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 5 195, 38.8%), neuroendocrine tumors (NET; n 5 77, 15.3%), mammary cancer (MAM; n 5 68, 13.5%), hepatocellular carcinoma (HCC; n 5 59, 11.8%), cholangiocellular carcinoma (CCC; n 5 40, 8.0%), or urologic tumors (URO; n 5 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). In quantitative analysis, the mean TBR max 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 TBR mean 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). Conclusion: 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.

Predictive Value of 99mTc-MAA SPECT for 90Y-Labeled Resin Microsphere Distribution in Radioembolization of Primary and Secondary Hepatic Tumors

“…In previous work we evaluated uptake on 99m Tc-MAA scintigraphy and SPECT within the same patient cohort (11). Those results are also included in this analysis (Table 1).…”

“…The relevance of pretherapeutic imaging is also conferrable to various other tumor primaries. Recently, we reported on 99m Tc-MAA uptake by various tumor entities, including somewhat rare radioembolization indications such as sarcoma (11). There was a wide variation in mean tumor-to-background ratio (TBR), with the highest values occurring for NETs, HCC, and CCC, whereas breast cancer, CRC, and sarcoma had the lowest values.…”

Partition Model–Based 99mTc-MAA SPECT/CT Predictive Dosimetry Compared with 90Y TOF PET/CT Posttreatment Dosimetry in Radioembolization of Hepatocellular Carcinoma: A Quantitative Agreement Comparison

“…0.9) did not change appreciably with tumor size, confirming the robustness of our approach. Average 99m Tc-MAA uptake in TV has been shown to depend on tumor type (23), and a large variation in uptake has been observed within each given tumor type. Therefore, an extension of the present work to tumor types other than HCC could be of interest.…”

Intraarterial Hepatic SPECT/CT Imaging Using 99mTc-Macroaggregated Albumin in Preparation for Radioembolization

“…A detailed discussion of considerations of normal hepatic perfusion and hepaticoenteric arterial anatomy in the context of radioembolization has been published elsewhere (10,(12)(13)(14)(15)(16). In a recent publication by Ilhan et al, SPECT/CT images were reviewed for tumor uptake distribution and graded on the basis of the concentration of 99m Tc-MAA and distribution within the tumor (17). Most lesions were of grade 1 (high uptake, homogeneous distribution) or grade 2 (high uptake, heterogeneous distribution).…”