Table 3 Summary of calculated volume and dose to (a) ipsilateral breast and tumor bed, to (b) axillary levels I, II, and III and to (c)sentinel lymph node (SLN) clips
a) Dose to ipsilateral breast and tumor bed | ||||
|---|---|---|---|---|
Supine (n = 23) | Prone (n= 23) | Comparison (two-tailed unpaired t-test) | ||
Ipsilateral breast mean dose (%) ± SD* | 96 ± 3.8 | 95 ± 1.8 | p = 0.26 (CI†† = -0.77 to2.8) | |
V95% ipsilateral breast | 77 ± 6.5 | 74 ± 5.3 | p = 0.09 (CI = -0.52 to 6.5) | |
V95% tumor bed | 99 ± 1.7 | 98 ± 4.6 | p = 0.33 (CI = -1.1 to 3.1) | |
b) Dose to axillary volumes | ||||
Mean dose (%) ± SD | Level I | 66 ± 20 | 36 ± 30 | p< 0.0001 (CI =15 to 45) |
Level II | 6 ±15 | 3 ± 3 | ||
Level III | 3 ± 2 | < 1 ± 0.4 | ||
Mean V95% ± SD | Level I | 37 ± 18 | 14 ± 19 | p < 0.0001 (CI = 12 to 34) |
Level II | 0 | 0 | ||
Level III | 0 | 0 | ||
Mean V90% ± SD | Level I | 50 ± 20 | 21 ± 25 | p< 0.0001 (CI = 16 to 43) |
Level II | 1 ± 5 | 0 | ||
Level III | 0 | 0 | ||
Mean V50% ± SD | Level I | 67 ± 19 | 35 ± 33 | |
Level II | 5 ± 17 | < 1 ± 2 | ||
Level III | 0 | 0 | ||
c) Dose to sentinel lymph node (SLN † ) clips | ||||
Supine ( n = 9) | Prone ( n = 7) | |||
SNB clips in treatment field | 9 | 2 | ||
V95% SLN clips ± SD | 47 ± 43 | 0 ± 0 | p<0.0001 (95% CI =29 to 65) | |
SLN clips receiving > 90% dose | 8 | 1 | ||
Mean dose to SLN clips (%) ± SD | 95 ± 5 | 43 ± 34 | ||