Preliminary clinical assessment of dynamic 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for evaluating the clinicopathological grade in patients with non-Hodgkin's lymphoma: a prospective study.

OBJECTIVE

We prospectively assessed the diagnostic capacity of dynamic and dual-time-point F-fluorodeoxyglucose PET/computed tomography and explored the most appropriate scan timing for clinicopathological discrimination of non-Hodgkin's lymphoma.

METHODS

Thirteen patients underwent dynamic scans dynamic scans (5-15, 15-25, and 25-35 minute postinjection) and consecutive dual-time-point scans (1- and 2-hour postinjection). For five indolent and 16 aggressive lymphomas, we statistically compared the maximum standardized uptake value (SUVmax) and the retention index of the SUVmax (RI-SUVmax) for each scan and explored the diagnostic capacities using receiver operating characteristic (ROC) curve analyses.

RESULTS

SUVmax increased progressively over time in all lymphomas and was significantly higher for aggressive lymphoma than for indolent lymphoma in each timephase. RI-SUVmax of dynamic scans (RI-SUV-dynamic) was significantly higher in aggressive than in indolent lymphoma. The cutoff values obtained a sensitivity of 94%, positive-predictive value of 94%, and accuracy of 91% for SUVmax analyses of the dynamic second and third phases, 1-hour early phase, and 2-hour delayed phase, and a sensitivity of 88%, positive-predictive value of 93%, and accuracy of 86% for RI-SUV-dynamic. In contrast, for the dynamic first phase, the cutoff value of SUVmax yielded moderate sensitivity of 69%, a positive-predictive value of 92%, and an accuracy of 71%. The area under the ROC curve (AUC) of the RI-SUV-dynamic had the highest value (0.938), whereas the AUCs of the other ROC analyses were not significantly different.

CONCLUSION

The dynamic second and third phase could potentially provide good predictors of clinicopathological discrimination, as can the early and delayed phases.