Correlation of Traditional Point a With Anatomic Location of Uterine Artery and Ureter in Cancer of the Uterine Cervix

• Published in: International journal of radiation oncology, biology, physics Vol. 69; no. 2; pp. 498 - 503
• Main Authors: Wang, Kung-Liahng, M.D, Yang, Yuh-Cheng, M.D, Chao, K. S. Clifford, M.D, Wu, Meng-Hao, M.D, Tai, Hung-Chi, B.S, Chen, Tze-Chien, M.D, Huang, Ming-Chao, M.D, Chen, Jen-Ruei, M.D, Su, Tsung-Hsien, M.D, Chen, Yu-Jen, M.D., Ph.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2007
• Subjects: Adult; Angiography; ARTERIES; Arteries - anatomy & histology; BLADDER; BRACHYTHERAPY; Brachytherapy - methods; CARCINOMAS; Cervical cancer; Cervix Uteri - blood supply; CORRELATIONS; Female; Hematology, Oncology and Palliative Medicine; Humans; Laparoscopy; Laparotomy; Laparotomy - methods; Lymph Node Excision; Middle Aged; PATIENTS; Point A; Prospective Studies; Prostheses and Implants; RADIATION DOSES; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; SPECIFICATIONS; Ureter - anatomy & histology; Ureter - diagnostic imaging; URETERS; Urinary Bladder; Uterine Cervical Neoplasms - blood supply; Uterine Cervical Neoplasms - diagnostic imaging; Uterine Cervical Neoplasms - radiotherapy; Uterus - blood supply; Brachytherapy; Laparoscopy; Laparotomy; Point A; Cervical cancer
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2007.03.038

Purpose Point A, used for dose specification for intracavitary brachytherapy for cervical cancer, is the point at which the uterine artery and ureter cross. This study assessed compatibility of commonly used traditional point A (TPA) and actual anatomic point A (APA). Methods and Materials We visualized and placed radiopaque clips at the APA during pelvic and paraaortic lymphadenectomy in 11 patients with cervical carcinoma. Orthogonal and oblique radiographs were obtained after insertion of brachytherapy applicators. We measured the distance between the TPA and APA and estimated the brachytherapy dose to each of the two points. Results A total of 64 brachytherapy treatments were performed. The mean distances between the TPA and APA were 5.2 ± 1.0 cm on the right and 5.4 ± 1.1 cm on the left. The estimated brachytherapy doses delivered to the APA as a percentage of the presumed 500-cGy fraction size to the TPA were 35.2% (176.6 ± 59.0 cGy) on the right and 30.0% (150.2 ± 42.9 cGy) on the left. The marked discrepancy in the position of the two points was not related to individual kinetic variations during brachytherapy treatment, tumor size, or bladder filling. Conclusions The conventional TPA does not provide an accurate estimate of the APA determined during lymphadenectomy, indicating a need to reevaluate the current practice for determining the brachytherapy prescription for cervical cancer. ( ClinicalTrials.gov Identifier, NCT00319462)