What are the dose limits to the bladder, rectum, and vaginal points in cervical cancer brachytherapy for 2D and 3D planning?
1. In cervical cancer brachytherapy, 2D International Commission on Radiation Units (ICRU) doses are max point doses. Typically in 2D planning the max allowed dose to the rectal point dose is <72 Gy, the max bladder point dose is <80 Gy, and the max vaginal point dose is <120 Gy.
2. With 3D planning, limits are volume based and quantified as D2cc which is defined as the min dose within the 2-cc volume of greatest dose. The bladder limit is D2cc <90 Gy equivalent 2 Gy dose (EQD2), rectum and sigmoid limit is D2cc <75 Gy EQD2. (Viswanathan A et al., Brachy 2012)