title: Predictive value of intratumoral 99mTc-macroaggregated albumin uptake in patients with colorectal liver metastases scheduled for radioembolization with 90Y-microspheres.
abstract: (90)Y radioembolization is a promising therapy for patients with primary and secondary liver malignancies. Pretherapeutic assessment consists of hepatic angiography and (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) perfusion scintigraphy to estimate the liver-to-lung shunt and exclude extrahepatic (99m)Tc-MAA deposition. However, the predictive value of intratumoral (99m)Tc-MAA uptake remains unclear.
  
  
  METHODS
  One hundred four patients with chemotherapy-refractory liver-dominant metastatic colorectal cancer were treated with (90)Y radioembolization between December 2006 and December 2010. All of the patients underwent angiographic assessment and perfusion scintigraphy with (99m)Tc-MAA before lobar (90)Y radioembolization. For inclusion, patients must have undergone pretherapeutic and follow-up MR imaging (6 wk and 3 mo after radioembolization, respectively). The degree of intratumoral (99m)Tc-MAA uptake was rated, and liver metastases were classified according to changes in tumor diameter on both an individual and a patient basis using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Response at both time points, MAA uptake, and catheter position were then statistically analyzed in a linear and generalized linear mixed model at a significance level of 0.05 (P value).
  
  
  RESULTS
  Sixty-six patients with a total of 435 colorectal liver metastases (mean number of lesions ± SD, 6.6 ± 2.8; mean lesion size ± SD, 33.8 ± 21.2 mm; lesion size range, 10-154 mm) were included in this analysis. According to the patient-based analysis, 3 patients had partial response, 49 stable disease, and 6 progressive disease after 6 wk. After 3 mo, 5 patients showed partial response, 26 stable disease, and 17 progressive disease. There was no association of patient-based tumor response with overall (99m)Tc-MAA uptake (P = 0.172) or with catheter position (P = 0.6456). Furthermore, an interaction effect of (99m)Tc-MAA uptake and catheter position in relation to tumor response was not found (P = 0.512). Moreover, in lesion-based analysis according to RECIST 1.1 there was no association of tumor response with degree of (99m)Tc-MAA uptake, catheter position, or interaction of (99m)Tc-MAA uptake and catheter position (P = 0.339, 0.593, and 0.658, respectively).
  
  
  CONCLUSIONS
  Response to (90)Y radioembolization was found to be independent of the degree of (99m)Tc-MAA uptake. Therefore, therapy should not be withheld from patients with colorectal liver metastases lacking intratumoral (99m)Tc-MAA accumulation.
authors: Department of Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany.
authors: Gerhard
authors: G
authors: Ulrich
authors: Oliver
authors: O
authors: Dudeck
authors: Christian
authors: C
authors: Furth
authors: Juri
authors: J
authors: Ruf
authors: Oliver S
authors: OS
authors: Grosser
authors: Daniela
authors: D
authors: Adolf
authors: Marvin
authors: M
authors: Stiebler
authors: Jens
authors: J
authors: Ricke
authors: Holger
authors: H
authors: Amthauer
mesh_terms: D000328:Adult; D000368:Aged; D001692:Biological Transport; D015179:Colorectal Neoplasms / Q000473:pathology*; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000532:radiotherapy* / Q000556:secondary; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013668:Technetium Tc 99m Aggregated Albumin / Q000378:metabolism*; D016896:Treatment Outcome; D047368:Tumor Burden / Q000528:radiation effects; D015021:Yttrium Radioisotopes / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes