Table 5.
Conformity and Intermediate dose spillage for singular and synchronously treated lesions
| All patients | No Radiation Pneumonitis (n = 85) | Symptomatic Radiation Pneumonitis (n = 8) | P value |
| Conformity Index (RxV / PTV) | |||
| Median | 1.05 | 1.00 | 0.04 |
| Range | 0.89–1.44 | 0.98–1.09 | |
| Intermediate Dose Spillagea (R50V /PTV) | |||
| No deviation (%) | 36 (42.4%) | 2 (28.6%) | 0.78† |
| Minor deviation (%) | 45 (52.9%) | 5 (71.4%) | |
| Major deviation (%) | 4 (4.7%) | 0 (0.0%) | |
| Singular lesions | No Radiation Pneumonitis (n = 77) | Symptomatic Radiation Pneumonitis (n = 6) | P value |
| Conformity Index (RxV / PTV) | |||
| Median | 1.05 | 0.99 | 0.01 |
| Range | 0.89–1.44 | 0.98–1.03 | |
| Intermediate Dose Spillagea (R50V /PTV) | |||
| No deviation (%) | 32 (41.6%) | 2 (40.0%) | 1.00† |
| Minor deviation (%) | 42 (54.5%) | 3 (60.0%) | |
| Major deviation (%) | 3 (3.9%) | 0 (0.0%) | |
| Synchronously treated lesions | No Radiation Pneumonitis (n = 8) | Symptomatic Radiation Pneumonitis (n = 2) | P value |
| Conformity Index (RxV / PTV) | |||
| Median | 1.07 | 1.06 | NR |
| Range | 0.96–1.17 | 1.04–1.09 | |
| Intermediate Dose Spillage (R50V /PTV) | |||
| No deviation (%) | 4 (50.0%) | 0 (0.0%) | 0.56 |
| Minor deviation (%) | 3 (37.5%) | 2 (100.0%) | |
| Major deviation (%) | 1 (12.5%) | 0 (0.0%) | |
Abbreviations: RxV Volume receiving prescription dose, PTV Planned Target Volume, R50V Volume receiving 50% of the prescription dose. NR Not reportable given small patient number size. Symptomatic Radiation Pneumonitis = RTOG G3+ or CTCAE G2–3+ RP
aOf the entire cohort, only one patient was not able to have Intermediate Dose Spillage calculated due to a large PTV size of 370 cm3. This patient developed symptomatic radiation pneumonitis
Bolded P-values indicate statistical significance
All P-values are from Wilcoxon Rank Sum test unless otherwise noted
†P-value from Fischer exact test