Prospective study of Na[¹⁸F]F PET/CT for cancer staging in morbidly obese patients compared with [^99mTc]Tc-MDP whole-body planar, SPECT and SPECT/CT

Figures & data

Figure 1. Patient flow chart.

Table 1. Summary of main patient characteristics.

Characteristic	N/Mean (± SD)
Mean age (years)	59.0 ± 10.9
Female:Male	102:15
Weight (kg)	105.9 ± 12.2
BMI (kg/m^2)	46.5 ± 6.1
Injected activity MBq (mCi)
Na[^18F]F	247.9 ± 37 (6.7 ± 1.0)
[^99mTc]Tc- MDP	1109 ± 28.1 (30 ± 0.8)
Mean time between PET/CT and bone scan	8 ± 5 days
Primary Tumor
Breast cancer	98
Prostate cancer	15
Others	4
Indication
Primary staging	71
Restaging	46

Figure 2. Diagnostic test characteristics of Na[¹⁸F]F PET/CT, [^99mTc]Tc-MDP WBS, SPECT, and SPECT/CT using a patient and lesion-based optimistic and pessimistic analysis (with 95% confidence intervals).

Table 2. Pairwise comparison of the diagnostic test characteristics of Na[¹⁸F]F-PET/CT with [^99mTc]Tc-MDP WBS, SPECT and SPECT/CT: p-values for the McNemar test (proportions) and DeLong test (AUC).

Na[^18F]F-PET/CT	Analysis	[^99mTc]Tc-MDP WBS	SPECT	SPECT/CT
A. Patient-based analysis
Sensitivity	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
Specificity	Optimistic	<0.0001	<0.0001	0.182*
	Pessimistic	<0.0001	<0.0001	0.001
PPV	Optimistic	<0.0001	<0.0001	0.009
	Pessimistic	<0.0001	<0.0001	0.001
NPV	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
PLR	Optimistic	<0.0001	<0.0001	0.012
	Pessimistic	<0.0001	<0.0001	0.001
NLR	Optimistic	<0.0001	0.001	0.002
	Pessimistic	<0.0001	<0.0001	0.002
Accuracy	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
AUC	Optimistic	<0.0001	<0.0001	0.0043
	Pessimistic	<0.0001	<0.0001	0.0046
B. Lesion-based analysis
Sensitivity	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
Specificity	Optimistic	<0.0001	<0.0001	0.617*
	Pessimistic	<0.0001	<0.0001	0.012
PPV	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	0.001
NPV	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
PLR	Optimistic	<0.0001	<0.0001	0.001
	Pessimistic	<0.0001	<0.0001	0.003
NLR	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
Accuracy	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001
AUC	Optimistic	<0.0001	<0.0001	<0.0001
	Pessimistic	<0.0001	<0.0001	<0.0001

Values marked with * are considered not statistically significant after Benjamini–Hochberg false discovery rate adjustment. PPV: positive predictive value; NPV: negative predictive value; PLR: positive likelihood ratio; NLR: negative likelihood ratio; AUC: area under the curve.

Figure 3. ROC curve of Na[¹⁸F]F PET/CT, [^99mTc]Tc-MDP WBS, SPECT, and SPECT/CT using a patient and lesion-based optimistic and pessimistic analysis.

Table 3. Patient and lesion-based ROC curve analysis of Na[¹⁸F]F-PET/CT, [^99mTc]Tc-MDP WBS, SPECT and SPECT/CT.

	Optimistic		p Value	Pessimistic		p Value
	AUC	95% CI		AUC	95% CI
A. Patient-based ROC curve analysis
Na[^18F]F-PET/CT	0.957	0.912–0.999	–	0.936	0.885–0.987	–
[^99mTc]Tc-MDP WBS	0.618	0.511–0.724	<.001	0.549	0.441–0.657	<.001
SPECT	0.711	0.610–0.812	<.001	0.629	0.524–0.734	<.001
SPECT/CT	0.788	0.695–0.882	.0043	0.754	0.658–0.851	.0046
B. Lesion-based ROC curve analysis
Na[^18F]F-PET/CT	0.978	0.956–0.999	–	0.962	0.932–0.991	–
[^99mTc]Tc-MDP WBS	0.538	0.458–0.602	<.001	0.477	0.404–0.549	<.001
SPECT	0.607	0.537–0.676	<.001	0.527	0.454–0.599	<.001
SPECT/CT	0.733	0.673–0.792	<.001	0.735	0.674–0.796	<.001

DeLong’s p-values are reported for the comparison of the AUC with Na[¹⁸F]F-PET/CT. All p-values are considered statistically significant after Benjamini–Hochberg false discovery rate adjustment.