Simultaneous assessment of renal function with hybrid SPECT/CT during whole-body bonescintigraphy (WbBS) in patients with prostate carcinoma (PC) and concomitant urological diseases with impaired renal drainage
Authors:   University Specialized Hospital for Active Treatment in Oncology, Clinic of Nuclear Medicine, Sofia, Bulgaria, Mihaylova Maria , Piperkova Elena ,   University Specialized Hospital for Active Treatment in Oncology, Clinic of Nuclear Medicine, Sofia, Bulgaria, Chavdarova Lidia ,   University Specialized Hospital for Active Treatment in Oncology, Clinic of Nuclear Medicine, Sofia, Bulgaria
Published: June 2024

Introduction: Whole-body bone scintigraphy (WbBS) is the „gold standard“ worldwide for early detection and evaluation of treatment of bone metastatic tumors, incl.PC.Due to the known renal excretion of the osteotropic RPh – 99mTc-methylene diphosphonate (99mTc-MDP), it is possible to perform an „early“ assessment of renal function, followed by a „late“ standard WbBS with SPECT/CT. Aim: The aim of the present study was to evaluate and indicate the diagnostic utility of a single administration of 99mTc-MDP with a dual protocol implemented in the CNM for sequential scintigraphic assessment of renal function and early detection, staging and evaluation of the treatment effect of bone metastases in patients with PCand concomitant urological diseases. Materials and methods: We present three patients with PC, referred for restaging of the oncological disease and performing WbBS in the CNM in USHATO, Sofia, Bulgaria. According to the indications and assessment of a nuclear medicine physician, a one-day protocol was carried out and introduced in the CNM, starting with dynamic renal scintigraphy (DRS) at the time of bo-lus i.v.injection of 99mTc-MDP and subsequent after the 2nd hour planar WbBS with hybrid target or wholebody SPECT/CT scan. Results: The first patient is with metastatic PC after complex treatment.Due to elevated levels of creatinine, „early“ DRS and „late“ restaging WbBS were performed, with reported full therapeutic effect of bone-metastatic disease and isosthenuric changes in right kidney, but with altered secretory-excretory phases and reduced total GFR.The second case is a patient with high-risk CP, who underwent hormonal and definitive radiation therapy, with episodes of renal colic. DRS revealed a hydronephrotic type nephrogram on the right, and a subsequent CT scan showed osteoporotic compression fractures of two vertebrae, without bon metastasis. An additional SPECT/CT finding is a calcium-dense calculus as a probable cause of the hydronephrotic changes. The third patient, is with high-risk CP and undergonetreatment. Initial DRSshowed secretory-excretory dysfunction of the right kidney with retention in the pyelocaliceal system. SubsequentWbBSand SPECT/CT revealed a complete therapeutic effect of a solitary bony lesion in the 6th right rib and malrotation of the right kidney with a staghorn calculus in the pyelon. All patients are referred for urological control. Conclusion: DRS performed with hybrid SPECT/ CT, in the course of routine WbBS, for re-staging of patients with CP, gives along with bone metastatic follow-up, valuable functional information about the separated renal function, drainage and morphological guidance for pathological changes from concomitant urological diseases.