The prognostic value of fluorodeoxyglucose positron emission tomography metabolic tumor volume in solitary colorectal liver metastasis

The prognostic role of whole-body volumetric positron emission tomography/computed tomography parameters in treatment naive colorectal cancer patients with liver metastases

PURPOSE

The present study aimed to predict the prognostic role of quantitative 18 F-fluorodeoxyglucose PET/computed tomography parameters such as maximum standardized uptake value (SUV max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) obtained from primary tumor, lymph node metastases, and liver metastasis (LM) in patients with colorectal LM (CLM).

MATERIAL AND METHOD

The research was designed as a retrospective study and 66 patients with CLM were enrolled between January 2017 and December 2018. Primary tumor SUV max (PSUV max ), liver SUV max (LSUV max ), and lymph node SUV max (LnSUV max ) values obtained from the primary tumor, liver, and lymph nodes were recorded. In addition, total MTV (TMTV) and total TLG (TTLG) values were obtained by summing the values obtained from the primary tumor (PMTV and PTLG), lymph nodes (LnMTV and LnTLG), and liver (LMTV and LTLG). Univariate and multivariate Cox regression analysis was used to measure the effects of prognostic variables on mortality and survival.

RESULT

In univariate Cox regression analysis, PMTV ( P  = 0.001), LnMTV ( P  = 0.008), LnTLG ( P  = 0.008), LnSUV max ( P  = 0.047), and TTLG ( P  = 0.038) were identified as prognostic factors for overall survival. No statistically significant relationship was found between MTV and TLG values of LM and overall survival. In multivariate analysis, PMTV ( P  = 0.022) was identified as an independent prognostic factor.

CONCLUSION

In conclusion, our study demonstrated that the PMTV value used in evaluating treatment-naive patients diagnosed with CLM is an independent prognostic factor for survival. Our results need to be confirmed with more studies involving more patients.

The Usefulness of Total Tumor Volume as a Prognostic Factor and in Selecting the Optimal Treatment Strategy of Chemotherapeutic Intervention in Patients with Colorectal Liver Metastases

BACKGROUND

Few reports have discussed the association between total tumor volume (TTV) and prognosis in patients with colorectal liver metastases (CRLM). The present study aimed to evaluate the usefulness of TTV for predicting recurrence-free survival and overall survival (OS) in patients receiving initial hepatic resection or chemotherapy, and to investigate the value of TTV as an indicator for optimal treatment selection for patients with CRLM.

PATIENTS AND METHODS

This retrospective cohort study included patients with CRLM who underwent hepatic resection (n = 93) or chemotherapy (n = 78) at the Kobe University Hospital. TTV was measured using 3D construction software and computed tomography images.

RESULTS

A TTV of 100 cm3 has been previously reported as a significant cut-off value for predicting OS of CRLM patients receiving initial hepatic resection. For patients receiving hepatic resection, the OS for those with a TTV ≥ 100 cm3 was significantly reduced compared with those with a TTV < 100 cm3. For patients receiving initial chemotherapy, there were no significant differences between the groups divided according to TTV cut-offs. Regarding OS of patients with TTV ≥ 100 cm3, there was no significant difference between hepatic resection and chemotherapy (p = 0.160).

CONCLUSIONS

TTV can be a predictive factor of OS for hepatic resection, unlike for initial chemotherapy treatment. The lack of significant difference in OS for CRLM patients with TTV ≥ 100 cm3, regardless of initial treatment, suggests that chemotherapeutic intervention preceding hepatic resection may be indicated for such patients.

Prognostic Significance of Pretreatment 18F-FDG PET/CT Volumetric Parameters in Patients With Colorectal Liver Metastasis: A Systematic Review and Meta-analysis

PURPOSE

Colorectal liver metastasis (CRLM) remains a clinical challenge due to the lack of reliable prognostic parameters. We performed a systematic review and meta-analysis of the prognostic value of pretreatment 18F-FDG PET/CT volumetric parameters for hepatic metastatic lesions (HMLs) in patients with CRLM.

METHODS

A systematic search was performed using the following combination of keywords: CRLM, FDG, PET, and prognosis. The inclusion criteria were studies using 18F-FDG PET/CT as an imaging tool before treatment, including volumetric parameters (metabolic tumor volume [MTV] and total lesion glycolysis [TLG]) for HMLs, and reported survival data. Event-free survival and overall survival were considered as survival markers. The effect on survival was determined by the effect size of the hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Our systematic search identified 668 records, and a total of 10 studies comprising 494 patients were included. The pooled HRs of the prognostic value of the MTV and TLG for event-free survival were 1.55 (95% CI, 1.21-1.99; P = 0.0006) and 1.64 (95% CI, 1.23-2.19; P = 0.0009) with significance, respectively. The pooled HRs of the prognostic value of the MTV and TLG for overall survival were 1.72 (95% CI, 1.32-2.23; P < 0.0001) and 2.09 (95% CI, 1.48-2.96; P < 0.0001) with significance, respectively.

CONCLUSIONS

Higher MTV and TLG for HMLs before treatment were identified as worse prognostic parameters in patients with CRLM. The MTV and TLG of 18F-FDG PET/CT could be used as predictors of prognosis.

Preoperative 18F-FDG PET/computed tomography predicts survival following resection for colorectal liver metastases

OBJECTIVE

The liver is the most frequent metastatic site from colorectal cancer and about 20% of these patients are treated by surgical resection. However, the 5-year disease-free survival (DFS) following resection is only about 25% and 5-year overall survival (OS) about 38%. The aim of the study was to evaluate the ability of metabolic and volumetric measurements from fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) prior to resection for colorectal liver metastases (CLM) to predict survival.

PATIENTS AND METHODS

Preoperative F-FDG PET/CT examinations were assessed. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum, mean and peak standardized uptake values and tumor to background ratio, were obtained for all CLM. Cutoff values were determined for each of these parameters by using receiver operating characteristic analysis dividing the patients into two groups. DFS, liver recurrence-free survival (LRFS), OS and cancer-specific survival (CSS) for patients over and under the cutoff value were compared by using the Kaplan-Meier method and log-rank test.

RESULTS

Twenty-seven patients who underwent F-FDG PET/CT prior to resection for CLM were included. Low values of total MTV and TLG were significantly correlated to improved 5-year LRFS (P = 0.016 and 0.006) and CSS (P = 0.034 and 0.008). Patients who developed liver recurrence had significantly higher total MTV and TLG compared to patients without liver recurrence (P = 0.042 and 0.047).

CONCLUSION

Low values of total MTV and TLG were significantly correlated to improved LRFS and CSS and may improve the risk stratification of patients considered for resection for CLM.

Current state of the art imaging approaches for colorectal liver metastasis

One of the most common cancers worldwide, colorectal cancer (CRC) has been associated with significant morbidity and mortality and therefore represents an enormous burden to the health care system. Recent advances in CRC treatments have provided patients with primary and metastatic CRC a better long-term prognosis. The presence of synchronous or metachronous metastasis has been associated, however, with worse survival. The most common site of metastatic disease is the liver. A variety of treatment modalities aimed at targeting colorectal liver metastases (CRLM) has been demonstrated to improve the prognosis of these patients. Loco-regional approaches such as surgical resection and tumor ablation (operative and percutaneous) can provide patients with a chance at long-term disease control and even cure in select populations. Patient selection is important in defining the most suitable treatment option for CRLM in order to provide the best possible survival benefit while avoiding unnecessary interventions and adverse events. Medical imaging plays a crucial role in evaluating the characteristics of CRLMs and disease resectability. Size of tumors, proximity to adjacent anatomical structures, and volume of the unaffected liver are among the most important imaging parameters to determine the suitability of patients for surgical management or other appropriate treatment approaches. We herein provide a comprehensive overview of current-state-of-the-art imaging in the management of CRLM, including staging, treatment planning, response and survival assessment, and post-treatment surveillance. Computed tomography (CT) scan and magnetic resonance imaging (MRI) are two most commonly used techniques, which can be used solely or in combination with functional imaging modalities such as positron emission tomography (PET) and diffusion weighted imaging (DWI). Providing up-to-date evidence on advantages and disadvantages of imaging modalities and tumor assessment criteria, the current review offers a practice guide to assist providers in choosing the most suitable imaging approach for patients with CRLM.

The metabolic clinical risk score as a new prognostic model for surgical decision-making in patients with colorectal liver metastases

BACKGROUND AND OBJECTIVES

Selection for surgery in patients with colorectal liver metastases (CRLM) remains inaccurate. We evaluated if CRLM baseline metabolic characteristics, assessed by [18]F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸ FDG-PET/CT), could predict postoperative outcomes.

METHODS

In a retrospective series of patients undergoing surgery for CRLM, we defined two groups: the long-term survival (LTS) and early relapse (ER) groups, where the postoperative recurrence-free survivals were ≥5 years or <1 year, respectively. We analyzed the patients in whom baseline ¹⁸ FDG-PET/CT was available. Clinicopathologic parameters, clinical risk score (CRS), and baseline ¹⁸ FDG-PET/CT characteristics were compared between LTS and ER groups. A metabolic CRS (mCRS) was implemented, adding one point to the standard five-point CRS when the highest tumor standardized uptake values (SUV_max )/normal liver mean SUV (SUV_mean(liver) ) ratios were >4.3, defining low- and high-risk mCRS by scores of 0 to 2 and 3 to 6, respectively.

RESULTS

From a series of 450 patients operated for CRLM (mean follow-up of 58 months), we included for analysis 23 and 30 patients in the LTS and ER groups, respectively. Clinicopathologic parameters and CRS were similar in the LTS and ER groups. Median SUV_max /SUV_mean(liver) ratios were higher in ER vs LTS patients (4.2 and 2.8, P = .008, respectively). mCRS was increased in ER patients (P = .024); 61% of LTS patients had low-risk mCRS and 73% of the ER patients had high-risk mCRS (P = .023).

CONCLUSIONS

¹⁸ FDG-PET/CT characteristics combined with traditional CRS may represent a new tool to improve selection for surgery in patients with CRLM.

Prognostic significance of 18F-FDG PET/CT in patients with colorectal cancer liver metastases after hepatectomy

INTRODUCTION

Colorectal cancer liver metastasis (CRLM) can be cured with surgery. To improve survival, optimal selection of CRLM patients should be done cautiously, which may be facilitated by preoperative [F-18] fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT).

METHODS

A total of 245 patients with CRLM between February 2007 and January 2015 were retrospectively studied. All clinical variables, pathological data, and various PET/CT parameters were correlated with disease-free survival (DFS) and overall survival (OS). Metastatic tumor maximum standardized uptake value (SUVmax) and normal liver mean SUV (SUVmean) ratio was selected for group classification.

RESULTS

The median DFS in months were 24.5 months and median OS were 41.7 months. Multivariate analysis found an increased risk of worse prognosis in DFS for primary colon cancer T3∼T4, N2 stage, neoadjuvant chemotherapy, synchronous metastasis, multiple metastatic tumor number and metastatic tumor SUVmax/normal liver SUVmean ratio >4.3. The DFS rate of each group classified by SUV ratio was 58.1%, 39.0%, and 33.6% vs. 39.3%, 20.8%, and 15.8% at 1, 3, and 5 years (p = 0.017). Patients with multiple tumors and SUV ratio of >4.3 showed worst survival (OS rate: 74.2%, 41.5%, and 24.2%, p = 0.001 at 1, 3, and 5 years, respectively).

CONCLUSIONS

PET/CT variables can be a valuable prognostic factor in patients with CRLM for the prediction of recurrence. Preoperative PET/CT may improve risk stratification and optimize outcomes of patients with CRLM.