Keywords:
Breast, Oncology, Digital radiography, Radiation therapy / Oncology, Radiotherapy techniques
Authors:
R. Estoesta, D. Naehrig, L. Attwood, E. Claridge-Mackonis, D. Martin, M. Pham, J. Toohey, S. Carroll; Sydney/AU
DOI:
10.1594/ranzcr2015/R-0081
Results
Planning measurements (Table 1)
Compared with FB,
vDIBH results in statistically significant reduction in heart mean dose (1.63Gray (Gy) vs.
3.62Gy,
p = 0.0000002),
maximum dose (33.61Gy vs.
45.76Gy,
p = 0.0004),
V30 (0.24% vs.
3.67%,
p = 0.000002),
V20 (0.46% vs.
4.88%,
p = 0.0000005),
and heart volume (490.55cc vs.
546.81cc,
p = 0.0004).
These results are reflected in the LAD mean dose (5.92Gy vs.
20.63Gy,
p = 0.000001),
maximum dose (22.46Gy vs.
41.54Gy,
p = 0.0000001) and V30 (1.66% vs.
38.16%,
p = 0.000005).
The left lung volume is larger in the vDIBH sample (1845.52cc vs.
1156.33cc,
p = 0.00000001) and the mean lung dose for the vDIBH sample is also slightly lower (6.38% vs.
7.11%,
p = 0.01).
The PTV metrics that measured did not show any statistical significant difference.
Treatment Verification
EPID verification shows a mean central axis displacement of 3mm from the planned position for the vDIBH group,
and 2mm for the FB cohort. All patient treatments were given within the set-up tolerance requirements used in the department (action level of 1 cm).