Article Figures & Data
Tables
Characteristic Hypothyroid, n (%*) rhTSH, n (%*) P Sex (female/male) 216 (82.4)/84 (80.8) 46 (17.6)/20 (19.2) 0.71 Age (<60/≥60 y) 244 (83.3)/56 (76.7) 49 (16.7)/17 (23.3) 0.19 Histology (PTC/FTC) 281 (82.4)/19 (76.0) 60 (17.6)/6 (24.0) 0.42 T (T ≤ T2/>T2) 229 (83.3)/70 (78.7) 46 (16.7)/19 (21.3) 0.32 N (N0/N1) 203 (79.0)/81 (88.0) 54 (21.0)/11 (12.0) 0.06 ↵* Row wise.
Parameters of iodine kinetics Hypothyroid (n = 300) rhTSH (n = 66) P Activity (MBq) 3,417 ± 599 3,284 ± 728 0.34 Thyroid uptake (%) 4.2 ± 1.8 3.8 ± 1.6 0.12 Thyroid half-life (h) 30.6 ± 15.0 30.1 ± 14.6 0.86 Thyroid cumulated activity (MBq*d) 287 ± 209 250 ± 192 0.08 Thyroid residence time (h) 2.1 ± 1.5 1.9 ± 1.3 0.26 Thyroid dose (Gy) 801 ± 587 702 ± 540 0.09 Whole-body half-life (h) 19.3 ± 7.7 16.4 ± 4.6 ≤0.01 Whole-body cumulated activity (MBq*d) 1,695 ± 547 1599 ± 498 0.31 Whole-body residence time (h) 11.9 ± 3.3 11.8 ± 3.4 0.64 Remaining-body dose (mGy) 90 ± 30 86 ± 27 0.36 Male PTC patients Female PTC patients Parameters of iodine kinetics Hypothyroid (n = 79) rhTSH (n = 16) P Hypothyroid (n = 202) rhTSH (n = 44) P Activity (MBq) 3,480 ± 515 3,586 ± 441 0.19 3,382 ± 644 3,161 ± 791 0.04 Thyroid uptake (%) 4.9 ± 2.0 4.1 ± 1.3 0.14 3.9 ± 1.7 3.6 ± 1.7 0.32 Thyroid half-life (h) 38.1 ± 19.9 32.3 ± 15.5 0.22 28.0 ± 12.0 29.6 ± 14.7 0.57 Thyroid cumulated activity (MBq*d) 406 ± 284 298 ± 180 0.21 242 ± 152 225 ± 169 0.19 Thyroid residence time (h) 2.9 ± 2.1 2.0 ± 1.1 0.16 1.8 ± 1.1 1.8 ± 1.3 0.68 Thyroid dose (Gy) 1,139 ± 797 836 ± 505 0.21 674 ± 427 630 ± 475 0.22 Whole-body half-life (h) 22.7 ± 11.6 18.0 ± 6.6 0.06 18.1 ± 5.1 15.9 ± 3.7 0.01 Whole-body cumulated activity (MBq*d) 1,859 ± 557 1,754 ± 350 0.53 1,622 ± 527 1,547 ± 548 0.46 Whole-body residence time (h) 12.9 ± 3.4 11.8 ± 2.0 0.23 11.6 ± 3.1 11.9 ± 3.9 0.86 Remaining-body dose (mGy) 92 ± 28 91 ± 20 0.95 89 ± 30 85 ± 30 0.45 - TABLE 4
Dosimetric Results for PTC Patients with More Than 4-Week Hypothyroidism in Comparison to rhTSH PTC Patients
Parameters of iodine kinetics Hypothyroid (n = 31) rhTSH (n = 60) P Activity (MBq) 3,298 ± 714 3,274 ± 736 0.79 Thyroid uptake (%) 4.5 ± 1.8 3.7 ± 1.6 0.07 Thyroid half-life (h) 38.0 ± 19.9 30.3 ± 14.8 0.05 Thyroid cumulated activity (MBq*d) 351 ± 272 244 ± 174 0.07 Thyroid residence time (h) 2.6 ± 2.0 1.8 ± 1.2 0.09 Thyroid dose (Gy) 985 ± 763 685 ± 488 0.07 Whole-body half-life (h) 21.6 ± 12.8 16.5 ± 4.7 0.02 Whole-body cumulated activity (MBq*d) 1,682 ± 530 1,602 ± 508 0.54 Whole-body residence time (h) 12.3 ± 2.7 11.9 ± 3.5 0.34 Remaining-body dose (mGy) 85 ± 28 87 ± 28 0.88 - TABLE 5
Dosimetric Results for Hypothyroid PTC Patients with GFR ≥ Versus < 60 mL/min/1.73m2 in Comparison to rhTSH PTC Patients
Parameters of iodine kinetics Hypothyroid normal GFR (n = 227) rhTSH (n = 60) P Hypothyroid low GFR (n = 20) rhTSH (n = 60) P Activity (MBq) 3,385 ± 634 3,274 ± 736 0.36 3,508 ± 512 3,274 ± 736 0.23 Thyroid uptake (%) 4.1 ± 1.8 3.7 ± 1.6 0.28 4.7 ± 1.5 3.7 ± 1.6 0.02 Thyroid half-life (h) 31.2 ± 15.5 30.3 ± 14.8 0.73 27.2 ± 8.3 30.3 ± 14.8 0.76 Thyroid cumulated activity (MBq*d) 277 ± 195 244 ± 174 0.14 311 ± 171 244 ± 174 0.06 Thyroid residence time (h) 2.0 ± 1.5 1.8 ± 1.2 0.37 2.1 ± 1.1 1.8 ± 1.2 0.16 Thyroid dose (Gy) 774 ± 548 685 ± 488 0.17 873 ± 481 685 ± 488 0.06 Whole-body half-life (h) 19.4 ± 8.0 16.5 ± 4.7 ≤0.01 19.0 ± 4.5 16.5 ± 4.7 0.02 Whole-body cumulated activity (MBq*d) 1,619 ± 473 1,602 ± 508 0.89 2,325 ± 807 1,602 ± 508 ≤0.01 Whole-body residence time (h) 11.6 ± 2.8 11.9 ± 3.5 0.88 15.7 ± 4.7 11.9 ± 3.5 ≤0.01 Remaining-body dose (mGy) 86 ± 25 87 ± 28 0.94 127 ± 45 87 ± 28 ≤0.01 Parameters of iodine kinetics Hypothyroid (n = 27) rhTSH (n = 312) P Activity (MBq) 403 ± 88 412 ± 83 0.11 Thyroid uptake (%) 4.8 ± 3.5 3.6 ± 5.2 ≤0.01 Thyroid half-life (h) 15.0 ± 2.6 12.5 ± 3.1 ≤0.01 Thyroid cumulated activity (MBq*d) 18 ± 9 14 ± 12 ≤0.01 Thyroid residence time (h) 1.1 ± 0.5 0.8 ± 0.7 ≤0.01 Thyroid dose (Gy) 51 ± 27 39 ± 23 ≤0.01 Whole-body half-life (h) 13.6 ± 3.7 11.5 ± 4.0 ≤0.01 Whole-body cumulated activity (MBq*d) 197 ± 69 169 ± 74 0.01 Whole-body residence time (h) 11.6 ± 3.1 9.9 ± 4.2 ≤0.01 Remaining-body dose (mGy) 11 ± 4 10 ± 3 0.01 - TABLE 7
Literature Compilation of Dosimetric Studies Examining Iodine Kinetics in Hypothyroid and rhTSH Patients
First author and year of publication THW/rhTSH (n) Age THW/rhTSH (y) Latency OP-RIT (d)* THW TSH (mU/L) Body dose, half-life or residence time Thyroid dose, half-life or residence time Menzel 2003 (6) 163/64 50/57 ≥28 Ø∼50 rhTSH < THW ? Sisson 2003 (7) 87/10 44/? ? Ø117 rhTSH < THW ? Hänscheid 2006 (8) 33/29 ?/? ? Ø84 rhTSH < THW rhTSH > THW Vaiano 2007 (9) 29/17 46/52 ≥28 ? rhTSH < THW rhTSH > THW Remy 2008 (10) 218/36 48/44 ≥35 Ø69 rhTSH < THW ? Carvalho 2012 (12) 50/50 50/48 ≥56 Ø59 rhTSH < THW ? Ravichandran 2014 (13) 81/22 ?/? ≥35 ? rhTSH < THW rhTSH < THW Grenfell 2015 (15) 31/19 49/48 21 (median) ? rhTSH = THW ? Guo 2015 (14) 9/6 41/58 ≥28 ? rhTSH < THW ? Ravichandran 2016 (32) 28/14 ?/? ≥28 Ø88 rhTSH < THW ? Data presented in this publication 281/60 46/51 18 (median) Ø51 rhTSH = THW rhTSH = THW ↵* Or if not reported, time of L-T4 withdrawal.
THW = thyroid-hormone withdrawal; OP–RIT = time between surgery and radioiodine therapy (d).
