Table 1.
Patient characteristics
| Variable | Patient subgroup | |||
| Definite MIFC (n = 14) | Benign (n = 4) | Borderline MIFC/WIFC (n = 5 ) | MIFC+ (n = 3) | |
| Histology | MIFC with ≤4 vessels invaded | 3 FTUMP, 1 Hürthle cell adenoma | Classified as MIFC, but >4 (n = 2), 5 (n = 1), 7 (n = 1) or a “large” number of vessels invaded | MIFC, but 1 each with PTC, PDTC, or MTC in contralateral lobe; patient with MIFC + PDTC had 6 vessels invaded |
| Age, years, mean ± SD | 47 ± 15 | 35 ± 10 | 57 ± 19 | 52 ± 15 |
| Females, % (n) | 79% (11) | 75% (3) | 100% (5) | 100% (3) |
| Follicular tumor characteristics | ||||
| Size, mean ± SD, mm <10.0 mm, % (n) Multifocality, % (n) |
36 ± 20 14% (2) 7% (1) |
27 ± 15 0 0 |
41 ± 33 0 0 |
30 ± 22a 0 0b |
| Tumor invasion, % (n) | ||||
| None Capsular invasion only Vascular invasion only Vascular invasion + capsular invasion Vessels invaded, mean ± SD |
0 57% (8) 0 43% (6) 1.8 ± 1.4 (n = 6) |
100% (4) 0 0 0 0 |
0 0 0 100% (5) 6.0 ± 1.4 (n = 2)c |
0 67% (2) 0 33% (1) 6 ( n = 1) |
| Lymph node involvement, % (n) | ||||
| N0 N1a N1b Nxd |
36% (5) 7% (1) 0 57% (8) |
50% (2) 0 0 50% (2) |
20% (1) 0 0 80% (4) |
0 0 33% (1)e 67% (2) |
| Distant metastasis, n (%) | ||||
| Any Lung Bone Other |
0 0 0 0 |
0 0 0 0 |
20% (1) f 20% (1) 0 0 |
0 0 0 0 |
| Stimulatedh serum Tg, μg/L, at baseline, mean | ||||
| ± SD ≥1.0 μg/L, % (n) |
0.5 ± 0.7 (n = 10) 30% (3) (n = 10) |
23 ± 11 100% (4) |
36 ± 69 100% (5) |
294 ± 509 33% (1) |
| RAIT | ||||
| None, % (n) Any, % (n) Cumulative activity, GBq, mean ± SD |
36% (5) 64% (9) 1.3 ± 1.1 |
75% (3) 1% (3) 1.1 |
60% (3) 40% (2) 1.6 ± 2.7 |
33% (1) 67% (2) 4.2 ± 5.3 |
| Follow-up, months, mean ± SD | 18 ± 13 | 19 ± 1 | 13 ± 10 | 18 ± 1 |
Due to rounding, percentages may not add to 100%.
FTC, follicular thyroid carcinoma; FTUMP, follicular tumor of uncertain malignant potential; MIFC, minimally invasive follicular thyroid carcinoma; MTC, medullary thyroid carcinoma; PDTC, poorly differentiated thyroid carcinoma; PTC, papillary thyroid carcinoma; SD, standard deviation; Tg, thyroglobulin; TgAb, anti-thyroglobulin antibodies.
Primary tumor sizes for the other thyroid cancers were PTC, 3 mm, MTC, 7 mm, PDTC, data not available.
All 3 patients had a single follicular tumor, but had another thyroid cancer in the contralateral lobe.
Average excludes patients with “>4” vessels invaded (n = 2) or a “large” number of vessels invaded (n = 1)
No Nx patient was found to have lymph node metastasis on the post-RAIT scan.
This patient’s lymph node metastases were from the co-existing PDTC.
This patient’s distant metastases were diffuse lung metastases of FTC.
The subgroups respectively include 1 patient each with a history of colon or breast cancer.
All Tg testing was performed following ≥2 weeks of thyroid hormone withdrawal, with serum thyrotropin >40 mIU/L.
TgAB titers ≥115 IU/mL were considered to be TgAb-positive.