Table 3.
Treatment details for radiation treatment by D’Amico risk criteria
| Low risk | Intermediate risk | High risk | Overall | P-value a,b | |
|---|---|---|---|---|---|
| EBRT (n) | 185 | 294 | 157 | 636 | |
| Use of ADT | |||||
| % receiving ADT, (n) | |||||
| Yes | 8% (15) | 44% (128) | 81% (127) | 43% (270) | < .001 |
| No | 92% (166) | 56% (166) | 19% (30) | 57% (362) | |
| Dose prescription for EBRT | |||||
| Conventional fractionation | 91% (157) | 95% (251) | 98% (141) | 95% (549) | .006 |
| Median dose (IQR), Gy | 79.2 (76.0, 79.2) | 79.2 (77.4, 79.2) | 79.0 (77.4, 79.2) | 79.2 (76.0, 79.2) | .516 |
| % receiving >75 Gy, (n) | 139 (89%) | 237 (94%) | 134 (95%) | 510 (93%) | .041 |
| Moderate fractionation | 1% (1) | 2% (6) | 1% (1) | 1% (8) | |
| Ultra-hypofractionation | 8% (14) | 3% (7) | 1% (2) | 4% (23) | |
| Radiation fields for EBRT | |||||
| % receiving pelvic radiation, (n) | |||||
| Yes | 4% (7) | 13% (36) | 40% (59) | 17% (102) | < .001 |
| No | 96% (165) | 87% (232) | 60% (87) | 83% (484) | |
| Use of image guidance | |||||
| % with IGRT, (n) | |||||
| Yes | 85% (132) | 85% (218) | 87% (125) | 85% (475) | .737 |
| No | 15% (24) | 15% (39) | 13% (18) | 15% (81) | |
| BT | |||||
| No. receiving BT | 95 | 57 | 9 | 161 | |
| Low-dose rate BT (n) | 81 | 34 | 7 | 122 | |
| I125 | 84% (67) | 68% (23) | 43% (3) | 77% (93) | .057 |
| Median dose (IQR), Gy | 145.0 (145.0, 145.0) | 144.0 (144.0, 145.0) | 111.2(94.3, 128.1) | 145.0 (144.0, 145.0) | .006 |
| dose 140–160 Gy | |||||
| Yes | 92% (54) | 91% (20) | 50% (1) | 90% (75) | |
| No | 8% (5) | 9% (2) | 50% (1) | 10% (8) | |
| Pd103 | 15% (12) | 29% (10) | 57% (4) | 21% (26) | |
| Median dose (IQR), Gy | 125.0 (125.0, 125.0) | 125.0 (125.0, 125.0) | 125.0 (125.0, 125.0) | 125.0 (125.0, 125.0) | .649 |
| Dose 110–125 Gy | |||||
| Yes | 83% (10) | 100% (10) | 100% (4) | 92% (24) | |
| No | 17% (2) | 0% (0) | 0% (0) | 8% (2) | |
| Cs131 | 1% (1) | 3% (1) | 0% (0) | 2% (2) | |
| High-dose rate BT (N) | 14 | 23 | 2 | 39 | |
| Median dose (IQR), Gy | 39.0 (39.0, 39.0) | 39.0 (39.0, 39.0) | — | 39.0 (39.0, 39.0) | .376 |
| Fractionation, Median | 6.5 (6.5, 7.3) | 6.5 (6.5, 6.5) | — | 6.5 (6.5, 6.5) | .565 |
| dose (IQR), Gy | |||||
| EB+BT | |||||
| No. receiving combined EB+BT | 33 | 57 | 36 | 126 | |
| IMRT | |||||
| Yes | 73% (24) | 93% (53) | 89% (32) | 87% (109) | .022 |
| No | 27% (9) | 7% (4) | 11% (4) | 13% (17) | |
| Median dose (IQR), Gy | 45.0 (45.0, 52.5) | 45.0 (45.0, 52.5) | 45.0 (45.0, 52.5) | 45.0 (45.0, 52.5) | .461 |
| No. with IGRT, (%) | |||||
| Yes | 86% (25) | 81% (44) | 71% (25) | 80% (94) | .31 |
| No | 14% (4) | 19% (10) | 29% (10) | 20% (24) | |
| EB+BT (low-dose rate) | 32 | 48 | 27 | 107 | |
| 1125 | 97% (29/30) | 81% (38/47) | 78% (21/27) | 85% (88/104) | .089 |
| Median dose (SD), Gy | 80.0 (80.0, 106.5) | 97.0 (80.0, 110.0) | 90.0 (80.0, 110.0) | 90.0 (80.0, 110.0) | .376 |
| EB-BT (high-dose rate) | 1 | 9 | 9 | 19 | |
| Median dose (IQR), Gy | 19.0 (19.0, 19.0) | 21.0 (19.0, 22.0) | 22.0 (22.0, 22.0) | 22.0 (19.9, 22.0) | .009 |
| Fractionation, Mean dose (SD), Gy | — | 7.0 (5.5, 9.5) | 5.5 (5.5, 5.5) | 5.5 (5.5, 7.0) | .036 |
ADT, androgen deprivation therapy; BT, brachytherapy; Cs131, Cesium 131; EBRT, external beam radiation therapy; EB+BT, combined external beam radiation therapy with brachytherapy; I125, iodine 125; IGRT, image guidance radiation therapy; IMRT, intensity modulated radiation therapy; IQR, interquartile range; Pd103, palladium 103; PSA, prostate-specific antigen; SD, standard deviation; VMAT, volumetric arc therapy
a
Pearson’s χ2 test for categorical variables and Wilcoxon rank sum test for continuous variables unless otherwise noted
b
Fisher’s exact test