Systematic review of the staging performance of 18F-fluorodeoxyglucose positron emission tomography in esophageal cancer

Limited additional value of positron emission tomography in staging oesophageal cancer

BACKGROUND

The detection of distant metastases in patients with oesophageal cancer may be improved with [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET), preventing unnecessary surgical explorations. The aim of this study was to assess the additional value of FDG-PET after a state-of-the-art preoperative staging protocol.

METHODS

All patients in this prospective cohort study were staged with multidetector computed tomography, endoscopic ultrasonography and external ultrasonography of the neck, both combined with selective fine-needle aspiration cytology. Patients considered eligible for curative surgery after these investigations underwent FDG-PET.

RESULTS

FDG-PET revealed suspicious hot spots in 30 (15.1 per cent) of 199 patients. Metastases were confirmed in eight (4.0 per cent). In six of these, distant metastases were confirmed before surgery, but exploratory surgery was necessary for histological confirmation in the other two. All eight upstaged patients had clinical stage III-IV disease before FDG-PET (6.6 per cent of 122 with stage III-IV disease). In seven patients (3.5 per cent) hot spots appeared to be synchronous neoplasms, mainly colonic polyps. However, those in the remaining 15 (7.5 per cent) were false positive, leading to unnecessary additional investigations.

CONCLUSION

FDG-PET improves the selection of patients with oesophageal cancer for potentially curative surgery, especially in stages III-IV. However, the diagnostic benefit is limited after state-of-the-art staging, and so broad implementation in daily clinical practice is questionable.

Positron emission tomography imaging as a cancer biomarker

The practice of oncology is changing, with novel biologic agents broadening our therapeutic armamentarium. Along with excitement and promise, multiple new challenges arise. The concept of 'individualized cancer care,' where therapies are selected based on the unique characteristics of a patient's tumor, is gaining favor as an approach to address the heterogeneity of cancer. As a result, we must strive to discover biomarkers with prognostic and predictive value to improve drug selection, alteration and development. Metabolic and molecular imaging with PET appears at the forefront of this critical field. In this review, we discuss cancer biomarker development, opportunities for PET to elucidate tumor biology and the potential role of PET in clinical research and practice.

Induction Chemotherapy in Barrett Cancer

OBJECTIVE

To study the impact of induction chemotherapy on surgical risk and outcome in locally advanced Barrett cancer.

BACKGROUND

Induction chemotherapy has become an accepted choice for the treatment of locally advanced adenocarcinoma of the esophagus and the esophagogastric junction. It has been shown that early assessment of metabolic response using positron emission tomography predicts response to chemotherapy. Metabolic response has also been revealed to be an independent prognostic factor.

METHODS

Surgical risk and outcome in metabolic responders were compared with those in nonresponders. The study design predefined a 12-week multicourse preoperative chemotherapy regimen in metabolic responders. In contrast, chemotherapy was stopped after a 2-week induction period in metabolic nonresponders. All patients were scheduled for surgical resection.

RESULTS

Of 110 evaluable patients, 50 metabolic responders and 54 nonresponders underwent resection. Postoperative complications occurred in 34%. Two patients (1.8%) died. There were no significant differences between responders and nonresponders in terms of postoperative morbidity and mortality. Major histologic remissions were seen in 58% of metabolic responders. Metabolic responders had an increased chance of having an R0 resection (96% vs. 74%; P=0.002) and a decreased risk of developing hematogenous or distant lymphatic recurrence (32% vs. 54%, P=0.019). This translated into better recurrence-free and overall survival.

CONCLUSIONS

Induction chemotherapy and early metabolic response assessment is a new concept in the treatment of locally advanced Barrett cancer. Metabolic responders undergoing multicourse preoperative chemotherapy have a good prognosis. The best treatment strategy for nonresponders remains to be defined.

FDG-PET/CT tumor segmentation-derived indices of metabolic activity to assess response to neoadjuvant therapy and progression-free survival in esophageal cancer: correlation with histopathology results

PURPOSE

To evaluate the diagnostic and prognostic abilities of PET tumor segmentation-derived indices of metabolic activity for the assessment of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer.

METHODS

Twenty-five patients with histologically confirmed esophageal cancer were retrospectively evaluated. The patients underwent PET-CT imaging before and after completion of neoadjuvant therapy. Images were evaluated visually and quantitatively with a three-dimensional threshold-based region-growing program, which calculates SUVm, SUVa of the entire tumor, metabolic tumor length (Lm) and volume (Vm) before and after therapy (SUVm1, SUVm2, SUVa1, SUVa2, Lm1, Lm2, Vm1, and Vm2, respectively). Percentage changes in these metabolic variables before and after therapy were also calculated (%SUVm, %SUVa, %Lm, %Vm, respectively).

RESULTS

SUVm1 (P = 0.018), SUVa1 (P = 0.019), Lm1 (P = 0.016), and Vm1 (P = 0.016) correlated with T-status. Advanced stage tumors (T3 + T4) had significantly higher glucose metabolism, metabolic length, and volume. Moreover, Lm1 >47.4 mm and Vm1 >29 cm3 were the best predictors of the level of tumor invasiveness. SUVm1 >12.7 and SUVa1 >5.9 could differentiate patients with positive lymph nodes from those without at presentation. %SUVa >32.3% and the SUVa1 >5.5 proved to be reliable predictors of pathologic response. SUVa2 >3.55 and SUVm2 >4.35 were the best predictors of disease progression during follow-up, with the latter having the best prognostic value.

CONCLUSIONS

This study showed that FDG-PET tumor segmentation-derived indices of metabolic activity play a definite role in the evaluation of response to neoadjuvant chemoradiotherapy and progression-free survival in patients with esophageal cancer.

R1-Resektion in der Chirurgie des oberen Gastrointestinaltrakts

Microscopically involved tumor margins are an important problem in the surgery of locally advanced esophageal and gastric carcinomas. We conducted a systematic review of the literature and a specific analysis of our own patient database. This article summarizes current knowledge of the incidence and prognosis of R1 resections in upper gastrointestinal cancers. Preoperative strategies for reducing the rate of R1 resections are presented, and the surgical options in case of R1 resection are discussed.

Multivariate random-effects approach: for meta-analysis of cancer staging studies

RATIONALE AND OBJECTIVES

Meta-analyses of diagnostic accuracy studies produce summary estimates of sensitivity and specificity. Cancer staging relies on staging systems and meta-analysis is often performed after dichotomization of the staging results. For each dichotomization, summary estimates of sensitivity and specificity can be calculated by repeated bivariate random-effects analyses. In this process, staging information is lost and under- and overstaging can not be adequately expressed.

MATERIALS AND METHODS

We propose a new multivariate random-effects approach, which is an extension of the bivariate random-effects approach. To illustrate the principles and outcomes of both approaches, we used data from a meta-analysisevaluating endoluminal ultrasonography in staging of rectal cancer. In the multivariate approach, results on correct staging and under- and overstaging were calculated. In addition, the results from this analysis were used to calculate sensitivity and specificity estimates for each dichotomization and these estimates were compared with the results of the repeated bivariate analyses.

RESULTS

By the multivariate analysis, results on correct staging and under- and overstaging were obtained. The sensitivity and specificity estimates for the dichotomizations, calculated from the results of this multivariate approach, were also comparable with the sensitivity and specificity estimates obtained by the repeated bivariate analyses.

CONCLUSIONS

The multivariate random-effects approach can be a useful meta-analytic method for summarizing cancer staging data presented in diagnostic accuracy studies.

18FDG uptake in oesophageal adenocarcinoma: linking biology and outcome

PURPOSE

Variable uptake of 18FDG has been noticed in positron emission tomography (PET) studies of patients with oesophageal adenocarcinoma. The aim of the present study was to investigate biological parameters involved in 18FDG uptake in oesophageal adenocarcinoma for selection of patients with increased 18FDG uptake and prediction of prognostic value of 18FDG PET.

PATIENTS AND METHODS

Preoperative PET scans were performed in 26 patients with histologically proven oesophageal adenocarcinoma. 18FDG uptake was semiquantitatively measured by SUV(BSAg. )Tumour sections were stained by immunohistochemistry for angiogenic markers (VEGF, CD31), glucose transporter-1 (Glut-1), hexokinase (HK) isoforms, for proliferation marker (Ki67), for macrophage marker (CD68) and for apoptosis marker (cleaved caspase-3). Cell densities, differentiation grade, degree of necrosis and mucus, T-stage and tumour size were assessed. In addition follow-up was analysed.

RESULTS

No association was found between 18FDG uptake and angiogenic markers. In contrast, a significant correlation was found between 18FDG uptake and Glut-1 expression. No correlations were found between 18FDG uptake and HK isoforms, Ki67 or cleaved caspase-3. Also, no correlations were found between 18FDG uptake and cell density, differentiation grade, CD68, mucus and necrosis. However, there was a significant correlation between 18FDG uptake and tumour size and between 18FDG uptake and tumour recurrence.

CONCLUSIONS

Glut-1 expression and tumour size seem parameters associated with 18FDG uptake in patients with biopsy proven oesophageal adenocarcinoma, and may be used to select oesophageal cancer patients in whom 18FDG-PET is of diagnostic value and may predict disease outcome.

Radiochemotherapy of esophageal cancer

Cancer of the esophagus continues to be a threat to public health. The common practice is esophagectomy for surgically resectable tumors and radiochemotherapy for locally advanced, unresectable tumors. However, local regional tumor control and overall survival of esophageal cancer patients after the standard therapies remain poor, approximately 30% of patients treated with surgery only will develop local recurrence, and 50% to 60% patients treated with radiochemotherapy only fail local regionally due to persistent disease or local recurrence. Esophagectomy after radiochemotherapy or preoperative radiochemotherapy has increased the complete surgical resection rate and local regional control without a significant survival benefit. Induction chemotherapy followed by preoperative radiochemotherapy has produced encouraging results. In addition to patient-, tumor-, and treatment-related factors, involvement of celiac axis nodes, number of positive lymph nodes after preoperative radiochemotherapy, incomplete pathologic response, high metabolic activity on positron emission tomography scan after radiochemotherapy, and incomplete surgical resection are factors associated with a poor outcome. Radiochemotherapy followed by surgery is associated with significant adverse effects, including treatment-related pneumonitis, postoperative pulmonary complications, esophagitis and pericarditis. The incidence and severity of the adverse effects are associated with chemotherapy and radiotherapy dosimetric factors. Innovative treatment strategies including physically and biologically molecular targeted therapy is needed to improve the treatment outcome of patients with esophageal cancer.

Oesophageal cancer in The Netherlands: Increasing incidence and mortality but improving survival

AIM

Oesophageal cancer is highly lethal with a 5-year relative survival of 10-15%. An increasing incidence has been reported for several parts of the Western world. We studied time trends in incidence, mortality and survival for oesophageal cancer in the Netherlands during 1989-2003.

METHODS

Data on incidence and survival were obtained from the Netherlands Cancer Registry and mortality data from Statistics Netherlands.

RESULTS

The age standardised incidence increased by 3.4% (p<0.001) and 1.9% (p=0.003) per year for males and females, respectively. This increase was almost exclusively caused by oesophageal adenocarcinomas. Age standardised mortality increased 2.5% (p<0.001) per year among males and 1.7% (p=0.002) per year among females. Relative survival improved significantly from 8.1% in 1989-1993 to 12.6% in 1999-2003 (p<0.001). Adjusted for age, stage, tumour location and surgery, the excess risk of death decreased by 22%.

CONCLUSION

Oesophageal carcinoma incidence is rising in the Netherlands. Mortality increased at a slightly lower pace due to improving survival.

The utility of positron emission tomography in staging of potentially operable carcinoma of the thoracic esophagus: results of the American College of Surgeons Oncology Group Z0060 trial

OBJECTIVES

The American College of Surgeons Oncology Group trial Z0060 is a prospective multi-institutional trial with a primary objective to evaluate whether positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) detects evidence of metastastic disease that precludes esophagectomy in patients with esophageal cancer who are surgical candidates after routine staging.

METHODS

Patients with resectable, biopsy-proven carcinoma were enrolled after computed tomography of chest and abdomen demonstrated no evidence of metastasis. FDG-PET was performed according to specified standards. FDG-PET findings suggesting metastases required confirmation and patients without metastases on PET were expected to proceed to surgery.

RESULTS

A total of 262 patients were registered. Of these, 199 were deemed eligible and of these, 189 patients were evaluable. Seventy-three patients were ineligible or unevaluable. Reasons for ineligibility included nonresectable disease by routine staging (39), missing or outdated staging procedures (12), PET technical protocol violations (10), no cancer (4), pre-PET induction therapy (3), claustrophobia (1), and other causes (4). There were 145 (78%) patients who went on to have surgery, 42 (22%) who did not, and 2 patients for whom the surgical status was not determined. The reasons for no resection included the following: M1 disease found by PET and confirmed (9), M1 disease found by PET and not confirmed (2), M1 disease at exploration not found by PET (7), decline or death before surgery (10), patient refusal of surgery (7), unresectable local tumor at exploration (5), and extensive N1 disease precluding operation (2). Eight (4.2%) patients undergoing resection had a recurrence in the first 6 months.

CONCLUSIONS

Although 22% of eligible patients did not undergo esophagectomy, FDG-PET after standard clinical staging for esophageal carcinoma identified confirmed M1b disease in at least 4.8% (95% confidence interval: 2.2%-8.9%) of patients before resection. Unconfirmed PET evidence of M1 disease and regional adenopathy (N1 disease) led to definitive nonsurgical or induction therapy in additional patients.

Role of positron emission tomography in the (re-)staging of oesophageal cancer

BACKGROUND

Various studies have demonstrated that 18F-Fluorodeoxyglucose-positron emission tomography (FDG-PET), measuring altered tissue glucose metabolism, is a promising non-invasive method for detecting both distant nodal and haematogenous metastases in patients with oesophageal carcinoma (OC) and might thus prevent futile esophagectomy. Moreover, FDG-PET is a promising tool in assessing response to non-surgical treatment, and might therefore be used for an early decision on whether treatment should be stopped or continued.

MATERIAL AND METHODS

Review of the recent literature regarding the diagnostic performance of FDG-PET in the preoperative staging of patients with OC and regarding diagnostic accuracy of FDG-PET in assessing response to neoadjuvant therapy in patients with OC compared to conventional techniques (especially computed tomography (CT) and endoscopic ultrasonography (EUS)).

RESULTS

A search of the literature resulted in the inclusion of 16 studies on the diagnostic value of FDG-PET. Sensitivity and specificity for the detection of locoregional metastases were moderate. Sensitivity and specificity were reasonable for distant metastases. The diagnostic accuracy of FDG-PET in assessing response to treatment was similar to the accuracy of EUS, but significantly higher than that of CT.

CONCLUSIONS

The staging value of FDG-PET in OC patients is limited in the detection of locoregional metastases; however; its value is higher in the detection of distant lymphatic and haematogenous metastases. Moreover, FDG-PET is a valuable tool for the non-invasive assessment of histopathologic tumour response after neoadjuvant therapy..

The role of integrated computed tomography positron-emission tomography in esophageal cancer: staging and assessment of therapeutic response

Computed tomography (CT) and endoscopy/endoscopic ultrasonography are usually performed to initially stage patients with esophageal cancer, to determine primary tumor response, and to detect nodal and distant metastases after preoperative therapy. Positron-emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose and integrated CT-PET are useful in the initial staging of patients with esophageal cancer as well as in the prediction of pathologic response, disease-free interval, and overall survival after preoperative therapy. Importantly, integrated CT-PET imaging decreases the number of futile attempts at surgical resection, mainly because of the detection of occult distant metastases. The following sections review the use of integrated CT-PET imaging in determining the T, N, and M descriptors of the American Joint Commission on Cancer's 2002 guidelines for pathologic and clinical staging at initial diagnosis and after chemoradiation therapy in those patients being considered for surgical resection.

The role and clinical value of EUS in a multimodality esophageal carcinoma staging program with CT and positron emission tomography

BACKGROUND

EUS, CT, and positron emission tomography (PET) have all been used in the preoperative staging of esophageal cancer separately or in various combinations.

OBJECTIVE

Our purpose was to determine the value and role of EUS when used in conjunction with CT and PET imaging in staging cancer of the esophagus and gastroesophageal junction.

DESIGN

Retrospective single-center clinical trial.

SETTING

Academic tertiary care center.

PATIENTS

Data were examined for 56 patients who concomitantly underwent examination with EUS, CT, and PET in a multimodality staging program.

MAIN OUTCOME MEASUREMENTS

EUS, CT, and PET were examined for their ability to detect the primary tumor, local tumor stage, locoregional adenopathy, and distant metastases. With use of surgical resection as baseline therapy, the frequency at which EUS, CT, and PET affected and changed management was examined.

RESULTS

EUS is the only imaging test that identified all primary tumors and provided tumor staging. EUS identified a significantly greater number of patients (58.9%) with locoregional nodes than did CT (26.8%), P = .0006, or PET (37.5%), P = .02. CT identified 14.3% and PET identified 26.8% of patients with distant metastases. With CT alone, 15.2% of patients were not taken to surgery, whereas PET affected management by preventing surgery because of metastatic disease in 28.3% of patients. EUS changed management by guiding the need for neoadjuvant therapy in 34.8% of patients.

LIMITATIONS

Retrospective study, nonblinded study, lack of pathologic reference standard.

CONCLUSION

The primary strength of EUS in a multimodality staging strategy is in identifying patients with locally advanced disease and guiding the need for preoperative neoadjuvant therapy. EUS is not suited to determine resectability of esophageal cancer alone and thus is most effective when used in conjunction with other imaging tests such as CT and PET.

Current treatment approach to locally advanced esophageal cancer: is resection mandatory?

Ongoing controversy surrounds the question of whether locally advanced cancer of the esophagus should be resected or treated with nonsurgical methods. Survival after resection, particularly of patients with squamous cell cancer, remains poor. Results of recent studies suggest that in cases of squamous cell cancer there is no clear survival advantage favoring surgery, but local tumor control is significantly improved after resection. Besides this clinically relevant difference, important issues concerning the design and conduct of the most recent studies have not been investigated carefully and deserve critical discussion. Of particular note is the fact that surgery has not yet been compared with a nonsurgical approach in treating adenocarcinoma of the esophagus. Consequently, surgery remains the standard approach, at least for this cancer subtype. Response to induction chemotherapy and radiation will determine future treatment algorithms, and promising tools for predicting response are currently being investigated.

Is PET-based treatment planning the new standard in modern radiotherapy? The head and neck paradigm

The use of positron-emission tomography (PET) in the treatment planning process has become more and more popular over the years, although important questions such as how, when, and for which clinical benefit have never been answered. In this framework, the objective of this article is to review the evidence supporting the use of PET in radiotherapy treatment planning, with special emphasis on its application for head and neck tumors. The use of positron-labeled fluorodeoxyglucose for target volume selection should be discussed in terms of sensitivity and specificity in comparison with typical anatomic imaging modalities. It will not be of similar utility across all tumor sites. The use of PET for target volume delineation requires specific tuning of parameters such as image acquisition, processing, and segmentation, and this may vary from one tumor site to another. Molecular imaging with other tracers and "theragnostic" are in the pipeline, but how much the patient will gain from it and how these advances should be implemented in routine clinical practice are unresolved questions. Therefore, although integration of PET images into the radiotherapy process seems promising, for the moment it should remain in the research arena.

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.

Preoperative 18[F]-fluorodeoxyglucose positron emission tomography standardized uptake values predict survival after esophageal adenocarcinoma resection

BACKGROUND

Clinical staging modalities for esophageal cancer are inaccurate at determining prognosis, especially in early-stage patients. We performed a retrospective review of patients with esophageal adenocarcinoma imaged by positron emission tomography before surgical resection to determine whether 18[F]-fluorodeoxyglucose uptake predicted overall survival independently of clinical and pathologic stage.

METHODS

The study is a retrospective review of patients with adenocarcinoma of the esophagus treated by surgery. All patients were imaged with computed tomography and positron emission tomography imaging, and most patients had an endoscopic ultrasound. We compared positron emission tomography standardized uptake values (SUVmax) with clinical and pathologic stage and survival. Prognostic variables were assessed by log-rank test, and survival by the method of Kaplan and Meier.

RESULTS

From January 1996 through June 2004, 50 patients meeting study eligibility criteria were analyzed. Median follow-up for surviving patients was 27 months. The median SUVmax was 4.5. Stratification of patients by the median SUVmax predicted survival. The 3-year survival was 57% for patients with an SUVmax greater than 4.5 and 95% for patients with an SUVmax of 4.5 or less (p = 0.02). The survival advantage of the SUVmax 4.5 or less group was also seen in clinically early-stage patients (defined as no adenopathy on computed tomography and positron emission tomography, and by endoscopic ultrasound T1-2 N0), as well as in patients with pathologically early-stage disease (T-2 N0).

CONCLUSIONS

In surgically managed esophageal adenocarcinoma patients, SUVmax predicts overall survival. Moreover, SUVmax identifies patients who have a poor prognosis from a subset of patients that would otherwise be considered to have early-stage disease.

PET-Probe: Evaluation of Technical Performance and Clinical Utility of a Handheld High-Energy Gamma Probe in Oncologic Surgery

BACKGROUND

Positron emission tomography (PET) has become an invaluable part of patient evaluation in surgical oncology. PET is less than optimal for detecting lesions <1 cm, and the intraoperative localization of small PET-positive lesions can be challenging as a result of difficulties in surgical exposure. We undertook this investigation to assess the utility of a handheld high-energy gamma probe (PET-Probe) for intraoperative identification of ¹⁸F-deoxyglucose (FDG)-avid tumors.

METHODS

Forty patients underwent a diagnostic whole-body FDG-PET scan for consideration for surgical exploration and resection. Before surgery, all patients received an intravenous injection of 7 to 10 mCi of FDG. At surgery, the PET-Probe was used to determine absolute counts per second at the known tumor site(s) demonstrated by whole-body PET and at adjacent normal tissue (at least 4 cm away from tumor-bearing sites). Tumor-to-background ratios were calculated.

RESULTS

Thirty-two patients (80%) underwent PET-Probe-guided surgery with therapeutic intent in a recurrent or metastatic disease setting. Eight patients underwent surgery for diagnostic exploration. Anatomical locations of the PET-identified lesions were neck and supraclavicular (n = 8), axilla (n = 5), groin and deep iliac (n = 4), trunk and extremity soft tissue (n = 3), abdominal and retroperitoneal (n = 19), and lung (n = 2). PET-Probe detected all PET-positive lesions. The PET-Probe was instrumental in localization of lesions in 15 patients that were not immediately apparent by surgical exploration.

CONCLUSIONS

The PET-Probe identified all lesions demonstrated by PET scanning and, in selected cases, was useful in localizing FDG-avid disease not seen with conventional PET scanning.

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).

Esophageal Cancer: The Role of Integrated CT-PET in Initial Staging and Response Assessment After Preoperative Therapy

Esophageal cancer, an uncommon neoplasm, has been increasing in incidence over the past few decades. Optimal management of patients is determined by the stage of disease at presentation, patient performance status, and location of the primary cancer. Recently, there has been increasing use of multimodality therapy in suitable candidates that employs preoperative chemotherapy and/or radiation followed by surgical resection. This evolving treatment strategy together with the substantial morbidity and mortality associated with esophagectomy makes appropriate patient selection critical. Computed tomography (CT) and endoscopy/endoscopic ultrasonography are usually carried out to initially stage patients with esophageal cancer, to determine primary tumor response, and to detect nodal and distant metastases after preoperative therapy. Positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose and integrated CT-PET are useful in the initial staging of patients with esophageal cancer and in the prediction of pathologic response, disease-free interval, and overall survival after preoperative therapy. Importantly, integrated CT-PET imaging decreases the number of futile attempts at surgical resection, mainly because of the detection of occult distant metastases. The following sections review the use of integrated CT-PET imaging in determining the T, N, and M descriptors of the American Joint Commission on Cancer's 2002 guidelines for pathologic and clinical staging at initial diagnosis and after chemoradiation therapy in those patients being considered for surgical resection.

Novel Imaging Techniques in Melanoma

Cutaneous melanoma is one of the most deadly malignancies. Although it accounts for approximately 4% of all cancer cases, it ac-counts for approximately 79% of skin cancer-related deaths. In the past few years, the nuclear medicine platform used in the management of melanoma has extended to biochemical and structural imaging. In clinical practice, integrated positron emission tomography/CT devices allow anatomic and metabolic characterization of meta-static disease in a single study. Similarly, more accurate localization of sentinel nodes in a 3-D space now is feasible with hybrid single photon emission CT/CT system. In translational research, [18F]fluorodeoxyglucose probes have been designed to optimize the detection of melanoma tumor sites in vivo.

The current status of FDG-PET in tumour volume definition in radiotherapy treatment planning

Positron emission tomography (PET) scan, mainly using 18 F-fluoro-deoxyglucose (FDG) as a tracer, is currently widely accepted as a diagnostic tool in oncology. It may lead to a change in staging and therefore in treatment management. PET can also be used to define the target volume in radiation treatment planning and to evaluate treatment response. In this review, we focused on issues concerning the role of PET in target volume delineation, both for the primary tumour and regional lymph nodes. A literature search was performed using MEDLINE. Furthermore, the following questions were addressed: does PET allow accurate tumour delineation and does it improve the outcome of radiotherapy, in terms of reduced toxicity or a higher tumour control probability? Combined computer tomography (CT) and PET information seems to influence target volume delineation. Using (CT-) PET scan, interobserver variability is being reduced. Only few studies compared delineation based on PET with pathologic examination, showing a complex relation. Preliminary results concerning incorporation of PET information in to target volume delineation varies in different tumour sites. In the field of lung cancer, incorporation of PET seems to improve tumour coverage and spare normal tissues, which may lead to less toxicity or the possibility to escalate dose. In oesophageal cancer and in lymphoma, PET scan can be used to include PET positive lymph nodes in the target volume. In most other tumour sites not enough data are currently available to draw definitive conclusions about the role of PET in radiation treatment planning.

18F-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography Scanning Affects Surgical Management in Selected Patients With High-Risk, Operable Breast Carcinoma

BACKGROUND

The role of positron emission tomography (PET) scanning in determining the extent of disease in patients with breast cancer has not been defined. We investigated the utility of (18)F-2-fluoro-2-deoxy-D: -glucose (FDG)-PET scanning compared with conventional imaging with computed tomographic scanning and bone scanning in determining the extent of disease in patients with high-risk, operable breast cancer.

METHODS

This was a prospective study of patients who presented to Memorial Sloan-Kettering Cancer Center for operative treatment of breast cancer. Eighty eligible patients were enrolled and underwent computed tomographic chest, abdomen, pelvis, and bone scans, followed by FDG-PET. Changes in treatment based on scan findings were recorded by the operating surgeons. Imaging findings were verified by biopsy or long-term follow-up.

RESULTS

Eight (10%) of 80 patients were found to have metastatic disease that was seen on both conventional imaging and PET. Four additional patients (5%) had additional foci of disease on PET that affected treatment decisions. No patient had findings on conventional imaging alone. Conventional imaging studies resulted in a higher number of findings that generated additional tests and biopsies that ultimately had negative results (17% vs. 5% for PET). There was a statistically significant difference in specificity for PET compared with conventional imaging (P = .01).

CONCLUSIONS

Conventional imaging and PET were equally sensitive in detecting metastatic disease in patients with high-risk, operable breast cancer, but PET generated fewer false-positive results. FDG-PET scanning should be further studied in this setting and considered in the preoperative evaluation of selected patients with breast cancer.

Comparison of positron emission tomography, computed tomography, and endoscopic ultrasound in the initial staging of patients with esophageal cancer

INTRODUCTION

Improvement in esophageal cancer staging is needed. Positron emission tomography (PET), computed tomography (CT), and endoscopic ultrasound (EUS) in the staging of esophageal carcinoma were compared.

METHODS

PET, CT, and EUS were performed and interpreted prospectively in 75 patients with newly diagnosed esophageal cancer. Either tissue confirmation or fine needle aspiration (FNA) was used as the gold standard of disease. Sensitivity and specificity for tumor, nodal, and metastatic (TNM) disease for each test were determined. TNM categorizations from each test were used to assign patients to subgroups corresponding to the three treatment plans that patients could theoretically receive, and these were then compared.

RESULTS

Local tumor staging (T) was done correctly by CT and PET in 42% and by EUS in 71% of patients (P value > 0.14). The sensitivity and specificity for nodal involvement (N) by modality were 84% and 67% for CT, 86% and 67% for EUS, and 82% and 60% for PET (P value > 0.38). The sensitivity and specificity for distant metastasis were 81% and 82% for CT, 73% and 86% for EUS, and 81% and 91% for PET (P value > 0.25). Treatment assignment was done correctly by CT in 65%, by EUS in 75%, and by PET in 70% of patients (P value > 0.34).

CONCLUSIONS

EUS had superior T staging ability over PET and CT in our study group. The tests showed similar performance in nodal staging and there was a trend toward improved distant disease staging with CT or PET over EUS. Assignment to treatment groups in relation to TNM staging tended to be better by EUS. Each test contributed unique patient staging information on an individual basis.

Gastrointestinal malignancies evaluated with (18)F-fluoro-2-deoxyglucose positron emission tomography

(18)F-fluoro-2-deoxyglucose positron emission tomography has demonstrated high accuracy in the staging and evaluation of colorectal and esophageal carcinomas. FDG PET is demonstrating increasing utility in a number of other gastrointestinal tumours and clinical scenarios. The established clinical indications for its use, the diagnostic accuracy, and limitations will be reviewed. Data on the emerging indications and limitations for pancreatic, hepatocellular, and gastric carcinomas, as well as gastrointestinal stromal tumours, cholangiocarcinoma, and carcinoma of unknown primary will also be briefly discussed. The use of combined PET-CT is demonstrating further improvements in diagnostic accuracy.

A comparison between low-volume referring regional centers and a high-volume referral center in quality of preoperative metastasis detection in esophageal carcinoma

BACKGROUND AND AIM

An inverse correlation between hospital volume and esophageal resection mortality has been reported. In this study, we compared the quality of preoperative metastasis detection between a high-volume referral center with that of low-volume referring regional centers.

METHODS

In 573 patients diagnosed with esophageal cancer (1994-2003), the results of preoperative staging investigations (CT-scan, ultrasound of abdomen and neck, and chest x-ray) performed in 61 regional centers were re-evaluated and/or repeated in one referral center. The gold standards were a radiological result with > or =6 months follow-up, fine-needle aspiration, or the postoperative TNM-stage.

RESULTS

In the same group of patients, the preoperative investigations performed in regional centers detected true-positive malignant lymph nodes in 8% of patients and true-positive distant metastases in 7% of patients, whereas these percentages were 16% and 20%, respectively, in the referral center. In 72/573 (13%) patients, one or more metastases detected in the referral center had been missed in the regional centers. After allowing resectability in the presence of M1a lymph nodes, this would still have resulted in futile esophageal resections in 6% of patients. In contrast to the higher diagnostic sensitivity in the referral center, specificity was comparable between referral and regional centers.

CONCLUSIONS

This study found that, in assessing the operability of esophageal cancer, the diagnostic sensitivity of metastasis detection in a high-volume referral center was higher than that in referring regional centers. This resulted from both better CT-scanning equipment and more experienced radiologists in the referral center. Should the decision to perform esophagectomy have only been based on metastasis detection in these regional centers, over 1 in 20 patients would have undergone resection in the presence of metastases.

Staging in oesophageal cancer

Accurate staging defines groups for stage-specific treatment, minimising inappropriate treatment. Application of dedicated staging methods - including 16-64 multidetector computed tomography (CT), endoscopic ultrasonography with fine-needle aspiration (EUS-FNA) and positron emission tomography (PET) - results in better staging of oesophageal cancer. PET as a metabolic imaging technique that is usually applied after (or recently in combination with) CT (PET/CT) improves the accuracy of non-invasive staging, especially in locally advanced oesophageal cancer patients. Whether EUS-FNA or PET/CT should be performed as a first diagnostic step is still a matter of debate. Fluoro-2-deoxyglucose (FDG) PET is also promising tool in assessing neoadjuvant treatment response. Application of these dedicated staging methods has a learning curve, suggesting a prominent role for centralisation.

Molecular imaging: what can be used today

Biochemical cellular targets and more general metabolic processes in cancer cells can be visualised. Extensive data are available on molecular imaging in preclinical models. However, innovative tracers move slowly to the clinic. This review provides information on the currently available methods of metabolic imaging, especially using PET in humans. The uptake mechanisms of tracer methods and a brief discussion of the more ‘molecular’ targeted methods are presented. The main focus is on the different classes of tracers and their application in various types of cancer within each class of tracers, based on the current literature and our own experience. Studies with [¹⁸F]FDG (energy metabolism), radiolabelled amino acids (protein metabolism), [¹⁸F]FLT (DNA metabolism), [¹¹C]choline (cell membrane metabolism) as general metabolic tracer methods and [¹⁸F]DOPA (biogenic amine metabolism) as a more specific tracer method are discussed. As an example, molecular imaging methods that target the HER2 receptor and somatostatin receptor are described.

Multimodal treatment of gastrointestinal tract tumors: consequences for surgery

Formerly an exclusive business of surgery, gastrointestinal (GI) tumors are nowadays increasingly approached with multimodal strategies. Neoadjuvant concepts have had a particularly far-reaching impact on surgery and have contributed to improved survival. Modern pre-treatment staging and risk assessment provide the basis for decision on one of three general treatment concepts (1) Early cancers, confined to the mucosal/submucosal layers, are approached with primary surgery, without prior antineoplastic therapy. (2) Systemically metastasized tumors receive merely palliative treatment. (3) Locally advanced cancers are increasingly approached with neoadjuvant strategies. The benefit from these preoperative protocols is proven for diverse entities, but is evidently confined to a specific subgroup patients, i.e., the responders to neoadjuvant treatment. These are the ones benefiting most from subsequent surgical resection, which is required to ensure complete removal of the residual tumor tissue, as complete tumor regression occurs very rarely and cannot be proven without a specimen. The fact that responders will benefit and non-responders will not benefit or will even deteriorate during the neoadjuvant treatment makes early response prediction most demanding. An amazing new approach is the use of position emission tomography with fluro-desoxyglucose (FDG-PET) to assess the "metabolic response," which is possible as early as 14 days after initiation of the neoadjuvant protocol. This strategy offers the chance for modulating the surgical approach in accord i.e., with such metrobolic response termination of the protocol and proceeding to resection in the case of nonresponse. The future of GI cancer surgery is multimodal therapy in a response-based fashion and requires reponse-based trials for further evaluation.

Neoadjuvante Therapie von Plattenepithelkarzinomen des Ösophagus

Neoadjuvant treatment for locally advanced squamous cell carcinoma of the esophagus is widely used, despite minimal evidence of its efficacy. With only a minor effect on survival, the benefits of neoadjuvant radiotherapy alone appear to be limited. The same is true for neoadjuvant chemotherapy alone. While no single randomized study has shown a statistically significant result favoring neoadjuvant chemoradiation vs no treatment, the results of three meta-analyses indicate a prognostic benefit. Unfortunately, earlier chemoradiation protocols were associated with considerable side effects and contributed to perioperative morbidity and mortality. In contrast, modern chemoradiation protocols were revealed to be feasible when carried out in experienced institutions. Therefore, neoadjuvant chemoradiation is indicated in locally advanced stages. Patients should be referred to specialized centers for initial treatment planning and resection, and they should be enrolled in clinical studies whenever possible.

Progress and promise of FDG-PET imaging for cancer patient management and oncologic drug development

2-[(18)F]Fluoro-2-deoxyglucose positron emission tomography (FDG-PET) assesses a fundamental property of neoplasia, the Warburg effect. This molecular imaging technique offers a complementary approach to anatomic imaging that is more sensitive and specific in certain cancers. FDG-PET has been widely applied in oncology primarily as a staging and restaging tool that can guide patient care. However, because it accurately detects recurrent or residual disease, FDG-PET also has significant potential for assessing therapy response. In this regard, it can improve patient management by identifying responders early, before tumor size is reduced; nonresponders could discontinue futile therapy. Moreover, a reduction in the FDG-PET signal within days or weeks of initiating therapy (e.g., in lymphoma, non-small cell lung, and esophageal cancer) significantly correlates with prolonged survival and other clinical end points now used in drug approvals. These findings suggest that FDG-PET could facilitate drug development as an early surrogate of clinical benefit. This article reviews the scientific basis of FDG-PET and its development and application as a valuable oncology imaging tool. Its potential to facilitate drug development in seven oncologic settings (lung, lymphoma, breast, prostate, sarcoma, colorectal, and ovary) is addressed. Recommendations include initial validation against approved therapies, retrospective analyses to define the magnitude of change indicative of response, further prospective validation as a surrogate of clinical benefit, and application as a phase II/III trial end point to accelerate evaluation and approval of novel regimens and therapies.

The additional value of PET/CT over PET in FDG imaging of oesophageal cancer

PURPOSE

The aim of this study was to assess the value of combined PET/CT compared with PET reviewed side-by-side with CT, in patients with oesophageal cancer, before and after surgery.

METHODS

Forty-one FDG PET/CT studies were performed in 32 patients with oesophageal cancer, before surgery (n = 18) or during follow-up after resection of the primary tumour (n = 23). One hundred and fifteen sites suspicious for malignancy were evaluated. PET/CT was prospectively compared with PET reviewed side-by-side with CT, for detection, accurate localisation and characterisation of malignant sites. PET/CT performance in different anatomical regions was compared before and after surgery. The impact of fused data on patient management was retrospectively assessed.

RESULTS

PET/CT had an incremental value over PET for interpretation of 25 of 115 sites (22%), changing the initial characterisation of ten sites to either malignant (n = 1) or benign (n = 9), and defining the precise anatomical location of 15 sites. PET/CT provided better specificity and accuracy than PET for detecting sites of oesophageal cancer (81% and 90% vs 59% and 83% respectively, p < 0.01). Fusion was of special value for interpretation of cervical and abdomino-pelvic sites, for disease assessment in loco-regional lymph nodes before surgery and in regions of postoperative anatomical distortion. PET/CT had an impact on the further management of four patients (10%), by detecting nodal metastases that warranted disease upstaging (n = 2) and by excluding disease in sites of benign uptake after surgery (n = 2).

CONCLUSION

PET/CT improves the accuracy of FDG imaging in oesophageal cancer and provides data of diagnostic and therapeutic significance for further patient management.

Systemic treatment for oesophageal cancer

Oesophageal cancer, in particular adenocarcinomas, has shown a rapid and largely unexplained increase in incidence in the Western world. Despite advances in diagnostic and surgical techniques and improved pre- and postoperative care, the prognosis of most patients is poor. This Review will focus on the use of chemotherapy as part of multimodal treatment and for patients with metastatic disease. Randomised phase III trials have, for the most part, failed to demonstrate a survival advantage with the use of chemotherapy. It must be emphasised that many of these phase III trial were underpowered and do not meet today's standards. Recent phase II trials have suggested some progress when chemotherapy is incorporated into the management of patients with oesophageal cancer. However, confirmatory and adequately powered and designed phase III studies are urgently needed to improve patient outcomes and for better palliation of symptoms.

Diagnostic radiology and nuclear medicine

The diagnosis and accurate staging of esophageal adenocarcinoma remains one of the greatest challenges for non-invasive imaging techniques. All modalities have limitations and require a rational application of combined tools in order to assess the extent of loco-regional tumor and distant metastatic disease. The fundamental role remains defining organ-confined disease and mapping non-organ confined disease. Endoscopic ultrasound combined with multislice computed tomography (CT) is the mainstay of morphologic loco-regional staging. In recent years, functional metabolic 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) has emerged as a particularly useful adjunct to detect occult metastatic disease, to predict response to neoadjuvant therapy and to document recurrent disease. The current imaging algorithm and new developments in imaging assessment will be reviewed.