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Silvia Johansson

Publications and source records attributed to Silvia Johansson.

4 recordsLinked to original sources
PubMed2006

1-[11C]-acetate PET imaging in head and neck cancer--a comparison with 18F-FDG-PET: implications for staging and radiotherapy planning.

PURPOSE: The aim of this study was to evaluate the feasibility of using 1-[(11)C]-acetate positron emission tomography (ACE-PET) to detect and delineate the gross tumour volume of head and neck cancer before radiotherapy, and to compare the results with those obtained using (18)F-fluoro-2-deoxy-D: -glucose (FDG) PET. METHODS: Ten patients with histologically verified squamous cell carcinoma were investigated by FDG-PET and dynamic ACE-PET prior to radiotherapy. The two scans were performed on the same day or on consecutive days, except in one patient in whom they were done 5 days apart. Diagnostic CT or MRI was performed in all patients. The image data sets were analysed both visually and semi-quantitatively. All primary tumours and metastases were delineated automatically by using the 50% threshold of maximum radioactivity corrected for background. The mean standardised uptake value (SUV) and the tumour volumes were evaluated and compared. RESULTS: All ten primary tumours were detected by ACE-PET, while nine primaries were detected by FDG-PET and CT and/or MRI. The ACE SUV tended to be lower than the FDG SUV (5.3+/-2.7 vs 9.6+/-7.0, p=0.07). The tumour volumes delineated with ACE were on average 51% larger than the FDG volumes (p<0.05). ACE-PET identified 20/21 lymph node metastases, while only 13/21 lesions were detected by FDG-PET and 16/21 lesions by CT or MRI. CONCLUSION: ACE-PET appears promising for the staging of head and neck cancer. The biological information provided by both FDG and ACE must be carefully validated before it can be used in clinical routine for radiation treatment planning. More studies are needed to evaluate the differences in volumes and to confirm the clinical potential of both FDG and ACE-PET, especially in radiotherapy.

Acetates↗
PubMed2002

Dose response and latency for radiation-induced fibrosis, edema, and neuropathy in breast cancer patients.

PURPOSE: To study the incidence of various forms of late normal tissue injuries to determine the latency and dose-response relationships. METHODS: We retrospectively analyzed the clinical records of 150 breast cancer patients treated with radiotherapy after mastectomy in the mid to late 1960s. None of the patients had received chemotherapy as a part of their primary treatment. Radiotherapy was delivered to the parasternal, axillary, and supraclavicular lymph node regions. Almost all the patients continued to be checked at regular 3-month to 1-year intervals at our Oncology Department. Detailed records were available for the entire 34 years of the follow-up period. The patients were divided into 3 groups. The prescribed dose was either 11 x 4 Gy (treated with 60Co photons) or 11 x 4 Gy or 14-15 x 3 Gy (treated with both 60Co photons and electrons). The dose recalculation at the brachial plexus where the axillary and supraclavicular beams overlapped was performed in the early 1970s and expressed in cumulative radiation effect (CRE) units. It varied widely among the individual patients. The received dose has now been converted to biologic effective dose(3) units, and from that into the equivalent dose in 2-Gy fractions to plot the dose-response relationships. RESULTS: We present a comparison of the latency and frequency of fibrosis, edema, brachial plexus neuropathy, and paralysis in the three different subgroups and the total group. Dose-response relationships are shown at 5, 10, and 30 years after irradiation. CONCLUSION: The use of large daily fractions, combined with hotspots from overlapping fields, was the cause of the complications. Clear dose-response curves were seen for late radiation injuries. The incidence seen at 5 years did not represent the full spectrum of injuries. Doses that seem safe at 5 years can lead to serious complications later.

Brachial Plexus Neuropathies↗