Serial 18F-FDG Research Articles

18F-FDG Uptake and Calcifications in the Thoracic Aorta on Positron Emission Tomography/Computed Tomography Examinations

Vascular 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) uptake has been suggested as a means of identifying metabolically active atheroma, whereas vascular calcification is accepted as an indicator of atherosclerosis. This investigation describes the frequency and stability of 18F-FDG uptake and vascular calcification in the thoracic aorta on serial 18F-FDG positron emission tomography/computed tomography (PET/CT) studies and correlates the findings with clinical data and risk factors for cardiovascular disease (CVD). Serial 18F-FDG-PET/CT scans of 100 cancer patients who had at least 2 PET/CT studies were reviewed. Sites of aortic 18F-FDG uptake and calcifications were identified. Results were compared to assess the frequency and stability of the vascular findings and their correlation with clinical data. 18F-FDG aortic uptake was seen in 70% of the patients on the initial scan and changed on the second scan in 55% of the patients. Calcifications were often seen in patients with 18F-FDG uptake, but calcification and 18F-FDG uptake were present at the same site in only 2 cases. Both calcification and 18F-FDG uptake correlated with age. Patients with diabetes, hypertension, hyperlipidemia, or a history of CVD had significantly more calcifications. No correlation was seen between 18F-FDG uptake and calcification stability and the interval between scans, age, risk factors, or history of CVD. 18F-FDG vascular uptake was common on PET/CT and correlated with vascular calcifications, although the specific sites rarely overlapped. Calcifications were stable over time, but 18F-FDG uptake changed in more than half of the patients, supporting the postulate that inflammation in atheroma is a waxing and waning inflammatory process.

18F-FDG PET/CT Demonstrates Efficacy and Limitations of Hepatic Arterial Infusion Chemotherapy for Treating Colorectal Liver Metastases

Hepatic arterial infusion chemotherapy (HAIC) is a palliative therapy option for advanced, unresectable liver metastases from colorectal carcinoma. A woman with multiple colorectal liver metastases was treated with HAIC and systemic chemotherapy. Serial 18F-FDG PET/CT imaging showed local therapeutic response of liver metastases to regional delivery of chemotherapy, but concurrent disease progression at extra-hepatic sites suggesting ineffective systemic chemotherapy. Hepatic disease also progressed in the caudate lobe, likely due to variable regional arterial supply. This case is illustrative of the rationale for HAIC in the management of inoperable hepatic metastases and also demonstrates limitations of this approach. Keywords: FDG-PET/CT, hepatic arterial infusion chemotherapy, 18F-FDG PET/CT, Colorectal Liver Metastases, liver metastases, colorectal carcinoma, colorectal, neuroendocrine, hepatic neoplasm, liver disease, colorectal carcinoma HAIC, hepatic metastases, systemic chemotherapy, hepatic tissue, floxuridine, 5-fluorouracil, sigmoidectomy, colostomy, Hartmann's, rectum, leucovorin, oxaliplatin, post-radiation fibrosis, CT angiogram, 9m Tc-macroaggregated albumin, hepatic metastatic lesions, metastatic liver disease, solitary metastasis, oligometastases., radionuclide chemo-embolization therapy, celiac axis, common hepatic artery, proper hepatic artery, gastroduodenal artery, right hepatic artery, left hepatic artery, superior mesenteric artery, macroaggregated albumin

IgG4-associated Multifocal Systemic Fibrosis Detected by Cancer Screening with 18F-FDG Positron Emission Tomography/Computed Tomography

Serial fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)studies were performed with an interval of one year in a 62-year-old man with IgG4-associated multifocal systemic fibrosis(IMSF). He first underwent 18F-FDG PET/CT cancer screening, which revealed multiple 18F-FDG-avid uptakes in the pancreas, prostate, and lymph nodes in the upper mediastinum, pulmonary hila, porta hepatis, and the left iliac and inguinal regions. He was not symptomatic at this initial examination. The follow-up 18F-FDG PET/CT study showed disappearance of 18F-FDG-avid uptake foci in the pancreas despite no treatment having been administered, but demonstrated new lesions in the abdominal para-aortic region and more intense FDG uptake in the porta hepatis lesion. Serial 18F-FDG PET/CT studies might be useful in monitoring patients with IMSF, as well as evaluating the state of systemic involvement. Findings of 18F-FDG PET/CT may provide information useful for determining the optimal initiation of IMSF treatment.

P3.103. Serial 18F-FDG CT-PET scans during radical radiotherapy inpatients with squamous cell carcinoma of the head and neck

P3.103. Serial 18F-FDG CT-PET scans during radical radiotherapy inpatients with squamous cell carcinoma of the head and neck

Early Prediction of Response to Chemotherapy and Survival in Malignant Pleural Mesothelioma Using a Novel Semiautomated 3-Dimensional Volume-Based Analysis of Serial 18F-FDG PET Scans

The aim of chemotherapy for mesothelioma is to palliate symptoms and improve survival. Measuring response using CT is challenging because of the circumferential tumor growth pattern. This study aims to evaluate the role of serial (18)F-FDG PET in the assessment of response to chemotherapy in patients with mesothelioma. Patients were prospectively recruited and underwent both (18)F-FDG PET and conventional radiological response assessment before and after 1 cycle of chemotherapy. Quantitative volume-based (18)F-FDG PET analysis was performed to obtain the total glycolytic volume (TGV) of the tumor. Survival outcomes were measured. Twenty-three patients were suitable for both radiological and (18)F-FDG PET analysis, of whom 20 had CT measurable disease. After 1 cycle of chemotherapy, 7 patients attained a partial response and 13 had stable disease on CT assessment by modified RECIST (Response Evaluation Criteria in Solid Tumors) criteria. In the 7 patients with radiological partial response, the median TGV on quantitative PET analysis fell to 30% of baseline (range, 11%-71%). After 1 cycle of chemotherapy, Cox regression analysis demonstrated a statistically significant relationship between a fall in TGV and improved patient survival (P = 0.015). Neither a reduction in the maximum standardized uptake value (P = 0.097) nor CT (P = 0.131) demonstrated a statistically significant association with patient survival. Semiquantitative (18)F-FDG PET using the volume-based parameter of TGV is feasible in mesothelioma and may predict response to chemotherapy and patient survival after 1 cycle of treatment. Therefore, metabolic imaging has the potential to improve the care of patients receiving chemotherapy for mesothelioma by the early identification of responding patients. This technology may also be useful in the assessment of new systemic treatments for mesothelioma.

First-in-human study of the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-00299804, a small molecule irreversible panHER inhibitor in patients with advanced cancer

3599 Background: There are scientific rationale for inhibitors which provide combined and irreversible blockade of HER family members. PF-00299804 is an orally available, potent, irreversible small molecule inhibitor of the HER tyrosine kinases. Methods: The safety, tolerability, PK, PD, and efficacy of PF-00299804 administered orally once daily in 3-week cycles were assessed in patients with advanced solid tumors using an accelerated dose-escalation design. Safety assessments included adverse event (AE), laboratory, ECG, and LVEF assessments. PK parameters were determined after a single lead-in dose and on Day 14 by non-compartmental techniques. PD measures included assessment of HER-related signaling pathways via IHC analyses of serial skin and, in some patients, tumor biopsies. Serial 18F-FDG- PET/CT has been performed on a subset of patients with scans being classified according to modified EORTC criteria by a central reader. Results: 32 pts have been treated across 8 sequential dose levels ranging from 0.5 to 60 mg. The most common AEs were diarrhea, fatigue, nausea, and rash. 3/6 patients at 60 mg experienced a DLT [hand-foot syndrome (1), dehydration related to diarrhea(1), mucositis(1)]. Cmax and AUC of PF-00299804 increased with dose in an approximately proportional manner. Accumulation ranged from 3.3 to 6.8, suggesting a terminal t1/2>24 h. At the 30 mg dose level, mean Day 14 drug concentration was above the predicted efficacious concentration for tumor growth inhibition based on A431 xenograft model. Of 7 sets of PET data evaluated thus far, partial responses (PR) have been observed in 2 patients. A PR as assessed using RECIST criteria has been reported in 1 of 2 patients with advanced refractory NSCLC treated to date. Conclusions: Daily administration of PF-00299804 across many dose levels appears safe and tolerable. Diarrhea, fatigue, nausea, and rash are the most frequent AEs. Evaluation of 45 mg/d as the potential MTD is ongoing. Systemic exposures at doses = 30 mg exceed the threshold for efficacy as predicted from preclinical studies. Clinical and biological activity of PF-00299804 was observed including a PR in 1 of 2 patients with advanced refractory NSCLC. No significant financial relationships to disclose.

Brown fat in breast cancer patients: analysis of serial 18F-FDG PET/CT scans

It has recently been suggested that FDG accumulation in the brown adipose tissue varies as a function of age, sex and outdoor temperature. The aim of this study was to assess changes in FDG uptake in brown fat in patients based on serial PET/CT scans and to compare our results with previous findings. Early response to neoadjuvant chemotherapy in 33 female breast cancer patients was assessed by FDG PET. Five PET/CT scans were performed for each patient. PET/CT images were analysed retrospectively. PET scans were considered positive when diffuse, symmetrical, abnormal "USA" (uptake in supraclavicular area) fat was detected. A total of 163 PET images were analysed. Seventy-four PET scans (45%) revealed abnormal FDG uptake in the supraclavicular area. These foci were present on uncorrected and attenuation-corrected images. FDG uptake was identical on all five scans in only five patients. No significant relationship was found between abnormal FDG uptake and outdoor temperature, age or time interval between chemotherapy and PET. Abnormal FDG uptake in the neck seemed to predominantly occur in patients with a low body mass index (p<0.05). Most significant changes in the PET/CT scan results were observed during chemotherapy with docetaxel (p<0.05). When observed, bilateral uptake in the neck was more intense than background uptake (p<0.00001). This study shows that FDG uptake in the neck varies as a function of time, that it is unrelated to age or outdoor temperature, and that bilateral uptake is generally intense.

Intra-individual variability of cardiac uptake on serial whole-body 18F-FDG PET

To measure the variability of cardiac uptake on serial whole-body F-FDG PET scans. Two hundred and eighteen whole-body PET scans were performed in 47 patients with different primary malignancies between October 1996 and April 2003 on a dedicated PET system. The number of scans per patient ranged between four and nine. Two experienced nuclear medicine physicians reviewed the scans retrospectively using the non-attenuation corrected images to assess the cardiac FDG uptake. Patients with cardiac uptake less or equal to lung uptake were assigned in the "low" uptake group, and those with cardiac uptake more than the lung uptake were assigned to the "high" uptake group. The reproducibility of cardiac uptake on serial whole-body PET scans and the effect of age, sex, weight, diabetes and primary diagnosis on cardiac uptake was evaluated. There was very good reproducibility (intra-class correlation coefficient=0.77) of individual cardiac FDG uptake on serial whole-body PET scans. Diabetics (n=6) in comparison to non-diabetics were less likely to have high cardiac uptake (odds ratio (OR)=0.24, P<0.05). Patients with lymphoma (n=12) in comparison to patients with other primary diagnoses were more likely to have high cardiac uptake (OR=8.6, P<0.05). There was no association between cardiac uptake and age, sex or weight. Cardiac FDG uptake on whole-body PET does not appear to change significantly over time. It is likely that uptake is determined by individual characteristics; these likely include diabetes and primary diagnosis of lymphoma.