RT Journal Article SR Electronic T1 Predictive Value of Intratumoral 99mTc-Macroaggregated Albumin Uptake in Patients with Colorectal Liver Metastases Scheduled for Radioembolization with 90Y-Microspheres JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 516 OP 522 DO 10.2967/jnumed.112.112508 VO 54 IS 4 A1 Gerhard Ulrich A1 Oliver Dudeck A1 Christian Furth A1 Juri Ruf A1 Oliver S. Grosser A1 Daniela Adolf A1 Marvin Stiebler A1 Jens Ricke A1 Holger Amthauer YR 2013 UL http://jnm.snmjournals.org/content/54/4/516.abstract AB 90Y radioembolization is a promising therapy for patients with primary and secondary liver malignancies. Pretherapeutic assessment consists of hepatic angiography and 99mTc-macroaggregated albumin (99mTc-MAA) perfusion scintigraphy to estimate the liver-to-lung shunt and exclude extrahepatic 99mTc-MAA deposition. However, the predictive value of intratumoral 99mTc-MAA uptake remains unclear. Methods: One hundred four patients with chemotherapy-refractory liver-dominant metastatic colorectal cancer were treated with 90Y radioembolization between December 2006 and December 2010. All of the patients underwent angiographic assessment and perfusion scintigraphy with 99mTc-MAA before lobar 90Y 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 99mTc-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 99mTc-MAA uptake (P = 0.172) or with catheter position (P = 0.6456). Furthermore, an interaction effect of 99mTc-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 99mTc-MAA uptake, catheter position, or interaction of 99mTc-MAA uptake and catheter position (P = 0.339, 0.593, and 0.658, respectively). Conclusion: Response to 90Y radioembolization was found to be independent of the degree of 99mTc-MAA uptake. Therefore, therapy should not be withheld from patients with colorectal liver metastases lacking intratumoral 99mTc-MAA accumulation.