Abstract
For locally advanced cervical cancers, combination of intracavitary and intersititial brachytherapy has been increasingly employed. For the dose prescrition of the combined brachytherapy, traditional point dose prescrition to the point A has no more validity, but volume dose prescrition employing GEC-ESTRO volume definitions must be used. However, the method of dose optimization is not standardized and remains to be studied. In this study, inverse planning simulated annealing (IPSA) planning was compared with manual optimization based on the Manchester method. From 2010 to 2012, 9 patients underwent 25 sessions of combination of intracavitary and interstitial brachytherapy. Application was performed under local anesthesia with sedation without no serious complications. In these 25 sessions, mean number of intersitital applicators inserted into the parametia was 2 (range:2-6). For the optimization of the dwell points and dwell times, tandem and ovoid weighting distributon was determined at first accorind to the Manchester method. Thereafter, manual optimization including the dwell points in the interstitial applicators was performed to make the dose distribution encircing the HR-CTV adequately. The actual treatment was deliver by manual planning. In these 25 sessions, IPSA planning was done and dose parameters were compared with the manual optimizations. Concerning the HR-CTV coverage, manual optimization and IPSA gave same results with mean V100s by IPSA and manual optimization, 96% and 95%, respectively and mean D90, 112% and 114%, respectively. In contrary, IPSA gave significantly reduced dose to the rectum and bladder. D2cc of the rectum was 68% and 81% by IPSA and manual optimization, respectively, with a statistically significant difference. Similarly, bladder D2cc was 75% and 97% by IPSA and manual optimization, respectively, with a statistically significant difference. IPSA provides excellent HR-CTV coverage simultaneously with Organ at Risk sparings. In out department, IPSA is now used routinely in the combination therapy of intracavitary and intersitital brachytherapy for cervical cancer.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
