RT Journal Article
SR Electronic
T1 Dual phase parathyroid scintigraphy: Improved accuracy with quantitative SPECT
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 2717a
OP 2717a
VO 57
IS supplement 2
A1 Riham El Khouli
A1 Evrim Turkbey
A1 Melin Vranesic
A1 Martha Zeiger
A1 Harvey Ziessman
A1 Zsolt Szabo
YR 2016
UL http://jnm.snmjournals.org/content/57/supplement_2/2717a.abstract
AB 2717aObjectives Tc-99m Sestamibi dual phase imaging of the parathyroid is the standard pre-operative evaluation for parathyroid adenoma localization or at least lateralization. The scans are commonly evaluated qualitatively, yet variability between readers with different levels of experience has not been evaluated. The purpose of this study was to evaluate the inert-observer variability of the qualitative assessment of dual phase SPECT CT scans of the parathyroid and to develop and compare quantitative assessment using the standardized uptake values (SUVs) in patients with primary hyperparathyroidismMethods Early and delayed SPECT/CT scans were obtained in 33 patients with primary hyper-parathyroidism (xSPECT quant, Siemens Medical Solutions, Inc.). Operative data were available for 26 patients at the time of this analysis. Four of these patients had bilateral adenomas or hyperplasia, while 22 had unilateral adenomas. Two blinded readers separately evaluated the images qualitatively and the clinical readings were collected as a 3rd evaluation. Volumes of interest (VOIs) were placed over the parathyroid, ipsilateral thyroid, and contra-lateral thyroid glands. SUVmax, SUVpeak, SUVmean normalized to both body weight (SUVBW) and lean body mass (SUVLBW) were recorded. Uptake ratios were calculated for all SUV values. T-test was used to compare SUVs and uptake ratiors. Regression analysis and Receiver Operating Characteristic (ROC) curves were performed to assess for associations and diagnostic accuracyResults There was fair variability between the two readers as well as the readers and the clinical reading (agreement varies between 68 and 90% with Kappa coefficient varying between 0 and 0.75). There were significant differences in SUVmax and SUVpeak values at both early and delayed phases between the ipsilateral and contralateral thyroid lobes (p-values <0.05). The difference between the ipsilateral and contralateral SUV values in the early and delayed phases showed better diagnostic accuracy (AUC 0.91 for SUVpeak in the early phase, 0.94 SUVmax and 0.95 SUVpeak in the delayed phase) compared to 0.62, 0.78, and 0.86 for the qualitative method. The uptake ratio (delayed/early) of SUVpeak was significantly higher for the ipsilateral versus contralateral thyroid lobes (p-value 0.02). There was also significant correlation between parathyroid SUVs in the delayed phase and the weight of the gland on pathology (r=0.58-0.83 and p-value <0.05)Conclusions Quantitative analysis of SPEC CT of parathyroid and both ipsi- and contralateral thyroid gland with SUV measurements shows higher diagnostic accuracy than the commonly used qualitative method and can overcome the inter-observer variability of that subjective method. Uptake on the delayed image correlates most with adenoma weight