title: Visual evaluation and differentiation of renal oncocytomas from renal cell carcinomas by means of99mTc-sestamibi SPECT/CT.
abstract: BACKGROUND
  Despite the progress in the quality of multiphasic CT and MRI scans, it is still difficult to fully characterize a solid kidney lesion. Approximately 10% of all solid renal tumours turn out to be oncocytomas. In actual clinical practice, this is verified only following unnecessary surgery or a renal biopsy/ablation. The objective of our pilot study examines whether99mTc-sestamibi SPECT/CT can play a crucial role in the characterization of solid renal neoplasms and the differentiation of oncocytomas from renal cell carcinomas. The study included 27 patients identified with 31 solid renal lesions. All patients were discussed in a multidisciplinary conference, and a decision for surgery or biopsy was taken. Prior to invasive procedures, patients underwent a SPECT/CT with99mTc-sestamibi. Visual evaluation was performed, and any focal99mTc-sestamibi uptake detected on SPECT in the localisation of tumour was considered as positive.
  
  
  RESULTS
  Eleven out of 12 oncocytomas (91.6%) displayed positive uptake of99mTc-sestamibi. Three hybrid tumours (mixed-type oncocytoma and chromophobe renal cancer) were positive on SPECT/CT. One papillary renal cell carcinoma had a slight uptake of99mTc-sestamibi. The remaining 11 renal cell carcinomas were sestamibi negative.
  
  
  CONCLUSIONS
  Differentiation of benign renal oncocytomas from renal cell carcinomas seems very promising on99mTc-sestamibi SPECT/CT examination. Additional supplement to visual evaluation, i.e. quantitative tools, should be sought for an accurate estimate of biological behaviour and hence a secure diagnosis.
authors.affiliation: Radiology Department, Division of Medical Imaging and Technology, Karolinska University Hospital, C1-46, SE-141 86, Huddinge, Stockholm, Sweden. antonios.tzortzakakis@karolinska.se.
authors.forename: Antonios
authors.initials: A
authors.lastname: Tzortzakakis
authors.affiliation: Division of Urology, Karolinska University Hospital, Huddinge, Sweden.|Division of Radiology, Department for Clinical Science Intervention and Technology (CLINTEC), Karolinska Institute and Medical Physics and Nuclear Medicine, BOF Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Ove
authors.initials: O
authors.lastname: Gustafsson
authors.affiliation: Medical Radiation Physics and Nuclear Medicine, Functional Unit of Nuclear Medicine, Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Karlsson
authors.affiliation: Division of Urology, Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Linnea
authors.initials: L
authors.lastname: Ekström-Ehn
authors.affiliation: Division of Urology, Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Rammin
authors.initials: R
authors.lastname: Ghaffarpour
authors.affiliation: Division of Radiology, Department for Clinical Science Intervention and Technology (CLINTEC), Karolinska Institute and Medical Physics and Nuclear Medicine, BOF Karolinska University Hospital, Huddinge, Sweden.|Medical Radiation Physics and Nuclear Medicine, Imaging and Physiology, Karolinska University Hospital, Huddinge, Sweden.
authors.forename: Rimma
authors.initials: R
authors.lastname: Axelsson
keywords: 99mTc-sestamibi; Hybrid imaging; RCC; Renal oncocytomas; SPECT/CT