AUTHOR=Denniston Kyle A. , Verma Vivek , Bhirud Abhijeet R. , Bennion Nathan R. , Lin Chi 

TITLE=Effect of Akimbo versus Raised Arm Positioning on Breast and Cardiopulmonary Dosimetry in Pediatric Hodgkin Lymphoma

JOURNAL=Frontiers in Oncology

VOLUME=Volume 6 - 2016

YEAR=2016

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2016.00176

DOI=10.3389/fonc.2016.00176

ISSN=2234-943X

ABSTRACT=PURPOSE: In pediatric Hodgkin lymphoma (HL), radiotherapy (RT)-related late toxicities are a prime concern during treatment planning. This is the first study to examine whether arm positioning (raised versus akimbo) result in differential cardiopulmonary and breast doses in patients undergoing mediastinal RT. 

METHODS: Two treatment plans were made for each patient (akimbo/arms-raised); treatment was per Children’s Oncology Group AHOD0031 protocol, including AP/PA fields. The anterior midline T6-T7 disc space was used as an anatomic reference of “midline”. Heart/lungs were contoured for each setup. For females, breasts were also contoured and nipple positions identified. Volumetric centers of contoured organs were defined and three-dimensional distances from “midline” were computed. Analyzed dosimetric parameters included V5 (volume receiving ≥5 Gy), V10, V15, V20, and mean dose. Statistics were performed using the Mann-Whitney test.

RESULTS: Fifteen (6 female, 9 male) pediatric HL patients treated with mediastinal RT were analyzed. The median lateral distance from the breast center/nipple to “midline” with arms akimbo was larger than that with arms raised (8.6 vs. 7.7cm left breast, p=0.04; 10.7 vs. 9.2cm left nipple, p=0.04; 8.7 vs. 7.0cm right breast, p=0.004; 9.9 vs. 7.9cm, p=0.007 right nipple). Raised arm position was associated with a median 2.8/3.0cm decrease in breast/nipple separation, respectively. There were no significant differences in craniocaudal breast/nipple position based on arm positioning (p>0.05). Increasing breast volume was correlated with larger arm position-related changes in breast/nipple separation (r=0.74, p=0.06 / r=0.85, p=0.02). Akimbo positioning lowered median breast V5, V10, V15, and mean dose (p<0.05), with no differences observed in patients with both mediastinal and axillary disease for any parameters (p>0.05). Arm position had no significant effect on cardiopulmonary doses.

CONCLUSIONS: Akimbo arm positioning may be advantageous to decrease breast doses in female pediatric HL patients undergoing mediastinal RT, especially in the absence of axillary disease.