Can positron emission tomography improve the quality of care for head-and-neck cancer patients?

PURPOSE: Fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET) is a functional imaging modality that measures the relative uptake of 18FDG with PET. The purpose of this review is to assess the potential contribution of FDG-PET scans to the treatment of head-and-neck cancer patients. METHODS AND MATERIALS: Data were assessed from the literature with attention to what additional information may be gained from the use of FDG-PET in four clinical settings: (1) detection of occult metastatic disease in the neck, (2) detection of occult primaries in patients with neck metastases, (3) detection of synchronous primaries or metastatic disease in the chest, and (4) detection of residual/recurrent locoregional disease. RESULTS: Although the data are somewhat conflicting, FDG-PET appears to add little additional value to the physical examination and conventional imaging studies (supplemented by biopsy when appropriate) for the detection of subclinical nodal metastases, unknown primaries, or disease in the chest. However, FDG-PET scans are quite useful in differentiating residual/recurrent disease from treatment-induced normal tissue changes. A positive FDG-PET scan at 1 month after radiotherapy is highly indicative of the presence of residual disease, and a negative scan at 4 months after treatment is highly predictive of tumor eradication. CONCLUSIONS: Large-scale studies using newer generation equipment and more defined methods are needed to more rigorously assess the potential of FDG-PET in the detection of subclinical primary or simultaneous secondary tumors and of nodal or systemic spread. Currently, however, FDG-PET can contribute to the detection of residual/early recurrent tumors, leading to the timely institution of salvage therapy or the prevention of unnecessary biopsies of irradiated tissues, which may aggravate injury.     

Can we apply the same indication of endoscopic submucosal dissection for primary gastric cancer to remnant gastric cancer?

Background

Currently, remnant gastric cancer (RGC) is uncommon compared with gastric stump cancer, but early detection of gastric cancer and improved postsurgical survival will lead to increased incidence of RGC. Therefore, the indication of endoscopic submucosal dissection (ESD) for RGC is now required, but there have been no reports about this because of the lack of information for RGC.

Methods

A retrospective review was conducted on 105 patients who underwent completion total gastrectomy (CTG) and 5 patients who underwent ESD for RGC between January 1998 and December 2010 at Yonsei University Hospital.

Results

Forty-one (39 %) of 105 patients were diagnosed with early RGC. Among these patients, 6 had an absolute indication for ESD, whereas 11 met expanded criteria for ESD. In these patients, there was no association between the severity of the former gastric cancer and the current RGC. Also, none of these 17 patients had LN metastasis after CTG, and only 1 (2.4 %) of 41 early RGC patients had LN metastasis. Median operative time was 216 min for CTG and median hospital stay was 8 days. There were two major and five minor complications. One splenectomy was performed because of injury that occurred during CTG.

Conclusions

Applying the indication of ESD for primary gastric cancer to RGC would be possible, and it could be an alternative treatment option for selected patients with RGC.     

Does endoscopic follow-up improve the outcome of patients with benign gastric ulcers and gastric cancer?

This study investigated whether an endoscopic surveillance program for patients with "benign" gastric ulcers and gastric cancer leads to early detection of neoplasms and improves survival. The clinical course of all patients diagnosed between 1977 and 1986 as having either gastric ulcers or gastric cancer was followed for a minimum of 3 years. Of 597 patients with initially benign gastric ulcers, 452 (76%) returned for the recommended endoscopic follow-up examinations. In eight patients (1.8%), repeated biopsies disclosed malignant neoplasms; four of these patients (0.9%) had become asymptomatic. Survival curves were nearly identical in patients who complied and those who did not. Of 241 patients with gastric cancer, 72 underwent partial gastric resection with curative intent and survived the first year. Resectable cancer was detected in 5 of 48 patients who complied (10%); none of these patients died of cancer. However, 5-year actuarial survival rates were similar between the patients who complied and those who did not. Although endoscopic surveillance may detect resectable cancer in selected patients, it remains to be shown that such a strategy improves survival.     

Vessel probe CT protocol in the study of esophageal carcinoma: Can it improve preoperative T staging?

Aims

This study aims to compare transverse images and vessel probe (VP) in MPR mode reconstructions obtained by 16-row MDCT with the histological findings in the preoperative T staging of esophageal cancer.

Materials and methods

Thirty-one patients (23 M, 8 F, mean age 63.2) with endoscopic and histological diagnosis of esophageal carcinoma underwent CT examination. Esophageal lumen was distended by CO₂ and a biphasic technique with 35 s and 70 s delay was used after intravenous injection of contrast material. Transverse and VP in MPR mode images were evaluated and the following parameters were considered: presence and location of the tumor; esophageal wall thickness and enhancement; depth of visceral wall invasion; periesophageal fat morphology and infiltration of adjacent organs. Preoperative staging was performed and then it was compared with the histological findings considered as reference standard.

Results

Sensibility, negative predictive and accuracy values were 67%, 64% and 79% by using axial images for preoperative T staging, while the use of VP increased the previous values up to 83%, 78% and 89%, respectively.

Conclusions

In the preoperative staging of esophageal cancer, VP in MPR mode reconstructions obtained by 16-row MDCT increase the sensibility and diagnostic accuracy values in the T parameter evaluation compared with axial images.     

What is the accuracy of sentinel lymph node biopsy for gastric cancer? A systematic review

Background

In gastric cancer, the utility of sentinel lymph node (SLN) biopsy has not been established. SLN may be a good predictor of the pathological status of other lymph nodes and thus the necessity for more extensive surgery or lymph node dissection. We aimed to identify and synthesize findings on the performance of SLN biopsies in gastric cancer.

Methods

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from 1998 to 2009. Titles and abstracts were independently rated for relevance by a minimum of two reviewers. Techniques, detection rates, accuracy, sensitivity, specificity, and false-negative rates (FNRs) were analyzed. Analysis was performed based on the FNR.

Results

Twenty-six articles met our inclusion criteria. SLN detection using the dye method (DM) was reviewed in 18 studies, the radiocolloid method (RM) was used in 12 studies, and both dye and radiocolloid methods (DUAL) were used in 5 studies. The DM had an overall calculated FNR of 34.7% (95% confidence interval [CI] 21.2, 48.1). The RM had an overall calculated FNR of 18.5% (95% CI 9.1, 28.0). DUAL had an overall calculated FNR of 13.1% (95% CI −0.9, 27.2).

Conclusion

Application of the SLN technique may be practical for early gastric cancer. The use of DUAL for identifying SLN may yield a lower FNR than either method alone, although statistical significance was not met.

     

Is the recent WHO histological classification for gastric cancer helpful for application to endoscopic resection?

Background

Endoscopic resection is performed in undifferentiated-type early gastric cancer (UD-EGC), including poorly differentiated (PD) adenocarcinoma and signet ring cell (SRC) carcinoma. We previously found that different approaches are needed for PD adenocarcinoma and SRC carcinoma for curative resection. However, according to the 2010 WHO classification, diffuse-type PD adenocarcinoma and SRC carcinoma are categorized in the “poorly cohesive carcinomas.” Thus, we assessed whether the WHO classification is helpful when endoscopic resection is performed for treatment of UD-EGC.

Methods

We analyzed clinicopathological features of 1295 lesions with SRC carcinoma and PD adenocarcinoma treated by open surgery. We recategorized them into intestinal-type PD adenocarcinomas and poorly cohesive carcinomas (SRC carcinoma, diffuse-type PD adenocarcinoma). We also recategorized 176 lesions treated by endoscopic resection into intestinal-type PD adenocarcinomas and poorly cohesive carcinomas.

Results

According to the open surgery data, the rates of lymph node metastasis (LNM) and lymphovascular invasion were significantly lower in SRC carcinoma than in diffuse-type and intestinal-type PD adenocarcinomas. The rates of LNM and lymphovascular invasion were significantly higher in diffuse-type PD adenocarcinoma than in SRC carcinoma. Endoscopic resection data showed no recurrence if the carcinoma was curatively resected. However, the commonest cause of noncurative resection was different in SRC carcinoma and PD adenocarcinoma. A positive lateral margin was the commonest cause in SRC carcinoma versus a positive vertical margin in both intestinal-type and diffuse-type PD adenocarcinoma.

Conclusions

The clinical behavior differs in diffuse-type PD adenocarcinoma and SRC carcinoma. On the basis of LNM and outcomes of endoscopic resection, the recent WHO classification may not be helpful when endoscopic resection is performed for treatment of UD-EGC.

     

How useful is preoperative imaging for tumor,node, metastasis (TNM) staging of gastric cancer? A meta-analysis

Background

Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.

Methods

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.

Results

For pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.

Conclusions

The agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.

     

How useful is preoperative imaging for tumor,node, metastasis (TNM) staging of gastric cancer? A meta-analysis

Background

Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.

Methods

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.

Results

For pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.

Conclusions

The agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.

     

Do prostate cancer risk models improve the predictive accuracy of PSA screening? A meta-analysis

Despite the extensive development of prostate cancer (PCa) risk models that are used for patient–clinician decision-making for PCa screening, their predictive accuracy is unknown. In a meta-analysis of six different risk prediction models, results show that models have the potential to increase the sensitivity of PSA screening to detect any PCa (44% versus 21%).BackgroundDespite the extensive development of risk prediction models to aid patient decision-making on prostate screening, it is unknown whether these models could improve predictive accuracy of PSA testing to detect prostate cancer (PCa). The objective of this study was to perform a systematic review to identify PCa risk models and to assess the model's performance to predict PCa by conducting a meta-analysis.DesignA systematic literature search of Medline was conducted to identify PCa predictive risk models that used at least two variables, of which one of the variables was prostate-specific antigen (PSA) level. Model performance (discrimination and calibration) was assessed. Prediction models validated in ≥5 study populations and reported area under the curve (AUC) for prediction of any or clinically significant PCa were eligible for meta-analysis. Summary AUC and 95% CIs were calculated using a random-effects model.ResultsThe systematic review identified 127 unique PCa prediction models; however, only six models met study criteria for meta-analysis for predicting any PCa: Prostataclass, Finne, Karakiewcz Prostate Cancer Prevention Trial (PCPT), Chun, and the European Randomized Study of Screening for Prostate Cancer Risk Calculator 3 (ERSPC RC3). Summary AUC estimates show that PCPT does not differ from PSA testing (0.66) despite performing better in studies validating both PSA and PCPT. Predictive accuracy to discriminate PCa increases with Finne (AUC = 0.74), Karakiewcz (AUC = 0.74), Chun (AUC = 0.76) and ERSPC RC3 and Prostataclass have the highest discriminative value (AUC = 0.79), which is equivalent to doubling the sensitivity of PSA testing (44% versus 21%) without loss of specificity. The discriminative accuracy of PCPT to detect clinically significant PCa was AUC = 0.71. Calibration measures of the models were poorly reported.ConclusionsRisk prediction models improve the predictive accuracy of PSA testing to detect PCa. Future developments in the use of PCa risk models should evaluate its clinical effectiveness in practice.