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Biomedical subjects

M D Sapozink

Publications and source records attributed to M D Sapozink.

At least 37 records · Page 2Linked to original sources
PubMed1983

Intracranial Hodgkin's disease. A report of 12 cases and review of the literature.

Intracranial involvement by Hodgkin's disease is rare. Of the 30 previously reported cases, in many of which central nervous system (CNS) disease was documented postmortem, no associated risk factors have been elucidated, and response to treatment has been poor. This report cites 12 additional cases treated at the Stanford University Medical Center, five of whom have enjoyed prolonged freedom from intracranial relapse.

Adolescent↗
PubMed1983

Extramedullary lesions in non-lymphocytic leukemia: results of radiation therapy.

Fifty-four courses of radiotherapy were given to 33 patients with symptomatic extramedullary involvement by non-lymphocytic leukemia. Among them were 23 cases of granulocytic sarcoma. Analysis of the treatment response showed that age, hematopathologic type and quality of irradiation did not influence the radiation response. However, a dose response relationship could be demonstrated with a statistically significant difference in response among the four groups of patients treated to total doses of less than 1000 rad, 1000-1999 rad, 2000-2999 rad, and greater than or equal to 3000 rad (p = 0.003). We suggest irradiating all extramedullary lesions to at least 1100 ret.

Acute Disease↗
PubMed1983

Combined continuous ultra low dose rate irradiation and radiofrequency hyperthermia in the C3H mouse.

Intradermally inoculated RIF tumors and normal skin of male C3H mice were implanted with variable activities of Iodine 125 seeds or dummy seeds enclosed in Vicryl sutures, and subjected to 0, 1, 2 or 3 local radiofrequency heat treatments for 30 minutes. Each treatment raised the tumor volume to 44 degrees C. Gastrointestinal toxicity (assessed by weight change), skin reaction, tumor growth delay, and tumor cure were assessed. Neither radiofrequency treatment alone or continuous ultra low dose rate irradiation up to 16,000 rad over 180 days alone was successful in curing these tumors; however, combined modality treatments employing doses as low as 8,000 rad over 180 days plus two radiofrequency treatments did effect cures. Gastrointestinal toxicity was best correlated with hyperthermia treatments, while skin reactions secondary to hyperthermia were prolonged by continuous ultra low dose rate irradiation. Implications for clinical usage are discussed.

Animals↗
PubMedDate not supplied

The application of thermal dose in clinical trials.

When large human tumours are heated, spatial temperature (T) variation is high and poorly predictable with current hyperthermia technology. Invasive thermometry is thus necessary to document efficacy, and thermal mapping or multisensor thermometry can increase the yield of information without increasing the extent of invasiveness. The amount of temperature, time and spatial (T, t, x) data generated in a typical treatment is overwhelming, but can be made comprehensible by the application of thermal dose (TD) analysis. The isoeffective basis of the analysis reviewed here is likely to be modified as more biophysical information becomes available but, at present, serves the purpose of data condensation and treatment comparison. Real-time TD analysis may help to assure treatment reproducibility and may assist in discerning thermal dose-response relationships in prospective clinical trials.

Animals↗
PubMedDate not supplied

The accuracy of temperature measurement from within an interstitial microwave antenna.

Temperature measurement from within microwave interstitial antennas is a promising new development for hyperthermia. These antennas could enable the development of multipoint temperature regulation, leading to improved control of temperature distributions and therefore more effective hyperthermia treatments. In the complex environment of an antenna within a plastic catheter, measured temperatures were found to differ from the estimated local tissue temperature by up to 8 degrees C. In the design evaluated in this report the primary source of this error appears to be self-heating distal to the antenna junction, particularly in the outer copper conductor. The magnitude of self-heating is directly proportional to applied microwave power. Catheter wall thickness, tissue perfusion, and longitudinal temperature gradient also influence the measured temperature.

Humans↗
PubMedDate not supplied

Introduction to hyperthermia device evaluation.

From 10/81 to 1/87, the National Cancer Institute (NCI) of the U.S. Department of Public Health Services (PHS) contracted with four institutions to evaluate hyperthermia technology to be applied in the treatment of human malignancy. During the five year period 1981-1986, data were collected which now reside in a consensus database representing treatments of 792 separate sites or fields in a total of 573 patients. These patients were treated with one or more of 49 devices by the four institutions. Sixteen ultrasound (US) devices were evaluated in 195 sites. Nine magnetic induction (MI) devices were evaluated in 208 sites. Twenty radiative electromagnetic (EM) devices were evaluated in 488 sites. Four interstitial (IRF) devices were evaluated in 37 sites. Many sites were treated with multiple hyperthermia modalities. This first in a series of 13 reports describes the general objectives of the Contractors' Group, basic methods of device evaluation and brief details of the large variety of devices tested.

Electromagnetic Phenomena↗
PubMedDate not supplied

Phase I evaluation of hyperthermia equipment--University of Utah institutional report.

At the University of Utah Medical Center the thrusts of the effort with respect to the NCl Hyperthermia Equipment Evaluation Contract have been threefold. The first objective was the development of a reliable thermometry system for collecting temperature information as a function of space as well as time. The second objective was the evaluation and comparison of a number of hyperthermia devices, particularly with respect to deep-heating devices, and specifically as pertains to the BSD annular phased array system (AA) and its various configurations. The third objective was to develop methodology for analysing hyperthermia data which could be easily adapted toward device comparison. In the period from 10/81-1/86, a total of 137 patients were treated with one or more of 10 devices, totalling 199 device evaluations at the University of Utah Medical Center or the subcontracting institution, LDS Hospital. Of these, 132 device evaluations involved deep-seated tumours. The AA was found to be feasible for deep pelvic regional hyperthermia, although the frequency of reversible acute toxicity was high, and achievement of desired temperatures was frequently limited by one of several factors. The radiative electromagnetic wave applicators which were evaluated for treatment of superficial tumours were found to be mostly feasible for tumours of the thoracic and extremities regions, although the heating patterns were frequently too shallow or too small in area, when compared with the size of the lesion.

Equipment Design↗
PubMedDate not supplied

Myonecrosis following deep pelvic hyperthermia.

A case report is presented in which severe myonecrosis of the inferior anterior abdominal wall followed treatment of a recurrent pelvic tumour with an annular phased array (AA) deep heating device. This unusual complication has not been observed at this institution in 107 patients previously treated with deep pelvic or abdominal hyperthermia, who had undergone a total of 368 hyperthermia sessions. The injury was confirmed radiographically and histopathologically, and was associated with serum enzymatic elevations characteristic of muscular injury. The implications for clinical trials employing the AA or similar devices are discussed.

Abdominal Muscles↗
PubMedDate not supplied

A technique for combining microwave hyperthermia with intraluminal brachytherapy of the oesophagus.

A technique for combining microwave hyperthermia with 192Ir brachytherapy for the treatment of oesophageal carcinoma is described. This approach uses an intraluminal afterloading applicator and up to six microwave antennae to deliver both hyperthermia and brachytherapy, with minimal modification of the existing procedure for brachytherapy alone. Each microwave antenna includes a built-in thermistor to control temperature and balance power. Longitudinal temperature distributions were measured in situ from within the applicator, and at the applicator-tissue interface in vivo. Two-dimensional SAR and steady-state temperature distributions measured in muscle-equivalent phantom are presented and discussed. The technique appears to be capable of elevating tissue temperature to greater than 42 degrees C in a radially symmetric volume of length greater than 5 cm, with radial penetration of 0.5 cm. The clinical technique is relatively simple and well tolerated.

Brachytherapy↗
PubMedDate not supplied

Microwave applicator for transurethral hyperthermia of benign prostatic hyperplasia.

An applicator for heating the prostate gland using a transurethral approach is described. This technique uses three microwave antennas and a thermometry sensor attached to the outer surface of a balloon (Foley) type urological catheter. Each microwave antenna also includes a built-in thermistor to control temperature and balance power. The balloon catheter assures rapid and reproducible localization of the antennas in the prostatic urethra. The two-dimensional SAR and steady-state temperature distributions surrounding the applicator in tissue equivalent phantom are reported. Longitudinal temperature distributions measured in situ at the applicator-urethral interface and the longitudinal and radial temperature distributions measured in normal canine prostate are presented and discussed. The technique appears to be capable of elevating temperature to greater than 42 degrees C in a cylindrically symmetrical volume up to 5 cm length and 0.5 cm radial penetration surrounding the applicator.

Hot Temperature↗
PubMedDate not supplied

Adjuvant pelvic hyperthermia in advanced cervical carcinoma. I. Feasibility, thermometry and device comparison.

From 1981 to 1989, a total of 26 women with locally or regionally advanced carcinoma of the uterine cervix were treated with radiotherapy (RT) and pelvic regional hyperthermia (HT), in the Divisions of Radiation Oncology at the University of Utah Medical Center (UU) and the Kenneth Norris Jr Cancer Hospital of the University of Southern California (USC). HT was produced by the BSD-1000 HT system and the annular phased array (AA) applicator usually driven at 60-65 MHz, or the BSD-2000 HT system and the Sigma-60 (S60) applicator usually driven at 70-85 MHz. During the HT sessions acute toxicity was common, particularly because of pain within or outside the applicator, which was power-limiting in 43% of the patients overall. Pain was more easily manipulated, but more commonly power-limiting with the S60. Systemic stress was power-limiting in 22% of patients treated with the AA, but in no patients with the S60. Detailed thermal mapping and temperature analysis were performed on 26 patients. The mean overall average intratumour temperature achieved was 41 +/- 1.1 degrees C for 30 min; 5% and 35% of the monitored intratumour loci exceeded 43 degrees C and 42 degrees C, respectively. Temperatures recorded in the cervical os and proximal vagina appeared lower relative to the monitored normal structures in the region. Subacute treatment related toxicities occurred in five patients and included protracted pain (three) and superficial second degree burns (one), all of which resolved with supportive non-surgical therapy.

Adenocarcinoma↗
PubMedDate not supplied

Heating characteristics of a helical microwave applicator for transurethral hyperthermia of benign prostatic hyperplasia.

A new applicator for intraurethral hyperthermic treatment of benign prostatic hyperplasia is described. The applicator uses an insulated helical antenna wound on the outer surface of a silicone urological (Foley) balloon catheter. The balloon catheter assures rapid and reproducible localization of the antenna in the prostatic urethra. Two small cannulae are fixed to the exterior surface of the applicator. One holds a temperature control sensor at a fixed location, the other is used to map temperature along the applicator. Two-dimensional SAR and steady-state temperature distributions measured in a plane tangent to the applicator in a tissue-equivalent phantom are presented, as well as longitudinal temperature distributions measured in situ at the applicator-urethral interface. Prostatic temperatures were also measured intraoperatively. The applicator appears to be capable of elevating temperature to greater than 42 degrees C in a cylindrically symmetric volume of about 4 cm length and about 0.5 cm radial penetration surrounding the antenna. The heating characteristics of this applicator are similar to an earlier design that employed an array of three dipoles. The helical applicator is narrower, more flexible and simpler to use than the earlier design.

Biomedical Engineering↗
PubMedDate not supplied

Clinical hyperthermia in the 1990s: does the buck stop here?

Clinical hyperthermia in the USA is entering difficult times. To describe the present state of this art (1) all of the clinical manuscripts published in the International Journal of Hyperthermia and the International Journal of Radiation Oncology, Biology and Physics in the period from 1 January 1990 to 30 June 1993 were reviewed; (2) the Radiotherapy Research Division of the National Cancer Institute was queried as to existing extramural funding of clinical hyperthermia projects; and (3) individual institutions known to have active clinical research programmes in hyperthermia were surveyed as to the status of current studies. At the present time there are no hyperthermia trials being conducted by US cooperative groups. The majority of reports and active scientific protocols continue to deal with phase I and pilot studies. Many studies in several sites continue to suggest improvement in CR rate and local control over historical controls when hyperthermia is used as an adjunct to radiotherapy; however phase III proof of these hypotheses is still lacking. Extramural funding of clinical hyperthermia is limited and third party funding is decreasing. Details and future portents are discussed.

Clinical Protocols↗