Value of positron emission tomography in the diagnosis of recurrent oesophageal carcinoma

Oesophageal cancer: assessment of response and follow up

The prognosis for oesophageal cancer is poor with a median survival of 3-5 months and recurrences are frequent. The best chance of cure is successful surgery and pre-operative chemoradiotherapy is used to try and improve outcomes. However, patients may either not respond or may progress during therapy and it is important to differentiate the responders from non-responders. Clinical parameters such as weight gain and improvement in swallowing can be assessed but imaging is used in an attempt to improve outcomes.

Metastasis of the gastrointestinal tract: FDG-PET imaging

We assess the usefulness of F-18-fluoro-deoxyglucose (FDG) positron emission tomography (PET) in the evaluation of gastrointestinal metastases. Four cases (five lesions) in which metastases from three lung cancers and one malignant fibrous histiocytoma (MFH) of the femur were found in the gastrointestinal tract were reviewed (men/women 3 : 1, age 63-78 years, mean 72 years). The five lesions were duodenal, jejunal metastasis, and two stomach metastases from lung carcinoma, and rectal metastasis from MFH of the femur. FDG-PET was unable to detect small masses, but it was able to detect unforeseen lesions such as gastrointestinal metastases because FDG-PET is a whole-body scan in a single-operation examination. FDG-PET imaging provided valuable information for the diagnosis of gastrointestinal metastasis.

PET and PET/CT using 18F-FDG in the diagnosis and management of cancer patients

Positron emission tomography (PET) using 2-(18)F-fluoro-2-deoxy-D-glucose (FDG), a radioactive derivative of glucose, is an advanced imaging tool, based on the increased glucose consumption of cancer cells. FDG-PET provides information that is not obtainable with other imaging modalities, and is very effective in the diagnosis and management of patients with various types of cancers. However, there are some limitations, such as low FDG uptake in some cancers, substantial FDG uptake in inflammatory cells, and the lack of anatomical information and poor imaging quality of PET. A recently developed integrated PET/computed tomography (CT) system, which combines a PET camera and CT scanner in a single session, has overcome these drawbacks by providing both anatomical and functional imaging at the same position. PET and/or PET/CT using FDG is clinically useful in the detection of cancer, the differentiation of malignant and benign lesions, the staging of cancer before therapy, and the assessment of cancer therapy, as well as for determining the recurrence after therapy of most cancers, including lung cancer, gastrointestinal cancer, breast cancer, and malignant lymphoma. PET/CT has become the new standard approach to imaging in the diagnosis and management of many cancer patients.

Evolving role of (18)F-fluorodeoxyglucose positron emission tomography in the management of esophageal carcinoma

Positron emission tomography (PTE) and PET/CT imaging with (18)F-fluorodeoxyglucose are metabolic imaging modalities that depict tissues based on their level of glucose uptake. PET provides useful information in the primary staging of disease. PET performance in detecting locoregional nodal metastases is limited; however, it is the most accurate single noninvasive modality for detecting distant metastases. It is the imaging modality of choice for whole-body scanning in high-risk patients or patients who have clinically suspected recurrence, and is particularly helpful in determining which patients are the best candidates for surgical cure.

Present role and future prospects of positron emission tomography in clinical oncology

Positron emission tomography (PET) has emerged as a significant molecular imaging technique in clinical oncology and cancer research. PET with (18)F-fluorodeoxyglucose ((18)F-FDG) demonstrates elevated glucose consumption by tumor cells, and is used clinically for the accurate staging and restaging of cancer, planning of radiotherapy, and predicting response or lack of response in the early stages of treatment. Combined PET and computed tomography (PET-CT) provides both functional and morphological information of the disease to allow accurate diagnosis of cancer. PET with new radiotracers such as protein synthesis markers and proliferation markers, as well as hypoxia and receptor-binding agents, will offer patient-specific images in order to yield tailored diagnostic and prognostic information.

The importance of PET in the diagnosis and response evaluation of esophageal cancer

The major aims of imaging in esophageal cancer are to distinguish between locoregional and systemic disease (M-stage), to determine local tumor extension (T- and N-stage), to assess response to chemo- or chemoradiotherapy and to identify recurrence of cancer. The sensitivity of computed tomography (CT) for detection of distant metastases ranges between < 50% and > 90%. In esophageal cancer, F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) has been shown to detect metastatic disease in approximately 20% of patients who are considered as having only locoregional disease on CT. In locoregional pretherapeutic tumor staging, FDG-PET specificity of 80% is sufficient, but FDG-PET sensitivity of 50% is rather low. However, the initial staging of regional lymph nodes is less important because at the moment there is no pretherapeutic therapy stratification based on lymph node category. The accuracy for correct identification of recurrence in esophageal cancer is higher for FDG-PET than for CT scan. Unfortunately until today no reliable essays for prediction of response or prognosis exist for esophageal cancer in clinical practice for patients with neoadjuvant treatment. Thus the identification of parameters predicting response and/or prognosis is crucial for the future. Post-therapeutic assessment of tumor response by FDG-PET has been shown to correlate with histopathologic tumor regression and patient survival. Furthermore, quantitative measurements of tumor FDG-uptake may allow an early metabolic response evaluation after only 2 weeks of therapy. An association of metabolic response with histopathologic tumor regression and patient outcome 2 weeks after initiation of preoperative chemotherapy may be shown for esophageal cancer.

Carcinoembryonic antigen messenger RNA expression in blood predicts recurrence in esophageal cancer

PURPOSE

The clinical significance of isolated tumor cells (ITC) in blood has not been clearly established, particularly during follow-up in cancer patients. We conducted a longitudinal analysis of the relationship between ITC in blood during follow-up and clinicopathologic findings in patients with esophageal squamous cell carcinoma.

EXPERIMENTAL DESIGN

Blood samples obtained from 106 patients were examined by real-time RT-PCR assay targeting carcinoembryonic antigen (CEA) mRNA. Follow-up examination every 3 months after surgery included testing for CEA mRNA and tumor markers, as well as imaging.

RESULTS

Thirty-nine (36.8%) patients were positive for CEA mRNA expression. CEA mRNA positivity significantly correlated with tumor depth, lymph node metastasis, stage, and venous invasion. Recurrent disease was found in 34 of 106 (32.1%) cases. CEA mRNA was found in 28 (76.5%) patients experiencing relapse. Of these 28 patients, the number positive of CEA mRNA before detection by imaging, at the same time of detection by imaging, and after detection by imaging was 18 (52.9%), 8 (23.5%), and 2 (5.9%), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value for CEA mRNA were higher than those for serum CEA or squamous cell carcinoma. Patients positive for CEA mRNA experienced significantly shorter disease-free interval than those with negative CEA mRNA (P < 0.001). According to multivariate analysis, CEA mRNA positivity was an independent factor for disease-free interval.

CONCLUSIONS

Examination of CEA mRNA in peripheral blood during follow-up is useful for early detection of occult recurrence. We believe that CEA mRNA in blood will be a new marker for recurrence in esophageal squamous cell carcinoma.

Staging and follow-up of gastrointestinal tumors with PET/CT

Positron emission tomography (PET) is a functional imaging modality that has been documented to be useful in patient care. Oncologic PET imaging is used for a wide variety of neoplasms, mainly for staging and follow-up, differentiation of equivocal morphologic findings, therapy stratification, and monitoring. Because PET imaging is based on the physiologically mediated distribution of the administered tracer but not on anatomic information, the addition of computed tomography (CT) to PET may improve the interpretation of PET. Combined PET and CT offers several potential advantages over PET alone that may influence the clinical routine. PET/CT was introduced into clinical use only 3 years ago and has found widespread application within only 1 to 2 years. This article summarizes preliminary data of clinical applications for PET/CT in gastrointestinal tumors.

Squamous cell carcinoma-antigen messenger RNA level in peripheral blood predicts recurrence after resection in patients with esophageal squamous cell carcinoma

BACKGROUND

The aim of this study was to clarify whether preoperative squamous cell carcinoma-antigen messenger RNA (SCC-Ag mRNA) level in peripheral blood can be used to predict tumor recurrence after curative resection for esophageal squamous cell carcinoma.

METHODS

A prospective analysis was conducted for 46 consecutive patients who underwent curative esophagectomy and who had no residual tumor. The SCC-Ag mRNA level in the peripheral blood of each patient was measured preoperatively by using quantitative reverse transcriptase-polymerase chain reaction. Median follow-up period was 34 months.

RESULTS

Receiver operating characteristic analysis demonstrated that the optimal cutoff level of SCC-Ag mRNA was 40. Patients were divided into the high SCC-Ag mRNA level group (n = 14) and the low SCC-Ag mRNA level group (n = 32). The cumulative probabilities of tumor recurrence were higher in the high SCC-Ag mRNA level group (probability of recurrence was 71% at 2 years) than in the low group (22% at 2 years; P = .0005). SCC-Ag mRNA level (relative risk, 3.00; 95% confidence interval, 1.05-8.54; P = .040) was the strongest independent predictor of recurrence by multivariate analysis.

CONCLUSIONS

Preoperative SCC-Ag mRNA levels in the peripheral blood are the best predictive factor for recurrence in patients with esophageal squamous cell carcinoma who undergo curative resection (R0).

Potential novel application of dual time point SUV measurements as a predictor of survival in head and neck cancer

OBJECTIVES

To examine the potential of pre-treatment dual time point [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) as a tool for improving the assessment of head and neck cancer. Two main areas were investigated: (a) optimum time to start FDG scanning post-injection and (b) potential of SUV obtained from dual time point scanning as a prognostic indicator of survival.

METHODS

Twelve patients with advanced head and neck cancer were prospectively studied. Each patient was scanned using a Siemen's Ecat Exact-47 PET scanner at 1 h and 2 h post-injection. Maximum tumour uptake (SUVt) and ratio of maximum tumour/normal tissue uptake (SUVt/n) were recorded. The optimal time to initiate scanning was investigated by comparing SUVt and SUVt/n with the decision made by two experienced observers as to which scan they preferred to report from, given the choice of the 1 h and 2 h scan in each patient.

RESULTS

A significant difference between 1 h and 2 h SUVt (P<0.004, paired t-test) and between 1 h and 2 h SUVt/n (P<0.0003, paired t-test) was observed. All 2 h SUVt and SUVt/n were greater in magnitude than their respective 1 h SUVt and SUVt/n counterparts. The two observers reported an identical number of lesions from the 1 h and 2 h scans but preferred the 2 h data.

CONCLUSIONS

Tumour stage and the percentage difference in 1 h and 2 h SUVt showed potential as prognostic indicators of long-term survival.

Outcome and Treatment Strategy for Mid- and Lower-Thoracic Esophageal Cancer Recurring Locally in the Lymph Nodes of the Neck

The aim of the present study was to assess the outcome of treatment for patients with recurrent mid- and lower-thoracic esophageal cancers in whom recurrence was localized to the lymph nodes of the neck, and to determine the best strategy for further treatment. Between 1989 and 2001, 270 patients with mid- and lower-thoracic esophageal cancer underwent curative esophagectomy; 90 of those patients had a cancer recurrence. Our focus was on lymph node recurrence, especially when the recurrent cancers were localized to the lymph nodes in the neck. The outcomes of those patients and the efficacy of the strategies used to treat the recurrent cancers were determined. In 43 patients (48%), recurrent cancer initially appeared in the lymph nodes. Among the 43 patients, 15 (35%) had localized neck recurrence. The time between tumor recurrence and death among the 15 patients with localized neck recurrence was significantly longer than among the 28 patients with other recurrence patterns. In addition, 15 patients underwent lymph node resection, while 28 patients were treated non-surgically. The time between tumor recurrence and death was significantly longer in patients treated surgically. Of the 15 patients in whom recurrence affected the neck lymph nodes only, 10 (67%) were treated surgically; their 2-year survival rate after recurrence was 45%. The outcomes of recurrent esophageal cancers localized to the lymph nodes of the neck were better than those seen with other recurrence patterns, and salvage resection followed by chemoradiation therapy would seem to be indicated for those patients.