Potential benefits of crawl position for prone radiation therapy in breast cancer

Abstract

PurposeTo investigate crawl position with the arm at the treated side alongside the body and at the opposite side above the head for prone treatment in patients requiring breast and regional lymph node irradiation.MethodsPatient support devices for crawl position were built for CT simulation and treatment. An asymmetric fork design resulted from an iterative process of prototype construction and testing. The fork's large horn supports the hemi‐thorax, shoulder, and elevated arm at the nontreated side and the head. The short, narrow horn supports the arm at the treated side. Between both horns, the treated breast and its regional lymph nodes are exposed. Endpoints were pain, comfort, set‐up precision, beam access to the breast and lymph nodes, and plan dose metrics. Pain and comfort were tested by volunteers (n = 9); set‐up precision, beam access, and plan dose metrics were tested by means of a patient study (n = 10). The AIO™ (Orfit, Wijnegem, Belgium) prone breastboard (AIO™) was used as a reference regarding comfort and set‐up precision.ResultsPain at the sternum, the ipsilateral shoulder, upper arm, and neck was lower in crawl position than with bilateral arm elevation on AIO™. Comfort and set‐up precision were better on the crawl prototype than on AIO™. In crawl position, beam directions in the coronal and near‐sagittal planes have access to the breast or regional lymph nodes without traversing device components. Plan comparison between supine and crawl positions showed better dose homogeneity for the breast and lymph node targets and dose reductions to all organs at risk for crawl position.ConclusionsRadiation therapy for breast and regional lymph nodes in crawl position is feasible. Good comfort and set‐up precision were demonstrated. Planning results support the hypothesis that breast and regional lymph nodes can be treated in crawl position with less dose to organs at risk and equal or better dose distribution in the target volumes than in supine position. The crawl technique is a candidate methodology for further investigation for patients requiring breast and regional lymph node irradiation.

The relation between patient discomfort and uncompensated forces of a patient support device for breast and regional lymph node radiotherapy

“…Additionally, a comparative study (n = 10) was performed with the AIO breast board and prototype V10. This study confirms that the prone crawl patient position results in better comfort, stability, and set-up precision and permits a vast range of new favourable beam directions for WBI + LNI in comparison with the commonly used prone position (Boute et al, 2017).…”

“…In addition, this could be counter-productive and unpractical since first prototype iterations evolved rapidly. During further iterations (with more advanced prototypes), bigger sample sizes were used (Boute et al, 2017).…”

“…Since patients were only positioned for approximately 10 min (instead of 15 min for a real treatment), a comparative study was performed where ten patients received half of their WBI treatment sessions on the crawl breast board prototype and the other half on AIO™ device (Boute et al, 2017). In general, the prone crawl device scored best.…”

Crawl positioning improves set-up precision and patient comfort in prone whole breast irradiation

“…prone crawl swimming 19 . Dosimetric studies show reduced OAR doses with the crawl couch over supine setup in WBI + RNI 20,21 .…”

An observational study of post-operative Volumetric Modulated Arc Radiotherapy (VMAT) of breast cancer by immobilizing patients on All-in-one (AIOTM) solution Breast and Lung Board without usingthermoplastic mask: Risk of collusion of gantry with couch exists if acquisition of Cone-beam Computed Tomography (CBCT)is attempted for set-up verification.

“…However, authors have only presented the dosimetric comparison between the two positions. From the published literature and results presented, it is not clear if CBCT was used for set-up verification for management of supine breast cancerpatients in the Belgian Study [8]. Unlike study published by Boute B et al, breast and lung board in our study was positioned over regular carbon fibre couchof Elekta Versa HD linac and large majority of patients presented for postmastectomy radiotherapy rather than therapy of conserved breast.…”