In staging pediatric sarcoma, subsidiary FDG-PET scanning depicts important additional information and has a relevant impact on therapy planning when analyzed side-by-side with CIMs.

Pediatric HL patients with a negative PET in response assessment have an excellent prognosis while PET-positive patients have an increased risk for relapse.

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 6 SD, 6.6 6 2.8; mean lesion size 6 SD, 33.8 6 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 5 0.172) or with catheter position (P 5 0.6456). Furthermore, an interaction effect of 99m Tc-MAA uptake and catheter position in relation to tumor response was not found (P 5 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 5 0.339, 0.593, and 0.658, respectively). Conclusion: 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. Radi oembolization with 90 Y is a promising catheterbased liver-directed modality approved by the Food and Drug Administration for the treatment of patients with hepatic metastases of colorectal carcinoma (1-4). For this interventional technique, 90 Y-embedded microspheres of glass or resin are infused directly into the hepatic arteries, where they become lodged within the tumor microvasculature and irradiate the tumor by b-emission (5).Perfusion scintigraphy with 99m Tc-labeled macroaggregated albumin ( 99m Tc-MAA) is mandatory before 90 Y radioem...