BEDVH-A method for evaluating biologically effective dose volume histograms: Application to eye plaque brachytherapy implants

Abstract

BEDVH permits evaluation of the relative biological effectiveness for brachytherapy implants. For eye plaques, (TUMOR)BEDVH and (OAR)BEDVH were sensitive to implant duration, which may be manipulated to affect outcomes.

Dosimetry of 125I and 103Pd COMS eye plaques for intraocular tumors: Report of Task Group 129 by the AAPM and ABS

“…The abovementioned effects are under investigation. 129,130 Further, the dosimetric analysis performed for the current report does not consider the tissue-heterogeneity of the structures in and around the eye; further analysis is needed to evaluate these factors. 59 Image guidance for eye-plaque brachytherapy based on fundus photography/ophthalmoscopy and ultrasonography has been developed and used in the COMS study in the localization and delineation of eye tumors.…”

Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function

“…4,8,[23][24][25][26][27] Currently, the AAPM recognizes that the most accurate method to calculate eye plaque brachytherapy dose distributions is a verified MC code that accounts for material heterogeneities of the eye plaque and patient. 28 The MCNP5 radiation transport code was used in the current study to model COMS-style eye plaques of 10-22 mm in diameter with material compositions and geometry identical to those used in Gagne et al 29 The plaques were populated with one of three low-energy brachytherapy radionuclides, R 2 Pd; I; Cs f g , with 103 Pd (model 200, Theragenics, Corp.), 125 I (model 6711, Oncura/GE Health-Care, Inc.), and 131 Cs (model CS-1 Rev2, IsoRay Medical, Inc.) using the TG-43 hybrid approach. 30 With the assumptions used in the COMS, the eye was modeled as a 2.46 cm diameter sphere of liquid water.…”

“…The equation used to calculate BED for LDR temporary implant brachytherapy is that introduced by Dale 42 and employed by Gagne et al 29 BED…”

“…A monoexponential recovery constant value of l ¼ 0:46 h À1 was also assumed for all ROIs in this study. 29 ) to evaluate the biological effects of changing R as a function of tumor position and size. 125 I was selected as the reference radionuclide for comparison due to its initial employment in the COMS protocol.…”

Guidelines by the AAPM and GEC‐ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167

“…181 For example, changing implant duration for COMS plaques from 7 to 3 days increases the biologically effective dose by 14%. 190 This case study highlights a type of medical device where there are several plaque models in clinical use, but without FDA approval or CE Marking. Institutions using these devices must either obtain IRB approval or request the manufacturer to obtain FDA approval or CE Marking.…”