Table 4.
Normal tissue complication probability (NTCP), Relative risk (RR) ratio, number of patients with ∆NTCPIMRT – ro-IMPT in specific range for gastro-intestinal OARs toxicity
| Gastro-intestional OAR | NTCP (%) |
P-value IMRT vs. ro-IMPT |
Relative risk (RR) ratio (Mean ± S.D) |
∆NTCPIMRT – ro-IMPT (n/N) |
|||
|---|---|---|---|---|---|---|---|
| IMRT (Mean ± S.D) |
ro-IMPT (Mean ± S.D) |
≤5% | > 5 to ≤10% | > 10% | |||
| Stomach wall | |||||||
| U/P (Burman et al.) | 0.02 ± 0.01% | 0.01 ± 0.01% | 0.03* | 0.16 ± 0.24 | 9/9 | 0/9 | 0/9 |
| GB (Pan et al.) | 13.97 ± 5.33% | 10.55 ± 4.10% | 0.007* | 0.81 ± 0.19 | 6/9 | 3/9 | 0/9 |
| Duodenum | |||||||
| GB (Pan et al.) | 5.02 ± 0.57% | 1.87 ± 0.31% | 0.004* | 0.37 ± 0.28 | 9/9 | 0/9 | 0/9 |
| Grade ≥ 3 GI toxicity (Holyoake et al.) | 3.60 ± 0.54% | 3.74 ± 0.24% | 0.55 | 1.1 ± 0.22 | 9/9 | 0/9 | 0/9 |
| Small bowel loops | |||||||
| O/P (Burman et al.) | 0.26 ± 0.47% | 0.10 ± 0.23% | 0.07 | 0.24 ± 0.22 | 9/9 | 0/9 | 0/9 |
| StoDuo | |||||||
| GB (Pan et al.) | 7.81 ± 2.53% | 5.67 ± 2.15% | 0.008* | 0.76 ± 0.22 | 7/9 | 2/9 | 0/9 |
Abbreviations: IMRT Intensity-modulated radiotherapy, ro-IMPT Robust Intensity-modulated proton therapy, GB Gastric bleed, U/P ulceration/perforation, O/P obstruction/perforation, OAR organ at risk; Relative risk (RR) ratio NTCPro-IMPT/NTCPIMRT; ∆NTCPIMRT – ro-IMPT, n/N number of patients with specific ∆NTCP range/total number of patient (where N = 9), SD Standard deviation; NTCP derived using parameter from Pan et al., Burman et al., and Holyoake et al.
*Significant (P < 0.05)