The value of 18F-FDG PET/CT and 18F-DOPA PET/CT in determining the initial surgical strategy of patients with medullary thyroid cancer

Table 2 Detection of primary thyroid tumor and positive central and lateral compartments on ¹⁸F-FDG PET/CT, ¹⁸F-DOPA PET/CT and conventional imaging, respectively

	¹⁸F-FDG PET/CT	¹⁸F-DOPA PET/CT	US^a	MRI	CT^b
No. of evaluated thyroid glands	35 (100)	33 (100)	81 (100)	33 (100)	30 (100)
No. of total thyroidectomies	24 (69)	26 (79)	74 (91)	25 (76)	19 (63)
True positive, n	17	15	51	12	11
True negative, n	1	0	0	1	2
False positive, n	0	0	17	3	1
False negative, n	6	11	6	9	5
No. of evaluated central compartments	35 (100)	33 (100)	64 (100)	33 (100)	30 (100)
No. of operated central compartments^c	23 (66)	27 (82)	58 (91)	26 (92)	18 (63)
True positive, n	13	7	2	8	13
True negative, n	4	9	23	5	4
False positive, n	1	0	0	2	0
False negative, n	5	11	33	11	1
Sensitivity %	72%	39%	6%	42%	93%
Specificity %	80%	100%	100%	71%	100%
PPV %	93%	100%	100%	80%	100%
NPV %	44%	45%	41%	31%	80%
Accuracy %	74%	59%	43%	50%	94%
No. of evaluated lateral compartments	70 (100)	66 (100)	128 (100)	66 (100)	60 (100)
No. of operated lateral compartments	22 (31)	19 (29)	34 (27)	30 (45)	22 (37)
True positive, n	17	13	23	16	15
True negative, n	3	3	3	7	1
False positive, n	0	0	1	2	1
False negative, n	2	3	7	5	5
Sensitivity %	89%	81%	77%	76%	75%
Specificity %	100%	100%	75%	78%	50%
PPV %	100%	100%	96%	89%	94%
NPV %	60%	50%	30%	58%	17%
Accuracy %	91%	84%	76%	77%	73%

Abbreviations: PPV Positive predictive value, NPV Negative predictive value, US Ultrasound
^aOf 91 patients with a preoperative ultrasound, the thyroid and lymph node compartments were properly assessed in 81 and 64 patients, respectively
^b30 out of 31 patients with preoperative CT had a report available for analysis
^cOne patient had a palliative hemithyroidectomy with central compartment dissection, explaining why number of total thyroidectomies and central compartment dissection do not necessarily match. Sensitivity = true positive / (true positive + false negative). Specificity = true negative / (true negative + false positive). PPV = true positive / (true positive + false positive). NPP = true negative / (true negative + false negative. Accuracy = (true positive + true negative) / (true positive + true negative + false positive + false negative)

ISSN: 1470-7330