The Role of a Prone Setup in Breast Radiation Therapy

Abstract

Most patients undergoing breast conservation therapy receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy and image-guided radiation therapy have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials.

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

“…From this group, five patients were excluded from the planning study due to inadequate alignment (on either the prone CT or prone MRI scan) of the patients sternum on the prone breast board with respect to the hole for the ipsilateral breast to fall through. This problem has been encountered and described elsewhere [11].…”

“…Previous work demonstrated comparable imaging quality with supine versus prone positioning for breast radiotherapy target delineation purposes [10]. The use of the prone position for breast radiotherapy is increasing with reported improvements in organ at risk (OAR) doses and target dose coverage [11,12].…”

Feasibility evaluation of prone breast irradiation with the Sagittilt© system including residual-intrafractional error assessment

“…To date, several prone system are used in clinical practice [5,25]. However, comprehensive feasibility analysis of a certain product is lacking and the available data are rather addressed to the prone position itself than to other factors such as the applied immobilization system.…”

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

“…Finally, approaches were proposed which included the construction of a thermoplastic mould or reinforced polyvinyl chloride ring and Styrofoam™ (The Dow Chemical Company, Midland, MI) 17,31,32 to pull the lateral breast tissue anteriorly and upright and to decrease breast separation.…”