The role of 18F-FDG PET/CT in the evaluation of oesophageal carcinoma

18F-FDG-PET/CT to Detect Pathological Complete Response After Neoadjuvant Treatment in Patients with Cancer of the Esophagus or Gastroesophageal Junction: Accuracy and Long-Term Implications

PURPOSE

The curative strategy for patients with esophageal cancer without distant metastases consists of esophagectomy with preceding chemo(radio)therapy (CRT). In 10-40% of patients treated with CRT, no viable tumor is detectable in the resection specimen (pathological complete response (pCR)). This study aims to define the clinical outcomes of patients with a pCR and to assess the accuracy of post-CRT FDG-PET/CT in the detection of a pCR.

METHODS

Four hundred sixty-three patients with cancer of the esophagus or gastroesophageal junction who underwent esophageal resection after CRT between 1994 and 2013 were included. Patients were categorized as pathological complete responders or noncomplete responders. Standardized uptake value (SUV) ratios of 135 post-CRT FDG-PET/CTs were calculated and compared with the pathological findings in the corresponding resection specimens.

RESULTS

Of the 463 included patients, 85 (18.4%) patients had a pCR. During follow-up, 25 (29.4%) of these 85 patients developed recurrent disease. Both 5-year disease-free survival (5y-DFS) and 5-year overall survival (5y-OS) were significantly higher in complete responders compared to noncomplete responders (5y-DFS 69.6% vs. 44.2%; P = 0.001 and 5y-OS 66.5% vs. 43.7%; P = 0.001). Not pCR, but only pN0 was identified as an independent predictor of (disease-free) survival.

CONCLUSION

Patients with a pCR have a higher probability of survival compared to noncomplete responders. One third of patients with a pCR do develop recurrent disease, and pCR can therefore not be equated with cure. FDG-PET/CT was inaccurate to predict pCR and therefore cannot be used as a sole diagnostic tool to predict pCR after CRT for esophageal cancer.

Baseline and Post-treatment 18F-Fluorocholine PET/CT Predicts Outcomes in Hepatocellular Carcinoma Following Locoregional Therapy

BACKGROUND AND AIMS

¹⁸F-fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) is an emerging functional imaging technique in the diagnosis and management of hepatocellular carcinoma (HCC). The aim of this study was to assess the ability of a pre- and post-treatment ¹⁸F-FCH PET/CT to predict prognosis and treatment response in early-stage HCC.

METHODS

Patients with early- or intermediate-stage HCC planned for locoregional therapy were prospectively enrolled. Baseline demographic and tumor information was collected and baseline and post-treatment ¹⁸F-FCH PET/CT performed. Maximum standardized uptake values (SUVmax) were determined for each HCC lesion, and the difference between baseline and post-treatment SUVmax values were compared with progression-free survival outcomes.

RESULTS

A total of 29 patients with 39 confirmed HCC lesions were enrolled from a single clinical center. Patients were mostly men (89.7%) with hepatitis C or alcohol-related cirrhosis (65.5%) and early-stage disease (89.7%). Per-patient and per-lesion sensitivity of ¹⁸F-FCH PET/CT was 72.4% and 59.0%, respectively. A baseline SUVmax < 13 was associated with a superior median progression-free survival compared with an SUVmax of > 13 (17.7 vs. 5.1 months; p = 0.006). A > 45% decrease in SUVmax between baseline and post-treatment ¹⁸F-FCH PET/CT ("responders") was associated with a superior mean progression-free survival than a percentage decrease of < 45% ("non-responders," 36.1 vs. 11.6 months; p = 0.034).

CONCLUSIONS

Baseline and post-treatment ¹⁸F-FCH PET/CT predicts outcomes in early-stage HCC undergoing locoregional therapy. This technique may identify patients with an objective response post-locoregional therapy who would benefit from further therapy.

Impact of PET/CT on radiation treatment in patients with esophageal cancer: A systematic review

PURPOSE

With the advances in radiotracers, positron emission tomography/computed tomography (PET/CT) is recognized as a useful adjunct to anatomic imaging with CT, MRI and endoscopic ultrasonography (EUS). The objective of this review was to comprehensively analyze the roles of PET/CT for the radiotherapy of esophageal cancer.

METHODS

In this review, we focused on issues concerning the application of PET/CT in TNM staging, target volume delineation and response to therapy, both for the primary tumor and regional lymph nodes. Furthermore, the following questions were addressed: how does PET/CT guide appropriate treatment protocols, how does it allow accurate tumor delineation and how does it guide prognosis and future treatment decisions.

RESULTS AND CONCLUSION

For the staging of esophageal cancer, PET/CT played a crucial role in exploring distant malignant lymph nodes and metastasis with high sensitivity, specificity and accuracy. PET/CT using different radiotracer provided a serial of thresholding methods based on standardized uptake value (SUV) to assist in auto-contouring the gross tumor volume (GTV). The change in SUV may offer a potential paradigm of personalized treatment to definitive chemoradiotherapy (CRT). In total, PET/CT has sought to further optimize radiotherapy treatment planning for patients with esophageal cancer.

18F-FDG PET-CT after Neoadjuvant Chemoradiotherapy in Esophageal Cancer Patients to Optimize Surgical Decision Making

BACKGROUND

Prognosis of esophageal cancer patients can be significantly improved by neoadjuvant chemoradiotherapy (nCRT). Given the aggressive nature of esophageal tumors, it is conceivable that in a significant portion of patients treated with nCRT, dissemination already becomes manifest during the period of nCRT. The aim of this retrospective study was to determine the value and diagnostic accuracy of PET-CT after neoadjuvant chemoradiotherapy to identify patients with metastases preoperatively in order to prevent non-curative surgery.

METHODS

From January 2011 until February 2013 esophageal cancer patients deemed eligible for a curative approach with nCRT and surgical resection underwent a PET-CT after completion of nCRT. If abnormalities on PET-CT were suspected metastases, histological proof was acquired. A clinical decision model was designed to assess the cost-effectiveness of this diagnostic strategy.

RESULTS

156 patients underwent a PET-CT after nCRT. In 31 patients (19.9%) PET-CT showed abnormalities suspicious for dissemination, resulting in 17 cases of proven metastases (10.9%). Of the patients without proven metastases 133 patients were operated. In 6 of these 133 cases distant metastases were detected intraoperatively, corresponding to 4.5% false-negative results. The standard introduction of a post-neoadjuvant therapy PET-CT led to a reduction of overall health care costs per patient compared to a scenario without restaging with PET-CT ($34,088 vs. $36,490).

CONCLUSION

In 10.9% of esophageal cancer patients distant metastases were detected by standard PET-CT after neoadjuvant chemoradiotherapy. To avoid non-curative resections we advocate post-neoadjuvant therapy PET-CT as a cost-effective step in the standard work-up of candidates for surgery.

[18F]fludeoxyglucose positron emission tomography and computed tomography as a prognostic tool before liver transplantation, resection, and loco-ablative therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related death worldwide. Orthotopic liver transplantation (OLT) and resection are curative treatment options for well-selected patients with HCC, whereas loco-ablative therapy has been shown to prolong survival. Organ and treatment allocations for these patients are currently based on the number and size of tumors, as defined by the Milan criteria, and on functional capacity, and they are incorporated into the Barcelona Clinic Liver Cancer staging system and treatment strategy. Even though these staging criteria have markedly improved the outcomes of patients with HCC, they still lack accuracy in predicting the risk of tumor recurrence because they do not incorporate markers of tumor biology and behavior. Positron emission tomography (PET) and computed tomography (CT) with [(18) F]fludeoxyglucose ([(18) F]FDG) constitute an imaging modality for detecting tumor tissue that is metabolically active. Uptake of [(18) F]FDG is highly associated with tumor aggressiveness. In this review, we present the accumulating data on the use of [(18) F]FDG PET-CT as an in vivo biomarker and its predictive value in identifying patients at risk for HCC recurrence after liver transplantation, resection, or ablation. These data suggest that the introduction of [(18) F]FDG PET-CT into the imaging algorithm of patients planned for liver transplantation, resection, or ablation may improve outcomes.

False-positive finding in FDG-PET in a patient with seminoma and sarcoidosis

A 33-year-old white man with testicular cancer (seminoma) stage IIIa showed a response in mediastinal lymph node metastases after chemotherapy. However, the tumor markers increase slightly, and therefore an (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography was performed. Multiple FDG avid lesions were found in lymph node, liver and bone. The standardized uptake value (SUV) was discrete increase with a value of 2·8 to 5·7, which is more typical for inflammatory disease than a malignancy. The histological findings in a mediastinal lymph node reported a sarcoidosis, and therefore all lesions were diagnosed as a sarcoidosis. The one-year follow-up showed no further increase in tumor markers and no evidence for metastases.

Molecular mechanism of epigallocatechin-3-gallate in human esophageal squamous cell carcinoma in vitro and in vivo

Epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, has been shown to inhibit proliferation in various types of tumors. However, few studies concerning the role and mechanism of EGCG in esophageal squamous cell carcinoma are available. Therefore, the antitumor mechanism of EGCG needs to be investigated. The present study aimed to examine the antitumor effect of EGCG on the human esophageal squamous cell carcinoma cell lines, Eca-109 and Te-1, in vitro and in vivo. Cell viability was assessed using the MTT assay and tumor formation and growth in murine xenograft models with or without EGCG treatment. Cell cycle analysis and levels of reactive oxygen species (ROS) were detected using flow cytometry. Apoptosis was measured by Annexin/propidium iodide staining. Caspase-3 cleavage and vascular endothelial growth factor (VEGF) expression were detected using western blot analysis and immunohistochemistry in tumor cell lines and tumor xenografts, respectively. The results showed that EGCG inhibited proliferation in the Eca-109 and Te-1 cells in a time- and dose-dependent manner. Tumor cells were arrested in the G1 phase and apoptosis was accompanied by ROS production and caspase-3 cleavage. In a mouse model, EGCG significantly inhibited the growth of Eca-109 tumors by increasing the expression of cleaved-caspase-3 and decreasing VEGF protein levels. Taken together, the results suggest that EGCG inhibits proliferation and induces apoptosis through ROS production, caspase-3 activation, and a decrease in VEGF expression in vitro and in vivo. Furthermore, EGCG may have future clinical applications for novel approaches to treat esophageal squamous cell carcinoma.

Impact of pretreatment imaging on survival of esophagectomy after induction therapy for esophageal cancer: who should be given the benefit of the doubt?: esophagectomy outcomes of patients with suspicious metastatic lesions

PURPOSE

We examined survival of patients who underwent esophagectomy for locally advanced esophageal cancer with foci that were suspicious for metastatic disease on initial imaging but whose disease did not progress after induction chemoradiation treatment (CRT).

METHODS

The impact of pre- and posttherapy staging characteristics on survival of patients who underwent esophagectomy after CRT between 2003 and 2009 was evaluated using multivariable logistic regression. Survival of patients with and without possible metastatic disease on initial imaging was compared with the log-rank test.

RESULTS

During the study period, 71 (32%) of 220 patients who underwent CRT followed by esophagectomy had possible distant metastatic disease on initial imaging. Patients with initial suspicion of metastases had a 5-year survival of 24.8%. Overall survival of patients with and without possible metastatic disease on initial imaging was not significantly different (p = 0.4), but pretreatment positron emission tomography (PET) suggesting a liver lesion (hazard ratio [HR] 3.2, p = 0.003) predicted worse survival. Additional predictors of worse survival were clinical T4 status (HR 3.1, p = 0.001), post-CRT pathologic nodal status (HR 1.6, p = 0.04), and pathologically confirmed metastatic disease at or before resection (HR 3.1, p = 0.01). None of 10 patients with pathologic metastatic disease at resection lived longer than 2.5 years.

CONCLUSIONS

Patients with possible liver metastases on pretreatment PET and patients with confirmed metastatic disease at the time of surgery do not benefit from resection. However, patients with pretreatment imaging that shows possible metastatic disease in sites other than the liver still have reasonable long-term survival after resection.

Has integrated 18F FDG PET/CT improved staging, reduced early recurrence or increased survival in oesophageal cancer?

BACKGROUND

Survival in oesophageal cancer remains poor with high post-operative recurrence rates. PET/CT was introduced to the Three-Counties Cancer Network (3CCN) in 2006 to detect 'occult' metastatic disease not seen with conventional staging modalities. This study aims to determine whether the introduction of Integrated fluorodeoxyglucose (18F) Positron Emission Tomography (PET/CT) has changed the management, improved survival or reduced the rate of early post-operative recurrence in patients with operable oesophageal cancer.

METHODS

A retrospective review was undertaken of all patients diagnosed with oesophageal cancer in the 3CCN from 2005 to 2009. Early recurrence was defined as proven recurrence locally or at a distant site within one year of resection.

RESULTS

725 patients were identified. 200 (27.6%) patients underwent staging PET/CT. PET/CT altered treatment intent in 19 (9.5%) patients. 128 (17.7%) patients underwent oesophageal resection, 90 (70.3%) of which had a staging PET/CT. No significant difference was noted in post-operative mortality (4.4% Vs 5.3%, p = 0.8) or early recurrence where PET/CT was performed when adjusted for age, sex, stage or neo-adjuvant chemotherapy (p = 0.761, OR 1.136[95% CI 0.499-2.585]). PET/CT had no significant effect on survival (log-rank test; Chi-square 0.710, p = 0.4).

CONCLUSION

PET/CT has improved the accuracy of oesophageal cancer staging avoiding potentially unnecessary surgery. Ultimately however, its use has had no effect on early recurrence or survival rates. Inaccurate identification of occult metastatic disease prior to the introduction of staging PET/CT does not appear to be the primary cause of early recurrence in patients with oesophageal cancer.

Confirmation of histology of PET positive lymph nodes recovered by hand-video-assisted thoracoscopy surgery

PET/CT (Positron Emission Tomography-Computed Tomography) is an advanced diagnostic imaging device that combines both PET and an X-ray CT. This study evaluates the effects of PET/CT on detecting primary tumors and metastases, and looks at the therapeutic effect of minimally invasive surgery on esophageal cancer patients. Eighty patients with esophageal cancer were enrolled in the study between January, 2004 and December, 2007, who were randomly divided into two groups of 40, one of which was treated with hand-video-assisted thoracoscopy surgery (HVATS) esophagectomy and one of which was treated with conventional surgery. All patients underwent a PET/CT scan 2-3 weeks before their operation, and their cervical, thoracic and upper abdominal lymph nodes were biopsied. All the primary esophageal lesions showed high FDG uptake. The maximum standardized uptake value (SUV) was 3.78-25.64 (11.73±5.32), while the mean SUV was 3.65=16.92 (9.12±4.37). Using 2.5 as the SUV standard, all esophageal lesions were detected by PET/CT image. Of the 80 patients, 53 had lymph nodal metastases, with a total of 142 metastatic lymph nodes, which showed high FDG uptake. The maximum SUV was 2.77-14.63 (7.98±3.25), and the mean SUV was 2.31-12.84 (5.34±3.19). The visual analysis from the PET/CT scan showed a sensitivity of 86.62%, a specificity of 95.85%, a positive predictive value of 93.89%, a negative predictive value of 90.69% and an accuracy of 91.94%. The PET/CT scan showed a high sensitivity and specificity in detecting primary esophageal cancer and lymph nodal metastases. The mean post-surgery life expectancies for patients undergoing HVATS and conventional surgery are 27.93 months and 28.05 months, respectively. The two groups showed no statistically significant difference. We thus conclude that PET/CT combined with HVATS is a new choice for esophageal carcinoma patients.

Advantages of positron emission tomography-computed tomography imaging in esophageal squamous cell carcinoma

To explore the value of positron emission tomography-computed tomography (PET-CT) scan in esophageal squamous cell carcinoma (ESCC), we retrospectively summarize the results of PET-CT scan from 118 patients, with ESCC who underwent PET-CT scan in the different courses during treatment. Then, the results of PET-CT scan plus other conventional methods were analyzed to identify the value of PET-CT scan in diagnosis, staging, response evaluation, monitoring recurrence, and metastasis following treatment. It is suggested that PET-CT scan possess high value in diagnosis and gives more favorable indication in N and M staging. PET-CT scan should be translated into routine surveillance for postoperation follow up and is one of more helpful evaluators of response to chemoradiotherapy or chemotherapy.

Patterns of lymphatic drainage and lymph node involvement in esophageal cancer

The esophagus has a complex pattern of lymphatic drainage. Lymph node involvement and number of lymph node metastases are very important prognostic factors, and the newly revised TNM staging system for esophageal cancer reflects this. Knowledge of the location and nomenclature of the common nodal stations in the thorax and upper abdomen is essential for the accurate staging of these patients. PET-CT and EUS are essential in the routine staging of esophageal cancer patients. The aim of this pictorial review is to present the nodal stations, nomenclature and location of regional lymph nodes in esophageal cancer using PET-CT and EUS images from selected patient cases. We will review the EUS and PET-CT imaging for a number of patients with esophageal cancer, using cases which highlight the advantages and diagnostic pitfalls for these imaging modalities.

Comparative study between endoscopic ultrasonography and positron emission tomography-computed tomography in staging patients with esophageal squamous cell carcinoma

Treatment strategy of esophageal cancer mainly depends on accurate staging. At present, no single ideal staging modality is superior to another in preoperative tumor-node-metastasis (TNM) staging of patients with esophageal cancer. We aimed to investigate the efficacy of endoscopic ultrasonography (EUS) and positron emission tomography-computed tomography (PET-CT) for staging of esophageal cancer. We retrospectively studied 118 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy with or without neoadjuvant chemoradiotherapy (CRT) over a near 3-year period between January 2005 and November 2008 at a tertiary hospital in Taiwan. Patients were separated into two groups: without neoadjuvant CRT (group 1, n= 28) and with CRT (group 2, n= 90). Medical records of demographic data and reports of EUS and PET-CT of patients before surgery were reviewed. A database of clinical staging by EUS and PET-CT was compared with one of pathological staging. The accuracies of T staging by EUS in groups 1 and 2 were 85.2% and 34.9%. The accuracies of N staging by EUS in groups 1 and 2 were 55.6% and 39.8%. The accuracies of T and N staging by means of PET-CT scan were 100% and 54.5% in group 1, and were 69.4% and 86.1% in group 2, respectively. In group 2, 38 of 90 patients (42.2%) achieved pathologic complete remission. Among them, two of 34 (5.9%) and 12 of 17 (70.6%) patients were identified as tumor-free by post-CRT EUS and PET-CT, respectively. EUS is useful for initial staging of esophageal cancer. PET-CT is a more reliable modality for monitoring treatment response and restaging. Furthermore, the accuracy of PET-CT with regard to N staging is higher in patients who have undergone CRT than those who have not.

Non-small cell lung carcinoma: accuracy of PET/CT in determining the size of T1 and T2 primary tumors

OBJECTIVE

The purpose of this study was to compare the measurements of primary T1 and T2 non-small cell lung carcinomas (NSCLCs) at PET/CT to determine which modality has the more accurate correlation with the histologic findings.

MATERIALS AND METHODS

A retrospective study was performed with the images of 59 patients who underwent surgical resection of T1 and T2 NSCLC and preoperative PET/CT. The maximum measurement of the primary lung tumor was recorded on the PET and unenhanced CT (soft-tissue and lung windows) scans in the largest plane and compared with the maximum dimensions of the histologic specimen.

RESULTS

PET and CT measurements both had high concordance with the histologic measurements. CT soft-tissue window measurements had the highest concordance with histologic measurements, but PET had a smaller SD. The greatest linear correlation was between CT soft-tissue and CT lung window measurements, indicating they can be used interchangeably. Outliers were found in both the PET (four tumors) and the two CT (five tumors) groups owing to low (18)F-FDG uptake due to tumor type and surrounding consolidation, respectively.

CONCLUSION

PET is better for delineating primary NSCLC if surrounding collapse or consolidation is present. Otherwise, CT with either soft-tissue or lung windows is accurate. Owing to low FDG accumulation, CT is more accurate for assessment of alveolar cell carcinoma.

Production of hyperpolarized [1,4-13C2]malate from [1,4-13C2]fumarate is a marker of cell necrosis and treatment response in tumors

Dynamic nuclear polarization of (13)C-labeled cell substrates has been shown to massively increase their sensitivity to detection in NMR experiments. The sensitivity gain is sufficiently large that if these polarized molecules are injected intravenously, their spatial distribution and subsequent conversion into other cell metabolites can be imaged. We have used this method to image the conversion of fumarate to malate in a murine lymphoma tumor in vivo after i.v. injection of hyperpolarized [1,4-(13)C(2)]fumarate. In isolated lymphoma cells, the rate of labeled malate production was unaffected by coadministration of succinate, which competes with fumarate for transport into the cell. There was, however, a correlation with the percentage of cells that had lost plasma membrane integrity, suggesting that the production of labeled malate from fumarate is a sensitive marker of cellular necrosis. Twenty-four hours after treating implanted lymphoma tumors with etoposide, at which point there were significant levels of tumor cell necrosis, there was a 2.4-fold increase in hyperpolarized [1,4-(13)C(2)]malate production compared with the untreated tumors. Therefore, the formation of hyperpolarized (13)C-labeled malate from [1,4-(13)C(2)]fumarate appears to be a sensitive marker of tumor cell death in vivo and could be used to detect the early response of tumors to treatment. Given that fumarate is an endogenous molecule, this technique has the potential to be used clinically.

Myocardial metastasis from squamous cell carcinoma of the esophagus

A 62-year-old woman was admitted to our hospital because of cancer of the middle thoracic esophagus. We performed a right transthoracic subtotal esophagectomy with systemic three-field lymphadenectomy. Histopathological findings resulted in a diagnosis of well-differentiated squamous cell carcinoma staged as pT3N0M0, pStage IIA, with clear surgical margins. Although she had no clinical symptoms, solitary cardiac metastasis located in the ventricular septum close to the apex was detected on the follow-up computed tomography scans during postoperative month 6. Regardless of chemotherapy followed by radiotherapy, she died of the cancer 17 months after the initial operation. An autopsy revealed metastatic lesions to the heart, lungs, kidneys, and liver. There were two metastatic masses in the heart without direct invasion from the outside of the heart. In cases of esophageal cancer, tumor spread to the heart is usually caused by direct invasion; thus, solitary hematopoietic cardiac metastasis is quite rare.

Positron emission tomography for monitoring response to neoadjuvant therapy in patients with oesophageal and gastro-oesophageal junction carcinoma

AIMS

The aim of this review is to consolidate our knowledge on an important and rapidly expanding area of expertise. Numerous methods for predicting response (in terms of pathological response and survival) to neoadjuvant therapy (chemotherapy/chemo-radiotherapy) in oesophageal and junctional cancers have been proposed. This review concerns itself only with the use of positron emission tomography for such a purpose. At present there are no standardised criteria amongst PET trials as to what determines a response according to PET, what is the optimal time to perform PET in relation to the timing of neoadjuvant therapy, and what is the ideal method of quantifying PET tracer uptake.

METHODS

An electronic search was performed of PubMed, Ovid and Embase websites to identify studies, in the English language, using the search terms: PET; oesophageal; oesophago-gastric; survival; cancer; response; chemotherapy and chemo-radiotherapy. The reference lists were searched manually to identify further relevant studies.

RESULTS

Twenty-two studies were identified, all using (18)FDG as the tracer, using PET to predict response in terms of pathological response and survival following neoadjuvant therapy (chemotherapy/chemo-radiotherapy). PET had a varying degree of success in predicting both pathological response and survival outcomes, with only one study using PET to influence management decisions.

CONCLUSIONS

PET seems a promising technique, but large-scale conclusions are hindered by small study numbers, lack of criteria as to what constitutes a response and markedly differing PET imaging times. A large randomised trial concerning a homogeneous group of patients and tumours is required before PET might be used to influence management.