A prone technique for treatment of the breast, supraclavicular and axillary nodes

Abstract

Radiation therapy to women with large pendulous breasts presents dosimetric challenges when the whole breast (WB) and supraclavicular and axillary (SCF + AX) nodes need to be encompassed. The aim of this case study was to demonstrate the feasibility of planning and treating a pendulous breasted patient in the prone position. Computerised tomography (CT) images were acquired of the patient in both the prone and supine positions. A Perspex plate was added to the CDR Systems Inc. (Calgary, Canada) prone breastboard to minimize SCF + AX contour variations. Dosimetry was performed on both CT scans and the resultant treatment plans were evaluated for conformity, homogeneity, dose to the lung and maximum doses to the spinal cord (SC) and irradiated volume. The daily set-up in the prone position was monitored for stability and reproducibility. The patient completed her treatment course in the prone position. Minimal daily interventions were required to ensure the position was reproduced. Grade 3 skin toxicity was recorded in the SCF + AX region where the Perspex plate was added to the prone positioning device. There was minimal difference in dosimetry between prone and supine plans in the SCF + AX region. The prone WB plan showed improved homogeneity (prone 0.15; supine 0.22) and conformity (prone 0.90; supine 0.77). A simple addition to the breastboard has enabled a pendulous breasted woman with SC + AX involvement to be treated in the prone position. Set-up of this technique is achievable on a daily basis with minimal impact on workflow. It is a feasible alternative to supine treatment for this patient group.

The Comparison of the Radiation Load to the Heart and the Left Anterior Descending Coronary Artery for Various Modes of Radiation Treatment of the Breast Cancer Patients

“…All these results for controlled breathhold on top inspiration match the findings of other studies [11,15,16,17,18,19,20,21,22,23]. As it has been demonstrated by Chino et al, the maximum doses per heart were recorded in prone position, which is explained by 19 mm of anterior heart extrusion [2].…”

Reproducibility of repeated breathhold and impact of breathhold failure in whole breast and regional nodal irradiation in prone crawl position

“…Most treatment devices on the market support the patient’s shoulder while they are lying in prone position with extended arms. Irradiation of the lymph node regions in this position needs to go either through the supporting device and thereby creating a bolus effect that increases toxicity 11 , 27 , or using longer beam paths through healthy tissues, increasing OAR exposure and its associated risks. Furthermore, most prone positioning devices provide very little in the way of reproducible arm support 11 , which is especially relevant in WB + RNI because the target regions are influenced by arm position.…”

“…Despite the dosimetric benefits shown for decreased cardiopulmonary exposure with prone positioning in WB + RNI 9 – 12 , 30 , it is much easier to apply breathhold in the supine position to improve cardiopulmonary exposure using breathholding techniques that are already available at many centers 6 , 7 . For this reason, only a few papers report on WBI + RNI in prone position, almost always with free breathing 9 – 12 , 16 , 27 , 31 and most do not treat LNN MI.…”

Whole breast and regional nodal irradiation in prone versus supine position in left sided breast cancer

“…One of the major disadvantages of treating patients in this position, however, is that the support material itself obstructs the anterior beam access to the regional lymph nodes, which creates a bolus effect with possible associated skin toxicities. The use of other beam directions increases the trajectory through healthy tissues and therefore increases doses to OARs [18, 21]. …”