Lateral wedge with medial only cardiac shielding (LEMONADE) technique in left breast radiotherapy

Abstract

This dosimetric study analyzed the lateral wedge with medial only cardiac shielding (LEMONADE) technique for left breast radiotherapy (LBRT) against three other commonly used techniques which is a follow-up from our earlier publication of LEMONADE technique in left chest wall (LCW) radiotherapy.
 Dosimetric parameters of 30 consecutive patients who underwent LBRT with LEMONADE technique (P1) after breast conserving surgery (BCS) were compared with 3 other virtually reconstructed plans: no cardiac shielding with paired wedges; P2 (paired wedges and medial only Y-direction shielding) and P3 (paired wedges and bilateral Y-direction shielding).
 P1 had target volume (TV) coverage [mean 90% isodose coverage of 89.00% ± 3.96 vs 86.28% ± 4.80 and 84.43% ± 5.70 for P2 and P3, respectively]. While there is 3.07% drop in TV coverage compared to no cardiac shielding, the V26Gy of heart dropped from 5.26% to a negligible 0.56% for P1. Low dose region (TV receiving < 30Gy) is also significantly lesser for P1 compared to P2 and P3 (1.50% vs 3.61% and 5.65%).
 The earlier positive LEMONADE dosimetric study of LCW radiotherapy has been replicated in this study with much better dose volume parametres likely due to the physical properties of intact breast. LEMONADE is an easily re-producible and simple radiotherapy technique that can be implemented in most radiotherapy centres. Further study is needed on the use of LEMONADE technique in extreme hypofractionation.