Bi-Fang Lee

Prognostic Value of Whole-Body Total Lesion Glycolysis at Pretreatment FDG PET/CT in Non–Small Cell Lung Cancer

PURPOSE To determine whether whole-body total lesion glycolysis (TLG), which combines volumetric and metabolic information from fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), can provide a better evaluation of the prognosis for non-small cell lung cancer (NSCLC). MATERIALS AND METHODS The institutional review board approved this retrospective study, and the requirement to obtain informed consent was waived. The authors identified 105 consecutive patients with NSCLC who underwent staging FDG PET/CT before any therapy. These patients were free of brain metastasis and underwent standard treatment and subsequent clinical follow-up. Metabolic tumor volume (MTV), mean standardized uptake value (SUV), and maximum SUV of each tumor over the whole body were determined. Whole-body MTV and whole-body TLG are the summation of all the MTVs and summation of individual tumor volume multiplied by its mean SUV, respectively. Univariate and multivariate analyses were performed to assess the prognostic significance of whole-body TLG and other factors, including whole-body MTV, lung TLG, lung MTV, maximum SUV, sex, age, performance status, histologic subtype, T stage, N stage, clinical stage, and treatment method. RESULTS The median follow-up time was 3.1 years. The estimated median progression-free survival (PFS) and overall survival (OS) for the cohort was 10.8 months and 2.8 years, respectively. The 1-year PFS was 0.0% for patients with high whole-body TLG (>655) and 50.0% for those with low whole-body TLG (≤655). The 1-year OS was 58.8% for patients with high whole-body TLG and 84.1% for those with low whole-body TLG. Univariate analysis showed that whole-body TLG, whole-body MTV, lung TLG, lung MTV, maximum SUV, performance status, T stage, N stage, clinical stage, and treatment type (surgery vs other) were significant prognostic factors for PFS (P < .01 for all). With use of the forward stepwise multivariate Cox proportional hazards model, whole-body TLG (hazard ratio = 2.92; 95% confidence interval: 1.62, 5.26; P < .01) and surgical treatment (hazard ratio = 4.24; 95% confidence interval: 2.54, 7.07; P < .01) remained significant in PFS. CONCLUSION Whole-body TLG is of prognostic value for NSCLC. It may be a promising tool for stratifying patients with NSCLC for risk-adapted therapies.

Dual-Phase 18F-FDG PET in the Diagnosis of Pulmonary Nodules with an Initial Standard Uptake Value Less Than 2.5

OBJECTIVE A cutoff standard uptake value (SUV) of 2.5 has been commonly adopted for (18)F-FDG PET to evaluate pulmonary lesions, but false results can occur. Studies have shown the usefulness of delayed PET for improving accuracy. This study was designed to examine the efficiency of delayed PET of pulmonary nodules with an initial mean SUV less than 2.5. MATERIALS AND METHODS Dual-phase FDG PET studies were conducted with imaging 1 and 2 hours after FDG injection, and pulmonary lesions with an initial mean SUV less than 2.5 were identified. Nodules with pathologic reports were included in the study. The differences in mean SUV, maximal SUV, and retention index between benign and malignant pulmonary lesions were analyzed. Receiver operating characteristic analysis was performed to evaluate the discriminating validity of the retention index. RESULTS A total of 31 lesions (15 benign, 16 malignant) were included in the study. Among the benign lesions, 12 were granulomatous inflammation, including 10 tuberculosis lesions and two cryptococcosis lesions, and three were focal fibrosis. A retention index greater than 0% was observed in 87% of the benign lesions; 60% of the benign lesions had a retention index greater than 10%. Among the malignant lesions, 75% had a retention index greater than 0%, and 62% had a retention index greater than 10%. We found no significant differences in mean SUV, maximal SUV, and retention index between benign and malignant lesions. The area under the receiver operating characteristic curve did not differ from 0.5. CONCLUSION Delayed FDG PET is not useful for differentiating benign and malignant pulmonary nodules with an initial mean SUV less than 2.5 in geographic regions with epidemic granulomatous disease such as tuberculosis or in patients at high risk of granulomatous inflammation.

Changes in bone mineral density of lumbar spine after pelvic radiotherapy

Bone mineral densities (BMDs) of L2 to L5 were measured on 40 cervical cancer patients with radiotherapy and 40 matched controls. We found no significant difference in the BMDs between the two groups and no significant change in BMDs 1-7 years after the therapy in the patient group.

A False Positive 18F-FDG PET/CT Scan Caused by Breast Silicone Injection

We present here the case of a 40-year-old woman with a greater than 10 year prior history of bilateral breast silicone injection and saline bag implantation. Bilateral palpable breast nodules were observed, but the ultrasound scan was suboptimal and the magnetic resonance imaging showed no gadolinium-enhanced tumor. The 18F-FDG PET/CT scan showed a hypermetabolic nodule in the left breast with a 30% increase of 18F-FDG uptake on the delayed imaging, and this mimicked breast cancer. She underwent a left partial mastectomy and the pathology demonstrated a siliconoma.

Differences in 99mTc-HMPAO brain SPET perfusion imaging between Tourette's syndrome and chronic tic disorder in children

Early differential diagnosis between Tourettes syndrome and chronic tic disorder is difficult but important because both the outcome and the treatment of these two childhood-onset diseases are distinct. We assessed the sensitivity and specificity of brain single-photon emission tomography (SPET) perfusion imaging in distinguishing the two diseases, and characterized their different cerebral perfusion patterns. Twenty-seven children with Tourettes syndrome and 11 with chronic tic disorder (mean age 9.5 and 8.6 years, respectively) underwent brain SPET with technetium-99m hexamethylpropylene amine oxime (HMPAO). Visual interpretation and semi-quantitative analysis of SPET images were performed. On visual interpretation, 22 of 27 (82%) of the Tourettes syndrome group had lesions characterized by decreased perfusion. The left hemisphere was more frequently involved. None of the children with chronic tic disorder had a visible abnormality. Semi-quantitative analysis showed that, compared with children with chronic tic disorder, children with Tourettes syndrome had significantly lower perfusion in the left lateral temporal area and asymmetric perfusion in the dorsolateral frontal, lateral and medial temporal areas. In conclusion, using the visual approach, brain SPET perfusion imaging is sensitive and specific in differentiating Tourettes syndrome and chronic tic disorder. The perfusion difference between the two groups, demonstrated by semi-quantitative analysis, may be related more to the co-morbidity in Tourettes syndrome than to tics per se.

Reflex sympathetic dystrophy syndrome in stroke patients with hemiplegia-three phase bone scintigraphy and clinical characteristics.

In an attempt to investigate the correlation between three phase bone scintigraphy (TPBS) and the clinical manifestation of reflex sympathetic dystrophy syndrome (RSDS) in the upper extremity of hemiplegia, we collected 30 patients with cerebral vascular accidents (CVA) confirmed by head computed tomography (infarction or hemorrhage) within 3 months of their CVA event. All patients received TPBS after admission. Clinical assessment for the development of the RSDS was done at least 3 months (268 +/- 120 days) after the stroke. The correlation between the development of RSD and certain clinical variables (including sex, age, side affected, caused of stroke, and motor stage) were analyzed. Twelve patients (40%) manifested definite or probable RSDS, as assessed by Teppermans criteria, during the follow-up period. Nineteen patients (63%) exhibited radionuclide evidence of RSDS based on delayed bone scan criteria performed within 3 months (43 +/- 25 days) of the stroke. The positive delayed image of TPBS demonstrated a sensitivity = 92%; specificity = 56%; positive predictive value = 58%, and negative predictive value = 91%. The Kappa statistics for agreement between positive bone scan and RSDS development was 70% (Kappa = 0.43, p < 0.05). Neither sex, age, side affected, cause of stroke, or motor stage had a significant correlation with clinical RSDS. In conclusion, TPBS is a useful screening tool for the development of RSD in hemiplegic patients. However, the diagnosis of RSDS depends on the clinical evaluation and that TPBS as an adjunct assessment of RSDS must be interpreted with caution.

The Relationship between Brown Adipose Tissue Activity and Neoplastic Status: an 18F-FDG PET/CT Study in the Tropics

BackgroundBrown adipose tissue (BAT) has thermogenic potential. For its activation, cold exposure is considered a critical factor though other determinants have also been reported. The purpose of this study was to assess the relationship between neoplastic status and BAT activity by 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in people living in the tropics, where the influence of outdoor temperature was low.Methods18F-FDG PET/CT scans were reviewed and the total metabolic activity (TMA) of identified activated BAT quantified. The distribution and TMA of activated BAT were compared between patients with and without a cancer history. The neoplastic status of patients was scored according to their cancer history and 18F-FDG PET/CT findings. We evaluated the relationships between the TMA of BAT and neoplastic status along with other factors: age, body mass index, fasting blood sugar, gender, and outdoor temperature.ResultsThirty of 1740 patients had activated BAT. Those with a cancer history had wider BAT distribution (p = 0.043) and a higher TMA (p = 0.028) than those without. A higher neoplastic status score was associated with a higher average TMA. Multivariate analyses showed that neoplastic status was the only factor significantly associated with the TMA of activated BAT (p = 0.016).ConclusionsNeoplastic status is a critical determinant of BAT activity in patients living in the tropics. More active neoplastic status was associated with more vigorous TMA of BAT.

Peritoneal tuberculosis with elevated serum CA125 mimicking peritoneal carcinomatosis on F-18 FDG-PET/CT

Abstract18F-fluorodeoxyglucose positron emission tomography (F-18 FDG-PET) plays an important role in differentiating benign from malignant tumors. However, some false-positive findings, such as tuberculosis, may occur. We report a case referred for F-18 FDG whole-body PET computed tomography (PET/CT) scan owing to an elevated serum cancer antigen 125 (CA125). An FDG-PET/CT scan showed multiple hypermetabolic foci in the mesentery and peritoneum with further increase of FDG uptake on the delayed scan, mimicking peritoneal carcinomatosis. Subsequent laparoscopic biopsy showed granulomatous inflammation, and tuberculosis polymerase chain reaction showed a positive result. Serum CA125 returned to normal following treatment with anti-tuberculosis drugs. Peritoneal tuberculosis should be considered as a differential diagnosis in a tuberculosis endemic region.

Evolution of differential renal function after acute pyelonephritis

99mTc dimercaptosuccinic acid (DMSA) renal scans can provide accurate diagnosis of acute pyelonephritis, its sequelae (renal scars) and differential renal function (DRF). The purposes of this retrospective study were (1) to assess the relationship between DRF obtained during acute pyelonephritis and at follow-up, and (2) to elucidate the value of initial DRF in predicting subsequent renal scars. A total of 47 children were enrolled. All had both unilateral acute pyelonephritis diagnosed by initial DMSA renal scans, and follow-up DMSA renal scans. We found the correlation between initial and follow-up DRF poor (adjusted R2 = 0.396). Whether or not renal scars developed determined the follow-up DRF. Vesicoureteral reflux was significantly more common in children who developed renal scars. In addition, the higher the grade of vesicoureteral reflux, the lower the follow-up DRF and the improvement in DRF. When using a DRF of 46% as the cut-off value to predict subsequent renal scars, the sensitivity and specificity were 47.8% and 83.3%, respectively. Owing to the low sensitivity, initial DRF is not suitable for predicting the occurrence of renal scars.

Psoas muscle abscess causing fever of unknown origin: the value of Tc-99m (V) DMS imaging.

Tc-99m (V) DMS, a tumor-seeking agent, incidentally demonstrated the psoas muscle abscess in a 34-year-old woman who had systemic lupus erythematosus. This case illustrates the value of Tc-99m (V) DMS imaging in the diagnosis and management of such patients. Further studies with a large group of patients is necessary to verify this preliminary result.