A prospective evaluation of staging and target volume definition of lymph nodes by 18FDG PET/CT in patients with squamous cell carcinoma of thoracic esophagus

Lymph Node Response to Neoadjuvant Chemotherapy as an Independent Prognostic Factor in Metastatic Esophageal Cancer

OBJECTIVE

The aim of this study was to evaluate primary tumor (PT) and lymph node (LN) responses to neoadjuvant chemotherapy (NACT) for predicting long-term survival in patients with metastatic esophageal cancer (EC).

BACKGROUND

In evaluating NACT responses in patients with EC, imaging modalities typically target the PT in the esophagus, which is unmeasurable. Targeting measurable organs, like positive LNs, might provide more accurate assessments.

METHODS

We enrolled 251 patients with EC and clinically positive LNs that underwent curative resections, after triplet NACT. The percent reduction of PT area was measured with bidimensional computed tomography. The LN response was defined as the percent reduction of the sum of the short diameters in all positive LNs.

RESULTS

NACT reduced PTs and LNs by (median, range) 58.0% (38.1-94.9) and 34.5% (46.2-68.2), respectively. Based on the receiver-operating characteristic analyses for predicting a histological response and a 10% stepwise cutoff analyses of recurrence-free survival (RFS), responder/nonresponder cutoff values were ≥60% for PT area reductions and ≥30% for LN size reductions. 39.6% of patients showed discordant PT and LN responses. Compared with PT-responders, LN-responders had significantly less advanced pN (P < 0.0001) and pM (P = 0.015) in addition to less advanced pT (P < 0.0001) and better histological responses (P < 0.0001), and closer correlations to lymphatic, distant metastases and dissemination. A multivariate analysis of RFS identified 2 independent prognostic factors: the LN response [hazard ratio (HR) = 2.51, 95% confidence interval (CI) = 1.63-3.95, P < 0.0001] and the pN (HR = 2.72, 95% CI = 1.44-5.64, P = 0.0016), but not the PT response.

CONCLUSIONS

The LN response to NACT predicted long-term survival more precisely than the PT response in patients with metastatic EC.

Nodal FDG-PET/CT uptake influences outcome and relapse location among esophageal cancer patients submitted to chemotherapy or radiochemotherapy

PURPOSE

Our aim was investigate whether lymph node uptake is associated with survival and regional relapses, and relapse patterns with respect to the radiotherapy fields in esophageal cancer (EC).

MATERIALS AND METHODS

The FDG-PET/CT image datasets of 56 patients were analyzed. All patients underwent definitive or neoadjuvant radio/chemotherapy (RCT). All patients suffering from persistent or recurrent local/regional-only disease after RCT were considered for salvage resection. Patients with adenocarcinoma without metastatic disease were considered for planned resection (usually within 3 months of treatment).

RESULTS

Patients with PET-positive lymph nodes before treatment had a worse overall survival and a shorter disease-free survival than those without PET-positive nodes. They also had worse node and metastatic relapse-free survival. N2 patients had statistically significant poorer outcomes than N1-N0 patients and a better survival if the involved nodes were closer to the esophageal tumor. Involved node location by PET/CT also affected global, nodal and metastatic relapses. In addition, an increment of SUVmax value increased relative risk of death and increased relative risk of node and metastatic relapses. The first site of relapse was metastatic recurrence and, second, local recurrence. The most frequent were "in-field" loco/regional recurrence. We observed a relationship between patients classified-N1 and out-field nodal recurrence (p = 0.024), and between patients-N2 and in-field nodal recurrence. The number of PET-positive nodes was an independent significant prognostic predictor for relapse (p < 0.001).

CONCLUSION

Our study shows that only FDG-PET/CT can provide prognostic information in EC. Nodal PET/CT uptake influences outcome and relapse location among EC patients.

Systematic review and meta-analysis of the accuracy of 18F-FDG PET/CT for detection of regional lymph node metastasis in esophageal squamous cell carcinoma

Background

We performed a systematic review and meta-analysis to assess the accuracy of 18F-fluorodeoxyglucose positron emission tomography with computer tomography (18F-FDG PET/CT) for detection of regional lymph node metastasis in esophageal squamous cell carcinoma in per-patient and per-nodal station basis.

Methods

Electronic databases were researched for studies assessing the sensitivity and specificity of PET/CT to detect the regional lymph node metastasis published between January 2006 and December 2017 on esophageal squamous cell carcinoma. STATA software was performed to assess the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odd ratio (DOR) and summary receiver operating characteristic (SROC) curve. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and Deeks' Funnel Plot Asymmetry Test were performed to evaluate the study quality and publication bias of included studies.

Results

Nineteen studies were eligible for meta-analysis, comprising 1,089 patients with esophageal cancer who underwent 18F-FDG PET/CT before surgery. According to the content of the article, we divided the selected studies into per-patient basis group and per-nodal basis group (one of the articles was involved in both groups). For the per-nodal station basis group (12 studies, 5,681 stations), the pooled sensitivity and specificity estimates of 18F-FDG PET/CT for detecting regional lymph node metastasis were 66% [95% confidence interval (CI): 51-78%] and 96% (95% CI: 92-98%), respectively. The corresponding values on a per-patient basis group (8 studies; 506 patients) were 65% (95% CI: 49-78%) and 81% (95% CI: 69-89%) in sensitivity and specificity, respectively.

Conclusions

Overall, 18F-FDG PET/CT have a moderate to low sensitivity and a high to moderate specificity for detection of regional nodal metastasis in esophageal cancer. Therefore, since the false rate is considerable, extending the extent of lymph node dissection or radiotherapy target volume is necessary after diagnosis of regional nodal metastasis by 18F-FDG PET/CT.

Consensus and controversies on dose and target volume of three-dimensional conformal radiotherapy for esophageal carcinoma

Radiotherpay is the mainstay treatment for esophageal cancer. Three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy have been widely applied in routine clinical work, because they can raise the target dose and reduce the injury to normal tissue, and therefore raise the five-year survival rate to > 20%. In recent years, a number of studies on 3DCRT have been carried out with regard to radiation dose, target volume contour, and preventive lymph node irradiation, and this article will summarize these issues.

Potential impact of (18)FDG-PET/CT on surgical approach for operable squamous cell cancer of middle-to-lower esophagus

Background

Fluorodeoxyglucose-positron emission tomography (PET)/computed tomography (CT) is reported to have a significant advantage over CT for staging esophageal cancer (EC). However, whether PET/CT may play a useful role in guiding surgical approach remains undetermined.

Methods

Patients with potentially resectable squamous cell EC were randomized into either PET/CT group or CT group. The surgical data and survival outcomes were compared.

Results

Compared to the CT group, the right-sided approach was more frequently used (42.6% versus 25.5%, P=0.065) in the PET/CT group in order to allow surgical access to radiographically suspicious lymph nodes inaccessible from the left, thus enabling the removal of more involved lymph nodes (2.83 versus 1.76; P=0.039) as well as their stations (1.65 versus 1.08; P=0.042). Although the overall survival between the two groups was similar, the PET/CT group had a longer disease-free survival (DFS) than the CT group (27.1 months versus 18.9 months; P=0.019), especially in the subgroup of node-positive patients (22.5 months versus 13.5 months; P=0.02). Preoperative imaging arm was the only prognostic factor found to independently influence DFS.

Conclusion

For patients with middle-to-lower EC, surgical approaches directed by PET/CT may increase the likelihood of complete resection and affect DFS.

Prognostic value of FDG PET/CT in head and neck squamous cell carcinomas

Introduction

The purpose of this study was to evaluate the use of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to identify the presence of cervical lymph nodes metastases and extracapsular spread with histologic correlations in head and neck squamous cell carcinoma.

Methods

The medical records of 54 patients who underwent ¹⁸F-FDG PET/CT for head and neck squamous cell carcinoma before surgery were reviewed. Receiver operating characteristic (ROC) analysis was performed to differentiate patients with cervical lymph node metastasis from those without lymph node metastasis. The same statistical analysis was done to differentiate cervical lymph nodes with extracapsular spread from those without extracapsular spread.

Results

Metastatic disease was diagnosed histologically in 49% (26 of 54) of the patients. Extracapsular spread was present in ten of the 54 patients (19%). When ROC curve analysis and maximum standardized uptake (SUV_max) values were used to detect cervical lymph node metastasis, the area under the ROC curve was 0.96 and the optimal cutoff value for SUV_max was 4.05 based on ROC curve analysis. The sensitivity and specificity of SUV_max for the detection of cervical lymph node metastasis using this cutoff point were 92% and 88%, respectively. When ROC curve analysis and SUV_max values were used in order to detect extracapsular spread, the area under the ROC curve was 0.86, and the optimal cutoff value for SUV_max was 4.15 based on ROC curve analysis. Using this cutoff value, the sensitivity and specificity of SUV_max for the detection of extracapsular spread were 83% and 88%, respectively.

Conclusion

In our study, a median ¹⁸F-FDG PET/CT SUV_max cutoff value of 4.15 was found to be related with cervical lymph node metastasis and extracapsular spread in patients with head and neck cancer.

The impact of PET/CT on the management of hepatic and extra hepatic metastases from gastrointestinal cancers

PURPOSE

To investigate the efficacy of positron emission tomography/computed tomography (PET/CT) in detection and management of hepatic and extrahepatic metastases from gastrointestinal cancers.

MATERIALS AND METHODS

Between February 2008 and July 2010, patients histopathologically diagnosed with gastrointestinal cancer and showing suspected metastasis on CT screening were subsequently evaluated with PET/CT. All patients were subgrouped according to histopathological origin and localization of the primary tumor. Localization of gastrointestinal cancers was further specified as lower gastrointestinal system (GIS), upper GIS, or hepato-pancreato-biliary (HPB). Both accuracy and impact of CT and PET/CT on patient management were retrospectively evaluated.

RESULTS

One hundred and thirteen patients diagnosed histopathologically with gastrointestinal cancers were retrospectively evaluated. Seventy-nine patients had adenocarcinoma and 34 patients other gastrointestinal tumors. Forty-one patients were in the upper GIS group, 30 patients in the HPB group, and 42 patients in the lower GIS group. Evaluation the diagnostic performance of PET/CT for suspected metastasis according to histopathological origin of the tumor, revealed that the sensitivity of PET/CT - although statistically not different - was higher in adenocarcinomas than in non-adenocarcinomas (90% (95% CI, 0.78-0.96) vs. 71.4% (95% CI, 0.45-0.88), P=0.86). The specificity was not significantly different (85.7% (95% CI, 0.70-0.93) vs. 85% (95% CI, 0.63-0.94), P=1.00). In the overall patient group; CT was significantly more sensitive than PET/CT for detection of hepatic metastases (94.7% vs. 78.9%, P=0.042), whereas PET/CT was significantly more specific than CT (48% vs. 98.7%, P<0.001). In subgroup analysis, sensitivity was not significantly different (P>0.05) but specificity was significantly higher in PET/CT than CT (P<0.05). The specificity of PET/CT was highest in upper GIS (100%) and HPB (100%) subgroups. In the overall patient group; for detection of extrahepatic metastasis, the sensitivity of CT (75%) and PET/CT (87.5%) showed no significant difference (P=0.437). However, PET/CT was significantly more specific than CT (88.7% vs. 70.4%, P=0.007). In subgroup analysis, no significant difference was found between CT and PET/CT either in sensitivity or in specificity (P>0.05). The specificity of PET/CT was highest in the lower GIS subgroup (93%). The management of 45 patients (39.8%) was revised after PET/CT evaluation.

CONCLUSIONS

PET/CT has a higher specificity than CT in detecting suspected hepatic and extrahepatic metastases of gastrointestinal cancers, and has an impact of nearly 40% on changing patient management strategies.

Simultaneous modulated accelerated radiation therapy for esophageal cancer: A feasibility study

AIM: To establish the feasibility of simultaneous modulated accelerated radiation therapy (SMART) in esophageal cancer (EC).

METHODS: Computed tomography (CT) datasets of 10 patients with upper or middle thoracic squamous cell EC undergoing chemoradiotherapy were used to generate SMART, conventionally-fractionated three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (cf-IMRT) plans, respectively. The gross target volume (GTV) of the esophagus, positive regional lymph nodes (LN), and suspected lymph nodes (LN±) were contoured for each patient. The clinical target volume (CTV) was delineated with 2-cm longitudinal and 0.5- to 1.0-cm radial margins with respect to the GTV and with 0.5-cm uniform margins for LN and LN(±). For the SMART plans, there were two planning target volumes (PTVs): PTV66 = (GTV + LN) + 0.5 cm and PTV54 = CTV + 0.5 cm. For the 3DCRT and cf-IMRT plans, there was only a single PTV: PTV60 = CTV + 0.5 cm. The prescribed dose for the SMART plans was 66 Gy/30 F to PTV66 and 54 Gy/30 F to PTV54. The dose prescription to the PTV60 for both the 3DCRT and cf-IMRT plans was set to 60 Gy/30 F. All the plans were generated on the Eclipse 10.0 treatment planning system. Fulfillment of the dose criteria for the PTVs received the highest priority, followed by the spinal cord, heart, and lungs. The dose-volume histograms were compared.

RESULTS: Clinically acceptable plans were achieved for all the SMART, cf-IMRT, and 3DCRT plans. Compared with the 3DCRT plans, the SMART plans increased the dose delivered to the primary tumor (66 Gy vs 60 Gy), with improved sparing of normal tissues in all patients. The D_max of the spinal cord, V₂₀ of the lungs, and D_mean and V₅₀ of the heart for the SMART and 3DCRT plans were as follows: 38.5 ± 2.0 vs 44.7 ± 0.8 (P = 0.002), 17.1 ± 4.0 vs 25.8 ± 5.0 (P = 0.000), 14.4 ± 7.5 vs 21.4 ± 11.1 (P = 0.000), and 4.9 ± 3.4 vs 12.9 ± 7.6 (P = 0.000), respectively. In contrast to the cf-IMRT plans, the SMART plans permitted a simultaneous dose escalation (6 Gy) to the primary tumor while demonstrating a significant trend of a lower irradiation dose to all organs at risk except the spinal cord, for which no significant difference was found.

CONCLUSION: SMART offers the potential for a 6 Gy simultaneous escalation in the irradiation dose delivered to the primary tumor of EC and improves the sparing of normal tissues.

The application of functional imaging techniques to personalise chemoradiotherapy in upper gastrointestinal malignancies

Functional imaging gives information about physiological heterogeneity in tumours. The utility of functional imaging tests in providing predictive and prognostic information after chemoradiotherapy for both oesophageal cancer and pancreatic cancer will be reviewed. The benefit of incorporating functional imaging into radiotherapy planning is also evaluated. In cancers of the upper gastrointestinal tract, the vast majority of functional imaging studies have used (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Few studies in locally advanced pancreatic cancer have investigated the utility of functional imaging in risk-stratifying patients or aiding target volume definition. Certain themes from the oesophageal data emerge, including the need for a multiparametric assessment of functional images and the added value of response assessment rather than relying on single time point measures. The sensitivity and specificity of FDG-PET to predict treatment response and survival are not currently high enough to inform treatment decisions. This suggests that a multimodal, multiparametric approach may be required. FDG-PET improves target volume definition in oesophageal cancer by improving the accuracy of tumour length definition and by improving the nodal staging of patients. The ideal functional imaging test would accurately identify patients who are unlikely to achieve a pathological complete response after chemoradiotherapy and would aid the delineation of a biological target volume that could be used for treatment intensification. The current limitations of published studies prevent integrating imaging-derived parameters into decision making on an individual patient basis. These limitations should inform future trial design in oesophageal and pancreatic cancers.

Intensity modulated radiotherapy (IMRT) with concurrent chemotherapy as definitive treatment of locally advanced esophageal cancer

Background

To report our experience with increased dose intensity-modulated radiation and concurrent systemic chemotherapy as definitive treatment of locally advanced esophageal cancer.

Patients and methods

We analyzed 27 consecutive patients with histologically proven esophageal cancer, who were treated with increased-dose IMRT as part of their definitive therapy. The majority of patients had T3/4 and/or N1 disease (93%). Squamous cell carcinoma was the dominating histology (81%). IMRT was delivered in step-and-shoot technique in all patients using an integrated boost concept. The boost volume was covered with total doses of 56-60 Gy (single dose 2-2.14 Gy), while regional nodal regions received 50.4 Gy (single dose 1.8 Gy) in 28 fractions. Concurrent systemic therapy was scheduled in all patients and administered in 26 (96%). 17 patients received additional adjuvant systemic therapy. Loco-regional control, progression-free and overall survival as well as acute and late toxicities were retrospectively analyzed. In addition, quality of life was prospectively assessed according to the EORTC QLQs (QLQ-OG25, QLQ-H&N35 and QLQ-C30).

Results

Radiotherapy was completed as planned in all but one patient (96%), and 21 patients received more than 80% of the planned concurrent systemic therapy. We observed ten locoregional failures, transferring into actuarial 1-, 2- and 3-year-locoregional control rates of 77%, 65% and 48%. Seven patients developed distant metastases, mainly to the lung (71%). The actuarial 1-, 2- and 3-year-disease free survival rates were 58%, 48% and 36%, and overall survival rates were 82%, 61% and 56%. The concept was well tolerated, both in the clinical objective examination and also according to the subjective answers to the QLQ questionnaire. 14 patients (52%) suffered from at least one acute CTC grade 3/4 toxicity, mostly hematological side effects or dysphagia. Severe late toxicities were reported in 6 patients (22%), mostly esophageal strictures and ulcerations. Severe side effects to skin, lung and heart were rare.

Conclusion

IMRT with concurrent systemic therapy in the definitive treatment of esophageal cancer using an integrated boost concept with doses up to 60 Gy is feasible and yields good results with acceptable acute and late overall toxicity and low side effects to skin, lung and heart.

Meta-analysis of 18FDG PET-CT for nodal staging in patients with esophageal cancer

BACKGROUND

We aimed to evaluate the value of (18)FDG PET-CT for detection of regional nodal metastasis in patients with esophageal cancer before surgery.

METHODS

A computer search about PET-CT original articles was conducted from January 2000 to December 2012. The reference standard was histopathologic analysis. Two reviewers independently searched articles and extracted data. Sensitivity, specificity, diagnostic odds ratio, and likelihood ratio were pooled for PET-CT using bivariate models. Summary receiver operating characteristic (SROC) curves were also used to summarize overall test performance.

RESULTS

Across all seven studies on a per-station analysis (2232 stations), the pooled sensitivity and specificity with 95% confidence interval for PET-CT were 0.62 (0.40-0.79) and 0.96 (0.93-0.98). Across all 6 studies on a per-patient analysis (245 patients), corresponding values for PET-CT were 0.55 (0.34-0.74) and 0.76 (0.66-0.83).

CONCLUSIONS

(18)FDG PET-CT had lower sensitivity and accuracy for detection of regional nodal metastasis in patients with esophageal cancer before surgery.