Tumor volumes from ⁶⁸Ga-DOTATOC PET/CT scans to predict survival of patients with neuroendocrine tumors after PRRT with ¹⁷⁷Lu-DOTATATE

Ziel/Aim Currently, few studies have specifically investigated volumetric parameters in regard to their prognostic impact on neuroendocrine tumors (NET). In this study the total tumor load (TL), as well as the TL of specific organ systems of NET patients was segmented from 68Ga-DOTATOC PET/CT and correlated to overall survival after PRRT.

Methodik/Methods From 81 patients treated with PRRT between 2009 to 2016 tumor volumes were generated via a standardized semi-automatic delineation procedure using PARS Software (v3.0 Siemens). Segmentation of lesions above SUV_peak 4 was performed with delineation at 42% SUV_peak and lesions < 0,5mL were excluded. For evident lesions without available SUV_peak, segmentation was preformed manually. Total tumor volumes and tumor volumes from liver, bones, lymph-nodes and abdominal TL (consisting of mesenterial and peritoneal manifestations) were analysed by multivariate Cox regression.

Ergebnisse/Results In addition to automatic segmentation manual segmentation was performed in 86 lesions. Median overall survival (OS) was 38 months, median total TL was 201.27 mL, median liver TL was 168.13mL, median abdominal TL was 12.48mL, median bone TL was 0mL and the median lymphatic TL was 0.58mL. The abdominal TL had a HR 1.01 (p = 0.09), whereas total TL, liver TL, bone TL and lymph-node TL had an HR of 1 with non-significant p values.

Schlussfolgerungen/Conclusions We show that organ-specific tumor segmentation from PET/CTs might result in prognostic parameters in NET patients. In particular abdominal TL was associated with a shorter OS. The effect may be greater with a larger patient collective and a longer follow up period.

Publication History

Article published online:
08 April 2021