Anne Hoekstra

Intracoronary beta-radiation of de novo coronary lesions using a 186Re liquid-filled balloon system: Six-month results from a clinical feasibility study

Vascular brachytherapy has shown to be effective for in‐stent restenosis, but efficacy in de novo lesions remains uncertain. We evaluated feasibility and outcome of intracoronary beta‐radiation therapy in de novo coronary lesions using a 186Re liquid‐filled balloon system. Thirty‐three patients received 20 Gy 186Re beta‐radiation immediately after balloon angioplasty. The 6‐month restenosis rate was 41% (12/29) and restenosis was located within the target lesion in eight patients and at the edges of the injured and irradiated segment, outside the target lesion, in four patients. At 6 months, four patients (12%), all stented during the initial procedure, had experienced a late (> 30 days) total occlusion. Intracoronary beta‐radiation therapy of de novo coronary lesions using 186Re is technically feasible. No reduction in restenosis was observed. The high incidence of late total occlusions may have been prevented by avoiding new stent implantation and prolonging double antiplatelet therapy. Cathet Cardiovasc Intervent 2002;55:28–36.

One-year clinical experience with a fully digitized nuclear medicine department: organizational and economical aspects

At the department of nuclear medicine of the University Hospital Utrecht a single-modality PACS has been operational since mid-1990. After one year of operation the functionality, the organizational and economical consequences, and the acceptability of the PACS were evaluated. The functional aspects reviewed were: viewing facilities, patient data management, connectivity, reporting facilities, archiving, privacy, and security. It was concluded that the improved quality of diagnostic viewing and the potential integration with diagnosis, reporting, and archiving are highly appreciated. The many problems that have occurred during the transition period, however, greatly influence the appreciation and acceptability of the PACS. Overall, it is felt that in the long term there will be a positive effect on the quality and efficiency of the work.

The value of local 99mTc(Sn)-MDP bone to soft tissue uptake ratio in osteoporosis, before and during fluoride therapy.

The reproducibility and diagnostic value of local bone to soft tissue uptake ratio of99mTc(Sn)-MDP as a bone tracer was examined in a prospective study in 35 patients who were under investigation and/or treatment for postmenopausal osteoporosis. The ratio of tracer uptake in the second lumbar vertebra (L2) and both femoral shafts was calculated from the number of counts in suitable regions of interest. Results obtained with settings and calculations in the routine practice were compared to the results obtained by revision of all raw data in one run by one person. The results were compared to the serum alkaline phosphatase activity (AP) and to local bone mineral mass as determined by dual photon absorptiometry (DPA). In 15 patients serial measurements during fluoride therapy were also compared to serum osteocalcin values and to bone histomorphomatric data. The precision error of the calculation of uptake ratios from raw counts (including selection of region of interest) was 13.9% for the femoral shaft and 14.7% for L2. The mean difference between left and right femoral shaft in individuals was not significant and its variance was smallP > 0.1). There was a weak but significant linear correlation between local uptake ratio in the spine and AP in the total material (r=0.328P < 0.01). However, changes in local uptake ratio during therapy with fluoride in 15 patients were too small to be of any value and did not correlate with changes in alkaline phosphatase or osteocalcin or trabecular surface covered with osteoblasts. We conclude therefore that local uptake ratio of bone seeking isotopes has no value in assessing general metabolic bone activity in osteoportic patients, for diagnostic purposes or in the follow up of their response to therapy, except for the detection of local untoward reactions.

The detection of small carcinoma with 18F-FDG using a dual head coincidence camera

Tumour imaging with F18-fluorodeoxyglucose (18F-FDG) has yielded promising results for the detection of a variety of tumours. Owing to the high costs and limited availability of dedicated Positron emission tomography (PET) scanners, alternative methods of imaging the 511-KeV photons of positron emitters have been sought. With a dual head coincidence camera PET scanning of FDG is possible. The system parameters, such as sensitivity and spatial resolution, are already measured, but the clinical experience of this alternative imaging method is very limited. Two cases are described in which tumours with a diameter of 4 and 5 mm, respectively, were detected using a dual head coincidence camera. The presented cases support the use of this converted gamma camera in head and neck oncology.