Radiopharmaceutical Therapy Monitoring Protocol

For each PRRT cycle, laboratory analysis was performed 1 day prior to treatment, during the following inpatient stay and re-evaluated 2 and 6 weeks after each therapy. During follow-up laboratory parameters were re-evaluated every three months. Hematological parameters were determined with Common Terminology Criteria for Adverse Events (CTCAE) V5.0. Hematological and clinical parameters including WBC, erythrocytes, Hb, platelet count, cumulative absorbed kidney dose, Ki67, and post-therapeutical weight loss were determined and noted before and after each therapy cycle and during follow-up. Renal function was examined on the basis of glomerular filtration rate in plasma creatinine and the tubular extraction rate (TER) determined by ^99mTc MAG3 renal scintigraphy prior to each therapy cycle and during follow-up. Renal scintigraphy with ^99mTc-labelled MAG3 was performed on a doubled headed gamma camera (Siemens E.Cam; Siemens; Erlangen, Germany) equipped with a low-energy, high-resolution collimator according to previously described protocols [22 (link)]. The annual TER decrease (ml/min/1.73 m²) was normed to the lower limit as recently described by Werner et al. [23 (link)]. The annual decrease of the TER was determined by linear regression.