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Biomedical subjects

M D Sapozink

Publications and source records attributed to M D Sapozink.

At least 19 recordsLinked to original sources
PubMed1991

RTOG quality assurance guidelines for clinical trials using hyperthermia for deep-seated malignancy.

Quality assurance has been vague or lacking in many previous hyperthermia trials. Recent publications by the Hyperthermia Physics Center, the Center for Devices and Regulatory Health, and the Radiation Therapy Oncology Group have described general guidelines for quality assurance in equipment reliability and reproducibility, superficial applications, and microwave techniques. The present report details quality assurance factors that are believed to be important for hyperthermia of deep clinical sites, defined as extending at least 3 cm beyond the skin surface. This document will discuss patient and physician factors, as well as thermometric accuracy, assessment of specific absorption rates (SAR), assurance of adequate coverage of tumors by the energy deposition pattern of the treatment device, and recommended documentation of the location, quantity, and frequency of treatment, specifically oriented to deep hyperthermia. The recommendations are structured to facilitate compliance in multiinstitutional trials.

Clinical Protocols↗
PubMed1991

Treatment results of stereotactic interstitial brachytherapy for primary and metastatic brain tumors.

A total of 41 stereotactic interstitial brain implants in 39 patients were performed for recurrence after teletherapy (recurrence implant), or as part of initial treatment in conjunction with teletherapy (primary implant). Implanted tumors consisted of malignant gliomas (33), other primary brain tumors (3), and single metastatic lesions (3). All patients were temporarily implanted with Ir-192 using a coaxial catheter afterloading system; two patients were implanted twice. Survival post-implant for glioblastoma multiforme (GBM), 13 patients, was 10 months whether implanted primarily or for recurrence. Mean time to recurrence, measured from initiation of teletherapy to implantation, was 10 months. Twenty patients with anaplastic astrocytoma (AA) had a median survival post-implant of 23 months for primary implants (7 patients) and 11 months for recurrence implants (13 patients). Mean time to recurrence, measured from initiation of teletherapy to implantation, was 19 months. Three patients (9%) of the evaluable group required reoperation for symptomatic mass effect, all with initial diagnosis of AA. Survival for this subgroup was 14, 22, and 32 months post-implantation. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically feasible with negligible acute morbidity and mortality, and appeared to offer limited prolongation of control for a subset of patients with recurrent malignant gliomas. The role of this modality in primary treatment for malignant gliomas needs to be further defined by prospectively randomized trials.

Adolescent↗
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↗
PubMed1990

An interactive treatment planning system for ophthalmic plaque radiotherapy.

Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system.

Brachytherapy↗
PubMed1990

Transurethral hyperthermia for benign prostatic hyperplasia: preliminary clinical results.

A total of 21 patients with biopsy proved benign prostatic hyperplasia underwent treatment on a pilot protocol involving intracavitary transurethral radiating microwave (630 or 915 MHz.) antenna hyperthermia. Acute and subacute toxicity was mild and consisted primarily of bladder spasm (26% of the patients), hematuria (23%) and dysuria (9%), none of which significantly limited the achievement of desired temperatures during the treatment sessions. No chronic treatment-related morbidity or mortality was observed. Detailed thermal mapping, performed along the course of the prostatic urethra, recorded temperatures of 43C or more at greater than 75% of the loci. Highly significant increases in urine flow rate, decrease in post-void residual urine capacity and decrease in frequency of nocturia were observed. A marginally significant decrease in prostate volume was noted and, with a median followup of 12.5 months, only 3 patients have required subsequent prostatic resection. Transurethral hyperthermia represents a safe and promising outpatient approach to treatment of benign prostatic hyperplasia, particularly for patients who are not candidates for conventional surgical approaches because of medical or personal reasons. Further studies with the goal of optimizing the technique appear to be warranted, although long-term results would be best evaluated with prospective phase 3 trials.

Aged↗
PubMed1990

Thermochemotherapy in inoperable head and neck cancer.

A combined hyperthermia and chemotherapy approach was used to treat five patients with locally advanced or recurrent squamous cell carcinoma of the head and neck whose tumors had failed to respond to chemotherapy. In two patients, tumor had recurred after initial combined modality therapy (surgery/radiation) and had failed to respond to one course of cisplatin/5-fluorouracil (cisplatin/5-FU) chemotherapy. The three remaining patients were enrolled onto a phase II evaluation of induction chemotherapy with cisplatin/fluorouracil for advanced head and neck carcinomas and had failed to achieve a partial remission after one treatment cycle. Palpable cervical tumors were heated to 40 degrees to 42 degrees C for 30 to 40 minutes, during which time cisplatin (100 mg/m2) was infused intravenously. A 5-day infusion of 5-fluorouracil (1000 mg/m2/d) followed. Despite less than a partial response to previous cisplatin/fluorouracil chemotherapy alone, two patients had complete clinical resolution of the heated tumor volume with two cycles of the combined thermochemotherapy approach. One patient achieved a partial remission with this approach. The remaining two patients died shortly after the initial thermochemotherapy treatment, as a result of progressive tumor growth. The two complete responders were subsequently treated with radiation (1 patient) and radical neck dissection (1 patient) and remained without evidence of disease 2 and 26 months after the completion of therapy, respectively. The toxicity of this combined modality approach was acceptable and appeared to be no greater than had been experienced during earlier treatment with chemotherapy alone. Further studies using a combination of these treatment modalities for locally advanced head and neck carcinomas are warranted.

Aged↗
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↗
PubMed1988

Definitive radiation therapy in bile duct carcinoma.

Between 1980 and 1985, 24 patients with primary adenocarcinoma of the bile duct were treated with various combinations of surgery, biliary intubation, external irradiation, and transcatheter brachytherapy. Seventy-five percent of tumors were in the proximal bile ducts. Ten patients received no or only palliative radiation, Group 1, whereas 14 patients received definitive courses of radiation (4 by external beam irradiation, 2 by transcatheter irradiation, and 8 by both modalities), Group 2. Survival in Group 1 and Group 2 was significantly different (p less than 0.005) with median survivals of 2.0 and 12.8 months, respectively. This result may be in part due to differences in treatment and in part due to selection bias because the series is small, uncontrolled, and retrospective. Median survival of the 8 patients treated with combined modalities was 13.2 months (range 7.4-30.3) with 4 patients alive 8.7 to 16.2 months, 3 without cholangiographic evidence of disease. Complications of therapy were common, including bacterial sepsis (58%), cholangitis (38%), gastrointestinal bleeding (46%), intra or extrahepatic abscesses (33%), and recurrent biliary obstruction (25%). Cholangitis, hemorrhage, abscesses, and ulcers appeared more frequently in definitively treated patients, whereas recurrent biliary obstruction was absent in this group and frequent in Group 1. Differences in complication rates between groups were not statistically significant. Early diagnosis and management usually reversed a downhill clinical course in patients with abscess and hemorrhage. Both surgical and percutaneous techniques of biliary decompression, the usual initial form of therapy in bile duct cancer, are associated with frequent and serious complications. Although many of our complications may have derived from biliary decompression, it is possible that definitive treatment may have increased the frequency of serious complications.

Adenoma, Bile Duct↗
PubMed1988

Stereotactic interstitial brachytherapy of malignant astrocytomas with remarks on postimplantation computed tomographic appearance.

Seventeen patients were treated with stereotactically implanted high activity iodine-125 seeds, 12 patients for recurrent malignant astrocytomas (Protocol I) and 5 patients for newly diagnosed glioblastomas (Protocol II). Total radiation dosage to the recurrent tumors in Protocol I, including prior external beam irradiation, averaged 13,500 cGy. In the follow-up period of 6 to 50 months, the survival rate was 93% at 6 months, 60% at 12 months, 50% at 18 months, and 38% at 24 months after implantation. In Protocol II, brachytherapy was used as an interstitial radiation boost to the conventional treatment of newly diagnosed glioblastomas. External beam therapy and interstitial brachytherapy provided 11,000 cGy to these tumors. In the follow-up period of 15 to 27 months, there was a 100% survival at 12 months, 75% at 18 months, and 25% at 24 months after implantation. Eight of our 17 patients required reoperation for persistent or recurrent mass lesions at 6 to 15 months postimplantation; 7 were found to harbor masses of radionecrosis containing nests of anaplastic astrocytes; 1 had frank tumor recurrence. Median survival in this group of patients requiring reoperation was 18.7 months postimplantation. In a review of postimplantation computed tomographic scans, significant mass effect and crossover of hypodensity or enhancement into the corpus callosum or opposite hemisphere were found to have prognostic significance; persistent areas of contrast enhancement and excessive peritumoral hypodensity did not.

Adolescent↗
PubMed1987

Improved precision of interstitial brain tumor irradiation using the BRW CT stereotaxic guidance system.

A technique is described which enables precise temporary interstitial volume implantation of brain tumors using a CT stereotaxic guidance system. This technique has the advantages of designing irregular isodose distributions during the preplanning stage. Although the preplanning stage can be time-consuming, this is performed while the patient is in the hospital room and CT scanner time, anesthesia time, and operating room time is minimized for individual patients.

Astrocytoma↗
PubMed1986

Regional hyperthermia for clinically advanced deep-seated pelvic malignancy.

Forty-three patients with deep-seated pelvic malignancy have been treated at the University of Utah on a pilot protocol involving regional hyperthermia (HT) produced by the BSD-1000 HT system and the annular phased array applicator (AA) usually driven at 60 MHz. Acute toxicity consisted primarily of pain within the AA aperture (74%), pain outside the aperture (33%), and bladder spasm (26%) or systemic stress (25%). Systemic stress only infrequently was power limiting. The most common power-limiting factors were pain (33%) and excessive heating of normal tissues (23%). In 9 patients (21%), there was no power-limiting factor. Treatment-related complications were uncommon and consisted of superficial second degree burns (3 patients), small bowel obstruction (1 patient), and rectal fistula (1 patient), all of which resolved with supportive nonsurgical therapy. Detailed thermal mapping and thermal dosimetry were performed on 36 patients. Thermal dosimetry parameters were all rather disappointing; however, the protocol prioritized the prevention of complications, and patients with acute toxicity or other power-limiting factors were not pushed to achieve high thermal doses. A logistic regression analysis was performed to determine if any factors were correlated with response (PR + CR). "Concurrent radiation dose" and "number of satisfactory heat treatments" were highly and independently correlated with response (p = 0.002). Responders (median survival = 10 months) survived significantly longer (p = 0.0014) than nonresponders (median survival = 4 months). Four of the responders are alive and currently without evidence of disease.

Humans↗
PubMed1986

Abdominal regional hyperthermia with an annular phased array.

Twenty-eight patients with advanced upper-abdominal malignancy were treated at the University of Utah on a pilot protocol involving regional hyperthermia (HT) produced by the BSD-1000 HT system and the annular phased array applicator (AA), usually driven at 60 MHz. Eighty-two percent of the patients had widespread metastatic disease, and the mean tumor burden was 2,900 cc. Seventy-nine percent of the patients received concurrent radiotherapy. Acute toxicity consisted primarily of pain within the AA aperture (43%), systemic stress (43%), and nausea or vomiting (29%). Systemic stress was the most frequent power-limiting factor (46%). There were two treatment-related complications: sciatic neuritis from intramuscular injection (one) and pleural effusion from thermometry probe placement (one). Detailed thermal mapping and thermal dosimetry were performed on 26 patients. The mean thermal dosimetry parameters were quite low. Concurrent radiation doses were also quite low (mean, 1,500 rad) to avoid toxicity of sensitive organ systems within the abdomen. The objective response rate was only 18%, all partial, but 43% of the patients achieved effective symptomatic palliation. The five objective responders did survive significantly (P = .02) longer than the 23 nonresponders.

Abdominal Neoplasms↗
PubMed1985

Practical thermal dosimetry.

A relatively simple means of thermal dose documentation is presented. It has the advantage of greatly condensing the vast amount of data collected during a course of hyperthermia treatments. The formulation incorporates both temporal and spatial temperature transients and is applicable when comparing hyperthermia devices and in quality control for prospective hyperthermia treatment protocols.

Humans↗
PubMed1985

A comparison of deep regional hyperthermia from an annular array and a concentric coil in the same patients.

Twenty-two patients with advanced pelvic or abdominal malignancy (or both) were treated on successive occasions with hyperthermia produced by an annular array (AA) (60-80 MHz, 500-1800 W forward power) and a concentric coil (CC) (13.56 MHz, 350-1000 W forward power). Both devices were compared with respect to acute toxicity and power limitations. There was no power limiting factor in pelvic heating in 7/14 patients treated with the AA, however 13/14 experienced power limiting sacrococcygeal pain with the CC. The 9 patients who underwent abdominal heating had a variety of power limitations with both devices. Thermal mapping was performed in 23 treatments with the AA and in 19 with the CC. Composite thermal maps of patients with similar thermometry sites show that heating patterns produced by the CC were predictable from theory and static phantom measurements. The AA achieved broader regional heating, particularly at depth, but heating patterns were less predictable. Spatial thermal dose (TD) analysis revealed higher minimum tumor TDs and more favorable mean tumor/normal tissue TD ratios with the AA than with the CC. We conclude that the AA is superior to the CC for pelvic treatment and that both devices have limitations in abdominal treatment.

Abdominal Neoplasms↗
PubMed1984

Regional hyperthermia in the treatment of clinically advanced, deep seated malignancy: results of a pilot study employing an annular array applicator.

From October 1980 through December 1982, 46 patients were entered into a pilot study at the University of Utah Medical Center to assess the feasibility and safety of heating deep-seated, advanced, pelvic and abdominal malignancies with an annular array of electromagnetic wave (EMW) applicators. The patients, most of whom were heavily pretreated, were treated on a protocol in which most of the patients received combined hyperthermia and low dose X ray therapy. Discomforting local symptoms were the predominant treatment related acute side effects in 28 patients with pelvic disease, while systemic hyperthermia and associated symptoms were the predominant side effects in 18 patients with abdominal disease. Minor subacute toxicity was minimal and no serious treatment related, chronic toxicity was observed. The treatments of 22 patients with sufficiently detailed thermometry were analyzed at arbitrary index temperatures of 41 degrees C and 43 degrees C. Objective response rates in 22 evaluable patients were 67% and 9% for pelvic and abdominal sites respectively.

Abdominal Neoplasms↗