Optimization of FDG-PET/CT imaging protocol for evaluation of patients with primary and metastatic liver disease

Background

Accurate determination of the extrahepatic extent and intrahepatic distribution of disease is very important in patients with primary and metastatic liver disease for deciding whether a patient receives potentially curable surgery or palliative treatment. Our objective was to evaluate the efficacy of delayed phase FDG-PET/CT imaging in lesion detection and to define its clinical impact compared to triple-phase contrast enhanced CT (CECT).

Methods

30 patients underwent delayed phase FDG-PET/CT imaging (90 min whole body scan followed by a delayed abdominal scan at 120 min). Maximum standard uptake values (SUVs) and SUV ratios between tumor and normal liver parenchyma (T/N) were evaluated. In addition, comparison was made to CECT obtained within 10 days of the FDG-PET/CT to evaluate for lesion concordance within individual liver segments (Couinaud designation).

Results

Sites of primary malignancies included: colorectal (19), breast (3), pancreas (2), lung (2), carcinoid (2), cholangiocarcinoma (1), and hepatocellular carcinoma (1). There was a significant increase in SUV value of liver lesions between early and delayed acquisition (P < 0.001). Although there was not a significant reduction in liver background activity between the two studies, there was a strong increase in T/N ratio (P < 0.001) allowing better lesion detection by visual inspection. New lesions were identified in 5 of the 30 patients, which were not appreciated on the early scan. Delayed phase FDG-PET/CT identified one lesion which was not present on the corresponding CECT. Delayed phase FDG-PET/CT revealed extrahepatic sites of metastases not appreciated on CECT in 6 patients.

Conclusion

Delayed phase FDG-PET/CT protocol improved lesion detectability in primary and metastatic liver disease, revealing new lesions in 17% of the patients. Moreover, FDG-PET/CT identified extrahepatic disease not seen on CECT in 20% of the patients.

     

No diagnostic impact of routinely use of respiratory gating to characterize lung nodules with 18F-FDG PET/CT

Purpose

To evaluate diagnostic impact of routinely use of respiratory gated (RG) ¹⁸FDG PET/CT to distinguish benign and malignant lung nodules.

Diffusion-Weighted MRI in the Assessment of Early Treatment Response in Patients with Squamous-Cell Carcinoma of the Head and Neck: Comparison with Morphological and PET/CT Findings

Objective

To evaluate changes in apparent diffusion coefficients (ADC) as measured by magnetic resonance imaging (MRI) before and after the treatment of primary tumors and cervical metastases in patients with squamous-cell carcinoma (SCC) of the head and neck, and to compare these values to the results of widely used morphological criteria and [18F]-FDG PET/CT findings.

Material and Method

This was a longitudinal, prospective, single-center nonrandomized trial involving patients with head and neck SCC treated with chemotherapy alone or in combination with radiotherapy. Imaging examinations ([18F]-FDG PET/CT and diffusion-weighted MRI) were performed on the same day, up to one day prior to the beginning of the first treatment cycle, and on the 14th day of the first chemotherapy cycle. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) morphological criteria, as well as PET Response Criteria in Solid Tumors (PERCIST) metabolic criteria.

Results

Seventy-five lesions were examined in 23 patients. Pre- and post-treatment comparisons of data pertaining to all target lesions revealed reductions in tumor size and SUV, as well as increases in ADC values, all of which were statistically significant. The increase in ADC following treatment was significantly higher in patients classified as complete responders by both morphological criteria than that observed in any of the other patient groups of response. Patients with a complete metabolic response also showed greater increases in ADC values as compared to the remaining groups.

Conclusion

The assessment of tumor response based on diffusion-weighted MRI showed an increase in the ADC of cervical lesions following treatment, which was corroborated by morphological and metabolic findings. Associations between changes in ADC values and treatment response categories using morphologic criteria and [18F]-FDG PET/CT were only identified in complete responders.     

Normal SUV Values Measured from NaF18- PET/CT Bone Scan Studies

Objectives

Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans.

Methods

A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past history of cancer and metabolic bone diseases including but not limited to osteoporosis, osteopenia and Paget’s disease. Eleven studies met all the criteria.

Results

The average normal SUV_max values from 11 patients were: cervical vertebrae 6.84 (range 4.38–8.64), thoracic vertebrae 7.36 (range 6.99–7.66), lumbar vertebrae 7.27 (range 7.04–7.72), femoral head 2.22 (range 1.1–4.3), humeral head 1.82 (range 1.2–2.9), mid sternum 5.51 (range 2.6–8.1), parietal bone 1.71 (range 1.3–2.4).

Conclusion

According to our study, various skeletal sites have different normal SUV values. SUV values can be different between the normal bones and bones with tumor or metabolic bone disease. SUV can be used to quantify NaF-18 PET/CT studies. If the SUV values of the normal skeleton are known, they can be used in the characterization of bone lesions and in the assessment of treatment response to bone diseases.     

Combined approach of perioperative <Superscript>18</Superscript>F-FDG PET/CT imaging and intraoperative <Superscript>18</Superscript>F-FDG handheld gamma probe detection for tumor localization and verification of complete tumor resection in breast cancer

Background

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has become an established method for detecting hypermetabolic sites of known and occult disease and is widely used in oncology surgical planning. Intraoperatively, it is often difficult to localize tumors and verify complete resection of tumors that have been previously detected on diagnostic PET/CT at the time of the original evaluation of the cancer patient. Therefore, we propose an innovative approach for intraoperative tumor localization and verification of complete tumor resection utilizing ¹⁸F-FDG for perioperative PET/CT imaging and intraoperative gamma probe detection.

Methods

Two breast cancer patients were evaluated. ¹⁸F-FDG was administered and PET/CT was acquired immediately prior to surgery. Intraoperatively, tumors were localized and resected with the assistance of a handheld gamma probe. Resected tumors were scanned with specimen PET/CT prior to pathologic processing. Shortly after the surgical procedure, patients were re-imaged with PET/CT utilizing the same preoperatively administered ¹⁸F-FDG dose.

Results

One patient had primary carcinoma of breast and a metastatic axillary lymph node. The second patient had a solitary metastatic liver lesion. In both cases, preoperative PET/CT verified these findings and demonstrated no additional suspicious hypermetabolic lesions. Furthermore, intraoperative gamma probe detection, specimen PET/CT, and postoperative PET/CT verified complete resection of the hypermetabolic lesions.

Conclusion

Immediate preoperative and postoperative PET/CT imaging, utilizing the same ¹⁸F-FDG injection dose, is feasible and image quality is acceptable. Such perioperative PET/CT imaging, along with intraoperative gamma probe detection and specimen PET/CT, can be used to verify complete tumor resection. This innovative approach demonstrates promise for assisting the oncologic surgeon in localizing and verifying resection of ¹⁸F-FDG positive tumors and may ultimately positively impact upon long-term patient outcomes.

     

Anatomical Grading for Metabolic Activity of Brown Adipose Tissue

Background

Recent advances in obesity research suggest that BAT activity, or absence thereof, may be an important factor in the growing epidemic of obesity and its manifold complications. It is thus important to assess larger populations for BAT-activating and deactivating factors. ¹⁸FDG-PET/CT is the standard method to detect and quantify metabolic BAT activity, however, the manual measurement is not suitable for large studies due to its time-consuming nature and poor reproducibility across different software and devices.

Methodology/Main Findings

In a retrospective study, 1060 consecutive scans of 1031 patients receiving a diagnostic ¹⁸FDG-PET/CT were examined for the presence of active BAT. Patients were classified according to a 3-tier system (supraclavicular, mediastinal, infradiaphragmatic) depending on the anatomical location of their active BAT depots, with the most caudal location being the decisive factor. The metabolic parameters (maximum activity, total volume and total glycolysis) were measured on a standard PET/CT workstation. Mean age of the population was 60±14.6y. 41.61% of patients were female. Metabolically active BAT was found in 53 patients (5.1%). Female, younger and leaner patients tended to have more active BAT, higher metabolic activity and more caudally active BAT. In total, 15 patients showed only supraclavicular, 27 additional mediastinal, and 11 infradiaphragmal activity. Interestingly, the activation of BAT always followed a cranio-caudal gradient. This anatomical pattern correlated with age and BMI as well as with all metabolic parameters, including maximum and total glycolysis (p<0.001).

Conclusion

Based on our data we propose a simple method to grade or quantify the degree of BAT amount/activity in patients based on the most caudally activated depot. As new modalities for BAT visualization may arise in the future, this system would allow direct comparability with other modalities, in contrary to the PET-metrics, which are restricted to ¹⁸FDG-PET/CT.     

Role of 2-[18F] Fluoro-2-Deoxy-D-Glucose-Positron Emission Tomography/Computed Tomography in the Post-Therapy Surveillance of Breast Cancer

Purpose

To evaluate the usefulness of 2-[¹⁸F] fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the early detection of breast cancer tumor recurrences and its role in post-therapy surveillance.

Methods

FDG-PET/CT was performed on patients with increased serum CA 15-3 levels and/or clinical/radiologic suspicion of recurrence. A group of asymptomatic patients who underwent FDG-PET/CT in the post-therapy surveillance of breast cancer served as the controls. The results were analyzed based on the patients'' histological data, other imaging modalities and/or clinical follow-up. Recurrence was defined as evidence of recurrent lesions within 12 months of the FDG-PET/CT scan.

Results

Based on elevated serum CA15-3 levels (n = 31) and clinical/radiologic suspicion (n = 40), 71 scans were performed due to suspected recurrence, whereas 69 scans were performed for asymptomatic follow-up. The sensitivity and specificity of FDG-PET/CT were 87.5% and 87.1% in the patients with suspected recurrence and 77.8% and 91.7% in the asymptomatic patients. The positive predictive value in the patients with suspected recurrence (mainly due to elevated serum CA 15-3 levels) was higher than that in asymptomatic patients (P = 0.013). Recurrences were proven in 56.3% (40/71) of the patients with suspected recurrence and in 13% (9/69) of the asymptomatic patients (P<0.001). FDG-PET/CT resulted in changes in the planned management in 49.3% (35/71) of the patients with suspected recurrence and 10.1% (7/69) of the asymptomatic patients (P<0.001). After follow-up, 77.5% (55/71) of the patients with suspicious recurrences and 97.1% (67/69) of the asymptomatic patients were surviving at the end of the study (P<0.001).

Conclusions

FDG-PET/CT was able to detect recurrence, and the results altered the intended patient management in the post-therapy surveillance of breast cancer. FDG-PET/CT should be used as a priority in patients with increased serum CA 15-3 levels, or with clinical/radiologic suspicion of recurrence, and might be useful for asymptomatic patients.     

Clinicopathologic features and outcomes following surgery for pancreatic adenosquamous carcinoma

Background

The use of diagnostic ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging for the staging, restaging, and treatment monitoring of melanoma patients has become a well-recognized standard of care. It plays a key role in detecting sites of occult disease and is widely utilized in the medical and surgical planning of such patients. In the current report, we describe an innovative multimodality approach of perioperative ¹⁸F-FDG PET/CT imaging, intraoperative ¹⁸F-FDG handheld gamma probe detection, and intraoperative ultrasound for tumor localization and verification of resection of all sites of hypermetabolic tumor foci in a case of occult recurrent metastatic melanoma.

Case presentation

This report discusses a case of occult recurrent metastatic melanoma, isolated to three separate sites within the subcutaneous tissues of the left thigh region, which was not clinically apparent but was found on diagnostic restaging whole body ¹⁸F-FDG PET/CT scan utilizing an intravenous injection of 14.8 mCi ¹⁸F-FDG. Then, on the day of surgery, the patient received an intravenous injection of 12.8 mCi ¹⁸F-FDG. A multimodality approach of intraoperative handheld gamma probe detection, intraoperative ultrasound tumor localization, specimen PET/CT imaging, and postoperative PET/CT imaging was utilized for accomplishing and verifying the excision of all three sites of occult recurrent metastatic melanoma within the left thigh region.

Conclusion

This innovative multimodality approach of perioperative ¹⁸F-FDG PET/CT imaging, intraoperative ¹⁸F-FDG handheld gamma probe detection, and intraoperative ultrasound is promising combined technology for aiding in tumor localization and verification of excision and may ultimately impact positively upon long-term outcome of selected patients.     

Prevalence and risk factors of vertebral compression fractures in female SLE patients

Introduction

The present study objective was to evaluate the incidence of methotrexate (MTX)-specific liver lesions from the analysis of a liver biopsy of inflammatory arthritis patients with elevated liver enzymes.

Methods

A case-control study was performed with 1,571 arthritis patients on long-term low-dose MTX therapy. Results of liver biopsy were analyzed in 41 patients with elevated liver enzymes. The expression of autoimmune markers was also assessed. This population was compared with 41 disease control subjects obtained from the same database, also on MTX but without elevated liver enzymes, matched for age, sex and rheumatic disease.

Results

Compared with the disease controls, patients with liver biopsy showed lower disease duration and lower MTX exposure, weekly and cumulative doses, reflecting shorter treatment duration due to liver abnormalities. Liver biopsies showed 17 autoimmune hepatitis-like (AIH-like) lesions, 13 nonalcoholic steatohepatitis-like lesions, seven limited liver lesions, and two primary biliary cirrhoses. However, MTX-specific lesions with dystrophic nuclei in hepatocytes were seen in only two cases. Liver biopsy lesions were associated with autoimmune markers (P = 0.007); notably, AIH-like lesions were associated with rheumatoid arthritis and with the presence of the HLA-DR shared epitope.

Conclusions

MTX-specific liver lesions are rarely observed in arthritis patients under long-term MTX therapy and elevated liver enzymes.     

Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases

Background

The aim of this study was to compare the diagnostic accuracy of [¹⁸F]FDG-PET/MRI with PET/CT for the detection of liver metastases.

Methods

32 patients with solid malignancies underwent [¹⁸F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence. An imaging follow-up (mean interval: 185±92 days) and/-or histopathological specimen served as standards of reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both modalities. Accuracy was determined by calculating the area under the receiver operating characteristic (ROC) curve. Values of conspicuity and diagnostic confidence were compared using Wilcoxon-signed-rank test.

Results

The standard of reference revealed 113 liver lesions in 26 patients (malignant: n = 45; benign: n = 68). For PET/MRI a higher accuracy (PET/CT: 82.4%; PET/MRI: 96.1%; p<0.001) as well as sensitivity (67.8% vs. 92.2%, p<0.01) and NPV (82.0% vs. 95.1%, p<0.05) were observed. PET/MRI offered higher lesion conspicuity (PET/CT: 2.0±1.1 [median: 2; range 0–3]; PET/MRI: 2.8±0.5 [median: 3; range 0–3]; p<0.001) and diagnostic confidence (PET/CT: 2.0±0.8 [median: 2; range: 1–3]; PET/MRI 2.6±0.6 [median: 3; range: 1–3]; p<0.001). Furthermore, PET/MRI enabled the detection of additional PET-negative metastases (reader 1: 10; reader 2: 12).

Conclusions

PET/MRI offers higher diagnostic accuracy compared to PET/CT for the detection of liver metastases.     

Clinical utility of tumor genomic profiling in patients with high plasma circulating tumor DNA burden or metabolically active tumors

Background

This retrospective study was undertaken to determine if the plasma circulating tumor DNA (ctDNA) level and tumor biological features in patients with advanced solid tumors affected the detection of genomic alterations (GAs) by a plasma ctDNA assay.

Method

Cell-free DNA (cfDNA) extracted from frozen plasma (N?=?35) or fresh whole blood (N?=?90) samples were subjected to a 62-gene hybrid capture-based next-generation sequencing assay FoundationACT. Concordance was analyzed for 51 matched FoundationACT and FoundationOne (tissue) cases. The maximum somatic allele frequency (MSAF) was used to estimate the amount of tumor fraction of cfDNA in each sample. The detection of GAs was correlated with the amount of cfDNA, MSAF, total tumor anatomic burden (dimensional sum), and total tumor metabolic burden (SUVmax sum) of the largest ten tumor lesions on PET/CT scans.

Results

FoundationACT detected GAs in 69 of 81 (85%) cases with MSAF >?0. Forty-two of 51 (82%) cases had ≥?1 concordance GAs matched with FoundationOne, and 22 (52%) matched to the National Comprehensive Cancer Network (NCCN)-recommended molecular targets. FoundationACT also detected 8 unique molecular targets, which changed the therapy in 7 (88%) patients who did not have tumor rebiopsy or sufficient tumor DNA for genomic profiling assay. In all samples (N?=?81), GAs were detected in plasma cfDNA from cancer patients with high MSAF quantity (P?=?0.0006) or high tumor metabolic burden (P?=?0.0006) regardless of cfDNA quantity (P?=?0.2362).

Conclusion

This study supports the utility of using plasma-based genomic assays in cancer patients with high plasma MSAF level or high tumor metabolic burden.

     

Detection of Synchronous Cancers by Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography during Primary Staging Workup for Esophageal Squamous Cell Carcinoma in Taiwan

Aim

The aim of this retrospective study was to investigate the ability of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the detection of synchronous cancers during staging workup for esophageal squamous cell carcinoma.

Materials and Methods

We performed a retrospective chart review of 426 Taiwanese patients with esophageal cancer who received FDG-PET/CT during their primary staging workup between December 2006 and December 2011. We defined synchronous cancers as those occurring within 6 months of the FDG-PET/CT scan. All of the synchronous lesions were confirmed by histology or imaging follow-up. The study patients were followed for at least 18 months or were censored on the date of last follow-up.

Results

Fifty patients were excluded from analysis because of the presence of distant metastases. Of the remaining 376 patients, 359 were diagnosed with squamous cell carcinoma (SCC). We identified 17 patients with synchronous cancers, and all of them had a diagnosis of SCC. Synchronous head and neck cancers were the most frequent (n=13, 76.4%), followed by gastrointestinal cancers (colon cancer, n=2; hepatocellular carcinoma, n=1), and renal cell carcinoma (n=1). FDG-PET/CT successfully detected 15 synchronous cancers (12 head and neck cancers, 2 colon cancers, and 1 renal cell carcinoma). In contrast, conventional workup detected only 9 synchronous cancers (7 head and neck cancers, 1 hepatocellular carcinoma and 1 renal cell carcinoma). The sensitivity of FDG-PET/CT and conventional workup in detecting synchronous cancers were 88.2% and 52.9% respectively.

Conclusion

The most frequent synchronous lesions in patients with esophageal SCC were head and neck cancers in Taiwan. Our data indicate that FDG-PET/CT is superior to conventional workup in the detection of synchronous tumors during primary staging for esophageal squamous cell carcinoma.     

Regulation of cell cycle transition and induction of apoptosis in HL-60 leukemia cells by lipoic acid: role in cancer prevention and therapy

 

The most common semiquantitative method of evaluation of pulmonary lesions using ¹⁸F-FDG PET is FDG standardized uptake value (SUV). An SUV cutoff of 2.5 or greater has been used to differentiate between benign and malignant nodules. The goal of our study was to investigate the correlation between the size of pulmonary nodules and the SUV for benign as well as for malignant nodules.

Methods

Retrospectively, 173 patients were selected from 420 referrals for evaluation of pulmonary lesions. All patients selected had a positive CT and PET scans and histopathology biopsy. A linear regression equation was fitted to a scatter plot of size and SUV_max for malignant and benign nodules together. A dot diagram was created to calculate the sensitivity, specificity, and accuracy using an SUV_max cutoff of 2.5.

Results

The linear regression equations and (R²)s as well as the trendlines for malignant and benign nodules demonstrated that the slope of the regression line is greater for malignant than for benign nodules. Twenty-eight nodules of group one (≤ 1.0 cm) are plotted in a dot diagram using an SUV_max cutoff of 2.5. The sensitivity, specificity, and accuracy were calculated to be 85%, 36% and 54% respectively. Similarly, sensitivity, specificity, and accuracy were calculated for an SUV_max cutoff of 2.5 and found to be 91%, 47%, and 79% respectively for group 2 (1.1–2.0 cm); 94%, 23%, and 76%, respectively for group 3 (2.1–3.0 cm); and 100%, 17%, and 82%,, respectively for group 4 (> 3.0 cm). The previous results of the dot diagram indicating that the sensitivity and the accuracy of the test using an SUV_max cutoff of 2.5 are increased with an increase in the diameter of pulmonary nodules.

Conclusion

The slope of the regression line is greater for malignant than for benign nodules. Although, the SUV_max cutoff of 2.5 is a useful tool in the evaluation of large pulmonary nodules (> 1.0 cm), it has no or minimal value in the evaluation of small pulmonary nodules (≤ 1.0 cm).     

The Prognostic Significance of Metabolic Response Heterogeneity in Metastatic Colorectal Cancer

Background

Tumoral heterogeneity is a major determinant of resistance in solid tumors. FDG-PET/CT can identify early during chemotherapy non-responsive lesions within the whole body tumor load. This prospective multicentric proof-of-concept study explores intra-individual metabolic response (mR) heterogeneity as a treatment efficacy biomarker in chemorefractory metastatic colorectal cancer (mCRC).

Methods

Standardized FDG-PET/CT was performed at baseline and after the first cycle of combined sorafenib (600mg/day for 21 days, then 800mg/day) and capecitabine (1700 mg/m²/day administered D1-14 every 21 days). MR assessment was categorized according to the proportion of metabolically non-responding (non-mR) lesions (stable FDG uptake with SUVmax decrease <15%) among all measurable lesions.

Results

Ninety-two patients were included. The median overall survival (OS) and progression-free survival (PFS) were 8.2 months (95% CI: 6.8–10.5) and 4.2 months (95% CI: 3.4–4.8) respectively. In the 79 assessable patients, early PET-CT showed no metabolically refractory lesion in 47%, a heterogeneous mR with at least one non-mR lesion in 32%, and a consistent non-mR or early disease progression in 21%. On exploratory analysis, patients without any non-mR lesion showed a significantly longer PFS (HR 0.34; 95% CI: 0.21–0.56, P-value <0.001) and OS (HR 0.58; 95% CI: 0.36–0.92, P-value 0.02) compared to the other patients. The proportion of non-mR lesions within the tumor load did not impact PFS/OS.

Conclusion

The presence of at least one metabolically refractory lesion is associated with a poorer outcome in advanced mCRC patients treated with combined sorafenib-capecitabine. Early detection of treatment-induced mR heterogeneity may represent an important predictive efficacy biomarker in mCRC.

Trial Registration

ClinicalTrials.gov NCT01290926     

Maladie de La Peyronie: Bilan IRM chez 28 patients

Purpose

to determine diagnosis and prognosis value of MRI in Peyronie’s disease.

Material and Methods

thirty one penile MR examinations have been performed in 28 patients aged between 21 and 73. (1 tesla; surface coil; sagittal SET1, axial SET2 weighted, T1 before and after Gadolinium)

- In all cases but one, fibrous plaques were clinically palpable.

- Images were compared with clinical examination and evolution under anti-inflammatory drugs.

Results

- In 3 cases, MRI misdiagnosed one unique plague.

- In 2 additional cases, one of the 2 clinical plaques was not detected.

- In 5 cases, MRI depicted more lesions than palpation.

- Gadolinium Enhancement was always correlated with a good response to anti-inflamatory drugs but this treatment was also useful in one case who showed no enhancement.

Conclusion

MRI can be helpfull in the pretreatment assessment and int he follow-up of Peyronie’s disease.     

The Preliminary Study of 16α-[18F]fluoroestradiol PET/CT in Assisting the Individualized Treatment Decisions of Breast Cancer Patients

Objective

To evaluate the clinical value of 16α-[18F]fluoroestradiol (18F-FES) PET/CT in assisting the individualized treatment decisions of breast cancer patients.

Methods

Thirty-three breast cancer patients, who underwent both 18F-FES and 18F-FDG PET/CT from July 2010 to March 2013 in our center, were enrolled in this preliminary study. All the patients used 18F-FES PET/CT as a diagnostic tool with a clinical dilemma. We used the maximum Standardized Uptake Value (SUVmax) to quantify ER expression and a cutoff value of 1.5 to dichotomize results into ER positive and negative lesions. All patients were clinically followed up at least 6 months.

Results

In evaluating equivocal lesions on conventional work-up group (n = 4), three lung lesions and another iliac lesion were enrolled. As for three lung lesions, 18F-FES PET/CT showed one lesion with high uptake, which suggested it was an ER positive metastasis. The other two lesions were 18F-FES negative, which meant an ER negative metastasis or secondary primary tumor. Additionally, one iliac lesion was detected by MRI. 18F-FDG uptake was high at the suspected lesion, whereas 18F-FES uptake was absent; In predicting origin of metastasis group (n = 2), two breast cancer patients had secondary primary tumors were collected. They were 18F-FES negative, which showed low possibility of metastasis from breast cancer and they were all confirmed by biopsy. In detecting ER status in metastasis group (n = 27), 18F-FES PET/CT showed increased 18F-FES uptake in all metastatic lesions in 11 patients; absent in all lesions in 13 patients; and the remaining 3 patients had both 18F-FES positive and negative lesions. Totally, on the basis of the 18F-FES PET/CT results, we found changes in the treatment plans in 16 patients (48.5%, 16/33).

Conclusions

18F-FES PET/CT could assess the entire tumor volume receptor status; therefore, it may be used to assist the individualized treatment decisions of breast cancer patients.     

Is Intracranial Atherosclerosis an Independent Risk Factor for Cerebral Atrophy? A Retrospective Evaluation

Background

Our purpose was to study the association between the intracranial atherosclerosis as measured by cavernous carotid artery calcification (ICAC) observed on head CT and atrophic changes of supra-tentorial brain demonstrated by MRI.

Methods

Institutional review board approval was obtained for this retrospective study incorporating 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the intracranial cavernous carotids (ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These 4 groups were then combined into high (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify cortical and central atrophy. Demographics and cardiovascular risk factors were evaluated in subjects with high and low ICAC. Relationship between CT demonstrated ICAC and brain atrophy patterns were evaluated both without and with adjustment for cerebral ischemic scores and cardiovascular risk factors.

Results

Forty-six of the 65 (71%) patients had high ICAC on head CT. Subjects with high ICAC were older, and had higher prevalence of hypertension, diabetes, coronary artery disease (CAD), atrial fibrillation and history of previous stroke (CVA) compared to those with low ICAC. Age demonstrated strong correlation with both supratentorial atrophy patterns. There was no correlation between ICAC and cortical atrophy. There was correlation however between central atrophy and ICAC. This persisted even after adjustment for age.

Conclusion

Age is the most important determinant of atrophic cerebral changes. However, high ICAC demonstrated age independent association with central atrophy.

     

Positron Emission Tomography and Magnetic Resonance Imaging of the Brain in Fabry Disease: A Nationwide,Long-Time,Prospective Follow-Up

Background

Fabry disease is a rare metabolic glycosphingolipid storage disease caused by deficiency of the lysosomal enzyme α-galactosidase A—leading to cellular accumulation of globotriasylceramide in different organs, vessels, tissues, and nerves. The disease is associated with an increased risk of cerebrovascular disease at a young age in addition to heart and kidney failure.

Objective

The objective of this study was to assess brain function and structure in the Danish cohort of patients with Fabry disease in a prospective way using 18-fluoro-deoxyglucose (F-18 FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI).

Patients

Forty patients with Fabry disease (14 males, 26 females, age at inclusion: 10–66 years, median: 39 years) underwent a brain F-18-FDG-PET-scan at inclusion, and 31 patients were followed with FDG-PET biannually for up to seven years. All patients (except one) had a brain MRI-scan at inclusion, and 34 patients were followed with MRI biannually for up to nine years.

Image Analysis

The FDG-PET-images were inspected visually and analysed using a quantitative 3-dimensional stereotactic surface projection analysis (Neurostat). MRI images were also inspected visually and severity of white matter lesions (WMLs) was graded using a visual rating scale.

Results

In 28 patients brain-FDG-PET was normal; in 23 of these 28 patients brain MRI was normal—of the remaining five patients in this group, four patients had WMLs and one patient never had an MRI-scan. In 10 patients hypometabolic areas were observed on brain-FDG-PET; all of these patients had cerebral infarcts/hemorrhages visualized on MRI corresponding to the main hypometabolic areas. In two patients brain-FDG-PET was ambiguous, while MRI was normal in one and abnormal in the other.

Conclusion

Our data indicated that, in patients with Fabry disease, MRI is the preferable clinical modality—if applicable—when monitoring cerebral status, as no additional major brain-pathology was detected with FDG-PET.     

The use of PET/CT scanning technique for 3D visualization and quantification of real-time soil/plant interactions

Aims

Conventional methodology using destructive sampling, which is laborious and has poor spatial and temporal resolution, has limited our understanding of soil-plant interactions. New non-invasive tomographic techniques have the potential to significantly improve our knowledge. In this study we demonstrated the simultaneous use of PET (positron emission tomography) and CT (X-ray computed tomography) to (a) non-destructively image a whole plant growing in sand, and (b) to link the observed morphology with recently assimilated C. The PET scanner was used to detect and visualize the location of the short-lived radioisotope ¹¹C (with a half-life of 20.4?min) taken up by the plant through ¹¹C-labelled CO₂. This provided information on carbon translocation and the metabolism of photo-assimilates in the plant as well as root structure. The CT scanners yielded data on soil and root structure.

Methods

A medical PET/CT scanner was used to scan a fodder radish plant growing in a pot with test soil composed of homogenous sand. We constructed an air-plant-soil controller system (APS) to control the environmental conditions, such as CO₂, temperature and light during the experiment. The plant was allowed to assimilate ¹¹CO₂ for 90?min before PET scanning was initiated. We carried out PET scanning for 60?min. Subsequently, the aerial parts of the plant was cut off and the pot was rescanned using a micro-CT scanner to obtain more detailed information on structure of the root system and the growth medium structure.

Results

The acquired PET and CT images gave images clearly visualizing the architecture and morphology of root and soil. Using a CT scanner, we were able to detect the main taproot located at 0 to 30?mm depth. With the PET scanner, we were able to measure a signal down to 82?mm below the surface of the sand. We found the highest concentration of ¹¹C at the position of the main root. The PET images, at different time intervals, showed the translocation and metabolisation of photo-assimilates from top to root. Using the micro-CT scanner (voxel size of 90?μm), we were able to detect roots down to 100?mm depth. These findings correlated the PET signals measured down to 82?mm depth.

Conclusions

We conclude that the simultaneous use of PET and CT technologies was successfully applied for soil-plant studies. The combined PET/CT technology has potential to provide new fundamental insight into soil-plant interactions and especially into the effect of abiotic stresses in spite of the limitation due to spatial resolution.