131I Activity Administered, Total Radiation Absorbed Doses, and Grade III/IV Regimen-Related Toxicities
| Dose to Liver (Gy) (dose level) (no.) . | mCi131I3-150 . | Dose to Marrow3-151 (Gy) . | Dose to Spleen (Gy) . | Grade III/IV Toxicities . | |
|---|---|---|---|---|---|
| 3.5 | (Level 1) | 148 ± 42 | 7.3 ± 1.7 | 14.4 ± 5.0 | III GI (n = 1) (1 NE) |
| (n = 7) | (76-206) | (4-9) | (7.5-22.1) | ||
| 5.25 | (Level 2) | 215 ± 55 | 12.6 ± 2.5 | 16.6 ± 4.0 | None (1 NE) |
| (n = 7) | (142-309) | (10.5-17.7) | (9.1-21.7) | ||
| 7.0 | (Level 3) | 250 ± 83 | 24.8 ± 6.1 | 36.5 ± 13.8 | IV marrow (n = 1) |
| (n = 6) | (149-389) | (13.2-30.6) | (22.9-59.2) | ||
| 8.75 | (Level 4)3-152 | 304 ± 92 | 20.4 ± 7.3 | 52.4 ± 10.0 | None |
| (n = 3) | (226-405) | (14.7-28.6) | (41.7-61.5) | ||
| 10.5 | (Level 5)3-152 | 255 ± 73 | 18.3 ± 5.5 | 61.7 ± 21.1 | Grade III hepatic (n = 1) |
| (n = 6) | (148-350) | (11.6-24.0) | (34.0-92.8) | ||
| 12.25 | (Level 6) | 549 | 26.0 | 55.2 | Grade III-IV mucosal (n = 2) |
| (n = 2) | (486-613) | (24.1-28.0) | (46.7-63.7) | ||
| Dose to Liver (Gy) (dose level) (no.) . | mCi131I3-150 . | Dose to Marrow3-151 (Gy) . | Dose to Spleen (Gy) . | Grade III/IV Toxicities . | |
|---|---|---|---|---|---|
| 3.5 | (Level 1) | 148 ± 42 | 7.3 ± 1.7 | 14.4 ± 5.0 | III GI (n = 1) (1 NE) |
| (n = 7) | (76-206) | (4-9) | (7.5-22.1) | ||
| 5.25 | (Level 2) | 215 ± 55 | 12.6 ± 2.5 | 16.6 ± 4.0 | None (1 NE) |
| (n = 7) | (142-309) | (10.5-17.7) | (9.1-21.7) | ||
| 7.0 | (Level 3) | 250 ± 83 | 24.8 ± 6.1 | 36.5 ± 13.8 | IV marrow (n = 1) |
| (n = 6) | (149-389) | (13.2-30.6) | (22.9-59.2) | ||
| 8.75 | (Level 4)3-152 | 304 ± 92 | 20.4 ± 7.3 | 52.4 ± 10.0 | None |
| (n = 3) | (226-405) | (14.7-28.6) | (41.7-61.5) | ||
| 10.5 | (Level 5)3-152 | 255 ± 73 | 18.3 ± 5.5 | 61.7 ± 21.1 | Grade III hepatic (n = 1) |
| (n = 6) | (148-350) | (11.6-24.0) | (34.0-92.8) | ||
| 12.25 | (Level 6) | 549 | 26.0 | 55.2 | Grade III-IV mucosal (n = 2) |
| (n = 2) | (486-613) | (24.1-28.0) | (46.7-63.7) | ||
Values are the mean ± SD, with ranges in parentheses.
Abbreviation: NE, not evaluable.
Amount of 131I calculated to give the designated dose to liver. Actual dose administered, as determined by gamma counting of the intravenous bag and tubing before and after administration of the dose, differed from the calculated dose in some cases. The average of the percentage of calculated dose actually administered was 101.8%, with a SD of 8.8%.
Estimated radiation absorbed doses to marrow were calculated using published methods.41,42 Recently proposed marrow S values incorporated in MIRDOSE3 software60 would result in lower marrow doses than those noted here.
Three patients scheduled to be treated at these dose levels (2 at level 4 and 1 at Level 5) had their radiation absorbed dose to liver limited so that dose to marrow would not exceed 28 Gy. These patients received 283, 275, and 459 mCi 131I delivering estimated radiation doses to liver of 4.8, 6.1, and 9.2 Gy, respectively. These patients had no grade III/IV toxicities and were not counted as evaluable patients for purposes of dose escalation.