18F-FDG PET/CT surveillance at 3–6 and 12 months for detection of recurrence and second primary cancer in patients with head and neck squamous cell carcinoma

Background:

Early detection of recurrence of head and neck squamous cell carcinoma (HNSCC), which is often obscured by surgical or radiotherapy-induced tissue distortion, is essential for proper patient management.

Methods:

A total of 143 consecutive patients with previously untreated HNSCC were evaluated by whole-body fluorine 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and regular clinical follow-up after curative treatment. The ¹⁸F-FDG PET/CT was performed ∼3–6 and 12 months after treatment and findings suspicious for recurrence or SPC were confirmed using histopathology.

Results:

The sensitivities of 3–6- and 12-month PET/CT scans at patient level were 96% and 93%, respectively, and those of regular clinical follow-up were 11% and 19%, respectively (McNemar test, P<0.001). In patients with no clinical suspicion, PET/CT detected 95% and 91% of recurrent patients at 3–6 and 12 months, respectively. The sensitivity of PET/CT for the identification of SPC was 29% and 80% at 3–6 and 12 months, respectively. A positive interpretation of PET/CT was significantly associated with poor overall survival (log-rank test, P<0.001).

Conclusion:

The ¹⁸F-FDG PET/CT surveillance is beneficial for the detection of recurrence that may be missed by regular follow-up physical and endoscopic examinations of the head and neck area after curative treatment for HNSCC.     

Role of (18)F-choline PET/CT in evaluation of patients with prostate carcinoma

Background

Choline presents a high affinity for malignant prostate tissue. It can be labelled with positron emitting ¹⁸F, and used for the evaluation of patients with prostate carcinoma by PET/CT imaging. The aim of this paper is to summarise our experience with fluoromethylcholine (¹⁸F-choline) PET/CT in patients with prostate cancer.

Methods

In 4 months we investigated the patients with histopathological (or cytological) confirmed prostate cancer. Two observers evaluated the early and late ¹⁸F-choline PET images in correlation with corresponding localising CT images and using the semiquantitative standard uptake value (SUV) calculation.

Results

The ¹⁸F-choline PET/CT was made in 50 patients with prostate cancer. There were 18 patients after radical prostatectomy and 32 without surgery. In all patients without surgery the pathological uptake was seen in the prostate. In 14 (44 %) patients of this group there was evidence of metastatic spread in local or distant lymph nodes and/or bones. In out of 18 patients after radical prostatectomy the local recurrence was detected in 6 patients (33%) and distant metastases were present in 2 patients (10%).

Conclusions

¹⁸F-choline PET/CT seems to be useful imaging modality in patients with prostate carcinoma; it can demonstrate spread of the disease preoperatively and detect the local recurrence after radical prostatectomy.     

The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma

Background

The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS).

Methods

A comprehensive literature search of published studies through October 10^th, 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed.

Results

We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS

Conclusions

Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning.     

18F-FDG PET/CT as a diagnostic tool in patients with extracervical carcinoma of unknown primary site: a literature review

Background.

Carcinoma of unknown primary (CUP) represents a heterogeneous group of metastatic malignancies for which no primary tumor site can be identified after extensive diagnostic workup. Failure to identify the primary site may negatively influence patient management. The aim of this review was to evaluate ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) as a diagnostic tool in patients with extracervical CUP.

Materials and Methods.

A comprehensive literature search was performed and four publications were identified (involving 152 patients) evaluating ¹⁸F-FDG PET/CT in CUP patients with extracervical metastases. All studies were retrospective and heterogeneous in inclusion criteria, study design, and diagnostic workup prior to ¹⁸F-FDG PET/CT.

Results.

¹⁸F-FDG PET/CT detected the primary tumor in 39.5% of patients with extracervical CUP. The lung was the most commonly detected primary tumor site (∼50%). The pooled estimates of sensitivity, specificity, and accuracy of ¹⁸F-FDG PET/CT in the detection of the primary tumor site were 87%, 88%, and 87.5%, respectively.

Conclusions.

The present review of currently available data indicates that ¹⁸F-FDG PET/CT might contribute to the identification of the primary tumor site in extracervical CUP. However, prospective studies with more uniform inclusion criteria are required to evaluate the exact value of this diagnostic tool.     

Use of 18F-FDG PET/CT to locate primary malignancies in patients with hepatic cirrhosis and malignant ascites

Objective：Ascites in patients with hepatic cirrhosis is caused by cirrhosis in most cases.For most malignant ascites,the primary malignancy could be readily identified using conventional imaging methods,e.g.,computer tomography （CT） and magnetic resonance imaging （MRI）.However,in a small fraction of the patients,the primary malignancy remains occult even with these examinations.In this retrospective study,we assessed the usefulness of 18F-FDG PET/CT in patients with hepatic cirrhosis and malignant ascites of otherwise unknown origin.Methods：Twenty-eight patients with malignant ascites of unknown primary sites after CT,MRI and ultrasound during the period of five years between January 2008 and December 2012 had received 18F-FDG PET/CT.Medical records of these patients were reviewed and analyzed.Results：Elevated 18F-FDG absorption was found in 23 of 28 cases in the following sites：gastrointestinal tract （n=10,43.5％）,prostate （n=5,21.7％）,peritoneum （n=4,13.3％）,and ovary （n=4,13.3％）.Cancer was confirmed by pathology in 20 cases after open or laparoscopic surgeries.Five patients were found to have benign ascites,among which,3 were found to be false positive due to tuberculosis.SUV values were significantly higher for tumors than for benign lesions （mean values,6.95 vs.2.94; P=0.005）.Conclusions：The 18F-FDG PET/CT can be as a powerful imaging tool in identifying tissue origin in liver cirrhosis patients suspected of cancers or with cancers of unknown primary sites.     

Clinical value of F-FDG PET/CT in assessing suspicious relapse after rectal cancer resection

AIM: To evaluate the value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the restaging of resected rectal cancer.METHODS: From January 2007 to Sep 2008, 21 patients who had undergone curative surgery resection for rectal carcinoma with suspicious relapse in conventional imaging or clinical findings were retrospectively enrolled in our study. The patients underwent 28 PET/CT scans (two patients had two scans, one patient had three and one had four scans). Locoregional recurrences and/or distant metastases were confirmed by histological analysis or clinical and imaging follow-up.RESULTS: Final diagnosis was confirmed by histopathological diagnosis in 12 patients (57.1%) and by clinical and imaging follow-up in nine patients (42.9%). Eight patients had extrapelvic metastases with no evidence of pelvic recurrence. Seven patients had both pelvic recurrence and extrapelvic metastases, and two patients had pelvic recurrence only. ¹⁸F-FDG PET/CT was negative in two patients and positive in 19 patients. ¹⁸F-FDG PET/CT was true positive in 17 patients and false positive in two. The accuracy of ¹⁸F-FDG PET/CT was 90.5%, negative predictive value was 100%, and positive predictive value was 89.5%. Five patients with perirectal recurrence underwent ¹⁸F-FDG PET/CT image guided tissue core biopsy. ¹⁸F-FDG PET/CT also guided surgical resection of pulmonary metastases in three patients and monitored the response to salvage chemotherapy and/or radiotherapy in four patients.CONCLUSION: ¹⁸F-FDG PET/CT is useful for evaluating suspicious locoregional recurrence and distant metastases in the restaging of rectal cancer after curative resection.     

Dual PET/CT with F-DOPA and F-FDG in metastatic medullary thyroid carcinoma and rapidly increasing calcitonin levels: Comparison with conventional imaging

Background

To evaluate the role of a multi-imaging PET with ¹⁸F-DOPA and ¹⁸F-FDG in comparison with conventional imaging (CI) in recurrent medullary thyroid carcinoma (MTC).

Methods

18 MTC patients who had thyroidectomy were included; they presented with elevated and rapidly increasing calcitonin levels during follow up. CI had revealed metastatic deposits in 9 patients. Patients were referred to us for a PET/CT with ¹⁸F-DOPA and ¹⁸F-FDG. Histologic/cytologic confirmation of recurrent MTC was obtained in at least one PET-positive lesion in all patients.

Results

Foci of abnormal uptake were observed in 15 patients at ¹⁸F-DOPA and in 11 at ¹⁸F-FDG; 8 patients showed the same number of positive lesions with both tracers, 2 showed more lesions on ¹⁸F-FDG, 1 was positive at ¹⁸F-FDG alone and 5 at ¹⁸F-DOPA alone. In 3 patients with a DOPA-positive loco-regional relapse a re-operation with curative intent was offered. SUV_max values were higher for ¹⁸F-FDG compared to ¹⁸F-DOPA (mean 12.7 ± 4.1 vs. 5.5 ± 2.1, p < 0.05). Calcitonin was higher in PET-positive patients compared to PET negative ones, while no significant differences were observed between ¹⁸F-DOPA and ¹⁸F-FDG positive patients.

Conclusions

In MTC patients with rapidly increasing calcitonin levels during follow up, ¹⁸F-DOPA has a good sensitivity and a complementary role with ¹⁸F-FDG PET/CT in detecting metastatic deposits. In our experience, the sensitivity of a multi-imaging ¹⁸F-DOPA & ¹⁸F-FDG PET/CT approach is greater than that obtained with CI. The higher SUV_max values found with ¹⁸F-FDG in some patients may reflect more aggressive tumors.     

The role of F-FDG PET/CT in detecting metastatic deposits of recurrent medullary thyroid carcinoma: A prospective study

Aim

To assess the diagnostic role of ¹⁸F-FDG PET/CT performed with a hybrid tomograph in the detection of tumoral deposits of recurrent medullary thyroid carcinoma (MTC).

Methods

Nineteen MTC patients with elevated serum calcitonin levels (58–1350 pg/ml) after first treatment were enrolled (11 F, 8 M, mean age 53.4 years, 14 sporadic MTC, 5 MEN-related MTC). All patients had previously undergone total thyroidectomy and lymphoadenectomy. When referred to us, they were studied with ultrasound (US), ¹⁸F-FDG PET/CT, ¹¹¹In-pentetreotide scan, and contrast-enhanced whole-body CT (c.e. CT). In 4 patients with equivocal abdominal findings at ¹⁸F-FDG PET/CT and/or at c.e. CT, laparoscopy was also performed.

Results

¹⁸F-FGD PET/CT depicted metastases in 15 patients, ¹¹¹In-pentetreotide in 8, c.e. CT in 11, US in 6. In 2 patients, liver micrometastases were detected at laparoscopy only. At a lesion-by-lesion analysis, ¹⁸F-FDG PET/CT visualized a total of 26 metastatic deposits, c.e. CT 18, ¹¹¹In-pentetreotide 12, US 8. Final diagnosis was obtained by cytological or surgical findings. Four patients with evidence of limited metastatic spread to neck/upper mediastinum were re-operated, and in 2 of them serum calcitonin levels normalized.

Conclusions

In our study, ¹⁸F-FDG PET/CT was the most sensitive imaging modality in detecting metastases in recurrent MTC patients with increased serum calcitonin levels. Moreover, ¹⁸F-FDG PET/CT was useful in some patients to plan a more accurate re-operation. From a diagnostic point of view, a multimodality imaging approach is recommended in recurrent MTC, especially based on the combination of c.e. CT and ¹⁸F-FDG PET/CT.     

Thyroid lesions incidentally detected by 18F-FDG PET-CT — a two centre retrospective study

Background.

Incidental ¹⁸F-FDG uptake in the thyroid on PET-CT examinations represents a diagnostic challenge. The maximal standardized uptake value (SUV_max) is one possible parameter that can help in distinguishing between benign and malignant thyroid PET lesions.

Patients and methods.

We retrospectively evaluated ¹⁸F-FDG PET-CT examinations of 5,911 patients performed at two different medical centres from 2010 to 2011. If pathologically increased activity was accidentally detected in the thyroid, the SUV_max of the thyroid lesion was calculated. Patients with incidental ¹⁸F-FDG uptake in the thyroid were instructed to visit a thyroidologist, who performed further investigation including fine needle aspiration cytology (FNAC) if needed. Lesions deemed suspicious after FNAC were referred for surgery.

Results.

Incidental ¹⁸F-FDG uptake in the thyroid was found in 3.89% — in 230 out of 5,911 patients investigated on PET-CT. Malignant thyroid lesions (represented with focal thyroid uptake) were detected in 10 of 66 patients (in 15.2%). In the first medical centre the SUV_max of 36 benign lesions was 5.6 ± 2.8 compared to 15.8 ± 9.2 of 5 malignant lesions (p < 0.001). In the second centre the SUV_max of 20 benign lesions was 3.7 ± 2.2 compared to 5.1 ± 2.3 of 5 malignant lesions (p = 0.217). All 29 further investigated diffuse thyroid lesions were benign.

Conclusions.

Incidental ¹⁸F-FDG uptake in the thyroid was found in 3.89% of patients who had a PET-CT examination. Only focal thyroid uptake represented a malignant lesion in our study — in 15.2% of all focal thyroid lesions. SUV_max should only serve as one of several parameters that alert the clinician on the possibility of thyroid malignancy.     

Biological significance of fluorine-18-α-methyltyrosine (FAMT) uptake on PET in patients with oesophageal cancer

Purpose:

¹⁸F-FAMT as an amino-acid tracer for positron emission tomography (PET) is useful for detecting human neoplasms. ¹⁸F-FAMT is accumulated in tumour cells solely via L-type amino-acid transporter 1 (LAT1). This study was conducted to investigate the biological significance of ¹⁸F-FAMT uptake in patients with oesophageal cancer.

Methods:

From April 2008 to December 2011, 42 patients with oesophageal cancer underwent both ¹⁸F-FAMT PET/CT and ¹⁸F-FDG PET/CT before surgical treatment. The immunohistochemical analysis of LAT1, CD98, Ki-67, CD34, p53, p-Akt and p-mTOR was performed on the primary lesions. In vitro experiments were performed to examine the mechanism of ¹⁸F-FAMT uptake.

Results:

High uptake of ¹⁸F-FAMT was significantly associated with advanced stage, lymph node metastasis and the expression of LAT1, CD98, Ki-67 and CD34. LAT1 expression yielded a statistically significant correlation with CD98 expression, cell proliferation, angiogenesis and glucose metabolism. In vitro experiments revealed that ¹⁸F-FAMT was specifically transported by LAT1.

Conclusions:

The uptake of ¹⁸F-FAMT within tumour cells is determined by the LAT1 expression and correlated with cell proliferation and angiogenesis in oesophageal cancer. The present experiments also confirmed the presence of LAT1 as an underlying mechanism of ¹⁸F-FAMT accumulation.     

Lack of CD151/integrin α3β1 complex is predictive of poor outcome in node-negative lobular breast carcinoma: opposing roles of CD151 in invasive lobular and ductal breast cancers

Background:

The proposed involvement of CD151 in breast cancer (BCa) progression is based on findings from studies in invasive ductal carcinoma (IDC). The IDC and invasive lobular carcinoma (ILC) represent distinct disease entities. Here we evaluated clinical significance of CD151 alone and in association with integrin α3β1 in patients with ILC in context of the data of our recent IDC study.

Methods:

Expression of CD151 and/or integrin α3β1 was evaluated in ILC samples (N=117) using immunohistochemistry. The findings were analysed in relation to our results from an IDC cohort (N=182) demonstrating a prognostic value of an expression of CD151/integrin α3β1 complex in patients with HER2-negative tumours.

Results:

Unlike in the IDCs, neither CD151 nor CD151/α3β1 complex showed any correlation with any of the ILC characteristics. Lack of both CD151 and α3β1 was significantly correlated with poor survival (P=0.034) in lymph node-negative ILC N(−) cases. The CD151⁻/α3β1⁻ patients had 3.12-fold higher risk of death from BCa in comparison with the rest of the ILC N(−) patients.

Conclusions:

Biological role of CD151/α3β1 varies between ILC and IDC. Assessment of CD151/α3β1 might help to identify ILC N(−) patients with increased risk of distant metastases.     

Italian Multicenter Study on Accuracy of 18F-FDG PET/CT in Assessing Bone Marrow Involvement in Pediatric Hodgkin Lymphoma

Introduction

The present study investigated the utility of fluorine-18 (¹⁸F) fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing bone marrow involvement (BMI) compared with bone marrow biopsy (BMB) in newly diagnosed pediatric Hodgkin lymphoma (HL).

Comparison of Clinicopathological Features and Treatment Results between Invasive Lobular Carcinoma and Ductal Carcinoma of the Breast

Purpose

The purpose of this study was to assess the incidence of invasive lobular carcinoma (ILC) and to compare the clinicopathological features and treatment results after breast conserving surgery (BCS) followed by radiotherapy between ILC and invasive ductal carcinoma (IDC).

Methods

A total of 1,071 patients who underwent BCS followed by radiotherapy were included in the study. Medical records and pathological reports were retrospectively reviewed.

Results

The incidence of ILC was 5.2% (n=56). Bilateral breast cancer, lower nuclear grade, and hormone receptor-positive breast cancer were more frequent in patients with ILC than in those with IDC. There were no cases of lymphovascular invasion or the basal-like subtype in patients with ILC. There were no statistically significant differences in patterns of failure or treatment outcomes between patients with ILC and those with IDC. The development of metachronous contralateral breast cancer was more frequent in patients with IDC (n=27). Only one patient with ILC developed contralateral breast cancer, with a case of ductal carcinoma in situ.

Conclusion

The incidence of ILC was slightly higher in our study than in previous Korean studies, but was lower than the incidences reported in Western studies. The differences we observed in clinico pathological features between ILC and IDC were similar to those described elsewhere in the literature. Although there were no statistically significant differences, there was a trend toward better disease-specific survival and disease-free survival rates in patients with ILC than in those with IDC.     

A comparison of cell cycle markers in well-differentiated lobular and ductal carcinomas

Infiltrating lobular carcinoma (ILC) and infiltrating ductal carcinoma (IDC) are similar in many respects and their histologic features occasionally overlap. Despite the many similarities, some clinical follow-up data and the patterns of metastasis suggest that ILC and IDC are biologically distinct. Unfortunately, most breast cancer research has focused almost exclusively on the ductal subtype or has not stressed the biologic or molecular genetic distinctions between breast carcinoma subtypes. Several reports have suggested the possibility that ILCs and IDCs differ with respect to expression of antigens involved in proliferation and cell cycle regulation. Therefore, we undertook an immunohistochemical evaluation of cell cycle related antigens in ILCs, including histologic variants thought to represent aggressive neoplasms, and IDCs matched for histologic grade (Modified Bloom–Richardson Grade I). We believe that different antigent expression profiles could elucidate the biological distinctiveness of breast carcinoma subtypes and possibly provide diagnostically relevant information. We studied the expression of the following antigents in 28 archived, formalin-fixed ILCs and 34 well-differentiated IDCs: estrogen receptor (ER), progesterone receptor (PR), Her 2-neu, mib-1, cyclin D1, p27, p53, mdm-2 and bcl-2. 94% of ILCs and 100% of IDCs expressed ER; 75% of ILCs and 76% of IDCs expressed PR; 4% of ILCs and 13% of IDCs expressed c cerb B-2; ILCs and IDCs both expressed mib-1 in approximately 10% of lesional cells; 82% of ILCs and 54% of IDCs expressed cyclin D1; 90% of ILCs and 83% IDCs expressed p27 strongly; 4% of ILCs and 4% of IDCs expressed p53, 25% of ILCs and 33% of IDCs expressed mdm-2; 96% of ILCs and 100% of IDCs expressed bcl-2. None of the apparent differences were statistically significant. The ILC variants demonstrated immunophenotypes that were essentially similar to ILCs of the usual type. We conclude that ILCs and well-differentiated IDCs show similar proliferation and cell cycle control antigen profiles. Despite their unusual histologic features, most ILC variants appear to maintain a characteristic ILC immunophenotype.     

Biopsy validation of 18F-DOPA PET and biodistribution in gliomas for neurosurgical planning and radiotherapy target delineation: results of a prospective pilot study

Background

Delineation of glioma extent for surgical or radiotherapy planning is routinely based on MRI. There is increasing awareness that contrast enhancement on T1-weighted images (T1-CE) may not reflect the entire extent of disease. The amino acid tracer ¹⁸F-DOPA (3,4-dihydroxy-6-[18F] fluoro-l-phenylalanine) has a high tumor-to-background signal and high sensitivity for glioma imaging. This study compares ¹⁸F-DOPA PET against conventional MRI for neurosurgical biopsy targeting, resection planning, and radiotherapy target volume delineation.

Methods

Conventional MR and ¹⁸F-DOPA PET/CT images were acquired in 10 patients with suspected malignant brain tumors. One to 3 biopsy locations per patient were chosen in regions of concordant and discordant ¹⁸F-DOPA uptake and MR contrast enhancement. Histopathology was reviewed on 23 biopsies. ¹⁸F-DOPA PET was quantified using standardized uptake values (SUV) and tumor-to-normal hemispheric tissue (T/N) ratios.

Results

Pathologic review confirmed glioma in 22 of 23 biopsy specimens. Thirteen of 16 high-grade biopsy specimens were obtained from regions of elevated ¹⁸F-DOPA uptake, while T1-CE was present in only 6 of those 16 samples. Optimal ¹⁸F-DOPA PET thresholds corresponding to high-grade disease based on histopathology were calculated as T/N > 2.0. In every patient, ¹⁸F-DOPA uptake regions with T/N > 2.0 extended beyond T1-CE up to a maximum of 3.5 cm. SUV was found to correlate with grade and cellularity.

Conclusions

¹⁸F-DOPA PET SUV_max may more accurately identify regions of higher-grade/higher-density disease in patients with astrocytomas and will have utility in guiding stereotactic biopsy selection. Using SUV-based thresholds to define high-grade portions of disease may be valuable in delineating radiotherapy boost volumes.     

Prognostic value of post-treatment 18F-FDG PET/CT for advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy简

Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcinoma （HNSCC） after combined intra-arterial chemotherapy and radiotherapy （IACR）.Methods：Thirty-six patients with HNSCC who underwent IACR were recruited.The period from the end of IACR to the last post-treatment 18F-FDG PET/CT examination was 8-12 weeks.Both patient-based and lesion-based analyses were used to evaluate the PET/CT images.For lesion-based analysis,36 regions （12 lesions of recurrences and 24 scars at primary sites） were selected.The Kaplan-Meier method was used to assess the overall survival （OS） stratified by 18F-FDG uptake or visual interpretation results.Results：Twelve patients with recurrence were identified by six months after IACR.The sensitivity and specificity in the patient-based analysis were 67％ （8/12） and 88％ （21/24）,respectively.The mean OS was estimated to be 12.1 months （95％ CI,6.3-18.0 months） for the higher maximum standardized uptake value （SUVmax） group （n=7） and 44.6 months （95％ CI,39.9-49.3 months） for the lower SUVmax group （n=29）.OS in the higher SUVmax group （cut-off point,6.1） or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group （P＜0.001 and P＜0.05,respectively）.Conclusions：The SUVmax and visual interpretation of HNSCC on post-IACR 18F-FDG PET/CT can provide prognostic survival estimates.     

[18F]-fluoro-ethyl-l-tyrosine PET: a valuable diagnostic tool in neuro-oncology,but not all that glitters is glioma

Background

To assess the sensitivity and specificity of [¹⁸F]-fluoro-ethyl-l-tyrosine (¹⁸F-FET) PET in brain tumors and various non-neoplastic neurologic diseases.

Methods

We retrospectively evaluated ¹⁸F-FET PET scans from 393 patients grouped into 6 disease categories according to histology (n = 299) or distinct MRI findings (n = 94) (low-grade/high-grade glial/nonglial brain tumors, inflammatory lesions, and other lesions). ¹⁸F-FET PET was visually assessed as positive or negative. Maximum lesion-to-brain ratios (LBRs) were calculated and compared with MRI contrast enhancement (CE), which was graded visually on a 3-point scale (no/moderate/intense).

Results

Sensitivity and specificity for the detection of brain tumor were 87% and 68%, respectively. Significant differences in LBRs were detected between high-grade brain tumors (LBR, 2.04 ± 0.72) and low-grade brain tumors (LBR, 1.52 ± 0.70; P < .001), as well as among inflammatory (LBR, 1.66 ± 0.33; P = .056) and other brain lesions (LBR, 1.10 ± 0.37; P < .001). Gliomas (n = 236) showed ¹⁸F-FET uptake in 80% of World Health Organization (WHO) grade I, 79% of grade II, 92% of grade III, and 100% of grade IV tumors. Low-grade oligodendrogliomas, WHO grade II, had significantly higher ¹⁸F-FET uptakes than astrocytomas grades II and III (P = .018 and P = .015, respectively). ¹⁸F-FET uptake showed a strong association with CE on MRI (P < .001) and was also positive in 52% of 157 nonglial brain tumors and nonneoplastic brain lesions.

Conclusions

¹⁸F-FET PET has a high sensitivity for the detection of high-grade brain tumors. Its specificity, however, is limited by passive tracer influx through a disrupted blood–brain barrier and ¹⁸F-FET uptake in nonneoplastic brain lesions. Gliomas show specific tracer uptake in the absence of CE on MRI, which most likely reflects biologically active tumor.     

E-钙黏附蛋白和p120-连环素蛋白在乳腺浸润性小叶癌和导管癌中的表达差异及意义

目的 比较乳腺浸润性小叶癌(ILC)和浸润性导管癌(IDC)的临床病理学特征,探讨E-钙黏附蛋白(E-cadherin)和p120-连环素蛋白(p120-catenin)在ILC和IDC中的表达差异及意义.方法 中国医学科学院肿瘤医院1999年1月至2006年12月共收治ILC 123例,2000年收治IDC 334例.运用组织微阵列及免疫组织化学染色技术,对123例ILC和334例IDC患者的组织蜡块进行切片,并进行E-cadherin和p120-catenin表达的检测,同时对患者进行随访.结果 ILC和IDC患者的5年无瘤生存率(DFS)分别为61.8%和83.7%(P＜0.001),5年总生存率(OS)分别为81.7%和79.1%(P=0.055).在36例ILC和221例IDC患者中,E-cadherin表达缺失率分别为55.6%(20/36)和20.4%(45/221,P＜0.001),p120-catenin胞浆表达率分别为66.7%(24/36)和16.3%(36/221,P＜0.001).在ILC患者中,p120-catenin胞浆表达与E-cadherin表达缺失相关(P=0.002).ILC和IDC患者中,p120-catenin胞浆表达合并E-cadherin表达缺失的比率分别为55.6%(20/36)和4.1%(9/221,P＜0.001).结论 ILC具有不同于IDC的临床病理学特点及预后特征,E-cadherin和p120-catenin的检测有助于ILC和IDC的鉴别诊断.     

Diagnostic performance of Fluorine-18-Fluorodeoxyglucose positron emission tomography in the assessment of pleural abnormalities in cancer patients: A systematic review and a meta-analysis

Objective

To systematically review and meta-analyze published data about the diagnostic performance of Fluorine-18-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and PET/computed tomography (PET/CT) in the assessment of pleural abnormalities in cancer patients.

Methods

A comprehensive literature search of studies published through June 2013 regarding the role of ¹⁸F-FDG-PET and PET/CT in evaluating pleural abnormalities in cancer patients was performed. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR−) and diagnostic odd ratio (DOR) of ¹⁸F-FDG-PET or PET/CT on a per patient-based analysis were calculated. The area under the summary ROC curve (AUC) was calculated to measure the accuracy of these methods in the assessment of pleural abnormalities. Sub-analyses considering ¹⁸F-FDG-PET/CT and patients with lung cancer only were carried out.

Results

Eight studies comprising 360 cancer patients (323 with lung cancer) were included. The meta-analysis of these selected studies provided the following results: sensitivity 86% [95% confidence interval (95%CI): 80–91%], specificity 80% [95%CI: 73–85%], LR+ 3.7 [95%CI: 2.8–4.9], LR− 0.18 [95%CI: 0.09–0.34], DOR 27 [95%CI: 13–56]. The AUC was 0.907. No significant improvement considering PET/CT studies only and patients with lung cancer was found.

Conclusions

¹⁸F-FDG-PET and PET/CT demonstrated to be useful diagnostic imaging methods in the assessment of pleural abnormalities in cancer patients, nevertheless possible sources of false-negative and false-positive results should be kept in mind. The literature focusing on the use of ¹⁸F-FDG-PET and PET/CT in this setting remains still limited and prospective studies are needed.     

The role of F-FDG PET/CT for evaluation of metastatic mediastinal lymph nodes in patients with lung squamous-cell carcinoma or adenocarcinoma

Objectives

To evaluate the efficacy of ¹⁸F-FDG PET/CT in depicting metastatic mediastinal lymph nodes in patients with lung squamous-cell carcinoma (LSCC) or lung adenocarcinoma (LAC) in a tuberculosis-endemic country.

Methods

This study retrospectively reviewed patients with LSCC or LAC, who underwent preoperative ¹⁸F-FDG PET/CT to assess mediastinal lymph node metastasis. Patients with the short-axis of mediastinal lymph node ≤ 15 mm were included. PET/CT interpretation was analyzed in two ways. Firstly, with CT for anatomical localization, lymph nodes showing greater ¹⁸F-FDG uptake than vessel pool on PET were regarded malignant. Secondly, lymph nodes with positive uptake on PET were considered malignant, only when nodes had neither calcification nor higher attenuation than vessel pool on CT.

Results

One hundred and sixteen LSCCs and 234 LACs were evaluated. With CT for anatomical localization, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of PET were 78.6%, 45.5%, 53.4%, 31.4% and 87.0% in LSCC group, and 61.8%, 66.3%, 65.0%, 42.9% and 80.9% in LAC group. PET showed higher specificity and accuracy in LAC group compared with LSCC group (p = 0.001 and p = 0.038, respectively). Considering calcification or high attenuation on CT, the sensitivity, specificity, accuracy, PPV and NPV of PET/CT were 71.4%, 67.0%, 68.1%, 40.8% and 88.1% in LSCC group, and 54.4%, 86.1%, 76.9%, 61.7% and 82.2% in LAC group. Compared with PET, PET/CT possessed higher specificity and accuracy in LSCC group (p = 0.000 and p = 0.000, respectively), and higher specificity, accuracy and PPV in LAC group (p = 0.000, p = 0.000 and p = 0.022, respectively).

Conclusions

¹⁸F-FDG PET displays limited efficacy in assessing mediastinal lymph node metastasis with the short-axis diameter <15 mm in LSCC and LAC groups and higher false-positivity in LSCC group. The specificity and accuracy in LSCC and LAC groups are enhanced by interpreting attenuation characteristic on CT.