TABLE 2.
Studies of 131I-MIBG Therapy for Pheochromocytoma and PGL
|
131I-MIBG therapy |
Overall response |
|||||||||
| Reference | No. of patients | Disease status | Activity | No. of doses | Total activity | Objective* | Biochemical | Symptomatic response | Survival | Comments |
| 109 | 48 | Metastatic PHEO/PGL | High specific activity: 3.7–14.8 GBq (1.32–5.69 mCi)/kg | 1–4 | NA | 1 PR, no CR | NA | NA; no significant decrease in BP in patients with high systolic BP | NA | No significant toxicity |
| 107 | Group 1: 12 | 9/12 secreting | 555 MBq/dose every 3–4 mo | Maximum: 10; median: 7 | Maximum: 66.6 GBq; median: 39.4 | 1 CR, 3 PR (33%) | 5 PR (42%) | NA | 1.9 y | No grade 3–4 hematologic toxicity |
| 107 | Group 2: 16 | 9/16 secreting | 7.4–12.95 GBq/dose every 6–8 mo | Maximum: 6; median: 2 | 57.2 GBq (median: 24.1) | 2 CR, 3 PR (31%) | 2 CR, 3 PR (31%) | NA | 3 y | 6 patients had grade 3–4 thrombocytopenia |
| 116 | 10 | Metastatic; symptomatic | 5.6 GBq/dose (n = 9); 3.7 GBq every 4–12 mo (n = 1) | 1–4 (mean: 2) | 10–13.2 GBq (mean 11.6 ± 1.6) (310 ± 44.0 mCi) | 3 PR (30%) | 5 patients (50%) | 5 patients (50%) | Mean PFS: 17.5 mo (2–47 mo) | No grade 3–4 hematologic toxicity |
| 118 | 50 | Metastatic; 50% with SDHB mutation | Phase 2: high dose; 222–333 MBq (6–9 mCi)/kg | 1–3 | 18,204–145,003 GBq (492–3,919 mCi) | 27% after first treatment; 50% after second treatment | 35% after first dose; 71% after second dose | NA | OS at 5 y: 64% | Grade 3–4 hematologic toxicity in up to 87% |
| 111 | 33 | Metastatic PGL/PHEO | Mean first dose: 14.47 ± 4.8 GBq (391 ± 130 mCi) | 1–6 | Mean: 20.3 ± 11.24 GBq (549 ± 304 mCi); maximum: 1,223 | 38% | 60% | 86% | Median OS: 56 mo; median survival: 4.7 y | Bone marrow suppression in 12% |
| 106 | 116 (compilation of data from multiple studies at 10 institutions) | Metastatic PGL/PHEO | Mean dose: 158 (96–300) | 1–11 (mean: 3.3) | Mean: 490 (96–2,322) | 30% | 45% | 76% | 5 patients had CR lasting up to 16–58 mo; better responses were seen in those with soft-tissue disease | Mild adverse effects in 41%; 1 patient had fatal marrow aplasia; 45% of the responders had median PFS of 19 mo |
*
Complete response (CR) plus partial response (PR).
NA = not available; BP = blood pressure; PFS = progression-free survival; OS = overall survival.