Table 2.
Summary of dosimetric parameters and toxicities for radiotherapy
| IGBT alone | IGBT + EBRT | P-value | |
|---|---|---|---|
| Number, n(%) | 9 (17.6%) | 42 (82.4%) | |
| Dosimetric parameters, median (IQR) | |||
| HR-CTV volume (cc) | 76.8 (66.5–85.7) | 93.1 (55.9-103.1) | |
| HR-CTV V100 (%) | 80.0 (74.5–86.5) | 79.0 (68.8–83.3) | |
| HR-CTV D90 EQD2 (Gy) | 36.2 (34.2–39.9) | 77.9 (73.0-81.8) | |
| Rectum D2cc EQD2 | 15.5 (11.0-17.9) | 60.2 (57.9–67.5) | |
| Bladder D2cc EQD2 | 16.3 (13.2–22.1) | 64.9 (59.9–70.4) | |
| Sigmoid colon D2cc EQD2 | 15.9 (13.3–21.3) | 61.6 (58.5–69.1) | |
| Small intestine D2cc EQD2 | 20.1 (18.1–24.6) | 63.4 (59.5–67.1) | |
| Grade 2 acute toxicity, n(%) | 1 (11.1%) | 16 (31.4%) | 0.119 |
| Rectal toxicity | 0 (0%) | 5 (11.9%) | |
| Hematologic toxicity | 1 (11.1%) | 8 (19.0%) | |
| Urinary toxicity | 0 (0%) | 7 (16.7%) | |
| Grade 2 late toxicity, n(%) | 2 (22.2%) | 7 (16.7%) | 0.692 |
| Rectal toxicity | 1 (11.1%) | 3 (7.1%) | |
| Hematologic toxicity | 1 (11.1%) | 4 (9.5%) | |
| Urinary toxicity | 0 (0%) | 0 (0%) |
Abbreviation: D2cc, the minimum dose received by maximally irradiated 2 cm3 volume; D90, the minimum dose received by 90% of the target volume; EBRT, external beam radiotherapy; EQD2, equivalent dose in 2-Gy fractions; HR-CTV, high-risk clinical target volume; IGBT, image-guided brachytherapy; V100, the percent of the target volume that receives at least 100% prescription dose