Relationship between (18)F-fluorodeoxyglucose uptake in primary lesions and clinicopathological characteristics of esophageal squamous cell carcinoma patients

The role of primary tumor SUVmax in the diagnosis of invasion depth: a step toward clinical T2N0 esophageal cancer

Background

The controversy regarding optimal clinical T2N0 esophageal cancer treatment ultimately stems from the clinical staging modalities’ inaccuracy. Because most inaccuracies lie in clinical T2 to pathological T1, it is vital to discriminate whether the muscularis propria is invaded.

Methods

We investigated the association between the primary tumor maximal standard uptake value (SUVmax), and the pathological features and overall survival. We attempted to construct a discriminative model through logistic regression analysis.

Results

A total of 140 cN0 esophageal squamous cell carcinoma (ESCC) patients were enrolled. Primary tumor SUVmax differed significantly in paired pathological T categories (P<0.05), but not pT2 vs. pT3 (P=0.648). Age (≤65 vs. >65), biopsy differentiation grades (well or moderately vs. poorly vs. unknown), and primary tumor SUVmax (continuous) were independent risk factors for invasion depth. Subsequently, the age categories, the biopsy differentiation grade categories, and the primary tumor SUVmax categories (≤7.4 vs. >7.4) were included in the logistic regression analysis to construct a discriminative model, showing a good performance in discriminating pT2–3 vs. pT1 in terms of accuracy 87.1%, sensitivity 93.6%, specificity 73.9%, and area under the curve (AUC) 0.887 [95% confidence interval (CI): 0.822 to 0.951]. Of these factors, biopsy differentiation grades and primary tumor SUVmax showed significant differences in overall survival (P<0.05), while the age categories did not.

Conclusions

The novel baseline model comprised of age, biopsy differentiation grades, and primary tumor SUVmax provide much discriminative performance in determining whether the muscularis propria is invaded. Further studies are necessary to validate the findings and guide clinical practice for cT2N0 esophageal cancer.

FDG PET using SUVmax for preoperative T-staging of esophageal squamous cell carcinoma with and without neoadjuvant chemoradiotherapy

BACKGROUND

Accurate T-staging is pivotal for predicting prognosis and selecting appropriate therapies for esophageal squamous cell carcinoma (ESCC). The diagnostic performance of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for its T-staging is uncertain. We investigated use of FDG PET/CT for preoperative T-staging of patients with ESCC.

METHODS

Patients with ESCC given preoperative FDG PET/CT scans, either with (CRT[+] group) or without (CRT[-] group) neoadjuvant chemoradiotherapy, were retrospectively reviewed. Maximal standardized uptake value (SUVmax) of the primary tumors on FDG PET/CT scans were measured, and histopathological results were used as the reference standard. The associations between pathological T-stage and potential factors of age, tumor location, tumor grade, tumor size, and tumor SUVmax were analyzed. The cut-off levels of SUVmax for predicting different T-stages and for residual viable tumors after neoadjuvant chemoradiotherapy were determined using receiver operating characteristic analyses.

RESULTS

We enrolled 103 patients (45 in the CRT[-] group; 58 in the CRT[+] group). SUVmax, an independent predictive factor, positively correlated with the pathological T-stage in both groups (CRT[-] group: ρ = 0.736, p < 0.001; and CRT[+] group: ρ = 0.792, p < 0.001). The overall accuracy of the PET/CT with thresholded SUVmax for predicting the pathological T-stage was 73.3% in the CRT[-] group (SUVmax of T0: 0-1.9, T1: 2.0-4.4, T2: 4.5-6.5, T3: 6.6-13.0, T4: >13.0) and 67.2% in the CRT[+] group (SUVmax of T0: 0-3.4, T1: 3.5-3.9, T2: 4.0-5.5, T3: 5.6-6.2, T4: > 6.2). For CRT[-] group, the accuracy using an SUVmax cut-off of 4.4 to differentiate early (T0-1) from locally advanced disease (T2-4) was 82.2% (95% CI, 71.1-93.4%). For CRT[+] group, the accuracy using an SUVmax cut-off of 3.4 to predict residual viable tumors (non-T0) after completion of chemoradiotherapy was 82.8% (95% CI, 73.0-92.5%).

CONCLUSIONS

The FDG avidity of a primary esophageal tumor significantly positively correlated with the pathological T-stage. PET/CT with thresholded SUVmax was useful for predicting T-stage and differentiating residual viable tumors.

Usefulness of positron emission tomography-computed tomography in pre-operative evaluation of intra-thoracic esophageal cancer

Background

The purpose of the study was to clarify the usefulness of positron emission tomography-computed tomography (PET-CT) for pre-operative evaluation of intra-thoracic esophageal cancer, especially in terms of regional lymph node status.

Methods

Medical records of 93 consecutive cases from July 2007 to October 2012 were retrospectively reviewed. All patients underwent curative and complete esophagectomies for intra-thoracic esophageal cancer. We compared pre-operative maximum standard uptake values (SUVmax) of esophageal tumors and regional lymph nodes (LN) with other variables (chronic obstructive pulmonary disease, history of previous other primary cancer, gender, differentiation, and neoadjuvant therapy). In addition, the SUVmax of tumors and LNs were analyzed with pathologic findings.

Results

There was no significant difference of each tumor and LN SUVmax according to factors including chronic lung disease, age, history of previous other cancer, differentiation, and gender. Pre-operative evaluations by PET-CT were not accurate (tumor sensitivity 76.4%, specificity 25%; LN sensitivity 45.2%, specificity 54.8%). Receiver operating characteristic analysis showed that LN metastasis could not be appropriately diagnosed with SUVmax (P = 0.871). There was no difference in SUVmax between pathologically positive and negative LN subgroups. Tumor SUVmax correlated with the progression of esophageal cancer in patients without neoadjuvant therapy (P < 0.001). However, LN SUVmax had no correlation with overall pathologic stage. After neoadjuvant therapy, there were significant decreases in SUVmax in both pathologically positive and negative LN subgroups (P = 0.043, P = 0.008).

Conclusion

 Surgery should not be withheld in N-stage according to PET-CT findings and carefully considered in conjunction with other conditions.