Whole-body fluorodeoxyglucose positron emission tomography/computed tomography in patients with active polymyalgia rheumatica: evidence for distinctive bursitis and large-vessel vasculitis

Abstract

Objectives To investigate fluorodeoxyglucose (FDG) accumulation in large joints, bursas, and large vessels in patients with polymyalgia rheumatica (PMR) using 18-FDG positron emission tomography/computed tomography (PET/CT) and to differentiate PMR from similar diseases.

Methods Fourteen untreated patients with active PMR and 17 control patients with rheumatoid arthritis (n = 11) or other active rheumatic diseases (n = 6) underwent 18-FDG PET/CT. FDG uptake in large joints, bursas and vertebral spinous processes was evaluated by calculating maximum standardised uptake values and by visual scoring (scale 0–4). PET scan images were scored in seven vascular regions, and total vascular scores (range 0–21) were calculated.

Results Polymyalgia rheumatica patients showed increased FDG uptake in ischial tuberosities, greater trochanters, and lumbar spinous processes. Positive results at two or more of these sites showed high sensitivity (85.7%) and specificity (88.2%) for the diagnosis of PMR, and shoulder or hip-joint involvement showed low disease specificity. High FDG accumulations were found in the aortas and subclavian arteries of two PMR patients who were asymptomatic for temporal arteritis and scanty synovium and perisynovium, based on FDG uptake. PET/CT images of the 12 PMR patients without apparent vascular involvement showed synovitis and/or perisynovitis.

Conclusions Fluorodeoxyglucose-PET/CT may be useful for the detection of PMR lesions, which are difficult to identify using other methods.     

Repetitive 18F‐fluorodeoxyglucose positron emission tomography in giant cell arteritis: A prospective study of 35 patients

Objective

To study fluorodeoxyglucose (FDG) uptake in the different vascular beds and in the large joints of patients with giant cell arteritis (GCA) at diagnosis, during steroid treatment, and at relapse.

Methods

All consecutive patients admitted to our department with a diagnosis of GCA underwent FDG–positron emission tomography (PET) scan before treatment with methylprednisolone was started. PET scans were repeated at 3 and 6 months, if the initial PET scans showed vascular FDG uptake. PET scans were scored at 7 different vascular areas and a total vascular score (TVS) was calculated, ranging from 0 to 21.

Results

A total of 35 patients entered the study. At diagnosis, vascular FDG uptake was noted in 29 patients (83%), especially in the subclavian arteries (74%), but also in the aorta (>50%) and up to the femoral arteries (37%). TVS decreased from a mean ± SD score of 7.9 ± 5.5 at baseline to 2.4 ± 3.5 on repeat PET scan at 3 months (P < 0.0005), but did not further decrease at 6 months. The patients who relapsed had similar earlier decreases of TVS compared with those who did not relapse. FDG uptake in the shoulders at diagnosis correlated significantly with the presence of polymyalgia rheumatica (P = 0.005).

Conclusion

FDG uptake in the large vessels is a sensitive marker for GCA, which can involve the larger thoracic, abdominal, and peripheral arteries. Polymyalgia rheumatica symptoms in patients with GCA correlate with (peri)synovitis of the shoulders. Relapses of GCA cannot be predicted by results of former PET scintigraphies.

     

Differences in fluorodeoxyglucose positron emission tomography/computed tomography findings between elderly onset rheumatoid arthritis and polymyalgia rheumatica

Abstract

Objectives. To compare the fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings in patients with elderly-onset rheumatoid arthritis (EORA) with those in patients with polymyalgia rheumatica (PMR), two conditions with similar clinical presentations.

Methods. We retrospectively analyzed the FDG-PET/CT findings in 10 patients with EORA and 27 patients with PMR admitted to our department between 2006 and 2012.

Results: No significant difference was observed in the median patient ages at the time of FDG-PET/CT scans in the EORA and PMR groups (73.5 vs. 78.0 years, respectively). Significant differences in both FDG uptake scores and standardized uptake values were observed between the two groups in the ischial tuberosities, spinous processes, and wrists. No significant differences were detected in the shoulders and hips. However, specific uptake patterns were observed in each group: circular and linear uptake patterns were observed around the humeral head in the EORA group, whereas focal and non-linear uptake patterns were observed in the PMR group. Moreover, focal uptake in front of the hip joint, indicating iliopectineal bursitis, tended to be limited to the PMR group. High sensitivity (92.6%) and specificity (90%) were observed for PMR diagnoses when at least three of the following five items were satisfied: characteristic findings of shoulder and iliopectineal bursitis, FDG uptake in ischial tuberosities and spinal spinous processes, and lack of FDG uptake in the wrists.

Conclusion. The differences in the degree of uptake at each lesion and in uptake patterns at the shoulders and hips are potentially useful for obtaining a definitive diagnosis.     

FDG PET/CT metabolic tumor volume and total lesion glycolysis predict prognosis in patients with advanced lung adenocarcinoma

Purpose

We investigated fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT)-assessed metabolic tumor volume (MTV) and total lesion glycolysis (TLG) as prognostic factors in lung adenocarcinoma patients.

Methods

This retrospective study included 106 patients (19 stage I/II and 87 stage III/IV lung adenocarcinoma) who underwent FDG PET/CT before treatment. Standardized uptake value (SUV), MTV, and TLG (MTV × mean SUV) of each malignant lesion were measured. Whole MTV and whole TLG were the summation of all the MTV and TLG values in each patient. Survival analysis and FDG PET/CT parameters regarding epidermal growth factor receptor (EGFR) gene mutation status were evaluated.

Results

Univariate survival analysis of stage III/IV patients identified high whole MTV (≥90), high whole TLG (≥600), and stage IV as significant predictors of poor progression-free survival. For overall survival, high whole MTV (≥90), high whole TLG (≥600), EGFR mutation-negative, and stage IV were significant poor prognostic predictors. After multivariate survival analysis, high whole MTV (P = 0.001), high whole TLG (P = 0.027), and stage IV (P = 0.006) were independent predictors of poor progression-free survival. High whole MTV (P < 0.001), high whole TLG (P = 0.001), and EGFR mutation-negative (P = 0.001) were independent prognostic predictors for poor overall survival. In a survival analysis of stage I/II patients, none was an independent prognostic predictor. No significant differences were found in FDG PET/CT parameters for EGFR mutation-negative and EGFR mutation-positive patients.

Conclusions

Assessment of MTV and TLG by FDG PET/CT in advanced lung adenocarcinoma patients provides useful information regarding prognosis.     

High FDG uptake predicts poorer survival in locally advanced nonsmall cell lung cancer patients undergoing curative radiotherapy,independently of tumor size

Objectives

Despite radical radiotherapy and chemotherapy (CT), the prognosis of locally advanced nonsmall cell lung cancer (NSCLC) is poor. New prognostic indicators are being looked forward to improve the survival. [18F]-fluorodeoxyglucose (FDG) uptake on PET/CT has been observed as a prognostic marker mainly in early-stage disease. Our aim was to examine the prognostic value of FDG uptake in locally advanced NSCLC.

Materials and methods

Between 2009 and 2011, 103 NSCLC patients underwent disease staging using FDG PET/CT before conformal radiotherapy. Thoracic radiation was administered at a daily fraction of 2 Gy. Total dose was prescribed according to the tumor response against CT. All patients underwent CT. Survival was estimated using the Kaplan–Meier method.

Results

The median age of the patients was 59 years (range 39–83). The median follow-up time was 22.63 months (range 6–48.03 months). There was a statistically significant difference in overall survival (OS) between the low (<10.7) and high (≥10.7) standardized uptake value (SUVmax) groups (p = 0.006) on univariate analysis (3-year OS was 42 % in the low (<10.7) and 23 % in the high (≥10.7) SUVmax groups). On multivariate analysis with determining tumor size, tumor SUVmax provided additional significant prognostic information on OS (HR 1.046; 95 % CI 1.009–1.085, p = 0.015).

Conclusions

FDG uptake has predictive value in locally advanced NSCLC, independently of tumor size.     

Positron Emission Tomography in the Evaluation of Pulmonary Nodules Among Patients Living in a Coccidioidal Endemic Region

Background

Within a coccidioidal endemic region, pulmonary nodules due to coccidioidomycosis are common. Uptake of ¹⁸fluorodeoxyglucose (¹⁸FDG) by positron emission tomography with computed axial tomography (PET/CT) has been used to assess whether pulmonary nodules are malignant but inflammatory lesions can be positive. The purpose of this study was to compare by PET/CT the ¹⁸FDG uptake in pulmonary nodules likely due to coccidioidomycosis to that of nodules shown to be malignant among patients living in a coccidioidal endemic region.

Methods

We retrospectively reviewed patients who underwent a PET/CT at the Southern Arizona Veterans Affairs Health Care System between January 2008 and March 2012 who were subsequently found on biopsy to have pulmonary nodules that were coccidioidal or granulomatous or were due to malignancy.

Results

Among 245 diagnostic biopsies where the subject had a previous PET/CT, 15 (6.1 %) were either coccidioidal (n = 12) or granulomatous without an identified organism (n = 3). The median maximum standard unit of uptake (SUV_max) on PET/CT of coccidioidal or granulomatous lesions was 2.0 compared to 9.8 for malignant lesions (P < 0.001). The maximum diameter of the coccidioidal or granulomatous nodules was 2.1 cm compared to 3.0 cm for the malignant lesions (P = 0.009). On multivariable analysis, an elevated SUV_max was the only distinguishing feature between the malignant and the granulomatous lesions (OR 1.28, 95 % CI 1.05–1.55; P = 0.013).

Conclusions

Coccidioidal pulmonary nodules take up significantly less ¹⁸FDG than those due to malignancies, but there is considerable overlap between granulomatous and malignant lesions at lower SUV_max.     

F-18 FDG PET/CT in the assessment of patients with unexplained CEA rise after surgical curative resection for colorectal cancer

Purpose

We evaluated the role of quantitative assessment by maximum standardized uptake value (SUVmax) on F-18 fluorodeoxyglucose [F-18]FDG positron emission tomography/computed tomography (PET/CT) in stratifying colorectal cancer (CRC) patients with unexplained carcinoembryonic antigen (CEA) rise after surgical curative resection.

Material and methods

Forty asymptomatic patients (mean age, 64?±?12 years) with previous CRC and current serum CEA levels >5 ng/ml underwent [F-18] FDG PET/CT 13?±?3 months after complete surgical resection. The SUVmax was registered on anastomosis and peri-anastomotic tissue lesions, if present. The patients were followed for 24?±?9 months thereafter. Re-intervention, evidence of newly discovered distant metastases, and death were recognized as main events and constituted surrogate end points. The receiver-operator-curve (ROC) analysis was performed to estimate the optimal SUVmax cut-off to predict patients at high risk of main events. PET/CT results were then related to disease outcome (overall survival; OS).

Results

The mean SUVmax at the anastomotic site was 6.2?±?3 (range 2.6–15). At multivariate logistic regression analysis, the anastomotic SUVmax remained as the only significant contributor to the prediction of the events (p?=?0.004; OR 1.97). The ROC analysis recognized that the optimal threshold of SUVmax to differentiate patients was 5.7. A worse OS was observed in patients presenting with a SUVmax greater than 5.7 as compared to those having lesser (median survival: 16 vs. 31 months; p?=?0.002).

Conclusions

The quantitative assessment by SUVmax on [F-18]FDG PET/CT may be helpful in patients presenting with unexplained CEA rise after curative resection of CRC, by identifying those at risk of main events.     

Repetitive 18-fluorodeoxyglucose positron emission tomography in isolated polymyalgia rheumatica: a prospective study in 35 patients

Objective. To study fluorodeoxyglucose (FDG) deposition in differentvascular beds and in the large joints of patients with isolatedpolymyalgia rheumatica (PMR), and to investigate whether thereis a relation between FDG-positron emission tomography (PET)results and risk of relapse. Methods. All consecutive patients with isolated PMR underwenta FDG–PET scan before treatment with steroids was startedand—if logistics allowed—at 3 and 6 months. PETscans were scored at seven different vascular areas and a totalvascular score (TVS) was calculated, ranging from 0 to 21. FDGuptake in the shoulders, the hips and the processi spinosi ofthe vertebrae was scored as 0 (no uptake), 1 (moderate uptake)or 2 (intense uptake). Results. Thirty-five patients entered the study. At diagnosis,vascular FDG uptake was noted in 11 patients (31%), predominantlyat the subclavian arteries. Mean TVS was low. FDG uptake inthe shoulders was noted in 94% of patients, in the hips in 89%and in the processi spinosi of the vertebrae in 51%. The intensityof FDG uptake in the large vessels or in the shoulders, hipsor processi spinosi did not correlate with the risk of relapse. Conclusions. Only one in three patients has an (moderately)increased vascular FDG uptake, especially in the subclavianarteries. The vast majority has inflammation of shoulders andhips, and half of them have increased FDG-uptake at the processispinosi. Results of FDG–PET scans in patients with PMRdid not correlate with their risk of relapse. KEY WORDS: Polymyalgia rheumatica, Positron emission tomography, Vasculitis, Giant cell arteritis Submitted 5 July 2006; revised version accepted 11 October 2006.     

Predictors of positive 18F-FDG PET/CT-scan for large vessel vasculitis in patients with persistent polymyalgia rheumatica

Objective

Polymyalgia rheumatica (PMR) is often the presenting manifestation of giant cell arteritis (GCA). Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scan often discloses the presence of large vessel vasculitis (LVV) in PMR patients. We aimed to identify predictive factors of a positive PET/CT scan for LVV in patients classified as having isolated PMR according to well-established criteria.

Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography and computed tomography (FDG-PET/CT)

Background

The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT).

Methods

Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard.

Results

In all, 270 colorectal lesions 5?mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11?mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21?mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10?mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44?C221.67] and flat morphology (OR 7.78, 95% CI 1.79?C36.25) were significant factors that were associated with false-negative cases on PET/CT.

Conclusion

The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results.     

The prognostic value of positron emission tomography/computed tomography in rheumatoid arthritis patients with methotrexate-associated lymphoproliferative disorders

Recently, methotrexate-associated lymphoproliferative disorders (MTX-LPDs) in rheumatoid arthritis (RA) have been found to commonly occur in association with iatrogenic immunodeficiency. Several factors have been reported to be related to the prognosis. We herein investigate the efficacy of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in predicting the prognosis of MTX-LPD. We performed a retrospective analysis of the clinical features, characteristics, and outcomes of 18 patients with MTX-LPDs who were treated from 2004 to 2015. All of the patients were diagnosed with MTX-LPD based on the histological examination of biopsy specimens. Spontaneous regression was detected after the cessation of MTX in 5 of 18 cases (28%). The maximum standardized uptake value (SUVmax) of the FDG uptake on PET/CT was significantly lower, and the maximum size of the LPD-associated tumor was significantly smaller among the patients who showed spontaneous regression (p?=?0.01, p?=?0.04, respectively). Both the SUVmax and the maximum tumor size were related to better overall survival (p?=?0.02, p?=?0.04, respectively). Thus, PET/CT can be used to predict spontaneous regression and the prognosis at the diagnosis of MTX/LPD. Cases that showed spontaneous regression never relapsed during the follow-up period, despite the usage of several anti-rheumatoid arthritis drugs, including biological agents. The early detection of LPDs and the early cessation of MTX are important for the management of RA patients. An evaluation by F-FDG-PET/CT can be useful for predicting spontaneous regression and the prognosis.     

Is 18F-fluorodeoxyglucose positron emission tomography meaningful for estimating the efficacy of corticosteroid therapy in patients with autoimmune pancreatitis?

Background

Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic cancer (PC). Both conditions accumulate ¹⁸F-fluorodeoxyglucose (FDG), so FDG positron emission tomography (FDG-PET) is not discriminatory. This study aimed to evaluate the pattern of FDG accumulation, and the change in FDG uptake after steroid treatment in AIP and PC.

Methods

We compared FDG-PET patterns between 18 patients with AIP and 20 patients with PC, and also evaluated the short-term changes in FDG uptake after steroid therapy.

Results

FDG uptake was observed in 88.9% in AIP and 90.0% in PC. FDG uptake in extra-abdominal lymph nodes was seen more frequently in AIP, and uptake in salivary glands, eyes and biliary ducts was seen only in AIP. Follow-up PET was performed in 6 AIP patients and in 3 PC patients. Changes in SUV_max after steroid therapy were estimated within 1 week in 5 AIP patients and in all 3 PC patients, retrospectively. In 4 AIP patients, the change in SUV_max was more than 10%. On the other hand, in PC, SUV_max increased or remained almost unchanged (within 10%).

Conclusions

FDG-PET pattern at baseline, and a decrease in FDG uptake after a short steroid trial can be useful for discriminating AIP from PC.     

Predictive factors of [18F]-Choline PET/CT in 170 patients with increasing PSA after primary radical treatment

Aim

The purpose of this study was to evaluate the potential usefulness of [18F]-Choline PET/CT in the restaging of prostate cancer patients, who presented a rising PSA.

Materials and methods

We evaluated 170 prostate cancer patients, previously radically treated, that were referred for restaging with [18F]-Choline PET/CT.

Results

A total of 129 patients (median PSA 4.29 ng/ml at relapse) showed one or more areas of high uptake on PET/CT scan, while 41 patients with a median PSA of 1.07 ng/ml at relapse showed negative PET/CT scans. No false negative was found, while 31 patients were identified as false positive. Specificity of Choline PET/CT in our series was 56.9 %, while sensibility was 100 %. At the time of restaging, a PSA value superior or equal to 1 ng/ml was found to be a statistically significant predictive factor of PET positivity, either at the univariate (p < 0.0001) and at the multivariate analysis (p < 0.0001).

Conclusions

Based on our findings, [18F]-Choline PET/CT is confirmed as a useful diagnostic tool to detect early recurrence, in patients with increasing PSA after primary treatment. However, in case of a mild increase in PSA, positive results must be validated with other techniques, as specificity and positive predictive value of [18F]-Choline PET/CT decrease with the lower values of PSA.     

Predicting complete response to neoadjuvant CRT for distal rectal cancer using sequential PET/CT imaging

Background

Molecular imaging using positron emission tomography/computerized tomography (PET/CT) may add relevant incremental diagnostic information to standard structural cross-sectional imaging. Such information may allow identification of patients with rectal cancer that are more likely to develop complete tumor regression after neoadjuvant chemoradiation therapy (CRT). The objective of this report was to identify PET/CT features that are associated with a complete response after CRT.

Methods

99 cT2-4N0-2M0 distal rectal cancer patients (≤7 cm from anal verge) were included in this prospective single center trial (NCT 00254683). Patients underwent baseline PET/CT followed by 54 Gy and 5-fluorouracil-based neoadjuvant CRT. After completion of therapy, patients underwent 6- and 12-week PET/CT. Clinical assessment of tumor response was performed at 12 weeks and was blinded to radiological information. Patients were treated according to clinical assessment.

Results

There were seven patients with a complete pathological response (pCR) and 16 with a complete clinical response (cCR) (23 complete responders). Comparison of pCR exclusively and non-pCR revealed that only baseline primary tumor standard uptake value (SUV) was a significant predictor of response. Comparison of complete responders (pCR or cCR) and non-complete responders showed that depth of rectal wall uptake at baseline PET/CT (p = 0.002) and variation between baseline and 12-week maximum standard uptake value (SUVmax) of primary tumor (p = 0.001) were independent predictors for complete response at multivariate analysis. A decrease >67 % between baseline and 6-week or 76 % between baseline and 12-week SUVmax were associated with complete response (pCR or cCR; p = 0.02 and p < 0.001, respectively).

Conclusions

Positron emission tomography/computerized tomography at baseline, 6 and 12 weeks, may provide information regarding patients with a higher likelihood of developing complete tumor regression following neoadjuvant CRT.     

Repetitive 18F-fluorodeoxyglucose positron emission tomography in giant cell arteritis: a prospective study of 35 patients

OBJECTIVE: To study fluorodeoxyglucose (FDG) uptake in the different vascular beds and in the large joints of patients with giant cell arteritis (GCA) at diagnosis, during steroid treatment, and at relapse. METHODS: All consecutive patients admitted to our department with a diagnosis of GCA underwent FDG-positron emission tomography (PET) scan before treatment with methylprednisolone was started. PET scans were repeated at 3 and 6 months, if the initial PET scans showed vascular FDG uptake. PET scans were scored at 7 different vascular areas and a total vascular score (TVS) was calculated, ranging from 0 to 21. RESULTS: A total of 35 patients entered the study. At diagnosis, vascular FDG uptake was noted in 29 patients (83%), especially in the subclavian arteries (74%), but also in the aorta (>50%) and up to the femoral arteries (37%). TVS decreased from a mean +/- SD score of 7.9 +/- 5.5 at baseline to 2.4 +/- 3.5 on repeat PET scan at 3 months (P < 0.0005), but did not further decrease at 6 months. The patients who relapsed had similar earlier decreases of TVS compared with those who did not relapse. FDG uptake in the shoulders at diagnosis correlated significantly with the presence of polymyalgia rheumatica (P = 0.005). CONCLUSION: FDG uptake in the large vessels is a sensitive marker for GCA, which can involve the larger thoracic, abdominal, and peripheral arteries. Polymyalgia rheumatica symptoms in patients with GCA correlate with (peri)synovitis of the shoulders. Relapses of GCA cannot be predicted by results of former PET scintigraphies.     

High FDG uptake in PET/CT predicts worse prognosis in patients with metastatic gastric adenocarcinoma

Purpose

We evaluated the role of FDG-PET/CT in patients with metastatic gastric adenocarcinoma before palliative chemotherapy to predict prognosis and chemotherapeutic response.

Methods

The study included 35 consecutive newly diagnosed patients with metastatic gastric adenocarcinoma who underwent FDG-PET/CT before palliative chemotherapy. Maximum standardized uptake value (SUVmax) of the primary tumor was assessed to evaluate survival and chemotherapeutic response. Survival analysis was performed for time to progression and overall survival using the Kaplan–Meier method. Cox proportional hazard models were used to determine independent prognostic factors.

Results

All primary tumors were visualized using FDG-PET/CT (mean SUVmax = 8.1 ± 4.5, range 2.5–22.1). Sensitivity, specificity, and accuracy of FDG-PET/CT in detection of solid organ metastasis were 95.2% (20/21), 100% (14/14), and 97.1% (34/35), respectively. No significant difference of primary tumor SUVmax was found among the chemotherapeutic response groups. Univariate survival analysis demonstrated ECOG performance status (≥2), presence of solid organ metastasis, number of organs involved in distant metastasis (≥2), and SUVmax of the primary tumor (>8) as significant predictors for poor overall survival. Multivariate survival analysis showed SUVmax of the primary tumor (P = 0.048), presence of solid organ metastasis (P = 0.015), and ECOG performance status (P = 0.002) as significant independent prognostic predictors for overall survival.

Conclusions

High FDG uptake of the primary tumor in patients with metastatic gastric adenocarcinoma is associated with poor overall survival. Assessment of tumor FDG uptake has limited value for prediction of chemotherapeutic response, but provides useful information regarding prognosis.     

Hybrid Magnetic Resonance Imaging and Positron Emission Tomography With Fluorodeoxyglucose to Diagnose Active Cardiac Sarcoidosis

Objectives

The purpose of this study was to explore the diagnostic usefulness of hybrid cardiac magnetic resonance (CMR) and positron emission tomography (PET) using ¹⁸F-fluorodeoxyglucose (FDG) for active cardiac sarcoidosis.

Incidental Colonic 18F-Fluorodeoxyglucose Uptake: Do We Need Colonoscopy for Patients with Focal Uptake Confined to the Left-Sided Colon?

Background/Aims

Although access to [¹⁸F]2-fluoro-2-deoxyglucose (¹⁸F-FDG) positron emission tomography and computed axial tomography (PET/CT) for patients with malignancy has increased, little information is available on the suitability of PET/CT for diagnosis of advanced colonic neoplasms in oncology patients and on the clinical significance of incidental ¹⁸F-FDG focal uptake confined to the left-sided colon.

Methods

Patients who underwent ¹⁸F-FDG PET/CT followed, within 90 days, by colonoscopy were identified. Case–control analysis was undertaken to determine whether focal ¹⁸F-FDG uptake confined to the left-sided colon was associated with advanced neoplasms in the right-sided colon.

Results

One hundred ninety-five patients with colonic ¹⁸F-FDG uptake and 561 without colonic ¹⁸F-FDG uptake were identified. Of the 195 patients with focal colonic ¹⁸F-FDG activity, 103 patients (52.8 %) had 145 advanced colonic neoplasms, including 58 colon cancers and 11 metastatic cancers. In the detection of advanced colonic neoplasms, the sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT were 54.4, 82.4, 46.9, and 86.3 %, respectively. Overall accuracy was 76.2 %. Ten (8.0 %) of the 125 patients with focal ¹⁸F-FDG uptake confined to the left-sided colon had three colon cancers and seven advanced adenomas in the right-sided colon. Case–control analysis revealed that focal ¹⁸F-FDG uptake confined to the left-sided colon was associated with an advanced neoplasms in the right-sided colon (OR, 3.02; 95 % CI, 1.12–8.13; P = 0.023).

Conclusions

Colonic focal ¹⁸F-FDG uptake by oncology patients warrants endoscopic verification. Complete colon evaluation by colonoscopy is required, even for patients with focal ¹⁸F-FDG uptake confined to the left-sided colon.     

Is 18F‐fluorodeoxyglucose positron emission tomography scanning a reliable way to assess disease activity in takayasu arteritis?

Objective

¹⁸F‐fluorodeoxyglucose–positron emission tomography (FDG‐PET) scanning has been proposed as a new way of assessing disease activity in Takayasu arteritis (TA), but previous studies have used the nonvalidated National Institutes of Health (NIH) global activity criteria, and thus might be biased. This study was undertaken to determine the value of PET scanning for assessment of disease activity in TA, by comparing PET scan data with clinical, biologic, and magnetic resonance imaging (MRI) data assessed separately.

Methods

Twenty‐eight patients with TA (according to the American College of Rheumatology criteria) underwent a total of 40 PET scans. Images were reviewed by 2 pairs of independent nuclear medicine physicians and assessed for pattern and intensity of vascular uptake. TA activity data were obtained within 15 days of the PET scans.

Results

PET scanning revealed abnormal vascular uptake in 47% of the 40 examinations. The uptake intensity grade was 0 in 7 scans, grade 1 in 7 scans, grade 2 in 13 scans, and grade 3 in 13 scans. Morphologic analysis was conducted by grading the pattern of the vascular uptake as diffuse (73%), segmental (20%), or focal (13%). There was a trend toward an association between clinically active disease and the semiquantitative assessment of FDG uptake (P = 0.08). We found no statistical association between levels of acute‐phase reactants and intensity of uptake. There was no significant association between the semiquantitative assessment of FDG uptake and the presence of vascular wall thickening (P = 0.23), gadolinium uptake (P = 0.73), or the presence of vascular wall edema (P = 0.56).

Conclusion

Our findings indicate that there is no association between FDG vascular uptake intensity and clinical, biologic, or MRI assessment of disease activity. Previous studies using the nonvalidated NIH global activity criteria are likely biased.

     

Preoperative staging of clinically node-negative esophageal cancer by the combination of 18F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG–PET/CT)

Background

Although lymph node metastasis is a significant prognostic factor in patients with esophageal cancer, the sensitivity and specificity of conventional imaging modalities such as computed tomography (CT) and magnetic resonance imaging is limited in the diagnosis of lymph node metastasis. This retrospective study examined the usefulness of the combination of ¹⁸F-fluorodeoxyglucose-positron emission tomography (PET)/CT in the diagnosis of subclinical lymph node metastasis from esophageal cancer.

Methods

We compared the postoperative pathological findings and preoperative PET/CT findings in 81 consecutive clinically node-negative esophageal cancer patients who underwent esophagectomy with lymphadenectomy. All patients had resectable tumor (T1?CT3) and were node-negative based on preoperative conventional examinations.

Results

Of the 81 patients, 37 had pathological node metastasis in surgical specimens. A PET/CT diagnosis of node metastasis was made using several cut-off values of the maximum standardized uptake value (SUV_max). The sensitivity, specificity, and accuracy of PET/CT diagnosis were 32.4, 70.4, and 53.1?% at an SUV_max cut-off value of 1.8; 29.7?%, 79.5?%, and 56.8?% at 2.0; 21.6?%, 90.9?%, and 59.3?% at 2.5; 16.2?%, 95.4?%, and 59.3?% at 3.0; and 10.8?%, 97.7?%, and 56.8?% at 3.5, respectively. When an SUV_max cut-off value of 1.8 was employed, the disease-free survival rate was significantly worse in PET/CT-node-positive patients (PET-N(+)) than in PET-N(?) patients. Next, the effect of PET-N status on the prognosis was analyzed in pN(?)and pN(+) patients separately. Among the 44 pN(?) patients, PET-N status did not significantly affect the disease-free survival (p?=?0.879). In contrast, in the 37 pN(+) patients, DFS was significantly better in PET-N(?) patients than in PET-N(+) patients (p?=?0.002).

Conclusions

The diagnostic sensitivity of PET/CT for subclinical lymph node metastasis in clinically node-negative patients is low, but this combined modality can potentially identify patients with poor prognosis.