Use of Three Dimensional Conformal Radiation Therapy for Node Positive Breast Cancer Does Not Result in Excess Lung and Heart Irradiation

Abstract

Purpose: This work evaluates the use of target and organs at risk (OAR) dose-volume goals in 3D conformal radiotherapy (3DCRT) planning for node positive breast cancer (NPBC) patients undergoing regional nodal irradiation after lumpectomy/mastectomy. Methods: Dosimetric data for 262 NPBC patients receiving regional nodal and whole breast/chest wall (WB/CW) irradiation from 2000-2009 were analyzed. In all cases, target & OAR volumes were delineated on treatment CT scans for field generation and dose-volume histograms (DVHs) were generated. Cases were analyzed to identify how frequently they met treatment planning institutional dose-volume goals ("institutional guidelines" & standardized in 2005) and how this would affect OAR doses.

A Pilot Study of Cardiac MRI in Breast Cancer Survivors After Cardiotoxic Chemotherapy and Three-Dimensional Conformal Radiotherapy

“…To date nearly all studies evaluating outcomes by SPECT or other measures of cardiac injury have done so in breast cancer patients who did not have their radiation treatments planned with intent to treat IMC and with a heart constraint in place for dosimetric planning. Over the time period the patients in our study were treated, the heart constraint used for left-sided patients at our institution was ventricular V25 < 10% ( 32 ). This constraint results in higher MHD than currently accepted in clinical practice.…”

“…This Institutional Review Board approved trial (NCT02348684) was conducted by screening a Medical College of Wisconsin database from 2000 to 2008 for lymph node-positive breast cancer patients treated with post-operative 3DCRT RNI with a pre-determined heart constraint (32). Clinicopathologic data were obtained from patient medical records.…”

“…All contours were recreated and/or verified for the study patients for consistency. Heart contours included (1) the whole heart as defined by pericardium, and (2) the ventricular volume as defined by both ventricles and the left atrium, excluding pericardium (32). Eligibility criteria were prior anthracycline chemotherapy, no cardiac disease (including heart failure, coronary heart disease, significant valvular disease, or cardiac event such as myocardial infarction) pre-breast cancer diagnosis, and no recurrent breast cancer.…”

“…All patients received either left- or right-sided breast or chest wall irradiation, along with irradiation to the undissected axillary, supraclavicular, and IMC lymph nodes to doses of 45–50 Gy in 1.8–2 Gy fractions. The institutional cardiac dose constraints utilized during this time period required that less than 6% (ideal) and less than 10% (acceptable) ( 32 ) of the volume of the left ventricle received 25 Gy (V25), based on studies by Gagliardi and Gyenes ( 33 – 35 ). MHD was not constrained.…”

Dosimetry Evaluation of Treatment Planning Systems in Patient-Specific 3D Printed Anthropomorphic Phantom for Breast Cancer after Mastectomy using a Single-Beam 3D-CRT Technique for Megavoltage Electron Radiation Therapy

“…Cancer patients’ initial simulation or treatment planning system must be simulated to calculate and optimize a patient’s dose. Additionally, one of the cancer treatment planning technologies is 3D conformal radiation therapy (3D-CRT) [ 8 ], done using a three-dimensional volume-based charged particle radiation beam to achieve the suitability of the target volume area; the use of the beam’s eye view can lead to a maximum and minimum the doses to the target and surrounding normal tissue, respectively. 3D-CRT technology is widely used to treat surface area breast cancer.…”