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Objective: To compare the diagnostic accuracy of Ga-prostate-specific membrane antigen (PSMA)-HBED-CC PET/computed tomography (CT) imaging for the detection of androgen-dependent recurrent prostate carcinoma (ADPC) in Black South Africans (BSAs) versus White South Africans (WSAs) with increasing serum prostate-specific antigen (PSA) values below or equal to 10 ng/ml., Patients and Methods: A total of 61 patients with ADPC were prospectively included in the study (mean age: 66.7 years): 38 WSAs and 23 BSAs. Ga-PSMA-HBED-CC PET/CT imaging results obtained were related to serum PSA levels and to ethnicity., Results: A total of 41 (67%) patients had a positive Ga-PSMA-HBED-CC scan result. Ga-PSMA-HBED-CC PET/CT positivity was significantly higher in patients with PSA values more than 2 ng/ml [32/38 (84%) patients] when compared with patients with PSA values less than 0.5 ng/ml [6/11 (55%) patients] or PSA values of 0.5-2 ng/ml [3/12 (25%) patients] (P=0.0001). Mean PSA values proved not significantly different in patients presenting with extrapelvic involvement when compared with those with intrapelvic involvement or between patients who presented with bone involvement versus those who did not on Ga-PSMA-HBED-CC PET/CT) (P≥0.147). Age, Gleason-scores, median PSA values, the frequency of a positive scan result, the frequency of bone involvement, and extrapelvic involvement proved similar in WSAs and BSAs (P≥0.417)., Conclusion: Ga-PSMA-HBED-CC PET/CT imaging identified a recurrence in 67% of the patients under study. Higher PSA levels were associated with Ga-PSMA-HBED-CC PET/CT positivity and the detection rate. Imaging results obtained proved similar in BSAs and WSAs, suggesting that the tumor burden and growth rate of ADPC are similar in both races.

Background: The purpose of this study was to determine the potential role of Tc depreotide scintigraphy for the evaluation of bone metastases compared with Tc methylenediphosphonate (MDP) bone scintigraphy and for the prediction of treatment response in breast cancer patients in whom first- or second-line hormonal therapy was to be initiated., Methods: Twelve patients with a diagnosis of advanced breast cancer were included. All patients underwent both a bone scan and a depreotide scan and at least one other conventional imaging procedure, including plain film radiography (n=11), computed tomography (n=6) or magnetic resonance imaging (n=5), for confirmation of metastatic disease. The mean time interval between the bone scan and the depreotide scan was 30.6 days. Follow-up data were retrieved from routine clinical evaluation by means of physical examination, imaging and blood analysis., Results: On a patient basis we found a sensitivity, specificity and accuracy of, respectively 100%, 50% and 83.3% for the bone scan and 62.5%, 100% and 75% for the depreotide scan in the diagnosis of bone metastasis. In eight patients with available follow-up data two with a positive depreotide scan remained stable and five of six patients with a negative depreotide scan had progressive disease., Conclusion: In this small series of breast cancer patients Tc depreotide scintigraphy proves less sensitive but more specific as compared to Tc-MDP bone scintigraphy in measuring the extent of bone metastasis. On the other hand Tc depreotide scintigraphy elucidates, non-invasively, tumour characteristics and may be indicative for prognosis and response to hormonal treatment.

In this study, the potential of 99mTc-HYNIC Annexin-V scintigraphy to visualize primary head and neck carcinoma was assessed and compared with computed tomography (CT) findings and histology. Eighteen patients suspected of having primary head and neck carcinoma underwent a spiral CT scan and 99mTc-HYNIC Annexin-V scintigraphy within 1 week of each other, followed by resection of the suspected lesion. Results obtained by CT and scintigraphy were compared vs. histopathology. The diagnosis was primary head and neck carcinoma in 18 patients, accompanied by lymph node involvement in seven patients. 99mTc-HYNIC Annexin-V uptake was identified in five patients on planar images and in 17 patients on tomographic images (single-photon emission computed tomography, SPECT), corresponding to the pathological regions identified by CT. In the remaining patient, CT and 99mTc-HYNIC Annexin-V scintigraphy were false negative. In 11 patients, SPECT and CT scan were concordant, identifying all primary lesions and two sites of lymph node involvement. In the six remaining patients, CT and SPECT accurately identified the primary lesion, but were discordant with regard to the existence of lymph node involvement. In five of six patients, SPECT failed to identify lymph node involvement, whereas CT scan did not. In the remaining patient, CT scan was false positive for lymph node involvement, whereas SPECT was not. In this series, 99mTc-HYNIC Annexin-V allowed for the visualization of all primary head and neck tumours identified by CT scan, but failed to identify most of the sites of lymph node involvement.

Background: Human planning is a complex mental process that may be evaluated by the 'Tower of London' (TOL) task, which includes setting up and maintaining multiple subgoals at the same time. Although positron emission tomography and functional magnetic resonance imaging have provided reliable data on the recruitment of a neural network engaged in planning tasks, the experimental settings of these studies cannot be applied in clinical conditions. Hence, this study reports on the TOL task under classical neuropsychological test conditions using single photon emission computed tomography (SPECT) activation in 10 healthy subjects., Methods: Participants first performed a control task and then an activation task, i.e., the TOL planning task In the planning task, subjects were required to change, in the minimum number of moves possible, an initial arrangement of beads to match a goal arrangement. Subjects solved a set of eight TOL problems of increasing difficulty. A control task was designed such that it eliminates planning abilities, which is the process of interest. Planning times and accuracy were measured as performance parameters and functional imaging data were analysed with statistical parametric mapping (SPM99) to determine significant voxel-wise activations between the planning task and the control task., Results: Both overall and for each difficulty level, measures of accuracy were within the normal range. Similar results were found for the overall thinking time and thinking times of each difficulty level. That is, performance of the healthy subjects during the TOL task replicated the typical pattern of results found with appropriate control samples in the literature. Also, activation of the right prefrontal cortex was consistent with other functional imaging results, thereby validating the use of the TOL task in a SPECT activation paradigm., Conclusions: Based on the present study it may be concluded that the close resemblance of the test conditions of the SPECT activation procedure with those of the TOL task in the investigation room constitutes a major advantage for future application of the SPECT activation procedure in clinical conditions.