Individual Positioning: A Comparative Study of Adjuvant Breast Radiotherapy in the Prone Versus Supine Position

Abstract

Conformal breast radiotherapy is feasible in the prone position. Its primary advantage is the substantially lower radiation dose to the ipsilateral lung. The higher dose inhomogeneity and increased rate of Grade 1-2 skin toxicity, however, may be of concern.

The impact of imaging modality (CT vs MRI) and patient position (supine vs prone) on tangential whole breast radiation therapy planning

“…This is the first study to analyse target and OAR dose compliance differences due to imaging modality (CT vs MRI) for target volume determination, in both supine and prone positions, although several groups have examined differences in supine and prone positioning for WB radiotherapy (Table 6) [13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

“…Some authors report that prone positioning is better at heart dose and/or volume sparing than supine [15-17, 20, 23]. Some have reported no significant difference in heart dose between prone and supine positions [19,22]. One group identified a significant benefit of prone positioning on heart doses for women where the WB_CTV exceeded 1000 cm 3 for WB radiotherapy [18].…”

“…Several groups have examined differences in supine and prone positioning for WB radiotherapy [13][14][15][16][17][18][19][20][21][22][23][24], however few groups have examined the impact of imaging modality on breast radiotherapy planning. Mast et al observed that the mean volume of delineated glandular breast tissue was significantly larger on CT compared to that volumed on co-registered CT-MRI breast radiotherapy planning images acquired with the patient in the supine position [25].…”

A randomised trial of Supine versus Prone breast radiotherapy (SuPr study): Comparing set-up errors and respiratory motion

“…However, limitations of the study included potential overestimation of set-up errors through use of a patient contour-based match sensitive to soft-tissue distortions, recruitment of 15 patients over a 13-month period, and use of two treatment machines and multiple teams of therapists. More recently, set-up data has been published on 41 patients randomized to supine versus prone treatment (11). Each patient underwent a pre-RT CT-simulator plan-check, and EPI (3 times per week) on treatment.…”

A new three-dimensional conformal radiotherapy (3DCRT) technique for large breast and/or high body mass index patients: evaluation of a novel fields assessment aimed to reduce extra–target-tissue irradiation

“…Prone set-up yields the same advantages of lateral decubitus RT with a simpler set-up and better accuracy. Moreover, several studies have investigated prone RT where dosimetric studies 22,28 showed increased homogeneity and reduced lung doses with prone positioning in comparison with supine positioning, whereas in a large single-centre study by Stegman et al, 29 that reviewed the data of 245 patients treated over a 12-year period, planning was with opposed coplanar beams and the median hot spot percentage was 106% (interquartile range 104-108%) in the majority of cases.…”