A head-to-head comparison between two commercial software packages for hybrid dosimetry after peptide receptor radionuclide therapy

Abstract

Background Dosimetry after peptide receptor radionuclide therapy (PRRT) is increasing; however, comparing or pooling of dosimetric results can be challenging since different approaches are used. The aim of this study was to perform a head-to-head comparison of post-PRRT curve fitting and dosimetry obtained from two commercial software Hybrid Viewer Dosimetry and PLANET Dose. Methods Post-therapy imaging included planar scintigraphy at 0.5, 4, 24 and 72 h post-injection of [177Lu]Lu-DOTA-TATE for kinetics and SPECT/CT at 24 h for quantification. On planar imaging, 2 cm regions-of-interest were positioned within the inferior pole of the kidneys and kidney cortex was segmented on low-dose CT. On both planar and SPECT/CT, 2 cm spheres were positioned in the proximal humerus (red marrow equivalent) and in the region with the highest uptake in tumour lesions. TACs were estimated with mono- and bi-exponential fits in both software systems, after which tissue absorbed (kidney, red marrow, tumour) and biological effective doses (kidney) were calculated. Agreement-ICC, Spearman correlation and Bland-Altman plots were used to compare results. Results Mono-exponential fits showed the most comparable correlation between the measured and fitted data between both software. The ICC between absorbed dose outcomes was > 0.7 in tumour lesions and kidneys, but negative for the red marrow. Spearman correlation was > 0.9 for mono-exponential fits in kidneys and tumour lesions, and −0.7 in red marrow. Bi-exponential fits resulted in lower correlations and agreement values. Concordance between both software packages concerning the number of PRRT cycles with 7.4 GBq was observed based on a biological effective dose limit of 27 Gy to the kidneys. Conclusion [177Lu]Lu-DOTA-TATE dosimetry results of two software packages were comparable in the same dataset, despite the limited number of imaging time-points. However, these results should be verified in a larger cohort before pooling of clinical data, as the obtained results will depend on acquisition protocol, timing and lesions definition.

Clinical implementation of PLANET® Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

“…In a recent study, Huizing et al [16] compared dosimetry results obtained with Hybrid Viewer Dosimetry and PLANET ® Dose in ten patients using hybrid imaging data obtained from 0.5 h to 72 h post-injection of [ 177 Lu] Lu-DOTA-TATE. Although our study also concerned PLANET ® Dose, our reference method was Dosimetry Toolkit ® .…”

Dosimetry in Lu-177-PSMA-617 prostate-specific membrane antigen targeted radioligand therapy: a systematic review

“…Previous studies have shown that interpatient variability, differences in methodologies, models used for dose assessment, imaging system calibration, time-activity curve fitting, variation in organ volumes, intra-individual size variation, 2D/3D dosimetry approach and the number of imaging time points post-therapy, all are known to induce variations in absorbed dose estimates [31,33,36,47,48,57,58]. The use of various dosimetry software and techniques are also leads to variation in absorbed dose estimates for organs and tissues [59,60].…”

Clinical implementation of PLANET®Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE : comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

“…In order to preserve the experience and data acquired thus far with Dosimetry Toolkit® and OLINDA/EXM® V1.0, we needed to verify that the workstations would yield consistent results. Obviously, this can be achieved only if the same methodology is implemented in both platforms (38). Thus, our study, based on a fully 3D imaging protocol, evaluated dosimetric results obtained with the two dosimetry solutions, rst using a body phantom and then in 21 patients undergoing [177Lu]Lu-DOTA-TATE treatment, representing a total of 40 dosimetry analysis.…”