Bone involvement in patients with lymphoma: the role of FDG-PET/CT

Purpose: To evaluate the diagnostic impact and clinical significance of FDG-avid bone lesions detected by FDG-PET/CT in patients with lymphoma. Methods: The study population comprised 50 consecutive patients (mean age 41.7±15.5years; 27 female, 23 male; 41 staging, 9 restaging) with Hodgkin's disease (n=22) or aggressive non-Hodgkin's lymphoma (n=28) in whom FDG-avid bone lesions were detected by FDG-PET/CT. All patients had either direct biopsy of the FDG-avid bone lesion (n=18), standard bone marrow biopsy at the iliac crest (BMB; n=43) or both procedures (n=11). In 15 patients, additional MRI of the bone lesions was performed. All patients underwent FDG-PET/CT after the end of treatment. All CT images of FDG-PET/CT scans were analysed independently regarding morphological osseous changes and compared with FDG-PET results. Results: In the 50 patients, 193 FDG-avid lesions were found by PET/CT. The mean standardised uptake value was 6.26 (±3.22). All direct bone biopsies (n=18) of the FDG-avid lesions proved the presence of lymphomatous infiltration. BMB (n=43) was positive in 12 patients (27.9%). In CT, 32 of 193 (16.6%) lesions were detected without the PET information. No additional morphological bone infiltration was detected on CT compared with FDG-PET. All morphological bone alterations on CT scans persisted after the end of therapy. Additional PET/CT information regarding uni- or multifocal bone involvement resulted in lymphoma upstaging in 21 (42%) patients compared with the combined information provided by CT and BMB. Conclusion: In patients with FDG-avid bone lesions, FDG-PET is superior to CT alone or in combination with unilateral BMB in detecting bone marrow involvement, leading to upstaging in a relevant proportion of patient

Feasibility of integrated CT-liver perfusion in routine FDG-PET/CT

Objective: To integrate CT-perfusion into a routine, clinical contrast-enhanced (ce) PET/CT protocol for the evaluation of liver metastases and to compare functional CT and PET parameters. Materials and methods: Forty-six consecutive patients (mean age: 60 (34-82) years; 20 f, 26m) with known liver lesions (colorectal metastases (n=34), primary liver cancer (n=4), breast cancer (n=3), anal cancer, gastric cancer, esophageal cancer, GIST, duodenal cancer (all: n=1) who were referred for staging or therapy follow-up by [18F]-Fluoro-2-deoxy-D-glucose-positron-emission-tomography/computed-tomography imaging (FDG-PET/CT) were included. After acquisition of a low-dose PET/CT, a split-injection (70-90mL) ce-CT-protocol, including a 35-s CT-perfusion scan of the liver and a diagnostic ce-CT of the thorax and/or abdomen (70s delay, iv-contrast volume: 90mL, 4mL/s) was performed. CT-perfusion parameters (BF, BV, MTT,) and semi-quantitative PET-parameters (SUVmax, SUVmean, TLG, PETvol) were analyzed and compared. Results: CT-perfusion data could be obtained in all but one patient with shallow breathing. In all patients, diagnostic ce-PET/CT quality was adequate without the use of additional contrast media. Significant correlations (P<0.05) were found for each of BF, BV, MTT, and SUVmax, further, BF and MTT correlated with TLG. Several other correlations were seen for other perfusion and PET-parameters. Conclusion: Combined CT-perfusion/PET/CT-protocol without the use of additional contrast media is feasible and can be easily integrated in clinical routine. Perfusion parameters and PET-parameters are only partly correlating and therefore have to be investigated further at fixed time points during the course of disease and therap

Clinical value of a combined multi-phase contrast enhanced DOPA-PET/CT in neuroendocrine tumours with emphasis on the diagnostic CT component

Objective: To assess the clinical value of multi-phase, contrast-enhanced DOPA-PET/CT with emphasis on the diagnostic CT component in patients with neuroendocrine tumours (NET). Methods: Sixty-five patients with NET underwent DOPA-cePET/CT. The DOPA-PET, multi-phase CT and combined DOPA cePET/CT data were evaluated and diagnostic accuracies compared. The value of ceCT in DOPA cePET/CT concerning lesion detection and therapeutic impact was evaluated. Sensitivities, specificities and accuracies were calculated. Histopathology and clinical follow-up served as the standard of reference. Differences were tested for statistical significance by McNemar's test. Results: In 40 patients metastatic and/or primary tumour lesions were detected. Lesion-based analysis for the DOPA-PET showed sensitivity, specificity and accuracy of 66%, 100% and 67%, for the ceCT data 85%, 71% and 85%, and for the combined DOPA cePET/CT data 97%, 71% and 96%. DOPA cePET/CT was significantly more accurate compared with dual-phase CT (p < 0.05) and PET alone (p < 0.05). Additional lesion detection was based on ceCT in 12 patients; three patients underwent significant therapeutic changes based on the ceCT findings. Conclusion: DOPA cePET/CT was significantly more accurate than DOPA-PET alone and ceCT alone. The CT component itself had a diagnostic impact in a small percentage but contributed to the therapeutic strategies in selected patient

Combined PET/CT-perfusion in patients with head and neck cancers

Objectives: Computed tomography perfusion (CTP) can provide information about angiogenesis and blood-flow characteristics in tumours. [18F]Fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography (FDG-PET/CT) is one of the major oncological imaging techniques which provides information about viability of the tumour cell and partly also about its aggressiveness. The aim of the study was to investigate the relationship between FDG and CTP data in patients with head and neck cancers. Materials and methods: Forty-one patients with a clinically suspected head and neck cancer were prospectively included. All patients underwent a combined PET/CT with an integrated CTP examination in the area of the head and neck tumour. CTP data (BF, BV and MTT) and PET data (SUVmax, SUVmean, TLG, PETvol) were compared between tumours and (1) healthy contralateral tissue, (2) inflammatory lesions, (3) metastatic lymph nodes, and CTP data and PET data were correlated in tumours. Results: Thirty-five patients had a head and neck cancer. All CTP data were statistically different between tumours, inflammatory lesions, healthy tissue and metastatic lymph nodes; PET/CT data were in part significantly different. CTP and PET parameters were not significantly correlated. Conclusion: CTP and PET parameters were not significantly correlated; thus, the additional CTP values provide additional insights into tumour behaviour and their glycolytic status. Key Points : • Computed tomography perfusion (CTP) can be performed in combined positron emission tomography (PET)/CT. • CTP in addition to PET provides additional insights into tumour behaviour. • CTP can possibly differentiate between head and neck tumours and inflammatory lesions. • PET/CT with integrated CTP is possible without additional contrast medi

Preclinical Evaluation and Dosimetry of [111In]CHX-DTPA-scFv78-Fc Targeting Endosialin/Tumor Endothelial Marker 1 (TEM1)

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Concomitant statin use does not impair the clinical outcome of patients with diffuse large B cell lymphoma treated with rituximab-CHOP

Preclinical data indicated a detrimental effect of statins on the anti-lymphoma activity of rituximab. We evaluated the impact of concomitant statin medication on the response and survival of patients with diffuse large B cell lymphoma (DLBCL) receiving rituximab-cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) as first-line therapy. Medical histories of patients with DLBCL who were treated with R-CHOP as first-line therapy were assessed for concomitant statin use, response after completion of chemotherapy, event-free survival (EFS), and overall survival (OS). Furthermore, 2-[18F]fluor-2-deoxyglucose (FDG)-PET/CT results after completion of first-line therapy were compared between the groups. Overall, 145 patients with DLBCL treated with R-CHOP from January 2001 to December 2009 were analyzed. Twenty-one (15%) patients received statins throughout therapy. Five-year EFS was 67.3% in patients without statins compared with 79% in patients receiving statins during R-CHOP (HR, 0.47; 95% CI, 0.15-1.54, p = 0.2). Five-year OS was 81.4% for patients without statins compared with 93.3% for patients taking statins (HR, 0.58; 95% CI 0.07-4.55, p = 0.6). There were no statistically significant differences in the rates of complete remissions between the two groups (75% in the non-statin group versus 86% in the statin group, p = 0.45). A trend toward a lower rate of complete metabolic responses in FDG-PET/CT after chemotherapy was seen in patients without statin medication compared with the patients taking statins (84% versus 92%, p = 0.068). Concomitant statin use had no adverse impact on response to chemotherapy, EFS, and OS in patients treated with R-CHOP for DLBC

Clinical impact of 18F-choline PET/CT in patients with recurrent prostate cancer

Purpose: To investigate the clinical value of 18F-fluorocholine PET/CT (CH-PET/CT) in treatment decisions in patients with recurrent prostate cancer (rPCA). Methods: The study was a retrospective evaluation of 156 patients with rPCA and CH-PET/CT for restaging. Questionnaires for each examination were sent to the referring physicians 14-64months after examination. Questions included information regarding initial extent of disease, curative first-line treatment, and the treatment plan before and after CH-PET/CT. Additionally, PSA values at diagnosis, after initial treatment, before CH-PET/CT and at the end of follow-up were also obtained from the questionnaires. Results: Mean follow-up was 42months. The mean Gleason score was 6.9 at initial diagnosis. Initial treatment was: radical prostatectomy in 110 patients, radiotherapy in 39, and combined prostatectomy and radiotherapy in 7. Median PSA values before CH-PET/CT and at the end of follow-up were 3.40ng/ml and 0.91ng/ml. PSA levels remained stable, decreased or were below measurable levels in 108 patients. PSA levels increased in 48 patients. In 75 of the 156 patients (48%) the treatment plan was changed due to the CH-PET/CT findings. In 33 patients the therapeutic plan was changed from palliative treatment to treatment with curative intent. In 15 patients treatment was changed from curative to palliative. In 8 patients treatment was changed from curative to another strategy and in 2 patients from one palliative strategy to another. In 17 patients the treatment plan was adapted. Conclusion: CH-PET/CT has an important impact on the therapeutic strategy in patients with rPCA and can help to determine an appropriate treatmen

Protocol requirements and diagnostic value of PET/MR imaging for liver metastasis detection

Purpose: To compare the accuracy of PET/MR imaging with that of FDG PET/CT and to determine the MR sequences necessary for the detection of liver metastasis using a trimodality PET/CT/MR set-up. Methods: Included in this single-centre IRB-approved study were 55 patients (22 women, age 61 ± 11years) with suspected liver metastases from gastrointestinal cancer. Imaging using a trimodality PET/CT/MR set-up (time-of-flight PET/CT and 3-T whole-body MR imager) comprised PET, low-dose CT, contrast-enhanced (CE) CT of the abdomen, and MR with T1-W/T2-W, diffusion-weighted (DWI), and dynamic CE imaging. Two readers evaluated the following image sets for liver metastasis: PET/CT (set A), PET/CECT (B), PET/MR including T1-W/T2-W (C), T1-W/T2-W with either DWI (D) or CE imaging (E), and a combination (F). The accuracy of each image set was determined by receiver-operating characteristic analysis using image set B as the standard of reference. Results: Of 120 liver lesions in 21/55 patients (38%), 79 (66%) were considered malignant, and 63/79 (80%) showed abnormal FDG uptake. Accuracies were 0.937 (95% CI 89.5-97.9%) for image set A, 1.00 (95% CI 99.9-100.0%) for set C, 0.998 (95% CI 99.4-100.0%) for set D, 0.997 (95% CI 99.3-100.0%) for set E, and 0.995 (95% CI 99.0-100.0%) for set F. Differences were significant for image sets D-F (P < 0.05) when including lesions without abnormal FDG uptake. As shown by follow-up imaging after 50-177days, the use of image sets D and both sets E and F led to the detection of metastases in one and three patients, respectively, and further metastases in the contralateral lobe in two patients negative on PET/CECT (P = 0.06). Conclusion: PET/MR imaging with T1-W/T2-W sequences results in similar diagnostic accuracy for the detection of liver metastases to PET/CECT. To significantly improve the characterization of liver lesions, we recommend the use of dynamic CE imaging sequences. PET/MR imaging has a diagnostic impact on clinical decision making

Perfusion CT best predicts outcome after radioembolization of liver metastases: a comparison of radionuclide and CT imaging techniques

Objective: To determine the best predictor for the response to and survival with transarterial radioembolisation (RE) with 90yttrium microspheres in patients with liver metastases. Methods: Forty consecutive patients with liver metastases undergoing RE were evaluated with multiphase CT, perfusion CT and 99mTc-MAA SPECT. Arterial perfusion (AP) from perfusion CT, HU values from the arterial (aHU) and portal venous phase (pvHU) CT, and 99mTc-MAA uptake ratio of metastases were determined. Morphologic response was evaluated after 4months and available in 30 patients. One-year survival was calculated with Kaplan-Meier curves. Results: We found significant differences between responders and non-responders for AP (P 20ml/100ml/min had a significantly (P = 0.01) higher 1-year survival, whereas an aHU value >55 HU did not discriminate survival (P = 0.12). The Cox proportional hazard model revealed AP as the only significant (P = 0.02) independent predictor of survival. Conclusion: Compared to arterial and portal venous enhancement and the 99mTc-MAA uptake ratio of liver metastases, the AP from perfusion CT is the best predictor of morphologic response to and 1-year survival with RE. Key Points : • Perfusion CT allows for calculation of the liver arterial perfusion. • Arterial perfusion of liver metastases differs between responders and non-responders to RE. • Arterial perfusion can be used to select patients responding to RE