Published online Jun 28, 2013. doi: 10.4329/wjr.v5.i6.241
Revised: May 3, 2013
Accepted: May 18, 2013
Published online: June 28, 2013
Processing time: 124 Days and 4.9 Hours
AIM: To evaluate the response to treatment in patients with neuroendocrine tumor liver metastases following yttrium-90 (90Y) radioembolotherapy, as a function of image patterns at presentation for 90Y radioembolotherapy.
METHODS: The study cohort consisted of patients with hepatic metastatic neuroendocrine tumors treated with 90Y at our institution during a two-year time period. Hepatic metastases were evaluated on a pre-therapy study assessing relative arterial enhancement compared to liver, lesion size, necrosis of the lesion, and associated tumor burden in the liver. We used six response criteria: Response Evaluation Criteria in Solid Tumors (RECIST) size, World Health Organization (WHO) size, European Association for the Study of the Liver (EASL) necrosis guidelines, Choi size, Choi necrosis and combination of Choi size and necrosis.
RESULTS: About 65 lesions in 17 patients met study criteria and formed the cohort. Statistically significant response was found for lesions < 5 cm vs those ≥ 5 cm with RECIST (P = 0.04), WHO (P = 0.002) and combined Choi criteria (P = 0.02). Hyperenhancing lesions demonstrated greater response only with the Choi size criteria (P = 0.04). Lesions with ≤ 50% necrosis on the pre-scan had statistically significant greater response with the Choi necrosis criteria (P = 0.01). There was no statistical significance for response comparing lesions < 2 cm vs≥ 2 cm or in comparing the degrees of tumor burden.
CONCLUSION: Based on our findings in this study, it is suggested that initial imaging findings, as listed above, are not a good predictor of response to 90Y radioembolization.
Core tip: Treatment modalities for neuroendocrine tumor liver metastases (NETLM) include systemic chemotherapy, surgery, ablation, chemoembolization, and yttrium-90 (90Y) radioembolization. Radioembolotherapy is aimed at delivering high dose of radiation via intra-arterial administration. There are reports of good response rates of NETLM following radioembolization. There are a few reports on the selection criteria based on imaging features. To our knowledge, there are no reports that have evaluated multiple imaging features as selection criteria for 90Y radioembolization. Our goal is to evaluate for a specific imaging feature at presentation that may predict response to treatment. The response will be evaluated using various criteria of tumor response.