Dosimetric analysis in brachytherapy of carcinoma of the cervix

Image-guided cervix high-dose-rate brachytherapy treatment planning: Does custom computed tomography planning for each insertion provide better conformal avoidance of organs at risk?

“…Not only do pointedose values from OARs inaccurately reflect heterogeneity of dose distributions within these organs (16,17), but they give no indication of volumes of tissue exposed to these doses (18,19). Furthermore, the placement of these ICRU points of interest can vary greatly (20,21). The large uncertainties associated with point dose values, along with the flexibility of the TO used in our study may explain the discrepancies between our observations and Jones et al's.…”

The sculpted pear: An unfinished brachytherapy tale

“…Such programs produce complete sets of isodose distributions in several planes around the applicators, which can be superimposed on localization films providing a two-dimensional visual representation of the relationship of these distributions to the applicators, opacified bladder and/or catheter balloon or chain, and rectosigmoid contrast (58)(59)(60)(61)(62). Single or multiple reference points are chosen on these films at the interface of the opacified bladder/bladder balloon and rectosigmoid which are closest to the applicators, and at selected dose specification points within the implanted volume for dose calculations (60,63,64).…”

“…The significance of point dose calculations has been fraught with uncertainty due to the variability of data entry (digitization and identification of source locations), the effect of the shields in many vaginal applicators, the limited information about the spatial relationship between the bladder and the rectum and the sources, as well as varying combinations of external and implant doses, chemotherapy, and patient specific variables. Additionally, there is great variation in the placement of points of interest on localization films (59,60,(65)(66)(67)(68). The International Commission on Radiation Units and Measurements, Inc. (ICRU) 38 report attempted to provide a guide for selection of universal reference points for the bladder, rectum, and regional lymph nodes for reporting purposes (69).…”