Table 2 Treatment characteristics
All | Primary lung cancer | Metachronous lung cancer | p value | |
|---|---|---|---|---|
Total prescribed dose (Gy)a | 60 (50–75) | 60 (50–75) | 60 (50–75) | 0.8 |
Number of fractionsa | 3 (3–5) | 3 (3–5) | 3 (3–5) | 0.7 |
Dose per fractiona | 20 (12–20) | 20 (12–20) | 20 (12–20) | 0.4 |
Radiation treatment duration (days)a | 3 (3–14) | 3 (3–14) | 4 (3–8) | 0.7 |
GTV (mL)a | 8 (0.5–221.5) | 9.3 (0.5–131.9) | 5.1 (0.5–221.5) | 0.007 |
PTV (mL)a | 21.2 (2.8–167.3) | 27.5 (2.8–167.3) | 16.6 (3.8–35.9) | 0.001 |
GTV (V100) coverage (%)a | 100 (50–100) | 100 (50–100) | 100 (73–100) | 0.6 |
PTV (V100) coverage (%)a | 96 (40–100) | 96 (40–100) | 96 (65–100) | 0.2 |
Number of beamsa | 130 (25–303) | 131 (25–231) | 116 (88–303) | 0.4 |
Tracking technique | ||||
Fiducial | 72 (66.1%) | 19 (67.9%) | 0.3 | |
Direct soft tissue tracking 4D | 19 (17.4%) | 7 (25%) | ||
CT scan ITV | 18 (16.5%) | 2 (7.1%) | ||
Primary diagnosis to second metachronous lung cancer (months)' | 39.4 (13.9–121.4) | |||
First treatment of metachronous cancer | ||||
SABR | 7 (25%) | |||
Surgery | 21 (75%) | |||