Chemotherapy response evaluation with FDG–PET in patients with colorectal cancer

197

131

Molecular imaging with 18 F-FDG PET has been proven useful in the management of colorectal cancer. 18 F-FDG PET plays a pivotal role in staging before surgical resection of recurrent colorectal cancer and metastases, in the localization of recurrence in patients with an unexplained rise in serum carcinoembryonic antigen levels, and in the assessment of residual masses after treatment. Currently, there is increasing interest in the role of 18 F-FDG PET beyond staging. The technique appears to have significant potential for the characterization of tumors and for the prediction of prognosis in the context of treatment stratification and early assessment of tumor response to therapy. This systematic review provides an overview of the literature on the value of 18 F-FDG PET for monitoring and predicting the response to therapy in colorectal cancer. The review covers chemotherapy response monitoring in advanced colorectal cancer, monitoring of the effects of local ablative therapies, and preoperative radiotherapy and multimodality treatment response evaluation in primary rectal cancer. Given the added value of 18 F-FDG PET for these indications, implementation in clinical practice and systematic inclusion in therapeutic trials to exploit the potential of 18 F-FDG PET are warranted.

Section: Chemotherapy Response Monitoring In Advanced Colorectal Cancermentioning

confidence: 99%

Section: Chemotherapy Response Monitoring In Advanced Colorectal Cancermentioning

confidence: 99%

Monitoring and Predicting Response to Therapy with ¹⁸F-FDG PET in Colorectal Cancer: A Systematic Review

Geus-Oei¹,

Vriens²,

Laarhoven³

et al. 2009

197

131

“…Compared with morphologic imaging modalities such as CT and MRI, PET with the glucose analog 18 F-FDG returned superior results in monitoring therapy response and predicting survival in patients with various tumors (11)(12)(13)(14)(15). The first published results indicate a high prognostic power for 18 F-FDG PET in the prediction of survival after SIRT in patients with intrahepatic cholangiocellular carcinoma (16).…”

mentioning

confidence: 99%

¹⁸F-FDG PET/CT Predicts Survival After Radioembolization of Hepatic Metastases from Breast Cancer

Haug

Donfack²,

Trumm³

et al. 2012

100

90 Y radioembolization (selective internal radiation therapy [SIRT]) has emerged as a valuable therapeutic option in unresectable, chemotherapy-refractory hepatic metastases from breast cancer. The objective of the present study was to evaluate 18 F-FDG PET/ CT for predicting survival in these patients. Methods: Fifty-eight consecutive patients with hepatic metastases from breast cancer were treated with SIRT. Before therapy, all patients underwent MRI of the liver. 18 F-FDG PET/CT was performed at baseline and 3 mo after SIRT to calculate percentage changes in maximum 18 F-FDG standardized uptake value (SUV max ) relative to baseline. A decrease of more than 30% in the follow-up scan, compared with the baseline examination, indicated therapy response. Treatment response at 3 mo was also assessed in 43 patients using contrastenhanced MRI and CT on the basis of the Response Evaluation Criteria in Solid Tumors. All patients were followed to complete survival data. Results: Overall median survival after SIRT was 47 wk. Response as assessed with SUV max correlated significantly with survival after radioembolization, with responders having significantly longer survival (65 wk) than nonresponders (43 wk; P , 0.05). In multivariate analysis the change in SUV max was identified as the only independent predictor of survival (hazard ratio, 0.23; P , 0.005). Furthermore, a high pretherapeutic SUV max (.20) was associated with a significantly shorter median survival than was an SUV max of 20 or less (21 vs. 52 wk; P , 0.005). The presence of extrahepatic metastases (mean survival in both groups, 47 wk; P 5 0.92), hormone receptor status (estrogen, P 5 0.53; progesterone, P 5 0.79; Her-2/neu, P 5 0.49), and MRI/CT response (P 5 0.91) did not predict survival. Conclusion: The change in SUV max as assessed by 18 F-FDG PET/CT before and 3 mo after SIRT was identified as the only independent predictor of survival in patients with hepatic metastases of breast cancer. Breastcanceri s the most common malignancy affecting women in developed countries. Despite advances in adjuvant treatment, about 20% of patients with initially local disease will still develop metastases (1), frequently involving the liver. In most patients, curative surgical resection of liver metastases is not an option because of the presence of extrahepatic disease or multisegmental involvement of the liver. Other local therapies, such as radiofrequency ablation, are feasible in only a limited number of patients exhibiting only a few, small hepatic metastases. Despite significant advances in chemotherapeutic options in metastatic breast cancer, the presence of liver metastases limits survival in up to 60% of patients. Median survival in women exhibiting liver metastases of breast cancer has been estimated at about 18 mo (2).More recently, radioembolization using 90 Y-microspheres (selective internal radiation therapy [SIRT]) has emerged as a palliative treatment for hepatic metastases of various tumors (3-6). In hepatic metastases of breast cancer (7-9), reported...

“…18 F-FDG uptake can be quantified by glucose metabolic rates (MR glc ) derived from dynamic 18 F-FDG PET data. The value of baseline MR glc as a predictive parameter for treatment outcome has been shown for several tumor types, including non-small cell lung carcinoma and CRC (9), and its predictive value using changes in MR glc for the early evaluation of response during chemotherapy has been shown in many tumor types, including non-small cell lung carcinoma (10) and CRC (11).…”

mentioning

confidence: 99%

Chemotherapy Response Monitoring of Colorectal Liver Metastases by Dynamic Gd-DTPA–Enhanced MRI Perfusion Parameters and ¹⁸F-FDG PET Metabolic Rate

Vriens¹,

Laarhoven²,

Asten³

et al. 2009

In this study, we examined the in vivo relationship between functional tumor vasculature, determined by dynamic contrast-enhanced (DCE-) MRI, and tumor metabolism, determined by dynamic 18 F-FDG PET, during cytotoxic treatment of patients with colorectal liver metastases. Methods: Twenty-three patients underwent DCE-MRI (using gadolinium dimeglumine) and dynamic 18 F-FDG PET at baseline and after 3 treatment cycles, unless treatment was terminated because of toxicity. Parameters for vasculature (rate constant between extravascular extracellular space and blood plasma [k ep ] and volume transfer constant [K trans ]), extracellular space (v e ), tumor size (the maximal axial diameter of each included lesion [MAD]), and metabolism (glucose metabolic rates [MR glc ]) were derived, and changes during treatment were correlated. Overall survival (OS) and progression-free survival (PFS) served as outcome measures for the predictive abilities of pretreatment parameters and of treatment-related parameter changes. Results: Pretreatment MR glc and MAD were individually predictive for OS and PFS. During treatment, K trans increased significantly, but this increase could not be confirmed in a lesion-by-lesion analysis. MR glc decreased significantly (P , 0.001). No correlations were found for changes in DCE-MRI parameters and DMR glc . No relationship was found between changes in DCE-MRI parameters and OS or PFS. DMR glc was able to predict OS (P 5 0.008) after correction for confounders. Conclusion: The efficacy of cytotoxic chemotherapy assessed by reduction in tumor metabolism does not depend on pretreatment properties of the tumor vasculature determined by DCE-MRI. Cytotoxic chemotherapy does not alter DCE-MRI-derived properties of tumor vasculature but decreases glucose consumption of tumor cells.