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Biomedical subjects

D S Kapp

Publications and source records attributed to D S Kapp.

At least 19 recordsLinked to original sources
PubMed1992

Dosimetry of intracavitary placements for uterine and cervical carcinoma: results of orthogonal film, TLD, and CT-assisted techniques.

A total of 720 192Ir high-dose-rate (HDR) applications in 331 patients with gynecological tumors were analyzed to evaluate the dose to normal tissues from brachytherapy. Based on the calculations of bladder base, bladder neck, and rectal doses derived from orthogonal films the planned tumor dose or fractionation was altered in 20.4% of intracavitary placements (ICP) for cervix carcinoma and 9.2% of ICP for treatment of the vaginal vault. In 13.8% of intracervical and 8.1% of intravaginal treatments calculated doses to both the bladder and rectum were greater than or equal to 140% of the initially planned dose fraction. Doses at the bladder base were significantly higher than at the bladder neck (p less than 0.001). In 17.5% of ICP the dose to the bladder base was at least twice as high as to the bladder neck. The ratio of bladder base dose to the bladder neck was 1.5 (+/- 1.19 SD) for intracervical and 1.46 (+/- 1.14 SD) for intravaginal applications. The comparison of calculated doses from orthogonal films with in-vivo readings showed a good correlation of rectal doses with a correlation coefficient factor of 0.9556. CT-assisted dosimetry, however, revealed that the maximum doses to bladder and rectum were generally higher than those obtained from films with ratios of 1-1.7 (average: 1.44) for the bladder neck, 1-5.4 (average: 2.42) for the bladder base, and 1.1-2.7 (average: 1.37) for the rectum. When doses to the specified reference points of bladder neck and rectum from orthogonal film dosimetry were compared with the corresponding points on CT scans, similar values were obtained for both methods with a maximum deviation of +/- 10%. Despite the determination of multiple reference points our study revealed that this information was inadequate to predict doses to the entire rectum and bladder. If conventional methods are used for dosimetry it is recommended that doses to the bladder base should be routinely calculated, since single point measurements at the bladder neck seriously underestimate the dose to the bladder. Also the rectal dose should be determined at several points over the length of the implant due to the wide range of anatomic variations possible.

Brachytherapy↗
PubMed1992

Reduction of pain and local complications when buffered lidocaine solution is used as a local anesthetic in conjunction with hyperthermia treatments: results of a randomized trial.

Unbuffered lidocaine (pH = 6.5) is commonly employed as a local anesthetic prior to transcutaneous placement of catheters for use in temperature monitoring during hyperthermia treatments. The most frequent complaint associated with this procedure is stinging or burning pain at the injection site. Tender firm subcutaneous nodules at sites of lidocaine infiltration for catheter placement have also been noted in fields treated with radiation and hyperthermia. A reduction in the pain associated with lidocaine infiltration has been reported by the use of alkalinized (buffered) local anesthetic solutions. To confirm this finding in patients treated with hyperthermia for superficially-located tumors, a randomized prospective double blind trial comparing unbuffered (pH 6.5) and buffered (pH 7.3) 2% lidocaine (without epinephrine) was undertaken. Between March and October 1990, a total of 54 hyperthermia treatment fields were each randomized to buffered or unbuffered lidocaine to be used at the time of all catheter placements (146 placements). Patients were scored both for the pain noted during the infiltration of lidocaine and the pain noted with subsequent catheter placement. In addition, the development of subcutaneous nodules at the sites of catheter placement was monitored at the time of 3-week follow-up. Follow-up was available for all but two fields. Treatment fields that received the buffered anesthetic had a statistically significant reduction in the pain associated with infiltration of lidocaine (p less than 0.05) without any compromise in its therapeutic efficacy as observed on a linear Visual Analog Scale. Furthermore, the incidence of subcutaneous nodules was lower in the fields treated with the buffered solution (1/23 vs 7/29, p = 0.05 for buffered and unbuffered solutions, respectively). The results of this trial support the use of buffered lidocaine prior to catheter placement for hyperthermia treatments as a method of reducing pain at infiltration and the subsequent development of subcutaneous nodules.

Buffers↗
PubMed1992

Thermoradiotherapy for residual microscopic cancer: elective or post-excisional hyperthermia and radiation therapy in the management of local-regional recurrent breast cancer.

A Phase I/II study was undertaken to investigate the efficacy and side effects of combined hyperthermia and radiation therapy in the management of presumed or known microscopic residual tumors. Between February 1985 and March 1991, 262 fields in 89 patients with local-regional recurrent breast cancer were treated with externally administered hyperthermia and radiation therapy. Thirty-eight fields were treated for microscopic residual disease following excisional biopsy of nodular recurrences and 224 fields were treated electively for areas at high risk for local recurrences adjacent to fields with macroscopic residual disease. Mechanically mapped temperatures were monitored throughout the field in all treatments. All patients had at least one follow-up evaluation at three weeks or more following completion of treatment. The majority of the fields were in patients who had had extensive prior therapy including radiation therapy (54%), chemotherapy (71%), and hormonal therapy (51%). All fields received hyperthermia (1-6 treatments: average 1.74) and radiation therapy (average dose: 42.4 Gy); concurrent hormonal therapy was administered in 37% of the treatments and no fields received concurrent chemotherapy. The treatments were well tolerated, no life-threatening complications were noted. Averages for all fields of the minimum, maximum, and average measured interstitial temperatures were 40.2 degrees C, 45.3 degrees C, and 42.8 degrees C, respectively. The three-year actuarial local-control rate for all 262 treated fields was 68%. Parameters characterizing the initial breast cancer, the patient and tumor at the time of hyperthermia, and the treatment were studied in univariate and multivariate analysis for correlation with duration of local control within the hyperthermia treatment field. Parameters in the best five covariate model correlating with the duration of local control included: estrogen receptor status of the initial breast cancer; initial T-stage; time from initial breast cancer to first failure; age at hyperthermia; and concurrent radiation dose (p-value for model less than 0.000001). Six covariate models adding anatomic site of disease, field type, mean minimum temperatures, and mean percent temperatures greater than or equal to 40 degrees C all resulted in improved models. Randomized controlled studies stratifying for these pretreatment parameters are felt warranted to confirm the value of adjuvant hyperthermia in the elective treatment of areas of high risk for local-regional recurrent breast cancer and in fields following surgical excision of recurrent disease, particularly in patients in whom full dose radiation therapy cannot be safely administered.

Adult↗
PubMed1992

Parameters predictive for complications of treatment with combined hyperthermia and radiation therapy.

Pretreatment and treatment related factors were reviewed for 996 hyperthermia sessions involving 268 separate treatment fields in 131 patients managed with hyperthermia for biopsy confirmed local-regionally advanced or recurrent malignancies to ascertain parameters associated with the development of complications. A subset of 249 fields were identified in which multipoint or mapped temperature data were available for at least one treatment session per field. A total of 198 fields involved superficially located tumors (less than or equal to 3 cm from the surface), whereas 51 fields involved more deeply located tumors. Most of these patients had received extensive prior therapy: 77% had surgery, 75% chemotherapy, 65% radiation therapy and 28% hormonal therapy. They were treated with hyperthermia in conjunction with radiation therapy (244 fields) or hyperthermia alone (5 fields). The hyperthermia treatment objectives were to elevate intratumoral temperatures to a minimum of 43.0 degrees C for 45 minutes while maintaining maximum normal tissue temperatures to less than or equal to 43 degrees C and maximum intratumoral temperatures to less than or equal to 50 degrees C. The hyperthermia was given within 30 to 60 minutes following radiation therapy without the administration of additional analgesics. Hyperthermia treatment regimens using radiative electromagnetic, ultrasound, or radiofrequency interstitial techniques were individualized, with 3 to 4 days between hyperthermia treatments and an average of 3.6 treatments (range 1-14; standard deviation 2.2) utilized per field. A total of 38 complications in 33 treatment fields were noted; an incidence of 27/198 (13.6%) for fields with superficially located tumors, and 6/51 (11.8%) in fields with more deeply located tumors. Univariate analyses demonstrated statistically significant correlations between the maximum tumor temperature (p = 0.0005), average of the maximum tumor temperatures (p = 0.0006), the average of the % tumor temperatures greater than 43.5 degrees C (p = 0.0071), and the average number of hyperthermia treatments (p = 0.033), with the development of complications. The average of the maximum measured tumor temperature for fields without complications was 44.6 degrees C compared with 45.9 degrees C for fields with complications. The complication rate increased from 7.5% (9/120) in fields that received one or two hyperthermia treatments to 18.6% (24/129) in fields that received greater than two hyperthermia treatments. Multivariate logistic regression analyses revealed the best bivariate model predictive of the development of complications included average of the maximum tumor temperature and the number of treatments per field (p = 0.00012 for the bivariate model).(ABSTRACT TRUNCATED AT 400 WORDS)

Combined Modality Therapy↗
PubMed1992

Cancer metastatic to the penis: treatment with hyperthermia and radiation therapy and review of the literature.

Metastatic cancer to the penis is rare, its optimum treatment remains poorly defined and the outcome of patients with such metastases is poor. Hyperthermia in conjunction with radiation therapy has been shown to be an effective modality in the treatment of locally advanced or recurrent cancer and hyperthermia alone is under evaluation in treating benign disorders, such as hypertrophy of the prostate. Recently, 4 patients with symptomatic metastatic lesions to the penis (3 had primary prostatic cancer and 1 had rectal cancer) were treated with radiation therapy and hyperthermia. Treatment was well tolerated except for pain during hyperthermia, which limited the temperatures that could be obtained. All of the patients improved symptomatically, 1 achieved a complete response and 2 had partial responses. No significant complications were noted. Symptomatic control was maintained in all patients for the duration of their survival. This limited series suggests the possible role of local hyperthermia as an adjunct to radiation therapy in the treatment of metastases to the penis.

Adenocarcinoma↗
PubMed1992

Body conformable 915 MHz microstrip array applicators for large surface area hyperthermia.

The optimal treatment with hyperthermia of superficially located tumors which involve large surface areas requires applicators which can physically conform to body contours, and locally alter their power deposition patterns to adjust for nonuniform temperature caused by tissue inhomogeneities and blood flow variations. A series of 915 MHz microstrip array applicators satisfying these criteria have been developed and clinically tested. Clinical and engineering design tradeoffs for practical devices are discussed. Measurements taken in tissue equivalent phantoms and a summary of our clinical experiences with these microstrip arrays are presented.

Electric Conductivity↗
PubMed1991

Heterogeneity of heat response in murine, canine and human tumors: influence on predictive assays.

The heterogeneity of response to hyperthermia of cells taken from different regions of tumors was tested in a model tumor system (RIF-1) in the mouse and in specimens from spontaneous tumors taken from dogs and humans at the time of surgical resection. Cell survival was assayed by clonogenic survival in the murine tumor and by dansyl lysine staining in tumors from all three species. Using survival as an endpoint, it was found that the extent of heterogeneity depended on the temperature to which the tumor was heated and the duration of exposure. By increasing either of these factors, the coefficient of variation was increased. The large heterogeneity seen after in vivo heating could not be explained entirely by inhomogeneous heating within the tumor as evidenced by temperature mapping. It is concluded that other microenvironmental factors such as blood flow, pH, O2, and nutrient supply may cause variations in the heat response of the tumor cells in vivo. Little, if any, evidence of cellular heterogeneity was evident for all three species when comparisons were made between samples of 100-200 mg. The canine and human tumors were considerably more heat resistant when dansyl lysine was used as an endpoint. In the RIF-1 tumors, heterogeneity of heat response was greater after in vitro heating than after in vivo heating when small biopsy samples (10-20 mg) were taken, suggesting that some cellular heterogeneity was present.

Animals↗
PubMed1991

Secondary external-beam radiotherapy and hyperthermia for local recurrence after 125-iodine implantation in adenocarcinoma of the prostate.

At Stanford, six patients underwent a course of external radiotherapy after local recurrence following 125-iodine implantation. Four of the six patients also received concomitant hyperthermia. Four patients were initially managed with hormonal manipulation at time of local relapse and subsequently received external beam radiotherapy with or without hyperthermia. The hyperthermia was non-invasively induced using an annular phased array radiative electromagnetic system. Treatment was well tolerated, and none of the patients experienced severe rectal or bladder complications. Three patients are free from disease; one patient experience local-regional recurrence based on biopsy; one recurred in the bladder, was treated with cystoprostatectomy and subsequently succumbed to metastatic disease; and one patient died of presumed metastatic disease. External-beam irradiation with concurrent hyperthermia can be safely delivered to treat locally recurrent prostatic carcinoma after 125-iodine implantation.

Adenocarcinoma↗
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

RTOG quality assurance guidelines for interstitial hyperthermia.

This document specifies the current recommendations for quality assurance for hyperthermia administration with interstitial techniques as specified by the Radiation Therapy Oncology Group (RTOG). The document begins by providing a brief description of the physical principles behind the use of the three most commonly used methods of interstitial hyperthermia: radiofrequency (RF-LCF), microwave antennas, and ferromagnetic seeds. Emphasis is placed on features that effect quality assurance. Specific recommendations are provided for: a) Pretreatment planning and equipment performance checks, b) Implant considerations and documentation, c) Thermometry, and d) Safety procedures. Specific details regarding quality assurance issues that are common to all local and regional hyperthermia methods are outlined in previous documents sponsored by the RTOG. It is anticipated that technological advances may lead to future modifications of this document.

Documentation↗
PubMed1991

Hyperthermia and radiation therapy of local-regional recurrent breast cancer: prognostic factors for response and local control of diffuse or nodular tumors.

Over the past decade, hyperthermia has been extensively studied as an adjuvant to radiation therapy in the management of local-regional metastases from adenocarcinoma of the breast. A retrospective review of our experience from July 1982 to January 1990 identified 241 fields in 89 patients which satisfied the following criteria: biopsy confirmation of recurrent or metastatic adenocarcinoma of the breast; involvement of the chest wall and/or regional lymph nodes with diffuse or nodular metastases; treatment which included radiation therapy and externally administered hyperthermia during which mechanically-mapped and/or multipoint normal tissue and intratumoral temperatures were monitored; and at least one follow-up evaluation at 3 weeks or more after completion of treatment. The majority of fields were in patients who had extensive prior treatment including radiation therapy (68%), chemotherapy (86%), and hormonal therapy (58%). Treatment consisted of radiation therapy (average dose: 39.88 Gy) and hyperthermia (1-12 treatments; average 3.12); concurrent chemotherapy or hormonal therapy were also administered in 3% and 32% of the fields, respectively. Parameters characterizing the initial breast cancer, the patient and tumor at the time of hyperthermia, and the treatment were studied in univariate and multivariate analyses with complete response rate at the time of maximum tumor regression and duration of local control as endpoints. The treatments were well tolerated with no life-threatening complications noted. The means for all fields of the mean minimum, mean maximum, and mean average measured intratumoral temperatures were 40.3 degrees C, 44.6 degrees C, and 42.4 degrees C, respectively. At 3 weeks following completion of radiation therapy, response rates were: complete response (52%), partial response (8%), no response (17%), and continuing regression (monotonic regression to less than 50% of initial volume) was noted in 22% of the fields. At the time of maximum tumor regression local control was noted in 72% of the fields. Five parameters correlated with higher complete response in univariate and multivariate analysis: lower T-stage of the initial breast cancer; at the time of hyperthermia age less than 50 years, Karnofsky status greater than 95%, and the absence of distant metastases; and the use of concurrent hormonal therapy. The absence of a family history of breast cancer and concurrent radiation dose greater than or equal to 25 Gy significantly correlated with higher complete response in the univariate but not in the best multivariate models.(ABSTRACT TRUNCATED AT 400 WORDS)

Breast Neoplasms↗
PubMed1990

Adenoid cystic carcinoma of the salivary glands. Management of recurrent, advanced, or persistent disease with hyperthermia and radiation therapy.

Adenoid cystic carcinomas (ACC) of the salivary glands are aggressive tumors characterized by multiple late local recurrences and distant metastases. Current therapy includes wide local excision and high-dose postoperative radiation therapy (XRT) (5400 to 7000 cGy). Despite early aggressive treatment, local recurrence remains a major problem with limited safe and effective therapeutic options available. The excellent local responses obtained in four patients (six sites) with ACC of the head and neck treated either with additional low-dose irradiation (2160 to 3420 cGy) in conjunction with two to five hyperthermia (HT) treatments or with full dose XRT and HT as part of the overall treatment plan are reported. All HT treatments were for 45 minutes once steady state conditions were obtained. Monitored intratumoral temperatures for all treatments achieved average maximum (Tmax), average mean (Tave), and average minimum (Tmin) temperatures of 44.2 degrees C, 41.2 degrees C, and 38.9 degrees C, respectively. A complete response was obtained for all six fields with no significant long-term complications. Two patients remain alive and free of local disease at 42 and 63 months of follow-up. Two patients died--one with metastases (with persistent local control) and one with a local recurrence at 9 and 30 months, respectively, after XRT and HT. This is the first report of HT and low-dose XRT in the management of previously irradiated ACC and suggests a potential role for the use of this modality in the treatment of ACC.

Adult↗
PubMed1990

Radiation therapy in stage III ovarian cancer following surgery and chemotherapy: prognostic factors, patterns of relapse, and toxicity: a preliminary report.

Twenty patients with FIGO stage III epithelial ovarian cancer who had undergone maximum cytoreductive surgery (including pelvic and paraaortic lymph node dissection) and combination chemotherapy (4-10 cycles, median 6) were treated with irradiation to the abdomen and pelvis with 30 Gy followed by diaphragmatic/paraaortic and pelvis boost fields to 42 and 51.6 Gy, respectively. Second-look laparotomy was not performed. Seventeen of 20 patients completed the planned course of radiation. In 2 cases, failure to complete treatment was related to acute hematologic toxicity, and 1 patient refused further treatment. Five patients (29%) required treatment breaks ranging from 8 to 16 days (median, 12 days) due to pancytopenia. Actuarial overall survival and relapse-free survival at 3 years for the 17 patients who completed radiation was 69 and 47%, respectively, with follow-up ranging from 19 to 53 months (median: 24, mean: 27.6 months). Seven patients (41%) relapsed within the abdomen alone and 2 patients developed extraabdominal lymph node metastasis as their sole site of failure. The prognostic factors evaluated for correlation with relapse-free survival included histologic subtype, grade, amount of residual disease at the time of surgery, and nodal involvement; only residual tumor at surgery (none vs less than or equal to 2 cm or greater than 2 cm) was found to be statistically significant (P less than 0.01). Three-year overall survival correlated with amount of residual disease following the initial cytoreductive surgery. It was 100% for patients with no residual disease, 66.7% for less than or equal to 2 cm, and 26.7% for those with greater than 2 cm residual disease, respectively. Radiation treatment was well tolerated, with only one patient developing treatment-related bowel obstruction 7 months after radiation therapy. The results of this planned trimodality treatment approach compare favorably with those reported following surgery and chemotherapy, particularly in patients who have been maximally cytoreduced.

Adult↗