Standardized Added Metabolic Activity Predicts Survival After Intra-arterial Resin-Based 90Y Radioembolization Therapy in Unresectable Chemorefractory Metastatic Colorectal Cancer to the Liver

PET/CT Imaging Characteristics After Radioembolization of Hepatic Metastasis from Breast Cancer

PURPOSE

To define positron emission tomography/computed tomography (PET/CT) imaging characteristics during follow-up of patients with metastatic breast cancer (MBC) treated with yttrium-90 (Y90) radioembolization (RE).

MATERIALS AND METHODS

From January 2011 to October 2017, 30 MBC patients underwent 38 Y90 glass or resin RE treatments. Pre-RE PET/CT was performed on average 51 days before RE. There were 68 PET/CTs performed after treatment. Response was assessed using modified PERCIST criteria focusing on the hepatic territory treated with RE, normalizing SUVpeak to the mean SUV of liver uninvolved by tumor. An objective response (OR) was defined as a decrease in SUVpeak by at least 30%.

RESULTS

Of the 68 post-RE scans, 6 were performed at 0-30 days, 15 at 31-60 days, 9 at 61-90 days, 13 at 91-120 days, 14 scans at 121-180 days, and 11 scans at > 180 days after RE. Of the 30 patients, 25 (83%) achieved OR on at least one follow-up. Median survival was 15 months after the first RE administration. Highest response rates occurred at 30-90 days, with over 75% of cases demonstrating OR at that time. After 180 days, OR was seen in only 25%. There was a median TTP of 169 days among responders.

CONCLUSION

In MBC, follow-up PET/CT after RE demonstrates optimal response rates at 30-90 days, with progression noted after 180 days. These results help to guide the timing of imaging and also to inform patients of expected outcomes after RE.

Intra-arterial therapies for unresectable and chemorefractory colorectal cancer liver metastases: a systematic review and meta-analysis

BACKGROUND

A large proportion of patients with colorectal cancer liver metastases (CRCLM) not amenable to curative liver resection will progress on systemic therapy. Intra-arterial therapies (IAT) including conventional transarterial chemoembolization (cTACE), drug eluting beads (DEB-TACE) and yttrium-90 radioembolization (Y-90) are indicated to prolong survival and palliate symptoms. The purpose of this systematic review and meta-analysis is to compare the survival benefit and radiologic response of three intra-arterial therapies in patients with chemorefractory and unresectable CRCLM.

METHODS

A systematic search for eligible references in the Cochrane Library and the EMBASE, MEDLINE and TRIP databases from January 2000 to November 2016 was performed in accordance with PRISMA guidelines. Methodological quality of included studies was assessed using the MINORS scale. One-year overall survival rates and RECIST responder rates were pooled using inverse-variance weighted random-effects models. Overall survival outcomes were collected according to transformed pooled median survivals from first IAT with a subgroup analysis of patients with extrahepatic disease.

RESULTS

Twenty-three prospective studies were included and analyzed: 5 cTACE (n = 746), 5 DEB-TACE (n = 222) and 13 Y-90 (n = 615). All but five were clinical trials. Eleven of 13 Y-90 studies were industry funded. Pooled RECIST response rates with 95% confidence intervals (CI) were: cTACE 23% (9.7, 36), DEB-TACE 36% (0, 73) and Y-90 23% (11, 34). The pooled 1-year survival rates with CI were: cTACE, 70% (49, 87), DEB-TACE, 80% (74, 86) and Y-90, 41% (28, 54). Transformed pooled median survivals from first IAT and ranges for cTACE, DEB-TACE and Y-90 were 16 months (9.0-23), 16 months (7.3-25) and 12 months (7.0-15), respectively. Significant heterogeneity in inclusion criteria and reporting of confounders, including previous therapy, tumor burden and post-IAT therapy, precluded statistical comparisons between the three therapies.

CONCLUSION

Methodological and statistical heterogeneity precluded consensus on the optimal treatment strategy. Given the common use and significant cost of radioembolization in this setting, a more robust prospective comparative trial is warranted.

Evaluating tumor response with FDG PET: updates on PERCIST, comparison with EORTC criteria and clues to future developments

Eighteen years ago, the EORTC PET criteria standardized for the first time response assessment by FDG PET. Response assessment by FDG PET has been further developed and refined by PERCIST (PET response criteria in solid tumors). This review describes the data underlying these two systems for assessing tumor response on FDG PET/CT. It also summarizes recent clinical studies that have compared EORTC criteria and PERCIST with each other as well as with the anatomically based "response criteria in solid tumors" (RECIST). These studies have shown that response assessment by EORTC criteria and PERCIST leads to very similar response classifications. In contrast, there are significant differences between response assessment by PERCIST and RECIST. Preliminary data also suggest that response assessment by PERCIST is better correlated with patient outcome and may be a better predictor for the effectiveness of new anti-cancer therapies than RECIST. If correct, this could have a significant impact on oncologic drug development. However, confirmation of the better predictive value of response assessment by PERCIST by data from randomized trials is still lacking.