title: Systematic evaluation of tumoral 99mTc-MAA uptake using SPECT and SPECT/CT in 502 patients before 90Y radioembolization.
abstract: The aim of this study was to evaluate the (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) uptake of primary and secondary liver tumors in a large patient cohort before (90)Y radioembolization.
  
  
  METHODS
  We included 502 patients during the years 2005-2013 (55% male; mean age, 62 ± 11 y), who were examined with (99m)Tc-MAA SPECT or SPECT/CT before planned radioembolization. The patients had colorectal cancer (CRC; n = 195, 38.8%), neuroendocrine tumors (NET; n = 77, 15.3%), mammary cancer (MAM; n = 68, 13.5%), hepatocellular carcinoma (HCC; n = 59, 11.8%), cholangiocellular carcinoma (CCC; n = 40, 8.0%), or urologic tumors (URO; n = 14, 2.8%). SPECT with coregistered contrast-enhanced CT or MR imaging and SPECT/CT images of these patients were analyzed using dedicated software with regard to the (99m)Tc-MAA uptake of the liver tumors. Regions of interest were drawn around the lesions manually and quantified the uptake of up to 3 lesions per patient and also adjacent healthy liver tissue without evidence of tumor. We quantified maximum and mean counts per pixel and calculated tumor-to-background ratio (TBR). Data are reported as mean ± SD. Lesion uptake was classified as being homogeneously high (grade 1), heterogeneously high (grade 2), equal to that of the liver (grade 3), or low (grade 4).
  
  
  RESULTS
  Grade 1 uptake was seen in 230 of 1,008 lesions (with the highest rates in sarcoma [47%], MAM [37%], and NET [32%]), grade 2 in 706 lesions (with the highest rates in CRC [77%], HCC [75%], and CCC [74%]), grade 4 in 57 lesions (with the highest rates in pancreatic cancer [17%], sarcoma [SAR] [13%], and MAM [8%]), and grade 3 in only 15 lesions. In quantitative analysis, the mean TBRmax of all lesions was 4.8 ± 4.1 (range, 0.2-50.1), with the highest values in HCC (6.0 ± 4.7; range, 1.4-21.6), NET (5.4 ± 4.9; range, 0.8-43.0), pancreatic cancer (4.0 ± 2.8; range, 0.9-12.2), and CCC (4.7 ± 2.9; range, 0.9-11.6), and the lowest values in SAR (3.5 ± 1.8; range, 0.8-2.7) and MAM (3.6 ± 2.2; range, 0.9-11.6). The mean TBRmean was 1.9 ± 1.0 (range, 0.1-7.2), with the highest values in NET (2.2 ± 1.2; range, 0.2-7.2), HCC (2.1 ± 1.2; range, 0.3-6.3), and CCC (2.0 ± 1.0; range, 0.2-6.3) and the lowest values in MAM (1.7 ± 0.8; range, 0.2-4.1), CRC (1.8 ± 0.9; range, 0.4-6.6), and SAR (1.7 ± 1.1; range, 0.3-3.9).
  
  
  CONCLUSIONS
  The (99m)Tc-MAA uptake of different tumor entities shows a wide variation, with generally highest values for NET, HCC, and CCC and lowest values for MAM, CRC, and SAR. However, the variation of uptake within the different tumor entities is high.
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors: Harun
authors: H
authors: Ilhan
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors: Anna
authors: A
authors: Goritschan
authors: Institute of Clinical Radiology, University of Munich, Munich, Germany.
authors: Phillip
authors: P
authors: Paprottka
authors: Department of Diagnostic and Interventional Radiology, Krankenhaus Barmherzige Brüder, Munich, Germany; and.
authors: Tobias F
authors: TF
authors: Jakobs
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors: Wolfgang P
authors: WP
authors: Fendler
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors: Peter
authors: P
authors: Bartenstein
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, University of Vienna, Vienna, Austria.
authors: Marcus
authors: M
authors: Hacker
authors: Department of Nuclear Medicine, University of Munich, Munich, Germany Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, University of Vienna, Vienna, Austria alexander.haug@meduniwien.ac.at.
authors: Alexander R
authors: AR
authors: Haug
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000737:chemistry; D015901:Angiography, Digital Subtraction / Q000379:methods; D001943:Breast Neoplasms / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D018281:Cholangiocarcinoma / Q000473:pathology; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000473:pathology; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology; D012189:Retrospective Studies; D013668:Technetium Tc 99m Aggregated Albumin / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014571:Urologic Neoplasms / Q000473:pathology; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D000418:Albumins; D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes
keywords: MAA uptake; SPECT/CT; oncology; radioembolization