Search PubMed⌕ Search

Biomedical subjects

D S Kapp

Publications and source records attributed to D S Kapp.

At least 19 recordsLinked to original sources
PubMed1995

Thermal treatment parameters are most predictive of outcome in patients with single tumor nodules per treatment field in recurrent adenocarcinoma of the breast.

PURPOSE: In previously reported studies using radiation therapy (XRT) and hyperthermia (HT) for treatment of superficial metastases from adenocarcinoma of the breast, we have identified several pretreatment and treatment parameters that correlated with rate of initial complete response (ICR) recorded at 3 weeks and duration of local control (DLC). These parameters include minimal intratumoral temperature, Tmin, and the temperature exceeded by 90% of the measured intratumoral temperatures, T90. Recently, others have shown that thermal dose defined as the cumulative time of isoeffective treatments with T90 = 43 degrees C (CUM EQ MIN T90 43) was predictive of complete response in superficial tumors. We have assessed the prognostic value of several formulations of this parameter for both ICR and DLC in a relatively uniform patient population treated with XRT-HT. METHODS AND MATERIALS: The corresponding EQ MIN T90 43 were calculated for 332 HT treatments in 111 HT fields in 83 patients who started treatment between October 1982 and May 1992. Each field contained only one measurable superficially located nodular tumor recurrence or metastasis from adenocarcinoma of the breast that was treated with XRT-HT, had mapped or multiple point temperatures recorded, and had at least one posttreatment follow-up evaluation. The thermal doses from all treatments delivered to a field were added to obtain the total thermal dose, SUM EQ MIN T90 43. Logistic and life-table multivariate analyses were performed to determine which pretreatment parameters (including initial T-stage, prior XRT, and tumor volume at the time of HT) and treatment parameters (including XRT dose, Tmin, T90, thermal dose, and hormonal therapy) best correlated with ICR and DLC. RESULTS: Of the treatment parameters tested, SUM EQ MIN T90 43 had the strongest correlation with both ICR (p = 0.0002) and DLC (p = 0.0014). Also, SUM EQ MIN T90 43 contributed to the best multivariate models predictive of ICR and DLC. CONCLUSION: For this relatively uniform patient population, we have confirmed that SUM EQ MIN T90 43 is the treatment parameter most strongly correlated with not only response following XRT-HT, but also duration of local control. This formulation of thermal dose should permit prescriptions to be written for HT treatments. Prospective trials designed to confirm this thermal dose relationship are to be encouraged.

Adenocarcinoma↗
PubMed1995

Parametrial interstitial brachytherapy for advanced or recurrent pelvic malignancy: the Harvard/Stanford experience.

In this study we evaluate the long-term efficacy and safety of transperineal interstitial implants for advanced pelvic malignancy. A total of 139 patients were treated at Stanford University Medical Center and the Joint Center for Radiation Therapy with transperineal template interstitial brachytherapy for locally advanced or recurrent cancers arising in the pelvic organs. Most patients received whole pelvis external beam irradiation to a median dose of 4200 cGy followed by an implant for a median duration of 48 hr to a median implant dose of 3000 cGy (range 600-6000 cGy). Complete follow-up was obtained for 91% of the patients. Median follow-up for survivors is 57 months (range, 10-173 months). The crude disease-free survival rate was 22% at 5 years. The 5-year crude local tumor control rate was 25%. No dose-response relationship could be demonstrated for tumor control or complications. There were no acute treatment-related deaths. Three late deaths were seen which were directly related to treatment. Major bowel complications requiring surgery were seen in 17% of patients without locally recurrent disease, and fistulas were reported in 4% of these patients. We conclude that template parametrial implant brachytherapy offers a modest chance of cure for women with locally advanced pelvic malignancy. However, this treatment causes significant late morbidity.

Adolescent↗
PubMed1994

Thermometry of interstitial hyperthermia given as an adjuvant to brachytherapy for the treatment of carcinoma of the prostate.

PURPOSE: Recurrence in the prostatic gland remains a significant problem in the management of locally advanced prostatic cancer. Transperineal thermobrachytherapy has been utilized in an attempt to improve local tumor control. The purpose of this study was to quantitate the temperature distributions obtained in carcinoma of the prostate treated with interstitial radiofrequency-induced hyperthermia given in conjunction with 192Ir brachytherapy in a Phase I study. METHODS AND MATERIALS: From 1987 until 1992, 36 patients (5 with locally recurrent, 15 with Stage B, and 16 Stage C prostate cancers) were treated with interstitial brachytherapy implants supplemented with radiofrequency-induced hyperthermia. An array of 7-32 stainless steel trocar electrodes (outer diameter = 1.5 mm, interelectrode spacing = 8 mm) were implanted into the prostate gland through a perineal approach utilizing a specially designed template. Each trocar was electrically insulated along the length which traversed surrounding normal tissues. One to three additional plastic catheters were implanted for automated temperature mapping. Thirty-four of these procedures were performed following lymph node sampling. However, the last two removable interstitial hyperthermic prostate implants were done by the transperineal route under ultrasound guidance. A hyperthermia treatment (goal of 43 degrees C for 45 minutes) was given immediately prior to the insertion and immediately following the removal of the 192Ir. A computer-controlled radiofrequency-based generator (freq. 0.5 MHz) implementing electrode multiplexing was used to induce and maintain elevated temperatures. RESULTS: Transient local pain was the most common treatment limiting factor. The average values of the measured minimum, mean, and maximum temperatures were 38.9 degrees C, 41.9 degrees C, and 45.7 degrees C in tumor, and 37.7 degrees C, 39.8 degrees C, and 42.9 degrees C in surrounding normal tissue, respectively. The percentages of mapped temperatures exceeding 41 degrees C, 42 degrees C, and 43 degrees C were 67%, 46%, and 27% in tumor, and 26%, 11%, and 4% in normal surrounding tissue, respectively. CONCLUSION: From this study we conclude that heterogeneous temperature distributions were induced in the prostate; significant normal tissue protection was realized in part through the selective insulation of sections of each electrode; and interstitial radiofrequency-induced hyperthermia of the prostate is feasible and well tolerated, with further technical developments warranted.

Adenocarcinoma↗
PubMed1994

Interstitial hyperthermia and high dose rate brachytherapy in the treatment of anal cancer: a phase I/II study.

PURPOSE: The rate of local failure is sufficiently high following sphincter conserving surgery and radiation therapy for advanced anal cancers to warrant investigation of improved local treatment techniques. This Phase I/II study was undertaken to investigate the site-specific toxicities and response of Stage II and III anal cancers to interstitial thermoradiotherapy using a hot water interstitial system. METHODS AND MATERIALS: Between September 1988 and March 1991, 14 patients with primary carcinomas of the anal canal, UICC Stage T2-3, N0-1, M0, were treated with split-course external beam irradiation to the pelvis (30 Gy + 20 Gy) and 1 or 2 interstitial Iridium-192 high dose rate (Ir-192 HDR) implants (6-8 Gy each) immediately followed by interstitial hyperthermia (HT). Patients with tumor diameters > 3 cm were scheduled to receive chemotherapy consisting of 2 courses of 5-fluorouracil and mitomycin C given concomitantly with external beam radiation. Interstitial hyperthermia was induced by circulating warm water through the needles that were implanted to hold the Ir-192 source. The treatment goal was to achieve and maintain a temperature of 42.5 degrees C over a time period of 40 min. A 3-point thermocouple probe inserted into one or two additional needles was used for thermometry. The temperatures were recorded by manual mapping along these needles at steps of 0.5 or 1 cm. RESULTS: A total of 20 Ir-192 HDR-HT implants were performed in 14 patients. All but two patients completed the external beam irradiation; five patients received concomitant chemotherapy. Analysis of thermal parameters showed that minimum intratumoral temperatures (Tmin) of 42 degrees C, 42.5 degrees C, 43 degrees C, and 44 degrees C were achieved in 64%, 37.5%, 14%, and 7% of patients, respectively. Intratumoral mean Tmin, mean average, and mean maximum temperatures for these patients were 41.7 degrees C, 42.4 degrees C, and 43.4 degrees C, respectively. Brachytherapy and HT were well tolerated. Clinical complete responses (cCR) were obtained in 11/14 (78.5%) patients, complete histopathological responses (pCR) in 10/14 (71%). Only one patient with pCR recurred and succumbed to her disease. Patients with persistent disease (1 minimal and 3 partial responders, including 1 cCR) underwent abdominal-perineal resection but subsequently died from local-regional recurrence. One patient with pCR died from unrelated causes. Median survival for all patients from onset of radiation to death or last follow-up is 26 months. Eight patients are alive disease-free after a follow-up ranging from 16-44 months (median: 30, mean: 30 months). Treatment complications were limited to two patients who developed persistent ulcers. Sphincter function was maintained in 50% of patients. CONCLUSION: This study demonstrates that interstitial warm water hyperthermia in combination with brachytherapy for anal carcinomas is feasible and did not add to complications when compared to studies employing external beam irradiation and brachytherapy alone. The thermal parameters obtained by the warm water system compare favorably to those reported by others using radiofrequency and microwave systems.

Adult↗
PubMed1994

Radiation therapy of pineal region tumors: 25 new cases and a review of 208 previously reported cases.

PURPOSE: Malignant pineal region tumors are rare neoplasms arising in midline structures of the brain. This report analyzes the influence of histology, tumor location, radiation dose, treatment volume, age and cerebrospinal fluid findings on freedom from relapse, freedom from spinal relapse and survival. METHODS AND MATERIALS: Patient and treatment parameters of 25 cases of pineal region tumors managed at Stanford University are presented, and an additional 208 published cases were reviewed. Univariate and multivariate analysis were performed to delineate parameters predictive of freedom from relapse, freedom from spinal relapse, and survival for all 233 patients. RESULTS: The 5- and 10-year freedom from relapse for Stanford patients was 63% and 46%, respectively. The 5- and 10-year survival for Stanford patients was 67% and 61%, respectively. The 5- and 10-year freedom from relapse for the total 233 cases was 66% and 61%, respectively. The 5- and 10-year survival for all patients was 74% and 68%, respectively. For the entire group, biopsy confirmed germinoma and non-biopsied tumors had superior freedom from relapse compared to non-germinoma germ cell tumors (p = 0.03, p = 0.005, respectively). Non-biopsied patients had improved survival compared to non-germinoma germ cell tumors (p = 0.004). Pineal parenchymal tumors had worse freedom from relapse compared to non-biopsied patients (p = 0.04). For patients with suprasellar tumors, germinomas were associated with improved freedom from relapse compared to non-germinoma germ cell tumors (p = 0.02). Simultaneous pineal and suprasellar tumors had superior survival compared to solitary tumors of pineal (p = 0.04), suprasellar (p = 0.03), or third ventricle location (p = 0.03). Twenty-two patients (9.4%) developed isolated spinal relapse. Five- and 10-year spinal relapse rates for all patients were 11% and 13%. Survival after spinal relapse was 19%. Pineal parenchymal tumors had lower freedom from spinal relapse compared to non-biopsied patients (p = 0.001). For tumors located in the pineal gland, germinomas and pineal parenchymal tumors had lower freedom from spinal relapse than did non-biopsied patients (p = 0.006, p = 0.004, respectively). Pineal germinomas had lower freedom from spinal relapse than germinomas with suprasellar location (p = 0.04). Univariate and multivariate analysis identified tumor histology as the most significant predictor of freedom from relapse, freedom from spinal relapse and survival. CONCLUSION: Histologic type had the greatest impact on outcome. Treatment recommendations should be based on assessment of histologic type and extent of disease.

Adolescent↗
PubMed1993

Temperature differentials between treatment and pretreatment temperatures correlate with local control following radiotherapy and hyperthermia.

PURPOSE: To evaluate the influence of pretreatment tumor temperatures and the temperature differential between treatment and pretreatment temperatures on local tumor control in patients who underwent combined radiation therapy and hyperthermia. METHODS AND MATERIALS: Mapped intratumoral temperatures were measured immediately prior to and during hyperthermia in 138 hyperthermia fields among 59 patients with nodular (60 fields) or diffuse (78 fields) superficially-located tumors. In the nodular subgroup there were 40 fields with adenocarcinomas (31 breast, two prostate, seven other primary sites), six melanomas, nine squamous cell carcinomas, and five other histologies. The fields with diffuse tumor involvement consisted of 77 adenocarcinomas (67 breast, 10 other) and one melanoma. The maximum, minimum, and average temperatures were determined for both the pretreatment (pTmax, pTmin, pTave) and treatment (Tmax, Tmin, Tave) distributions and the differences, Dm = Tmin-pTmax, and Da = Tmin-pTave, computed. These quantities were averaged over treatments to produce the corresponding mean quantities for each hyperthermia field. Univariate and multivariate analyses were performed to determine treatment and pretreatment parameters which best correlated with the duration of local control. RESULTS: Pretreatment tumor temperatures were significantly lower than the oral temperatures with mean pTmax, mean pTmin, and mean pTave of 36.2 degrees C, 34.2 degrees C, and 35.4 degrees C, respectively. For the adenocarcinomas with diffuse involvement within the hyperthermia field, the covariates best correlating with local control duration on univariate analysis were concurrent radiation dose (p = 0.0026), Dm (p = 0.009), pTmax (p = 0.012) and Da (p = 0.036). Lower pTmax and larger Dm and Da were predictive for longer local control. In multivariate analyses, all thermal parameters lost power, however, the best model included Dm which was significant at the p = 0.040 level. For the nodular subgroup, nonthermal parameters and dichotomized thermal parameters were of prognostic significance for local control. CONCLUSION: For fields diffusely involved with adenocarcinoma significant correlations with duration of local control have been demonstrated both for a) low pretreatment temperatures and b) large differentials between treatment and pretreatment intratumoral temperatures. These correlations were also found in a dichotomized description for fields with nodular tumors. The results support the concept that pretreatment hypothermic conditions can lead to an increase in thermal sensitization and may help explain the excellent clinical results noted in the treatment of superficial tumors with radiation and hyperthermia. Further exploitation of this approach by planned cooling of superficially-located recurrent tumors prior to hyperthermia treatment warrants investigation.

Body Temperature↗
PubMed1993

Analysis of temperature distributions of interstitial hyperthermia using a hot water system.

PURPOSE: Interstitial hyperthermia is being increasingly used as an adjunct to brachytherapy in the treatment of implantable tumors. Of the several interstitial hyperthermia systems available, perhaps the simplest to use are the circulating hot water systems. An analysis of the thermal distributions obtained during our initial experience with interstitial hyperthermia using steel needles and the KHS-9 hot water system was therefore undertaken. METHODS AND MATERIALS: Between September 1988 and June 1991, 23 patients were treated with interstitial Iridium-192 high dose-rate brachytherapy immediately followed by interstitial hot water hyperthermia. A total of 32 implants were performed in these patients, of whom 14 presented with primary anal carcinomas, six with recurrent gynecological tumors, and three with subcutaneous metastases from malignant melanoma. All but the patients with anal cancers had failed in previously irradiated sites. One or two heat treatments were delivered to each tumor with the goal to reach and maintain an intratumoral temperature 42.5 degrees C over a period of 40 min. Temperature measurements were carried out by mapping three-point thermocouple probes along the track of one or two needles parallel to the implanted needles. RESULTS: Minimum intratumoral temperatures exceeded 42.0 degrees C in 41%, 42.5 degrees C in 19%, 43.0 degrees C in 13%, and 44.0 degrees C in 3% of treatments. The average minimum, maximum, and mean intratumoral temperatures for all treatments were 41.7 degrees C, 43.5 degrees C, and 42.6 degrees C, respectively. CONCLUSION: The temperature profiles obtained in this series compare favorable to those reported in literature for radiofrequency local current field systems and suggest the hot water device may be an alternative heating method. It is relatively simple to use, does not require shielding of the treatment room, and can easily be adapted to currently used brachytherapy systems. Further patient accrual and longer follow-up will be needed to assess the clinical results in terms of tumor response and duration of response.

Anus Neoplasms↗
PubMed1993

Long-term survival with adjuvant whole abdominopelvic irradiation for uterine papillary serous carcinoma.

BACKGROUND: The optimum management of uterine papillary serous carcinoma (UPSC), a clinically aggressive histologic variant of endometrial adenocarcinoma, is a controversial issue. METHODS: Ten patients with UPSC were reviewed who received whole abdominopelvic irradiation (WAP) as adjuvant therapy after a staging laparotomy and debulking surgery. RESULTS: Nine patients had clinical Stage I disease; the tumors in eight of them were upstaged based on laparotomy findings. There was greater than a 50% invasion of the myometrium in four of the hysterectomy specimens, and vascular space invasion was noted in seven patients. Peritoneal washings were positive in three of the nine specimens obtained; two others showed atypical cells. Five patients are alive with no evidence of disease at 102-133 months. Four patients are dead, and one patient is alive with disease. All recurrences were observed within 30 months of the initial diagnosis and were more common in the presence of deep myometrial invasion and vascular space involvement. Three of the four patients who died had pleural effusions that did not respond to hormonal and/or chemotherapy. Local irradiation produced long-term control of recurrences in two patients, including one with supraclavicular lymph node metastases who had no evidence of disease 117 months after radiation treatment to the involved nodes. CONCLUSIONS: These findings suggest that WAP be considered as an adjuvant therapy in the management of UPSC. The patients with the greatest benefit were those with early disease by surgical staging with or without positive peritoneal cytologic findings. For patients at high risk for pleural effusions and pulmonary metastasis, additional adjuvant therapy, such as innovative chemotherapy or low-dose lung irradiation, needs to be considered.

Adenocarcinoma↗
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↗