Biomedical subjects

J Oleson

Publications and source records attributed to J Oleson.

5 recordsLinked to original sources

PubMed1994

Heating rate modeling and measurements in phantom and in vivo of the human upper extremity in a defective 2450 MHz microwave oven.

Multiple door interlock switches in commercial microwave ovens are designed to prevent accidental exposure and injury. We report a) heating rate (degree/sec) measurements in a phantom of the human upper extremity in a 2450 MHz microwave oven having interlock switches deliberately bypassed; b) skin temperature measurements on the upper extremity of a human volunteer similarly exposed; c) perception of warmth and pain experienced by the volunteer during exposure; d) thermographic camera recordings of the volunteer's skin; and e) finite element modeling of specific absorption rate (SAR) in the volunteer's hand. Moderately severe pain was experienced at the fingertips after 5 sec of exposure, consistent with the modeled SAR, measured heating rates, and published data on the temperature threshold for pain. We estimate that an additional 9 sec of exposure would be required to produce irreversible injury, consisting of focal thermal injury in the fingertips and possibly the thenar and hypothenar eminences.

Computer Simulation↗

PubMed1992

Improved palliation of cerebral metastases in epithelial ovarian cancer using a combined modality approach including radiation therapy, chemotherapy, and surgery.

PURPOSE: Recent reports suggest an increasing incidence of CNS metastases in patients with ovarian cancer. We reviewed our experience in the management of brain metastases from ovarian carcinoma and merged our results with those of several other series reported in the literature to determine prognostic factors and the role of chemotherapy, radiation therapy, and surgery. PATIENTS AND METHODS: From 1977 to 1990, 15 of 795 patients who were treated for epithelial ovarian cancer at Duke University developed brain metastases. Fourteen of the patients were treated for their brain metastases; this included radiation therapy (RT; four), surgery and RT (one), RT and systemic chemotherapy (six), and all three treatment modalities (three). A meta-analysis was performed that combined the data from the current series with those of several recent clinical series that reviewed patients with brain metastases from ovarian carcinoma (67 patients total) to elucidate the impact of treatment and extent of disease on survival. RESULTS: In the current series, median survival (MS) after the diagnosis of brain metastases was 9 months. For the combined series, MS was 5 months. Thirteen patients who were treated with whole-brain RT and systemic chemotherapy (MS, 7 months), 10 patients who were treated with RT and surgery (MS, 10 months), and nine patients who were treated with all three modalities (MS, 16.5 months) had significantly longer survival than 19 patients who were treated with RT alone (MS, 3 months) (P = .05, P = .01, and P < .001, respectively). In a multivariate analysis, the only variable that provided prognostic information was treatment, namely the addition of systemic chemotherapy or surgery to RT for the treatment of brain metastases. CONCLUSION: Multimodal treatment of patients with brain metastases from ovarian cancer can result in significant palliation.

Adult↗

PubMed1991

Regional hyperthermia in patients with recurrent genitourinary cancer.

During a 6-year period, 53 patients with advanced tumors of the genitourinary tract were treated in Phase I protocols with deep regional hyperthermia in combination with irradiation (83%) or in combination with chemotherapy (11%). Primary tumors included those of bladder in 22 patients (41%), prostate in 20 patients (37%), kidney in 9 patients (17%), and ureter testicle or adrenal in 3 patients (5%). The majority (77%) had prior definitive therapy and had experienced treatment failure, and 11% had clinically important distant metastases. Treatment consisted of deep regional hyperthermia (mean of 4 sessions). In addition, 44 patients (83%) received irradiation (mean dose 39.2 Gy). The 1- and 3-year actuarial survival was 60% and 56%, respectively. Patients with carcinoma of the prostate had a 1- and 3-year survival of 82%. Complete response was observed in 7 patients (13%), partial response in 8 (15%), and nominal response in 13 (25%). Complete and partial response correlated well with histology of the tumor (adenocarcinoma), radiation dose (greater than 50 Gy), primary site (prostate, kidney), and treatment (hyperthermia-radiotherapy combination), (p = 0.02). There was no such correlation between response and thermal dose (p = 0.13). The treatment tolerance was good in 79% of patients. Treatment toxicity was limited to acute side effects, including pain during hyperthermia (47%), tachycardia greater than 140/min (7%), and blister formation in the treated area (4%). Phase II studies in previously untreated patients with locally advanced tumors of bladder, prostate, and kidney are needed for evaluation of the role of deep regional hyperthermia in the management of these cancers.

Actuarial Analysis↗

PubMed1989

Hyperthermia quality assurance guidelines.

These Hyperthermia Quality Assurance guidelines are a result of a joint workshop of the Hyperthermia Committee of the American College of Radiology and the Hyperthermia Physics Center, which is the national quality assurance program under Contract No. N01-CM-37512 with the National Cancer Institute. Hyperthermia technology presently lacks the kind of standardization in equipment, treatment procedures, patient monitoring, and treatment documentation available in radiotherapy. Therefore, preventing unacceptable variability in treatment data demands a strong commitment to in-house quality control procedures and to centralized quality assurance reviews in cooperative multi-institutional trials. This paper presents a set of test procedures necessary to ensure proper operation of equipment, suggests a frequency for such tests, and also includes guidelines on quality control procedures to be used during treatment to improve the safety, effectiveness, and reproducibility of hyperthermia treatments. A set of forms are presented to indicate the minimum data, albeit incomplete, that must be collected for acceptable documentation of treatment. These guidelines should be valuable not only to the new entrants in the field but also to those participating in multi-institutional cooperative hyperthermia trials. They have been approved by the Hyperthermia Committees of American College of Radiology, American Society for Therapeutic Radiology and Oncology, Radiation Therapy Oncology Group and the American Association of Physicists in Medicine.

Forms and Records Control↗

PubMed1989

Regional hyperthermia for advanced tumors: a clinical study of 353 patients.

A Phase I study using deep regional hyperthermia (HT) with an annular phased array was conducted in 14 U.S. medical centers from 1980 through 1986. There were 353 patients whose average age was 57 years. All patients had advanced recurrent or persistent tumors. Prior frequently complex, multimodality anti-cancer therapy was received by 71% of the patients. Gastrointestinal adenocarcinoma was present in 146 (41%) patients, genitourinary tumors in 86 (24%), soft tissue sarcomas in 46 (13%), malignant melanoma in 21 (6%) and 15% had other tumors. The sites treated included: pelvis 55%, abdomen 21%, liver 14%, thorax 6%, and other sites 3%. All patients received deep regional HT with an average frequency of 55 MHz. A total of 1412 HT treatments was administered to these 353 patients with an aim to increase the temperature in the volume of interest to greater than 42 degrees C for greater than or equal to 30 minutes. Thermal dose (TD in equivalent minutes at 42.5 degrees C) was less than 50 in 104 (29%), greater than or equal to 50 less than 100 in 30 (11%), greater than or equal to 100 in 26 (7%), and greater than 200 in 34 (10%). The remaining 150 (42%) patients had TD = 0. In addition to HT, 260 (74%) received radiotherapy (RT). RT was given at 180 or 200 cGy daily with an average total dose of 33.4 Gy. A total of 42 (12%) patients were given chemotherapy (CT) with HT, and 15 (4%) CT + HT + RT/HT alone was given to 47 (13%) patients. Complete response (CR) was obtained in 35 (10%) and partial response (PR) in 59 (17%) patients. CR was 12% in patients who received RT, vs 2% in those who did not receive it, p = 0.003. Radiation dose was an important factor influencing response, p less than 0.001. Thermal dose was not an important parameter influencing tumor response. A duration of CR ranged from 4 to 73 weeks with an average duration of 31 weeks and the median duration of 28 weeks. The overall 2-year survival was 13% with the median survival of 42 weeks. Patients with CR and PR had a 2 year survival of 41%, and a median survival of 71 weeks. This compared with 8% 2-year survival and 24 weeks median survival in patients who did not have CR or PR, p less than 0.001. Of the patients presenting with significant pain, 62% had complete or partial pain relief.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗