Physics Bucharest 2017

Organs at risk (OAR)-serial-parallel organisation

• Serial-parallel organisation-Functional Subunit Concept

Most organs are not clearly serial-like or parallel-like structure,

Examples- Heart (myocardium- parallel, coronary arteries –serial); Kidney (glomerulus- parallel, tubules-serial)

Report at least three dose – volume specifications

Include D mean (which if exceeded has high probability of serious complication) , D 2 %, and, V D

For tubular types of organ (e.g., the rectum), delineation of the wall is preferred to whole-organ delineation.

Emami B et al.,Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys 1991, 21(1):109-122. Bentzen SM, et al., Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC): an introduction to the scientific issues. Int J Radiat Oncol Biol Phys 2010, 76(3 Suppl):S3-9.