Clinical validation of ONCOFLASH® package in planar somatostatin receptor scintigraphy.

Objectives The objective of this study was to evaluate Oncoflash® package to reduce the acquisition time of planar somatostatin receptor scintigraphy (SRS) images indicated before realization of SPECT according to EANM guidelines.

Methods 71 consecutive SRS acquisitions in 59 patients were prospectively performed between January and December 2013. Acquisitions were performed in dynamic modality with two 7min30 images. On the one hand, these were summed to create a 15min untreated image. On the other hand, one single 7min30 image was processed with Oncoflash® package (Siemens, Erlangen, Germany). Each set of images was reviewed by three nuclear medicine physicians, blindly and independently (two seniors, one junior). Acquisition quality (good or bad), global exam interpretation (positive, inconclusive or negative) and lesion with maximal grade of uptake according to Krenning’s scale were recorded. High discordance rate (negative versus positive; gap ≥ 2 grades of uptake) for the analysis of the two sets of images were evaluated. Inter-observer variability was assessed by Cohen’s Kappa index (k).

Results Bad image quality was evaluated for 19.7% (42/213) and 18.3% (39/213) of untreated images and processed images with Oncoflash® package respectively (p=0.711). High discordance rate for global exam interpretation and lesion with maximal grade of uptake were 2.8% (6/213) and 1.4% (1/72) respectively. Inter-observer agreement study revealed k values between 0.51 and 0.61 for untreated images and between 0.56 and 0.62 for processed images with Oncoflash® package.

Conclusions Our results suggest the possibility of using the Oncoflash® module for the reconstruction of planar images of SRS allowing a reduction of acquisition time by a factor 2 without significant alteration of image quality or major impact on exam interpretation before performing SPECT acquisition.