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Per-Ulf Tunn

Publications and source records attributed to Per-Ulf Tunn.

4 recordsLinked to original sources
PubMed2006

Noninvasive magnetic resonance thermography of soft tissue sarcomas during regional hyperthermia: correlation with response and direct thermometry.

BACKGROUND: The objective of this study was to evaluate noninvasive magnetic resonance (MR) thermography for the monitoring of regional hyperthermia (RHT) in patients with soft tissue sarcomas of the lower extremities and pelvis. METHODS: Noninvasive MR monitoring during RHT was performed in 9 patients who had high-risk soft tissue sarcomas of the lower extremities or pelvis during neoadjuvant chemotherapy plus RHT in the scope of the European Organization for Research and Treatment of Cancer 62961/European Society for Hyperthermic Oncology RHT-95 study. Anatomic and temperature-sensitive data sets were acquired every 10 minutes before and during RHT (using gradient-echo-sequences with variable echo times). MR temperature distributions were derived from the phase differences by using the proton-resonance frequency shift method. A phase convolution setting phase shifts to zero in the fat tissue was performed as a drift correction. The mean MR temperatures in the tumor and muscles and the index temperatures (e.g., T90, which covers 90% of the target volume) and thermal doses were determined and compared with pathohistologic responses and direct temperature measurements if available. RESULTS: Thirty of 72 MR-thermography data sets (>40% of heat sessions) were evaluable. A significant correlation was observed between pathohistologic response (defined as a necrosis rate >or=90%) and standardized thermal parameters, such as thermal dose cumulative equivalent minutes at 43 degrees C to 90% of the target volume (T90) (P = .050), mean T90 (P = .048), or T50 (P = .050). The correlation of 13 conventional temperature measurements performed in selected patients and sessions invasively in the tumor or noninvasively in rectum and bladder revealed an excellent correlation with MR temperatures (R2 = .96). CONCLUSIONS: Noninvasive MR thermography of soft tissue sarcoma was feasible and suitable for validating the quality of heating during RHT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Osteosarcoma in children: long-term functional analysis.

Multimodal, limb-saving therapy is the treatment of choice in children with osteosarcoma. However, few data are available on long-term functional problems and disabilities in surviving patients. Seventy-eight children treated for Stage II-B osteosarcoma who were treated between 1970 and 1997 were evaluated. Beyond the clinical examination, functional results were assessed using the scoring system of the Musculoskeletal Tumor Society. Patients reported their physical disabilities when completing the Toronto Extremity Salvage Score. The most recent cohort of patients who had tumor resection combined with preoperative and postoperative chemotherapy had the best 10-year survival rate at 70%. Thirty-four children (44%) were treated by limb-sparing therapy with 25 children requiring an endoprosthesis. Ten of these 25 children (40%) required one or in some cases several replacements of the endoprostheses because of complications. The original prostheses were in place for a median of 4.9 years before the first exchange (range, 2.0-12.0 years). Evaluations with rating scales showed that the subjective estimation of disabilities by the Toronto Extremity Salvage Score was significantly higher than a rating of limb functions by a doctor using the Musculoskeletal Tumor Society score. Best results were observed in children with an endoprosthesis of the distal femur who achieved as much as 90% ability to do their daily life routine. Limb-saving therapy in children with osteosarcoma enables a return to activities of daily living in long-term survivors with a minimum of remaining disability.

Activities of Daily Living↗
PubMedDate not supplied

Osteoid osteoma: experience with laser- and radiofrequency-induced ablation.

The purpose of this study was to analyze the clinical outcome of osteoid osteoma treated by thermal ablation after drill opening. A total of 17 patients and 20 procedures were included. All patients had typical clinical features (age, pain) and a typical radiograph showing a nidus. In 5 cases, additional histological specimens were acquired. After drill opening of the osteoid osteoma nidus, 12 thermal ablations were induced by laser interstitial thermal therapy (LITT) (9F Power-Laser-Set; Somatex, Germany) and 8 ablations by radiofrequency ablation (RFA) (RITA; StarBurst, USA). Initial clinical success with pain relief has been achieved in all patients after the first ablation. Three patients had an osteoid osteoma recurrence after 3, 9, and 10 months and were successfully re-treated by thermal ablation. No major complication and one minor complication (sensible defect) were recorded. Thermal ablation is a safe and minimally invasive therapy option for osteoid osteoma. Although the groups are too small for a comparative analysis, we determined no difference between laser- and radiofrequency-induced ablation in clinical outcome after ablation.

Adolescent↗