Focal colorectal uptake in (18)FDG-PET/CT: maximum standard uptake value as a trigger in a semi-automated screening setting.

Background: Focal colorectal uptake in (18)FDG-PET/CT may be associated with a malignancy and can be quantified. This provides the basis for an automatic trigger threshold above which cases are flagged for colonoscopic evaluation and below which for individual assessment.

Purpose: To determine the lowest maximum standard uptake (SUVmax) in colorectal cancer that could be used as a threshold to trigger endoscopic evaluation and to evaluate whether the SUVmax needs to be further normalised to a priori known extrinsic factors.

Gastroenteropancreatic neuroendocrine tumors: standardizing therapy monitoring with 68Ga-DOTATOC PET/CT using the example of somatostatin receptor radionuclide therapy.

The purpose of this study was to standardize therapy monitoring of hepatic metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) during the course of somatostatin receptor radionuclide therapy (SRRT). In 21 consecutive patients with nonresectable hepatic metastases of GEP-NETs, chromogranin A (CgA) and 68Ga-DOTATOC PET/CT were compared before and after the last SRRT. On 68Ga-DOTATOC PET/CT, the maximum standard uptake values (SUVmax) of normal liver and hepatic metastases were calculated.

Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off.

Objective: To determine the performance of FDG-PET/CT in the detection of relevant colorectal neoplasms (adenomas > or =10 mm, with high-grade dysplasia, cancer) in relation to CT dose and contrast administration and to find a PET cut-off.

Methods: 84 patients, who underwent PET/CT and colonoscopy (n = 79)/sigmoidoscopy (n = 5) for (79 x 6 + 5 x 2) = 484 colonic segments, were included in a retrospective study. The accuracy of low-dose PET/CT in detecting mass-positive segments was evaluated by ROC analysis by two blinded independent reviewers relative to contrast-enhanced PET/CT.

Visualization of somatostatin receptors in prostate cancer and its bone metastases with Ga-68-DOTATOC PET/CT.

Purpose: To assess DOTATOC-affine somatostatin receptor expression in advanced prostate cancer and its bone metastases with regard to DOTATOC-mediated receptor therapies, using a Ga-68-DOTATOC PET/CT.

Procedures: Twenty consecutive patients with advanced prostate cancer underwent bone scintigraphy, followed by Ga-68-DOTATOC PET/CT within 3 weeks. Through side-by-side comparison with bone scintigraphy, the number of visible bone metastases on PET was determined.

Prostate carcinoma: diffusion-weighted imaging as potential alternative to conventional MR and 11C-choline PET/CT for detection of bone metastases.

In a technical development study approved by the institutional ethics committee, the feasibility of fast diffusion-weighted imaging as a replacement for conventional magnetic resonance (MR) imaging sequences (short inversion time inversion recovery [STIR] and T1-weighted spin echo [SE]) and positron emission tomography (PET)/computed tomography (CT) in the detection of skeletal metastases from prostate cancer was evaluated. MR imaging and carbon 11 ((11)C) choline PET/CT data from 11 consecutive prostate cancer patients with bone metastases were analyzed. Diffusion-weighted imaging appears to be equal, if not superior, to STIR and T1-weighted SE sequences and equally as effective as (11)C-choline PET/CT in detection of bone metastases in these patients.

Discordance analysis characteristics as a new method to compare the diagnostic accuracy of tests: example of complexed versus total prostate-specific antigen.

Background: ROC curve analysis is used to compare the overall diagnostic accuracy of tests, but its application to subgroups selected by a concentration range of only one marker may show severe biases. We developed a new approach, which we have named discordance analysis characteristics (DAC).

Methods: The DAC method is based on a generalization of the McNemar test so that for a given pair of cutoff values only those patients are analyzed who are categorized differently by the two tests compared.

A multicenter clinical trial on the use of complexed prostate specific antigen in low prostate specific antigen concentrations.

Purpose: The determination of complexed prostate specific antigen (cPSA) has been suggested to be promising for prostate cancer (PCa) diagnosis. In a multicenter trial we evaluate the diagnostic use of PSA forms in the low total PSA (tPSA) range.

Materials And Methods: A total of 283 white men with and 417 without PCa and tPSA concentrations between 0 and 6 ng/ml were retrospectively analyzed.

Bicycle riding has no important impact on total and free prostate-specific antigen serum levels in older men.

Objectives: To investigate whether bicycle riding significantly alters total prostate-specific antigen (tPSA), free PSA (fPSA), and percent free PSA (%fPSA) serum concentrations in potential candidates for prostate cancer screening.

Methods: Thirty-three men, ranging in age from 50 to 74 years (mean 61 +/- 8), rode a 13-mile bicycle course. Blood samples for PSA analysis were drawn immediately before and 1 hour after cycling for 90 minutes.