What new dose distribution statistics may be included in the optimization of dose distribution in radiotherapy for post-mastectomy patients

Abstract

Introduction.The main aim of this study was to evaluate the doses delivered to heart substructures and calculate normal tissue complication probability (NTCP) for the intensity modulation radiotherpy (IMRT) irradiated group of left-sided post-mastectomy patients. Material and methods. In this retrospective study for 30 randomly chosen breast cancer patients, the mean dose, V2, V4, V10, V20 and D2% in the heart substructures were evaluated. Results. The mean heart dose was 12.3 Gy, the mean left anterior descending artery (LAD) dose was 28.5 Gy. The average value of long-term cardiac mortality was 0.17%, pericarditis 0.0%, left ventricle perfusion defects 24.5% and LAD toxicity 0.2%. In the literature, for the IMRT technique for left-sided mastectomy patients, the mean heart dose ranged from 8.7-14.0 Gy and the V20 10.5-14%. Additional studies are needed to describe the cardiac toxicity. Conclusions. It is necessary to contour cardiac substructures for reliable assessment of the dose distribution, although the mean heart dose is simplification for modern radiotherapy techniques.

Evaluation of Heart Substructures as a Function of Dose and Radiation-Induced Toxicities in Left-Sided Breast Cancer Radiotherapy

“…Radiation-induced heart conditions are the most frequent treatment-related toxicities in left-sided breast cancer patients and have been widely investigated [1][2][3]. Besides the heart, cardiac substructures are also being studied lately in the context of dose to OARs [1][2][3].…”

“…Radiation-induced heart conditions are the most frequent treatment-related toxicities in left-sided breast cancer patients and have been widely investigated [1][2][3]. Besides the heart, cardiac substructures are also being studied lately in the context of dose to OARs [1][2][3]. Nevertheless, the reported data on the correlation between doses to cardiac substructures and cardiac changes during or postradiotherapy are limited [4][5][6][7].…”

Are we ready to change treatment planning for left-side breast cancer radiotherapy?

“…Recently, Mężyński and Kukołowicz [8] presented an interesting planning study where they evaluated the doses delivered to various heart substructures and calculated normal tissue complication probability (NTCP) for the intensity modulation radiotherapy (IMRT) irradiated group of left-sided post-mastectomy patients. The study's conclusion recommends contouring cardiac substructures for a reliable assessment of the dose distribution as the MHD is not sufficient for cardiac risk evaluation for modern radiotherapy techniques.…”