Alternative Means of Estimating 131I Maximum Permissible Activity to Treat Thyroid Cancer

Kenneth J. Nichols; William Robeson; Miyuki Yoshida-Hay; Pat B. Zanzonico; Fritzgerald Leveque; Kuldeep K. Bhargava; Gene G. Tronco; Christopher J. Palestro

doi:10.2967/jnumed.117.192278

Article Figures & Data

Figures

Tables

Download figure
Open in new tab
Download powerpoint
FIGURE 1.
Linear regression (A) and Bland–Altman plot (B) for method 2 vs. method 1 dose.
Download figure
Open in new tab
Download powerpoint
FIGURE 2.
Linear regression (A) and Bland–Altman plot (B) for method 3 vs. method 1 dose.
Download figure
Open in new tab
Download powerpoint
FIGURE 3.
Linear regression (A) and Bland–Altman plot (B) for method 4 vs. method 1 dose.
Download figure
Open in new tab
Download powerpoint
FIGURE 4.
Linear regression (A) and Bland–Altman plots (B) for method 2 MPA vs. method 1.
Download figure
Open in new tab
Download powerpoint
FIGURE 5.
Linear regression (A) and Bland–Altman plots (B) for method 3 MPA vs. method 1.
Download figure
Open in new tab
Download powerpoint
FIGURE 6.
Linear regression (A) and Bland-Altman plots (B) for method 4 MPA vs. method 1.

Tables

Figures

View popup

TABLE 1

Linear Regression and Bland–Altman Comparisons Versus Conventional Method 1 of Alternative Methods to Compute Total Blood Dose

Statistical measure	Blood only, method 2	Camera only, method 3	48-h camera only, method 4
Regression
R	0.98, P < 0.0001	0.94, ^*P < 0.0001	0.69, ^*P < 0.0001
Intercept	0.7 ± 0.6 cGy/GBq, P = 0.22	2.1 ± 1.0 cGy/GBq, ^*P = 0.05	1.6 ± 2.2 cGy/GBq, P = 0.49
Slope	0.97 ± 0.02, P < 0.0001	0.90 ± 0.04, ^*P < 0.0001	0.70 ± 0.09, ^*P < 0.0001
Bland–Altman
R	−0.07, P = 0.54	−0.12, P = 0.31	0.02, P = 0.84
Intercept	0.3 ± 0.6 cGy/GBq, P = 0.59	0.8 ± 1.1 cGy/GBq, ^*P = 0.44	−5. 0 ± 2.3 cGy/GBq, ^*P = 0.04
Slope	−0.01 ± 0.02, P = 0.54	−0.04 ± 0.04, ^*P = 0.31	0.02 ± 0.10, ^*P = 0.84

↵* P < 0.05 vs. method 2.

View popup

TABLE 2

Linear Regression and Bland–Altman Comparisons Among Methods of MPA

Statistical measure	Blood only, method 2	Camera only, method 3	48-h camera only, method 4
Regression
R	0.99, P < 0.0001	0.95, ^*P < 0.0001	0.75, ^*P < 0.0001
Intercept	0.4 ± 0.3 GBq, P = 0.20	3.2 ± 0.5 GBq, ^*P < 0.0001	6.1 ± 1.6 GBq,^*P = 0.0001
Slope	0.96 ± 0.02, P < 0.0001	0.69 ± 0.03, ^*P < 0.0001	0.86 ± 0.09, P < 0.0001
Bland–Altman
R	−0.18, P = 0.14	−0.74, ^*P < 0.0001	0.26, ^*P = 0.03
Intercept	0.2 ± 0.3 GBq, P = 0.43	3.3 ± 0.6 GBq, ^*P < 0.0001	1.2 ± 1.7 GBq, ^*P = 0.48
Slope	−0.03 ± 0.02, P = 0.14	−0.33 ± 0.04, ^*P < 0.0001	0.20 ± 0.09, ^*P = 0.03

↵* P < 0.05 vs. method 2.

View popup

TABLE 3

Comparison of Methods 2–4 Against Cases for Which MPA < 7.4 GBq by Conventional Method 1

Statistical measure	Blood only, method 2	Camera only, method 3	48-h camera only, method 4
κ	0.86 (very good agreement)	0.70^* (good agreement)	0.43^* (moderate agreement)
McNemar Δ	0.0%, P = 0.62	5.6%, P = 0.29	14.1%, ^*P = 0.02
Sensitivity	90%	70%	40%^*
Specificity	96%	96%	96%
Accuracy	94%	89%	80%^*
Positive predictive value	90%	88%	80%
Negative predictive value	96%	89%	80%^*

↵* P < 0.05 vs. method 2.

View popup

TABLE 4

Comparison of Dose Estimates of Methods 2–4 Against Conventional Method 1 Dose Estimates for Patients Grouped by Prior Treatments and Abnormal Renal Function

Patient group	Conventional, method 1	Blood only, method 2	Camera only, method 3	48-h camera only, method 4
PT+ and AF− (n = 26)	12 ± 9 cGy/GBq	12 ± 9 cGy/GBq, P = 0.63	13 ± 8 cGy/GBq, ^*P = 0.03	13 ± 11 cGy/GBq, P = 0.76
PT− and AF− (n = 22)	22 ± 17 cGy/GBq	21 ± 16 cGy/GBq, P = 0.22	23 ± 17 cGy/GBq, P = 0.25	14 ± 12 cGy/GBq, ^*P = 0.002
PT− and AF+ (n = 17)	29 ± 9 cGy/GBq	30 ± 10 cGy/GBq, P = 0.54	27 ± 11 cGy/GBq, P = 0.17	20 ± 13 cGy/GBq, ^*P = 0.0008
PT+ and AF+ (n = 6)	34 ± 13 cGy/GBq	35 ± 11 cGy/GBq, P = 0.51	30 ± 14 cGy/GBq, P = 0.11	29 ± 29 cGy/GBq, P = 0.52

↵* P < 0.05 vs. method 1.
PT+ = patients who had prior ¹³¹I treatment; AF− = patients with normal renal function; PT− = patients who did not have prior ¹³¹I treatment; AF+ = patients with abnormal renal function.

View popup

TABLE 5

Comparison of MPA of Methods 2–4 Against Conventional Method 1 MPA for Patients Grouped by Prior Treatments and Abnormal Renal Function

Patient group	Conventional, method 1	Blood only, method 2	Camera only, method 3	48-h camera only, method 4
PT+ and AF− (n = 26)	21.4 ± 9.3 GBq	20.9 ± 9.0 GBq, P = 0.14	18.0 ± 6.1 GBq, ^*P = 0.0003	23.4 ± 11.9 GBq, P = 0.08
PT− and AF− (n = 22)	13.9 ± 7.8 GBq	14.1 ± 7.7 GBq, P = 0.61	12.6 ± 6.2 GBq, ^*P = 0.03	21.0 ± 10.8 GBq, P = 0.002
PT− and AF+ (n = 17)	7.6 ± 2.4 GBq	7.6 ± 2.7 GBq, P = 0.92	8.5 ± 2.9 GBq, P = 0.09	13.3 ± 7.4 GBq, ^*P = 0.003
PT+ and AF+ (n = 6)	6.7 ± 2.7 GBq	6.5 ± 2.8 GBq, P = 0.29	7.6 ± 2.5 GBq, P = 0.12	10.6 ± 4.5 GBq, ^*P = 0.04

↵* P < 0.05 vs. method 1.
PT+ = patients who had prior ¹³¹I treatment; AF− = patients with normal renal function; PT− = patients who did not have prior ¹³¹I treatment; AF+ = patients with abnormal renal function.