Table 3 The mean (range) and p-values for Dmean, Dmax of both heart and LAD Conventional fractionation Hypofractionation Organ Parameter DIBH FB p-value DIBH FB p-value Heart Dmax (Gy)(*) 5.00 29.19 0.0015 3.85 24.75 0.0025 (2.00 – 10.00) (5.00 – 52.00) (1.00 – 8.00) (3.00 – 46.00) Dmean (Gy) 1.24 1.68 0.0106 0.84 1.14 0.0106 (1.03 – 1.43) (1.29 – 2.48) (0.70 – 0.97) (0.87 – 1.68) V20 (**) (%) 0.00 0.39 0.1574 0.00 0.33 0.1644 (0.00 -0.00) (0.00 -1.61) (0.00-0.00) (0.00 – 1.40) V40 (**) (%) 0.00 0.16 0.1719 0.00 0.07 0.1708 (0.00 -0.00)
(0.00 – 0.70) (0.00-0.00) (0.00 -3.00) LAD Dmax (Gy)(*) 4.25 19.62 0.0488 ITF2357 cost 3.10 16.75 0.0479 (2.00 – 11.00) (3.00 – 52.00) (1.00 – 8.00) (2.00
– 46.00) Dmean (Gy) 2.74 9.01 0.0914 1.86 6.12 0.9140 (0.80 – 7.55) (1.45 – 28.05) (0.54 – 5.13) (0.99 – 19.07) (*)EQD2 values using α/β =2.5 Gy for Pericardites in heart an for LAD. As shown in the Table 3 the maximum doses to the heart and LAD and the mean dose to the heart were significantly lower in DIBH, (Caspase-dependent apoptosis minimum 78.3% and 2.6% decrease with respect to FB, respectively) regardless of the schedule type. In our series the maximum HDAC inhibitor review dose to LAD exceeded 20 Gy in 3/8 patients in FB, while it was lower than 20 Gy in all patients in DIBH. TCP and NTCP analysis The TCP and NTCPs for lung and heart are reported in Table 4 as mean values with ranges. TCP values were increased in the hypo-fractionated schedule, as expected from the literature [17]. The NTCPs for Lung toxicity and long term cardiac mortality were at least 11.2% lower diglyceride for DIBH with respect to FB, but the difference was statistically significant
only for the long term cardiac mortality in the conventional fractionation. The NTCP for pericarditis and for LAD toxicity were 0% in all cases. Table 4 TCP and NTCP for FB and DIBH Conventional fractionation Hypofractionation Parameter DIBH FB p-value DIBH FB p-value TCP (%) 96.40 96.30 0.3604 99.99 100.00 0.3506 (92.5 – 98.23) (94.33 – 97.36) (99.97 – 100) (100.00- 100.00) Heart NTCP (%) [pericarditis] 0.00 0.00 —— 0.00 0.00 —— (0.00 – 0.00) (0.00 – 0.00) (0.00 – 0.00) (0.00 – 0.00) Heart NTCP (%) [long term mortality] 0.71 0.80 0.0385 0.72 0.87 0.0667 (0.69 – 0.74) (0.72 – 0.99) (0.69 – 0.75) (0.73 – 1.22) Lung NTCP (%) [pneumonitis] 6.58 11.48 0.2212 16.71 29.26 0.1618 (0.23 – 13.18) (0.77 – 33.54) (8.19 – 29.43) (9.57 – 97.70) Discussions The aim of this paper was to investigate clinical and dosimetric benefits of DIBH gating technique.