Table 3.

Comparison with previous WBRT planning studies that have the same PTV definition as ours.

Reference	Num. of patients	Breast site	Techniques compared	Key findings
Descovich et al. (2010)	15	Left	FIF, hybrid IMRT	Hybrid IMRT is preferred since it can reduce hot spot, provide better coverage and require less planning time.
Schubert et al. (2011)	10	Left	SOC, FIF, tangential IMRT (2 Fields), TOMO, topotherapy	TOMO, topotherapy and tangential IMRT can reduce high dose to target and normal tissue; TOMO results in increased low doses to normal tissue.
Jin et al. (2013)	20	Left	SOC, FIF, tangential IMRT (2 Fields), IMRT (7 Fields), VMAT (starting and ending angles were same as tangential beam angles)	Tangential IMRT is recommended since it has improved DHI and reduced dose to heart and lung.
Viren et al. (2015)	10	Left	FIF, tangential IMRT (2 Fields), tangential VMAT (two dual arcs of 50°–60°), continuous VMAT (dual arc of 240°)	Both VMAT techniques show improved DHI and better sparing of heart and ipsilateral lung. Continuous VMAT provides best dose coverage at the cost of significantly increased dose to contralateral breast.
Haciislamoglu et al. (2015)	15	Left	SOC, FIF, 9-field IMRT, TOMO, VMAT (Starting and ending angles of the arcs were 10° posterior to tangential fields)	TOMO shown reduced high and mean doses to heart and lung at the cost of increased low dose cloud.
Han et al. (2016)	10	Left and right	SOC, FIF, IMRT (10 to 12 fields), VMAT (3–4 partial arcs spanned from 305° to 152° for the left, 60° to 214° for the right), TOMO	TOMO is recommended since it provides the lowest LAR for all surrounding OARs.
Zhang et al. (2018)	50	Left	5-field IMRT, 6-field IMRT, FIF-DMPO-IMRT	FIF-DMPO-IMRT is recommended due to reduced heart and lung doses and treatment time.
Our study	15	Left	SOC, FIF, hybrid, IMRT, VMAT (starting and ending angle were same as tangential beam angles), MA-VMAT, NC-VMAT	MA-VMAT and NC-VMAT are recommended due to reduced doses and risks for heart, lung and contralateral breast.