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

Gastric cancer with limited peritoneal metastasis: Role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND AND OBJECTIVES

Peritoneal metastasis in gastric cancer is associated with a very poor prognosis with a median overall survival of seven to 15 months if treated with systemic chemotherapy only. Studies have shown improved survival with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected group of patients, when compared to systemic chemotherapy alone. In spite of promising results, this is not the standard of care till date. The aim of our study was to evaluate the long-term outcome for the patients of gastric cancer with peritoneal metastases undergoing cytoreductive surgery and HIPEC at our institute.

METHODS

Retrospective analysis of prospectively maintained data of all patients, who underwent cytoreductive surgery and HIPEC during the period of 2015-2023, was performed. All relevant pre-operative, peri-operative, post-operative and histopathological data was analyzed and overall survival and disease-free survival calculated.

RESULTS

Twenty-three patients of gastric cancer with peritoneal metastasis (PCI < / = 7) underwent cytoreductive surgery and HIPEC during the study period. At a median follow-up of 12 months, median disease-free survival (DFS) and overall survival (OS) were 12 months and 35 months, respectively. One-year and three-year DFS were 48.5% and 23%, respectively. One-year and three-year OS was 85% and 45.4%, respectively.

CONCLUSION

Cytoreductive surgery and HIPEC can be considered to be safe and effective treatment strategy in a select group of gastric cancer patients with peritoneal metastasis leading to a meaningful survival as compared to palliative systemic chemotherapy.

Adjuvant treatment for locally advanced gastric cancer: an Asian perspective

Standard adjuvant treatment for locally advanced gastric cancer (LAGC) is regionally different. Whereas perioperative chemotherapy is the standard in Western populations, D2 gastrectomy followed by adjuvant chemotherapy has been the standard in East Asia. Recently, the pivotal phase 3 PRODIGY and RESOLVE studies have demonstrated survival benefits of adding neoadjuvant chemotherapy to surgery followed by adjuvant chemotherapy over up-front surgery followed by adjuvant chemotherapy in Asian patients. Based on these results, neoadjuvant chemotherapy is considered one of the viable options for patients with LAGC. In this review, various aspects of neoadjuvant chemotherapy will be discussed for its optimal application in Asia. Candidates for neoadjuvant chemotherapy should be carefully chosen in consideration of the inaccurate aspects of radiological clinical staging and its potential benefit over up-front surgery followed by a decision on adjuvant chemotherapy according to the pathological stage. Efforts should continuously be made to optimally apply neoadjuvant chemotherapy to patients with LAGC, considering various factors, including a more accurate radiological assessment of the tumor burden and the optimization of post-operative chemotherapy. Future neoadjuvant trials involving novel agents for Asian patients should be designed based on proven Asian regimens rather than adopting Western regimens.

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

[68Ga]Ga-FAPI PET for the evaluation of digestive system tumors: systematic review and meta-analysis

PURPOSE

Digestive system tumors are a group of tumors with high incidence in the world nowadays. The assessment of digestive system tumor metastasis by conventional imaging seems to be unsatisfactory. [⁶⁸Ga]Ga-FAPI, which has emerged in recent years, seems to be able to evaluate digestive system tumor metastasis. We aimed to summarize the current evidence of [⁶⁸Ga]Ga-FAPI PET/CT or PET/MR for the assessment of primary tumors, lymph node metastases, and distant metastases in digestive system tumors. Besides, we also aimed to perform a meta-analysis of the sensitivity of [⁶⁸Ga]Ga-FAPI PET diagnosis to discriminate between digestive system tumors, primary lesions, and non-primary lesions (lymph node metastases and distant metastases).

MATERIALS AND METHODS

PubMed, MEDLINE and Cochrane Library databases were searched from the beginning of the database build to August 12, 2022. All studies undergoing [⁶⁸Ga]Ga-FAPI PET for the evaluation of digestive tumors were included in the screening and review. Screening and full text review was performed by 3 investigators and data extraction was performed by 2 investigators. Risk of bias was examined with the QUADAS-2 criteria. Diagnostic test meta-analysis was performed with a random-effects model.

RESULTS

A total of 541 studies were retrieved. Finally, 22 studies were selected for the systematic review and 18 studies were included in the meta-analysis. In the 18 publications, a total of 524 patients with digestive system tumors, 459 primary tumor lesions of digestive system tumors, and 1921 metastatic lesions of digestive system tumors were included in the meta-analysis. Based on patients, the sensitivity of [⁶⁸Ga]Ga-FAPI PET for the diagnosis of digestive system tumors was 0.98 (95% CI: 0.94-0.99). Based on lesions, the sensitivity of [⁶⁸Ga]Ga-FAPI PET for the diagnostic evaluation of primary tumor lesions of the digestive system was 0.97 (95% CI: 0.93-0.99); the sensitivity of [⁶⁸Ga]Ga-FAPI PET for the diagnostic evaluation of non-primary lesions (lymph node metastases and distant metastases) of the digestive system tumors was 0.94 (95% CI: 0.79-0.99).

CONCLUSION

[⁶⁸Ga]Ga-FAPI PET has high accuracy and its sensitivity is at a high level for the diagnostic evaluation of digestive system tumors. Clinicians, nuclear medicine physicians, and radiologists may consider using [⁶⁸Ga]Ga-FAPI PET/CT or PET/MR in the evaluation of primary tumors, lymph node metastases, and distant metastases in digestive system tumors.

Gastric Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Gastric cancer is the third leading cause of cancer-related deaths worldwide. Over 95% of gastric cancers are adenocarcinomas, which are typically classified based on anatomic location and histologic type. Gastric cancer generally carries a poor prognosis because it is often diagnosed at an advanced stage. Systemic therapy can provide palliation, improved survival, and enhanced quality of life in patients with locally advanced or metastatic disease. The implementation of biomarker testing, especially analysis of HER2 status, microsatellite instability (MSI) status, and the expression of programmed death-ligand 1 (PD-L1), has had a significant impact on clinical practice and patient care. Targeted therapies including trastuzumab, nivolumab, and pembrolizumab have produced encouraging results in clinical trials for the treatment of patients with locally advanced or metastatic disease. Palliative management, which may include systemic therapy, chemoradiation, and/or best supportive care, is recommended for all patients with unresectable or metastatic cancer. Multidisciplinary team management is essential for all patients with localized gastric cancer. This selection from the NCCN Guidelines for Gastric Cancer focuses on the management of unresectable locally advanced, recurrent, or metastatic disease.

The overriding role of surgery and tumor grade for long-term survival in patients with gastroenteropancreatic neuroendocrine neoplasms: A population-based cohort study

Background

Gastroenteropancreatic neuroendocrine neoplasms (GEP‐NENs) comprise a heterogeneous disease group. Factors that affect long‐term survival remain uncertain. Complete population‐representative cohorts with long‐term follow‐up are scarce.

Aim

To evaluate factors of importance for the long‐term survival.

Methods and results

An Observational population‐based study on consecutive GEP‐NEN patients diagnosed from 2003 to 2013, managed according to national guidelines. Univariable and multivariable survival analyses were performed to evaluate overall survival (OS) and to identify independent prognostic factors. One hundred ninety eligible patients (males, 58.9%) (median age, 60.0 years; range, 10.0–94.2 years) were included. The small bowel, appendix, and pancreas were the most common tumor locations. The World Health Organization (WHO) tumor grade 1–3 distributions varied according to the primary location and disease stage. Primary surgery with curative intent was performed in 66% of the patients. The median OS of the study population was 183 months with 5‐ and 10‐year OS rates of 66% and 57%, respectively. Only age, WHO tumor grade, and primary surgical treatment were independent prognostic factors for OS.

Conclusion

The outcomes of GEP‐NEN patients are related to several factors including age and primary surgical treatment. WHO tumor grading, based on the established criteria, should be routine in clinical practice. This may improve clinical decision‐making and allow the comparison of outcomes among different centers.

Comparison of 68Ga-FAPI and 18F-FDG Uptake in Gastric, Duodenal, and Colorectal Cancers

Background Accurate clinical staging is crucial to managing gastrointestinal cancer, but fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET/CT has limitations. Targeting fibroblast-activation protein is a newer diagnostic approach for the visualization of tumor stroma, and gallium 68 (⁶⁸Ga)-labeled fibroblast-activation protein inhibitors (FAPIs), hereafter ⁶⁸Ga-FAPIs, present a promising alternative to ¹⁸F-FDG. Purpose To compare the diagnostic efficacy of ⁶⁸Ga-FAPI PET/CT in primary and metastatic lesions of gastrointestinal malignancies with that of ¹⁸F-FDG PET/CT. Materials and Methods Images from patients with gastric, duodenal, and colorectal cancers who underwent contemporaneous ¹⁸F-FDG and ⁶⁸Ga-FAPI PET/CT between October 2019 through June 2020 were retrospectively analyzed. ¹⁸F-FDG and ⁶⁸Ga-FAPI uptakes were compared by using the Wilcoxon signed-rank test. The McNemar test was used to compare the diagnostic performance between the two techniques. Results Thirty-five patients (median age, 64 years [interquartile range, 53-68 years]; 18 men) were evaluated. In treatment-naive patients (n = 19), ⁶⁸Ga-FAPI PET/CT led to upstaging of the clinical TNM stage in four (21%) patients compared with ¹⁸F-FDG PET/CT. Tracer uptake was higher with ⁶⁸Ga-FAPI PET/CT than with ¹⁸F-FDG PET/CT in primary lesions (gastric cancer: 12.7 vs 3.7, respectively, P = .003; colorectal cancer: 15.9 vs 7.9, P = .03), involved lymph nodes (6.7 vs 2.4, P < .001), and bone and visceral metastases (liver metastases: 9.7 vs 5.2, P < .001; peritoneal metastases: 8.4 vs 3.6, P < .001; bone metastases: 4.3 vs 2.2, P < .001; lung metastases: 4.4 vs 1.9, P = .01). In addition, the sensitivity of ⁶⁸Ga-FAPI PET/CT was higher than that of ¹⁸F-FDG PET/CT in the detection of primary tumors (100% [19 of 19] vs 53% [10 of 19], respectively; P = .004), lymph nodes (79% [22 of 28] vs 54% [15 of 28], P < .001), and bone and visceral metastases (89% [31 of 35] vs 57% [20 of 35], P < .001). Conclusion Gallium 68 fibroblast-activation protein inhibitor PET/CT was superior to fluorine 18 fluorodeoxyglucose PET/CT in the detection of primary and metastatic lesions in gastric, duodenal, and colorectal cancers, with higher tracer uptake in most primary and metastatic lesions. Published under a CC BY 4.0 license.

Gallbladder cancer revisited: the evolving role of a radiologist

Gallbladder cancer is the most common malignancy of the biliary tract. It is also the most aggressive biliary tumor with the shortest median survival duration. Complete surgical resection, the only potentially curative treatment, can be accomplished only in those patients who are diagnosed at an early stage of the disease. Majority (90%) of the patients present at an advanced stage and the management involves a multidisciplinary approach. The role of imaging in gallbladder cancer cannot be overemphasized. Imaging is crucial not only in detecting, staging, and planning management but also in guiding radiological interventions. This article discusses the role of a radiologist in the diagnosis and management of gallbladder cancer.

Updates on Management of Gastric Cancer

PURPOSE OF REVIEW

Gastric adenocarcinoma is the fifth most common and the third most lethal cancer worldwide. Surgery is the only chance of cure, but recurrence is common, even with complete resection.

RECENT FINDINGS

Advances in diagnosis and staging, genomic classification, surgical resection and treatment of peritoneal disease, systemic chemotherapy and chemoradiation, and targeted and immune therapies have led to the current multidisciplinary approach to gastric adenocarcinoma. Treatment of gastric cancer is rapidly evolving in an effort to combat this challenging disease.

The clinical implications of FDG-PET/CT differ according to histology in advanced gastric cancer

BACKGROUND

The prognostic impact of preoperative 18F-FDG PET/CT in advanced gastric cancer (AGC) remains a matter of debate. This study aims to evaluate the prognostic impact of SUVmax in preoperative 18F-FDG PET/CT of AGC according to histologic subtype, with a focus on the differences between tubular adenocarcinoma and signet ring cell (SRC) carcinoma.

METHODS

As a discovery set, a total of 727 AGC patients from prospective database were analyzed according to histologic subtype with Cox proportional hazard model and p-spline curves. In addition, another 173 patients from an independent institution was assessed as an external validation set.

RESULTS

In multivariate analysis, high SUVmax in preoperative 18F-FDG PET/CT of AGC was negatively correlated with disease-free survival (DFS) and overall survival (OS) in patients with diffuse type (DFS: HR 2.17, P < 0.001; OS: HR 2.47, P < 0.001) or SRC histology (DFS: HR 2.26, P = 0.005; OS: HR 2.61, P = 0.003). This negative prognostic impact was not observed in patients with intestinal type or well or moderately differentiated histology. These findings have been consistently confirmed in a validation set. The p-spline curves also showed a gradual increase in log HR as SUVmax rises only for SRC histology and for diffuse-type AGC. Finally, a novel predictive model for recurrence of AGC with diffuse type or SRC histology was generated and validated based on the preoperative SUVmax.

CONCLUSIONS

Preoperative high SUVmax of AGC is a poor prognostic factor in those with diffuse type or SRC histology. This study is the first to demonstrate the differential prognostic impact of preoperative PET/CT SUVmax in AGC according to histologic subtype and provide a clue to explain previous discrepancies in the prognostic impact of preoperative PET/CT in AGC. Prospective studies are required to validate the role of preoperative SUVmax in AGC.

Gastric Adenocarcinoma: A Multimodal Approach

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Prognostic value of pretreatment standardized uptake value of F-18-fluorodeoxyglucose PET in patients with gastric cancer: a meta-analysis

Background

F-18- fluorodeoxyglucose Positron emission tomography (¹⁸FDG-PET) has been widely used in clinical practice. However, the prognostic value of the pretreatment standardized uptake value (SUV) for patients with gastric cancer remains controversial.

Methods

Major databases were systematically searched. The quality of the included studies was assessed using the Newcastle–Ottawa scale; the PET protocols were also evaluated. The pooled hazard ratio (HR) for overall survival (OS) and recurrence-free survival (RFS) were used to estimate the effect size. Data from the included studies were analyzed using Review Manager Software version 5.2.

Results

Eight studies with 1080 patients were included. The pooled HR for OS of six studies including 672 patients was 1.72 (95% CI [1.28–2.3], p = 0.0004, I² = 0%), indicating that patients with high SUVs may have poor prognosis. The pooled HR for RFS was 1.70 (95% CI [1.20–2.39], p = 0.003, I² = 0%). Subgroup analysis based on the cutoff values determining method indicated that the receiver operating characteristic (ROC) method could better define the cutoff value. Subgroup analysis based on the therapeutic strategies used subsequently indicated the significant prognostic value of SUV.

Conclusion

In conclusion, our meta-analysis indicated that pretreatment SUV in primary lesions can be an important prognostic factor for overall survival and recurrence-free survival in patients with gastric cancer. High SUVs may indicate poor prognosis.

Predictive Role of the Number of 18F-FDG-Positive Lymph Nodes Detected by PET/CT for Pre-Treatment Evaluation of Locally Advanced Gastric Cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of the numbers of metabolically positive lymph nodes (MPLN) detected by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in patients with locally advanced gastric cancer (LAGC).

METHODS

We retrospectively analyzed the records of 50 patients with LAGC (stage T2-T4) who had undergone pre-operative PET/CT examination and laparotomy (total gastrectomy, n = 11; subtotal gastrectomy, n = 13; distal gastrectomy, n = 22; and bypass with gastrojejunstomy, n = 4). The numbers of MPLN were determined by combining visual observations with semi-quantitative measurements of the maximized standardized uptake value (SUVmax). Performance was investigated in terms of predicting post-surgical overall survival (OS).

RESULTS

The median post-surgical OS was 32.57 months (range 3.0-94 months). The numbers of MPLN were moderately correlated with the numbers of histological positive LN (r = 0.694, p = 0.001). In univariate analyses, the numbers of MPLN (≤ 2 vs. ≥3), PET/CT LN (positivity vs. negativity), SUVmax of LN (< 2.8 vs. ≥ 2.8), TNM stage (I, II vs. III, IV), and surgery type (R0 vs. non-R0) were significantly associated with OS. In multivariate analysis, surgery type (R0 vs. non-R0) and numbers of MPLN (≤ 2 vs. ≥ 3) were both independent factors for poor OS.

CONCLUSIONS

This explored study indicates that the number of MPLN could provide additional information for LAGC prognosis. Patients with MPLNs ≥ 3 may be at the risk of the more bad outcomes, and the further clinical trials are needed.

Preoperative Use of PET/CT in Patients With Colorectal and Gastric Cancer and Its Impact on Treatment Decision Making

The advantages of primary positron emission tomography–computed tomography (PET-CT) evaluation of both cancers needs to be clarified. This study aimed to investigate the efficacy of PET-CT compared with computed tomography (CT) in preoperative evaluation of colorectal and gastric cancer patients, and to determine its effects on treatment decision-making. We prospectively evaluated patients who presented with both types of cancer in our clinic between September 2008 and June 2010, using PET-CT and CT. We compared the results with histopathologic findings and determined the changing treatment strategies. In detecting local lymph node positivity, for colorectal cancer patients the sensitivity of PET-CT was 30% and that of CT was 20%; the specificities were the same (100%). For gastric cancer patients, the sensitivity of PET-CT was 38.9% and that of CT was 22%; the specificities were 100% and 83%, respectively. In detecting metastasis, for colorectal cancer patients the sensitivity of PET-CT was 80% and that of CT was 50%; the specificities were similar (100% versus 95%). For gastric cancer patients, the sensitivity of PET-CT was 72% and that of CT was 34%; the specificities were similar (95% versus 90%). In detecting liver metastasis, for colorectal cancer patients the sensitivity of PET was 75% and that of CT was 50%; the specificities were similar (100% versus 95%). For gastric cancer patients, the sensitivity of PET-CT was 57% and that of CT was 28%; the specificities were similar (95% versus 91%). PET-CT findings altered treatment decisions in 16% of patients (n = 10; 9 gastric cancer and 1 colorectal cancer). A high rate of treatment strategy alteration in gastric cancers was seen with PET-CT; its usage is preferred in colorectal cancer staging only for high-risk patients and those with equivocal findings.

Clinical Value of a One-Stop-Shop Low-Dose Lung Screening Combined with (18)F-FDG PET/CT for the Detection of Metastatic Lung Nodules from Colorectal Cancer

PURPOSE

The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with (18)F-fluoro-2-deoxyglucose positron emission tomography with CT ((18)F-FDG PET/CT) compared with conventional lung setting image of (18)F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer.

METHODS

From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with (18)F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of (18)F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of (18)F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed.

RESULTS

Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of (18)F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were <1 cm in size. The sensitivity, specificity, and diagnostic accuracy of the modalities were 60.6 %, 85.2 %, and 71.1 % for conventional lung setting image and 83.3 %, 88.9 %, and 85.8 % for additional LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional lung setting image and additional LD-HRCT were 0.712 and 0.827 respectively.

CONCLUSION

Additional LD-HRCT with maximum inspiration was superior to conventional lung setting image of (18)F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer (P < 0.05).

Synchronous second primary cancers in patients with squamous esophageal cancer: clinical features and survival outcome

BACKGROUND/AIMS

Unexpected diagnosis of synchronous second primary cancers (SPC) complicates physicians' decision-making because clinical details of squamous esophageal cancer (EC) patients with SPC have been limited. We evaluated clinical features and treatment outcomes of patients with synchronous SPC detected during the initial staging of squamous EC.

METHODS

We identified a total of 317 consecutive patients diagnosed with squamous EC. Relevant clinical and cancer-specific information were reviewed retrospectively.

RESULTS

EC patients with synchronous SPC were identified in 21 patients (6.6%). There were significant differences in median age (70 years vs. 63 years, p = 0.01), serum albumin level (3.3 g/dL vs. 3.9 g/dL, p < 0.01) and body mass index (20.4 kg/m(2) vs. 22.8 kg/m(2), p = 0.01) between EC patients with and without SPC. Head and neck, lung and gastric cancers accounted for 18.2%, 22.7%, and 18.2% of SPC, respectively. Positron emission tomography-computed tomography (PET-CT) detected four cases (18.2%) of SPC that were missed on CT. Management plans were altered in 13 of 21 patients (61.9%) with detected SPC. Curative esophagectomy was attempted in 28.6% of EC patients with SPC (vs. 59.1% of patients without SPC; p = 0.006). EC patients with SPC had significantly lower 5-year survival than patients without SPC (10.6% vs. 36.7%, p = 0.008).

CONCLUSIONS

Synchronous SPC were found in 6.6% of squamous EC patients, and PET-CT contributed substantially to the detection of synchronous SPC. EC patients with SPC had poor survival due to challenges of providing stage-appropriate treatment.

Perioperative chemotherapy for gastroesophageal cancer in British Columbia: a multicentre experience

BACKGROUND

In 2006, perioperative epirubicin, cisplatin, and 5-fluorouracil (ecf), compared with surgery alone, demonstrated a significant survival benefit in resectable gastroesophageal cancers. We report the results of our experience with that protocol.

METHODS

The BC Cancer Agency (bcca) is a multicentre institution that treats most oncology patients for the province. Characteristics of the 83 bcca patients with localized gastric, gastroesophageal junction, or lower esophageal cancer who initiated perioperative chemotherapy either ecf or epirubicin, cisplatin, and capecitabine (ecx) from 2008 to 2011 were abstracted to an anonymous database and analyzed.

RESULTS

Of the 83 patients in the cohort [66 men; median age: 62 years (range: 37-79 years)], 87.9% completed 3 cycles of perioperative chemotherapy, and 93.9% (n = 78) underwent an attempt at surgery (2 patients died of chemotherapy toxicities, 1 refused surgery, and 2 developed disease progression before surgery). In 11 of the surgeries (14.1%), tumours could not be resected because of unresectability (n = 1), liver metastasis (n = 1), and peritoneal carcinomatosis (n = 9). One patient died of surgical complications. The 6 patients (7.2%) who achieved a pathologic complete response are all alive and recurrence-free. Of 46 patients (55.4%) who subsequently began postoperative chemotherapy, 44.5% completed 3 cycles. Estimated median survival was 40.3 months. Weight loss was the only significant prognostic factor for worse overall survival.

CONCLUSIONS

Our multicentre experience confirmed the feasibility of the magic protocol in a real-world scenario and showed that ecx is also an adequate regimen in the perioperative setting. Weight loss was the only significant prognostic factor for worse overall survival. All patients who achieved a pathologic complete response are recurrence-free after a median follow-up of 40.3 months.

FDG PET/CT diagnosis of clinically occult gastric cancer

AIM: To investigate the use of fluorodeoxyglucose (FDG) positron emission tomography ( PET)/CT imaging in diagnosis of clinically occult gastric cancer.

METHODS: The imaging data for 26 patients with clinically occult gastric cancer who underwent FDG PET/CT imaging were reviewed retrospectively. They were hospitalized for metastatic tumors and therefore underwent FDG PET/CT for detecting carcinoma of unknown primary origin. They were finally diagnosed with gastric cancer by endoscopy (n = 24) or laparoscopy (n = 2). Based on imaging manifestations, the patients were divided into three groups: easily diagnosed, suspected, and hardly diagnosed.

RESULTS: PET imaging showed 57.7% (15/26) of intensively positive cases, 23.1% (6/26) of positive cases, and 19.2% (5/26) of negative cases. CT imaging showed 76.9% (20/26) of intensively positive cases, 11.5% (3/26) of positive cases, and 11.5% (3/26) of negative cases. The percentages of easily diagnosed, suspected, and hardly diagnosed patients were 53.8% (14/26), 34.6% (9/26) and 11.5% (3/26), respectively.

CONCLUSION: FDG PET/CT imaging can help diagnose clinically occult gastric cancer in about 88.4% of patients.

Predictive value of pretreatment metabolic activity measured by fluorodeoxyglucose positron emission tomography in patients with metastatic advanced gastric cancer: the maximal SUV of the stomach is a prognostic factor

PURPOSE

Few studies have evaluated metabolic activity by (18)F-FDG PET as a prognostic factor in advanced gastric cancer (AGC). We investigated its prognostic role in metastatic AGC.

METHODS

We enrolled 82 patients with metastatic AGC, who were treatment-naive and underwent pretreatment (18)F-FDG PET/CT scanning. In each patient, the maximal standardized uptake value (SUVmax) was measured in each target lesion. Stomach(SUVmax) was defined as SUVmax in the stomach, while Total(SUVmax) was defined as the highest SUVmax among all the target lesions.

RESULTS

The stomach was the organ most frequently displaying the highest SUVmax among all the target lesions (in 67.1% of patients). A Total(SUVmax) value of 11.5 was the value with the maximum sum of sensitivity and specificity from receiver-operating characteristic curves for progression-free survival (PFS). PFS was significantly longer in patients with a Total(SUVmax) value <11.5 than in those with a Total(SUVmax) value ≥11.5 (P = 0.023); however, overall survival (OS) was not (P = 0.055). A Stomach(SUVmax) value of 6.0 was derived by similar methods. PFS and OS were significantly longer in those with a Stomach(SUVmax) value <6.0 than in those with a Stomach(SUVmax) value ≥6.0 (P = 0.001 and P = 0.006, respectively). Furthermore, those with a low Total(SUVmax) and those with a low Stomach(SUVmax) showed better chemotherapeutic responses (P = 0.016 and P = 0.034, respectively). Among patients with histologically undifferentiated carcinomas, those with lower Total(SUVmax) and those with lower Stomach(SUVmax) showed longer median PFS (P = 0.027 and P = 0.005, respectively) and OS (P = 0.009 and P <0.001, respectively). Multivariate analysis demonstrated Stomach(SUVmax) as an independent predictor of PFS (P = 0.002) and OS (P = 0.038).

CONCLUSION

Pretreatment metabolic activity may be a useful prognostic marker in patients with metastatic AGC undergoing palliative chemotherapy. Notably, Stomach(SUVmax) was the single, most robust factor predicting prognosis.

Clinicopathological characteristics and computed tomography features of mucinous gastric carcinoma

This study investigated the clinicopathological characteristics of mucinous gastric carcinoma (MGC) and assessed whether multidetector-row computed tomography (MDCT) could differentiate MGC from non-mucinous gastric carcinoma (NGC). Clinicopathological data from 542 patients with gastric carcinoma (23 MGC, 519 NGC), who underwent pre-operative MDCT examination and curative or palliative gastrectomy, were analysed. Only seven of the 23 patients with MGC were correctly diagnosed pre-operatively by endoscopic biopsy. The MGC patients had larger tumours, a higher frequency of lymph node metastases, were more likely to have tumours of tumour, node, metastasis stages III and IV, and were less likely to have a curative resection than NGC patients. In addition, five MGC patients had calcifications in the thickened gastric wall. In conclusion, MGC is rare and is detected mostly at an advanced stage. The diagnostic sensitivity of MGC by endoscopic biopsy was relatively low, whereas MDCT was helpful in distinguishing MGC from NGC.

Japanese Gastric Cancer Association Task Force for Research Promotion: clinical utility of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography in gastric cancer. A systematic review of the literature

Since April 2010, the Japanese Public Health Insurance System has covered the costs incurred for performing ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) imaging for patients with advanced gastric cancer. The aim of this review was to evaluate the clinical impact of PET for patients with gastric cancer. A systematic literature search was performed in PubMed/MEDLINE using the keywords "gastric cancer" and "PET" to search for relevant articles published from January 2000 to September 2010. The clinical impact of selected articles was assessed by the authors to evaluate the following: (a) tumor staging, (b) diagnosis for recurrent disease, (c) evaluation of treatment response, and (d) screening for gastric cancer. FDG uptake increases in papillary adenocarcinoma, tubular adenocarcinoma, and solid-type poorly differentiated adenocarcinoma. This uptake is also associated with glucose transporter 1 expression. The sensitivity and specificity of FDG-PET for metastatic lymph node detection were 21-40% and 89-100%, respectively. The sensitivity and specificity for distant metastasis detection were 35-74% and 74-99%, respectively. Treatment response can be detectable at an earlier stage by PET than by computed tomography (CT), because FDG uptake by cancer cells decreases according to the treatment response. In summary, although PET has limitations such as frequent false-negative cases in signet-ring cell carcinoma and non-solid type poorly differentiated carcinoma, it can contribute to the selection of a more appropriate treatment modality by detecting distant metastases and treatment response.

Diagnostic criteria, specific mutations, and genetic predisposition in gastrointestinal stromal tumors

In 1998, gastrointestinal stromal tumor (GIST) emerged as a distinct oncogenetic entity and subsequently became a paradigm of targeted therapies in solid tumors. Diagnosis of GIST relies on both histology and immunohistochemistry. Ninety-five percent of GISTs express either KIT or DOG-1. Approximately 80%-90% of GISTs harbor gain-of-function mutations of either KIT or platelet-derived growth factor receptor alpha polypeptide (PDGFRA) receptor tyrosine kinase (RTK). More than 100 different mutations have been described, some of which are associated with specific clinical and/or histological characteristics. Detection of KIT or PDGFRA mutations is recommended in advanced GISTs because they are highly predictive of tumor response to RTK inhibitors, as well as in KIT-negative cases to confirm diagnosis. In most cases, GISTs are sporadic, but in rare cases, they are related with genetic predisposition, such as neurofibromatosis type 1, Carney triad, Carney-Stratakis syndrome, and inherited KIT or PDGFRA germline mutations.

R0 resection in the treatment of gastric cancer: Room for improvement

Gastric carcinoma is one of the most frequent malignancies in the world and its clinical behavior especially depends on the metastatic potential of the tumor. In particular, lymphatic metastasis is one of the main predictors of tumor recurrence and survival, and current pathological staging systems reflect the concept that lymphatic spread is the most relevant prognostic factor in patients undergoing curative resection. This is compounded by the observation that two-thirds of gastric cancer in the Western world presents at an advanced stage, with lymph node metastasis at diagnosis. All current therapeutic efforts in gastric cancer are directed toward individualization of therapeutic protocols, tailoring the extent of resection and the administration of preoperative and postoperative treatment. The goals of all these strategies are to improve prognosis towards the achievement of a curative resection (R0 resection) with minimal morbidity and mortality, and better postoperative quality of life.

Islet cell tumours

Pancreatic endocrine tumours can cause hormonal symptoms by over-secretion of hormones. They are less aggressive than exocrine pancreatic cancer, but carry a variable prognosis. The tumours are either sporadic or hereditary, as part of the multiple endocrine neoplasia type 1 syndrome. Despite the rarity of these tumours, they evoke significant interest in the research community and important advances have been made over the past years. This chapter provides an overview of the tumours and recent advances in the field. Hereditary forms of pancreatic endocrine tumours are caused by mutations in the MEN1 gene. Menin, the protein encoded by this gene, has been shown to interact with numerous transcription factors and proteins involved in cell-cycle control, shedding some light on the importance of the protein. Several genes have been shown to be up- or down-regulated, suggesting candidates to be further evaluated for a role in tumourigenesis. Several advances have been made in prognostication; a tumour-node-metastasis system has been evaluated and seems to have prognostic value, and several new molecular prognostic markers are under evaluation. It is hoped that the tumour-node-metastasis system and other prognostic markers will be adopted in clinical routine and improve prognostication and treatment choices. Surgery is still the only cure, but several new palliative drugs and interventions are in use or under investigation. Radiofrequency ablation is increasingly used for liver metastases, and a number of new chemotherapy drugs are being tested. Despite improvements in treatment, no clear improvement in survival has been demonstrated.

Feasibility of using 18F-FDG PET/CT for pretherapeutic evaluation of advanced gastric cancer

AIM: To investigate the feasibility of using ¹⁸F-FDG PET/CT for pretherapeutic evaluation of advanced gastric cancer.

METHODS: The clinical records of 40 advanced gastric cancer patients who underwent ¹⁸F-FDG PET/CT before treatment were reviewed retrospectively. Of these patients, 14 patients underwent radical gastrectomy, and the other patients underwent chemotherapy or palliative gastrectomy. The lymph nodes were classified into two groups (N₁ + N₂ group and N₃ group) based on anatomic sites. Lymph node metastasis was assessed on group basis. All PET/CT images were interpreted according to visual evaluation and standardized uptake values (SUVs).

RESULTS: The diagnostic sensitivity of ¹⁸F-FDG PET/CT, PET and CT for primary tumors was 97.5%, 65% and 90%, respectively. The sensitivity, specificity, and accuracy of 18F-FDG PET/CT for N₁ + N₂ metastases were 71.4%, 77.8% and 85.7%, respectively, while the sensitivity of PET/CT for N₃ metastases was 100%. PET/CT detected 21 cases of metastases undetected by routine method. Accordingly, the TNM stage of tumors was upgraded in 40% of patients.

CONCLUSION: It is feasible to use ¹⁸F-FDG PET/CT for pretherapeutic evaluation of advanced gastric cancer, and the diagnostic outcomes revealed by PET/CT may have a clinically significant impact on the choice of initial therapy.

Promises and challenges of positron emission tomography for assessment of sarcoma in daily clinical practice

A correct histological diagnosis, careful staging and detection of tumour response to treatment are all crucial in the management of sarcomas. Imaging is important in all of these stages. Sarcomas have distinct biological and treatment-related features posing challenges for imaging. For example, size measurements may not adequately reflect response rates. Techniques which can measure tissue function rather than generate merely anatomical data such as positron emission tomography (PET) are rapidly gaining interest. We discuss the importance of imaging in different stages of patient management, emphasising the unique characteristics of sarcoma. Furthermore, we discuss the potential of PET for the various indications, focussing on therapy evaluation.

Preoperative staging of colorectal cancer: CT vs. integrated FDG PET/CT

Accurate preoperative staging is essential in determining the optimal therapeutic planning for individual patients. The computed tomography (CT) in the preoperative staging of colorectal cancer, even if controversial, may be useful for planning surgery and/or neoadjuvant therapy, particularly when local tumor extension into adjacent organs or distant metastases are detected. There have been significant changes in the CT technology with the advent of multi-detector row CT (MDCT) scanner. Advances in CT technology have raised interest in the potential role of CT for detection and staging of colorectal cancer. In recent studies, MDCT with MPR images has shown promising accuracy in the evaluation of local extent and nodal involvement of colorectal cancer. Combined PET/CT images have significant advantages over either alone because it provides both functional and anatomical data. Therefore, it is natural to expect that PET/CT would improve the accuracy of preoperative staging of colorectal cancer. The most significant additional information provided by PET/CT relates to the accurate detection of distant metastases. For the evaluation of patients with colorectal cancer, CT has relative advantages over PET/CT in regard to the depth of tumor invasion through the wall, extramural extension, and regional lymph node metastases. PET/CT should be performed on selected patients with suggestive but inconclusive metastatic lesions with CT. In addition, PET/CT with dedicated CT protocols, such as contrast-enhanced PET/CT and PET/CT colonography, may replace the diagnostic CT for the preoperative staging of colorectal cancer.

The predictive value of 18F-FDG-PET early evaluation in patients with metastatic gastric adenocarcinoma treated with chemotherapy plus cetuximab

BACKGROUND

The aim of the study was to evaluate whether the therapy-induced reduction of the (18)F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) maximum standardized uptake value in patients with advanced gastric adenocarcinoma treated with chemotherapy plus cetuximab could predict the objective response and outcome early during the treatment.

METHODS

The study was performed as a part of a phase II trial evaluating cetuximab plus the leucovorin/5-fluorouracil/irinotecan (FOLFIRI) regimen. The objective response was evaluated according to the response evaluation criteria in solid tumors (RECIST) every 6 weeks. The early metabolic response evaluated by 18F-FDG-PET was assessed according to our own evaluated cutoff value (<35%) after receiver operating characteristic (ROC) analysis.

RESULTS

Twenty of 22 patients had positive baseline 18F-FDG-PET. The best RECIST response was: complete response (CR), 3; partial response (PR), 9; stable disease (SD), 8. Twelve patients (60%) were classified as metabolic responders and 8 (40%) as nonresponders. At the median follow-up time of 11 months, median time to disease progression (TTP) and overall survival (OS) for early metabolic responders versus nonresponders were 11 versus 5 months (P = 0.0016) and 16 versus 6 months (P = 0.1493), respectively.

CONCLUSION

The early metabolic response evaluated by 18F-FDG-PET predicted the clinical outcome in this series of patients with advanced gastric cancer treated with chemotherapy plus cetuximab.

Role of 18F-fluorodeoxyglucose positron emission tomography imaging in surgery for pancreatic cancer

AIM: To evaluate the role of positron emission tomo-graphy using 18F-fluorodeoxyglucose (FDG-PET) in the surgical management of patients with pancreatic cancer, including the diagnosis, staging, and selection of patients for the subsequent surgical treatment.

METHODS: This study involved 53 patients with proven primary pancreatic cancer. The sensitivity of diagnosing the primary cancer was examined for FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of carcinoembrionic antigens (CEA) and carbohydrate antigen 19-9 (CA19-9). Next, the accuracy of staging was compared between FDG-PET and CT. Finally, FDG-PET was analyzed semiquantitatively using the standard uptake value (SUV). The impact of the SUV on patient management was evaluated by examining the correlations between the SUV and the histological findings of cancer.

RESULTS: The sensitivity of FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of CEA and CA19-9 were 92.5%, 88.7%, 46.4%, 37.7% and 69.8%, respectively. In staging, FDG-PET was superior to CT only in diagnosing distant disease (bone metastasis). For local staging, the sensitivity of CT was better than that of FDG-PET. The SUV did not correlate with the pTNM stage, grades, invasions to the vessels and nerve, or with the size of the tumor. However, there was a statistically significant difference (4.6 ± 2.9 vs 7.8 ± 4.5, P = 0.024) in the SUV between patients with respectable and unresectable disease.

CONCLUSION: FDG-PET is thus considered to be useful in the diagnosis of pancreatic cancer. However, regarding the staging of the disease, FDG-PET is not considered to be a sufficiently accurate diagnostic modality. Although the SUV does not correlate with the patho-histological prognostic factors, it may be useful in selecting patients who should undergo subsequent surgical treatment.

PET/CT in oncology: for which tumours is it the reference standard?

Positron emission tomography (PET)/computed tomography (CT) has a growing role in the imaging of many cancers. As our experience has grown over the past number of years so has our understanding for which cancers it is particularly useful. The value of PET/CT at each stage of the cancer journey is different for each cancer. This review attempts to tease out the role of PET/CT in the common cancers with particular emphasis on where it is the imaging investigation of choice.

Detection of distant metastases in patients with oesophageal or gastric cardia cancer: a diagnostic decision analysis

Computed tomography (CT) is presently a standard procedure for the detection of distant metastases in patients with oesophageal or gastric cardia cancer. We aimed to determine the additional diagnostic value of alternative staging investigations. We included 569 oesophageal or gastric cardia cancer patients who had undergone CT neck/thorax/abdomen, ultrasound (US) abdomen, US neck, endoscopic ultrasonography (EUS), and/or chest X-ray for staging. Sensitivity and specificity were first determined at an organ level (results of investigations, i.e., CT, US abdomen, US neck, EUS, and chest X-ray, per organ), and then at a patient level (results for combinations of investigations), considering that the detection of distant metastases is a contraindication to surgery. For this, we compared three strategies for each organ: CT alone, CT plus another investigation if CT was negative for metastases (one-positive scenario), and CT plus another investigation if CT was positive, but requiring that both were positive for a final positive result (two-positive scenario). In addition, costs, life expectancy and quality adjusted life years (QALYs) were compared between different diagnostic strategies. CT showed sensitivities for detecting metastases in celiac lymph nodes, liver and lung of 69, 73, and 90%, respectively, which was higher than the sensitivities of US abdomen (44% for celiac lymph nodes and 65% for liver metastases), EUS (38% for celiac lymph nodes), and chest X-ray (68% for lung metastases). In contrast, US neck showed a higher sensitivity for the detection of malignant supraclavicular lymph nodes than CT (85 vs 28%). At a patient level, sensitivity for detecting distant metastases was 66% and specificity was 95% if only CT was performed. A higher sensitivity (86%) was achieved when US neck was added to CT (one-positive scenario), at the same specificity (95%). This strategy resulted in lower costs compared to CT only, at an almost similar (quality adjusted) life expectancy. Slightly higher specificities (97–99%) were achieved if liver and/or lung metastases found on CT, were confirmed by US abdomen or chest X-ray, respectively (two-positive scenario). These strategies had only slightly higher QALYs, but substantially higher costs. The combination of CT neck/thorax/abdomen and US neck was most cost-effective for the detection of metastases in patients with oesophageal or gastric cardia cancer, whereas the performance of CT only had a lower sensitivity for metastases detection and higher costs. The role of EUS seems limited, which may be due to the low number of M1b celiac lymph nodes detected in this series. It remains to be determined whether the application of positron emission tomography will further increase sensitivities and specificities of metastases detection without jeopardising costs and QALYs.

Gastrointestinal stromal tumour

Gastrointestinal stromal tumours are the most common mesenchymal neoplasm of the gastrointestinal tract and are highly resistant to conventional chemotherapy and radiotherapy. Such tumours usually have activating mutations in either KIT (75-80%) or PDGFRA (5-10%), two closely related receptor tyrosine kinases. These mutations lead to ligand-independent activation and signal transduction mediated by constitutively activated KIT or PDGFRA. Targeting these activated proteins with imatinib mesylate, a small-molecule kinase inhibitor, has proven useful in the treatment of recurrent or metastatic gastrointestinal stromal tumours and is now being tested as an adjuvant or neoadjuvant. However, resistance to imatinib is a growing problem and other targeted therapeutics such as sunitinib are available. The important interplay between the molecular genetics of gastrontestinal stromal tumour and responses to targeted therapeutics serves as a model for the study of targeted therapies in other solid tumours.

Distinguishing benign from malignant gallbladder wall thickening using FDG-PET

OBJECTIVE

Because thickening of the gallbladder wall is observed not only in patients with gallbladder cancer but also in those with benign diseases such as chronic cholecystitis and gallbladder adenomyosis, it is difficult to distinguish between benign and malignant gallbladder wall thickening by conventional techniques of diagnostic imaging such as computed tomography (CT), magnetic resonance imaging (MRI), and abdominal ultrasonography (US). In the present study, we attempted to distinguish between benign and malignant gallbladder wall thickening by means of fluorine-18-fluorodeoxyglucose (FDG)-Positron emission tomography (PET).

METHODS

FDG-PET was performed in 12 patients with gallbladder wall thickening detected by CT or US, to determine whether it was benign or malignant. Emission scans were taken, beginning 45 minutes after intravenous administration of FDG, and SUV was calculated as an indicator of glucose metabolism.

RESULTS

Of the 12 patients, 4 showed positive uptake of FDG in the gallbladder wall. Of these 4 patients, 3 had gallbladder cancer. The remaining one, who had chronic cholecystitis, had false-positive findings. The other 8 patients had negative uptake of FDG in the gallbladder wall. Two of these 8 underwent surgical resection, which yielded a diagnosis of chronic cholecystitis. The other 6 patients exhibited no sign of gallbladder malignancy and have been followed without active treatment.

CONCLUSIONS

FDG-PET appears able to distinguish between benign and malignant gallbladder wall thickening.

Recent evidences of the use of 18F-fluorodeoxyglucose positron emission tomography in the management of colorectal cancer

Positron emission tomography is considered a potentially useful diagnostic tool in the management of a variety of malignancies. It has been used for staging, evaluation of recurrent and metastatic disease, evaluation of tumoral response to neoadjuvant therapy, and providing prognostic information. However, some data are available about its definitive role in the colorectal cancer population. In this review, the most recent evidences and future perspectives are presented for the use of the 18F-fluorodeoxyglucose positron emission tomography in the management of patients with colorectal cancer.

Nuklearmedizinische Diagnostik von Lebertumoren

Standard nuclear medical procedures, such as functional, blood-pool and colloid scintigraphy, play a minor role in the routine workup of liver tumors. However, these techniques are capable of assessing specific organ functions and frequently allow the diagnosis of unclear liver lesions. The sensitivity of scintigraphic procedures can be increased using tomographic imaging (SPECT), the specificity with the introduction of hybrid scanners such as SPECT/CT. Whole body positron emission tomography with 18F-fluoro-deoxy-glucose (FDG) in combination with CT scanning (PET/CT) represents one of the most sensitive imaging modalities for the detection of hepatic metastases and extrahepatic tumor manifestations. For the staging and follow-up of colorectal cancer, FDG-PET/CT represents a standard imaging modality. Metastases from neuroendocrine tumors can be detected using PET and specific tracers such as [68Ga]DOTATOC and [18F]DOPA. Molecular imaging with PET allows the quantification of metabolic processes which can be used for the assessment of an early response to treatment.

Diagnosis and staging of small bowel tumours

Small bowel neoplasms comprise only 1% of gastrointestinal neoplasms. Despite their rarity, it is important to diagnose small bowel tumours early to maximize patient survival.

Upper gastrointestinal tumours: diagnosis and staging

Upper GI tumours have a dismal prognosis. Only early diagnosis and accurate staging can optimize patient management.