-Ya Zhang and Chu Zhang and Hong-Yong Wang and Lei Yu and Xiao-Jun Ren and Tie-Jun Wang}, title = {Computed Tomography{\textendash}Guided Interstitial Brachytherapy for Locally Advanced Cervical Cancer: Introduction of the Technique and a Comparison of Dosimetry With Conventional Intracavitary Brachytherapy}, volume = {27}, number = {4}, pages = {768--775}, year = {2017}, doi = {10.1097/IGC.0000000000000929}, publisher = {BMJ Specialist Journals}, abstract = {Objective We present a new technique of 3-dimensional computed tomography{\textendash}guided interstitial (IS) brachytherapy (BT) for locally advanced cervical cancer, offering a more advantageous clinical treatment approach.Materials/Methods Interstitial BT was performed using an applicator combining uterine tandem and metal needles; needles were inserted freehand under real-time 3-dimensional computed tomography guidance. Twenty-eight patients with bulky tumors and/or parametrial extension (tumor size \> 5 cm) after external beam radiotherapy received IS BT. Dosimetric outcomes of the IS BT including the total dose (external beam radiotherapy and high dose-rate BT) D90 for the high-risk clinical target volume (HR-CTV) and D2cc for the organs at risk (OARs) were investigated and compared with a former patient group consisting of 30 individuals who received the conventional intracavitary (IC) BT.Results The mean D90 values for HR-CTV in the IC BT and IS BT groups were 76.9 {\textpm} 5.7 and 88.1 {\textpm} 3.3 Gy, respectively. Moreover, 85.7\% of the patients received D90 for HR-CTV of 87 Gy or greater in the IS BT group, and only 6.7\% of the patients received D90 for HR-CTV of 87 Gy or greater in the IC BT group. The D2cc for the bladder, rectum, and sigmoid were 84.7 {\textpm} 6.8, 69.2 {\textpm} 4.2, and 67.8 {\textpm} 4.5 Gy in the IC BT group and 81.8 {\textpm} 6.5, 66.8 {\textpm} 4.0, and 64.8 {\textpm} 4.1 Gy in the IS BT group. The mean number of needles was 6.9 {\textpm} 1.4, with a mean depth of 2.9 {\textpm} 0.9 mm for each IS BT. Interstitial BT was associated with only minor complications.Conclusions The IS BT technique resulted in better dose-volume histogram parameters for large volume tumors (\>5 cm) compared with the conventional IC BT and acceptable risk of acute complications in locally advanced cervical cancer and is clinically feasible.}, issn = {1048-891X}, URL = {https://ijgc.bmj.com/content/27/4/768}, eprint = {https://ijgc.bmj.com/content/27/4/768.full.pdf}, journal = {International Journal of Gynecologic Cancer} }