Anatomical site-specific modalities for hyperthermia

The clinical application of hyperthermia in the treatment of deep-seated tumors remains an empirical science. The pleomorphic nature of the neoplasms and the great diversity in the anatomy and physiology of the individual tumor locations make the treatment of nearly every neoplasm a unique challenge. A wide variety of devices is required, both for the administration of hyperthermia and for the measurement of the temperatures achieved. At Stanford University, these include the BSD Medical Corp. annular phased array system, an isospherical ultrasound device, and interstitial radiofrequency for deep heating. Ultrasound transducers and a variety of microwave applicators are used for superficial hyperthermia. Six illustrative case studies, selected from the 91 patients treated in our program since October 1981, are presented, with discussion and comparison of treatment devices. Difficulties in deep heating were encountered in several instances, believed secondary to the thickness of the s.c. fat, the relatively high heat-induced tumor blood flow, and the presence of adjacent bone. It is suggested that ultimate improvement in clinical results will be possible once a better understanding is achieved of such anatomical and physiological factors.

Production of systemic hyperthermia in the rat

The design of clinical trials employing whole-body hyperthermia in cancer therapy has been hampered due to lack of a suitable animal model. We describe a technique for reproducibly and efficiently inducing whole-body hyperthermia in Sprague-Dawley rats, using halothane and oxygen anesthesia and immersion in a hot water bath. Core body temperatures of between 41.5 and 43 degrees C were induced and maintained for periods of up to 200 min and survival curves were determined. The time of exposure at a given temperature that resulted in death in 50% of the animals within 24 hr after heating (LD50/24 hr) was calculated by linear logistic regression analysis. LD50 24 hr values of 115, 61, 57, 25 and 16 min were obtained for temperatures of 41.75, 42.0, 42.25, 42.5 and 42.75 degrees C respectively. This heating technique is compared to several more toxic methods for inducing whole-body hyperthermia with respect to possible pharmacological and physiological differences.

Development and decay of systemic thermotolerance in rats

The development and decay of thermotolerance to the lethal effect of systemic hyperthermia were investigated in Sprague-Dawley rats. Systemic hyperthermia was induced by partial submersion of gas-anesthetized rats in a controlled-temperature water bath. Survival was determined for rats challenged for periods of 10 to 90 min at 42.5 degrees at intervals of 24 to 144 hr after a sublethal conditioning exposure of 41.8 degrees for 1 hr. Survival curves and times of exposure at 42.5 degrees lethal to 50% of the animals (LD50) were determined for the conditioned animals and compared with those obtained for simultaneously treated control (unconditioned) rats. The thermotolerance ratios (LD50 for conditioned animals at various times after sublethal conditioning exposure divided by the LD50 for the control animals) were calculated and compared with the ratios reported in the literature for cells heated in vitro or for tissues heated locally in vivo. Pretreatment of rats at 41.8 degrees for 1 hr resulted in an increase in the LD50 for rats challenged 24 to 96 hr later, with a maximum increase noted at 48 hr (56.5 min compared with 25 min for control; thermotolerance ratio, 2.3). The animals remained relatively resistant to the second heat treatment at 96 hr and returned to control levels of heat sensitivity by 120 hr. The development and kinetics of thermotolerance to lethality induced by wholebody hyperthermia need to be considered in the design of multiple-fraction treatment plans.

Intense eosinophilic stromal infiltration in carcinoma of the uterine cervix: a clinicopathologic study of 14 cases

Stromal responses to tumor, usually characterized by the intensity of the lymphoplasmacytic infiltration, have been felt to be of prognostic significance in a wide range of neoplasms. Little attention has been focused on stromal reactions composed primarily of infiltration by eosinophilic leukocytes. We describe here the clinical and histopathological findings in 14 patients with invasive carcinoma of the uterine cervix in whom pronounced eosinophilic infiltration was observed in the stroma in the initial diagnostic biopsy material. These patients tended to have early stage disease, had associated increased lymphoplasmacytic stromal response, and were somewhat younger than the patients lacking this intense eosinophilic infiltration. A suggestion of improved survival was noted in patients with intense stromal eosinophilia treated primarily with radiation therapy.

Ependymomas of the spinal cord

Many patients with spinal cord ependymomas (SCE) undoubtedly benefit from post-operative radiation therapy; however, because of the wide variability in the total doses given, the optimal post-operative dose for SCE remains unclear. Several recent papers recommend total doses of 4000 rad to 5000 rad in 4 1/2 to 6 weeks. Unfortunately, only a small number of patients reported in the literature have been consistently treated to these high dose recommendations. Nine consecutive adult patients with SCE have been treated in a consistent way at Yale-New Haven Hospital with total doses of approximately 4500 rad to 5000 rad at 180 rad to 200 rad per day. The acute and chronic morbidity from such treatment has been minimal and no patient has had a local recurrence at 8 months to 8 years following treatment.

The role of the radiation oncologist in the management of gynecologic cancer

Optimal management of patients with gynecologic malignancies requires a multidisciplinary approach with close cooperation between the primary care physician, the gynecologic oncologist and the radiation therapist. In order to obtain maximum survival rates with minimal morbidity, treatment should be based on a detailed knowledge of tumor localization, potential sites of occult spread, and tumor-host interactions. A careful delineation of patterns of recurrence will permit the identification of patients at increased risk for treatment failure and will aid in the design of alternative treatment protocols tailor-made to control potential site(s) of tumor spread. The technological advances in radiation oncology and their influence on survival rates are presented, with illustrations taken from the literature and from the recent results of the Patterns of Care Study for treatment of carcinoma of the cervix. The role of radiation therapy in the treatment of carcinomas of the cervix, uterus, and the epithelial tumors of the ovary are reviewed, emphasizing treatment protocols based on consideration of technical, tumor, and host factors. Ongoing clinical research trials and potential areas for further improvement in the management of gynecologic malignancies are discussed.

Thermal tolerance to whole body hyperthermia

Thermal tolerance, that is, a reduced sensitivity to a succeeding heat treatment, has been noted in vitro and following local hyperthermia in normal tissues and malignant tumors. However, information is sparse concerning thermal tolerance following systemic hyperthermia, thereby limiting our ability to design optimally fractionated systemic hyperthermia treatment protocols. A technique for reproducibly inducing systemic hyperthermia in the rat is described, and the survival curve for rats exposed at 42.5 degrees C for periods of up to 75 minutes is presented. Using this system, increased survival of rats to systemic hyperthermia at 42.5 degrees C was demonstrated 30 hours after an initial sublethal conditioning exposure (41.8 degrees C for 1 hour). The LD50 (the time of exposure lethal to 50% of the rats) at 42.5 degrees C was increased by a factor of approximately 2 in the animals exposed to the sublethal conditioning. This increase in LD50 demonstrates the development of thermal tolerance to killing by whole body hyperthermia.

Pretreatment prognostic factors in carcinoma of the uterine cervix: a multivariable analysis of the effect of age, stage, histology and blood counts on survival

From January, 1953 through December, 1977, 910 previously untreated patients with invasive carcinoma of the uterine cervix (Stages IB-IVB) were seen at Yale-New Haven Medical Center and affiliated hospitals. An extensive retrospective analysis was undertaken in an attempt to identify prognostically significant pretreatment factors. The patients studied were uniformly staged according to the current FIGO recommendations and the majority of patients had been treated under standardized protocols combining external beam radiation therapy and intracavitary radium. Pretreatment parameters, including prior medical illnesses, gross tumor characteristics, histology, and blood parameters were studied, employing stepwise Cox regression analyses to identify the possible effects of all factors and all two-way interactions among factors on survival, disease-free survival and freedom from local-regional failure, controlling for stage of disease. FIGO stage, patient age at diagnosis, pretreatment neutrophil count and hematocrit, uterine position, prior subtotal hysterectomy, histology, history of diabetes mellitus and number of pregnancies were all found to have prognostic significance. When other factors including stage of disease were controlled for, increased tumor size was associated with decrease disease-free survival and local-regional control rates.

Carcinoma of the cervical stump: comparison of radiation therapy factors, survival and patterns of failure with carcinoma of the intact uterus

Eighty-nine patients with previously untreated invasive carcinoma of the cervical stump were seen at Yale-New Haven Hospital from 1953 through 1977. This represented 9.4% of the carcinomas of the cervix seen during this time period. Eighty-five of the 89 patients (95.5%) had "true" cancers of the cervical stump diagnosed 2 years or more after subtotal hysterectomy, while 4 of the 89 patients (4.5%) had "coincident" cancers diagnosed within 2 years of the subtotal hysterectomy. All cervical cancers were staged by the F.I.G.O. classification. Patient characteristics, methods of management, failure sites and survival of patients with carcinoma of the cervical stump were compared to those patients with carcinoma in the intact uterus. Patients with cervical stump cancers were treated in a similar manner to those with carcinomas of the intact uterus, using a combination of external beam irradiation and intracavitary radium. The stump cancer patients had a similar stage distribution to the patients with cancers of the intact uterus but, on the average, they were older and received less irradiation. The patterns of failure were similar on a stage for stage basis, but the survival and disease-free survival for stump cancer patients were superior to those of the patients with carcinoma of the intact uterus. The 5-year disease-free survival rates according to stage for the patients with carcinoma of the cervical stump were: 83.8% for Stage I, 77.6% for Stage II, 51.0% for Stage III, and 37.1% for Stage IV; compared with 84.2%, 60.9%, 30.1% and 18.3% for the intact uterus in the same stages.

High-dose fraction radiation therapy for intracranial metastases of malignant melanoma: a comparison with low-dose fraction therapy

Malignant melanoma is considered unresponsive to conventional radiation therapy when it is delivered at a daily dose rate of 130--300 rad/fraction. Previous studies have suggested that this is in part due to a large shoulder on the radiation survival curve and that higher dose fractions might be beneficial. High-dose fraction therapy is effective for local control of cutaneous, lymph node, and soft-tissue metastases. Results in 46 patients treated with high- or low-dose fractions for intracranial metastases over the last decade in the Melanoma Unit and Department of Radiotherapy at Yale have been examined. Twenty-six patients received high-dose fraction therapy, generally 600 rad/fraction/week to 2400--3600 rad; 20 patients received low-dose fraction radiotherapy with 125--400 rad/fraction daily. All patients were given steroids, and most received chemotherapy. Results in both groups were similar. Comparison of high- and low-dose fraction patients revealed: improvement in 38 and 35%, respectively, stability in 23 and 25%, and deterioration in 38 and 40%. Median survival was three months in the high-dose fraction group and 2 1/2 months in the low-dose fraction group. Presence of hepatic metastases had no significant influence upon median survival in patients who received high-dose fraction radiotherapy. In patients receiving low-dose fraction, survival was 2 1/4 months with and three months without hepatic metastases. Death in most patients resulted from progression of central nervous system disease. Side effects, especially headache, were more prominent in the high-dose fraction group. However, in no instance did side effects require discontinuation of therapy. The greater ease of delivery for weekly high-dose fraction radiotherapy outweighed any other difference between the regimens.

Combined modality therapy for advanced Hodgkin's disease: long-term followup data

From 1969 to 1979, 155 patients with advanced Hodgkin's disease were treated with a combined modality protocol (combination chemotherapy and irradiation to all sites of disease). The actuarial 10-year survival of all patients who started therapy is 78%, and the relapse-free survival is 67%. Within the group of patients with advanced disease, age greater than 40 years and/or stage IV disease with multiple extranodal sites of involvement adversely affected prognosis. Since 1978, these patients have been treated with MOPP-ABVD and irradiation, with a resulting 3-year survival of 87% compared with 58% for those treated with MVVPP in prior years. A comparison between MVVPP and MOPP, also begun in 1978, has thus far yielded no significant differences. Second malignancies have occurred in four patients apparently cured of their Hodgkin's disease: two patients with acute leukemia and two with non-Hodgkin's lymphoma. Avascular necrosis of bone has developed in nine patients. There have not been other serious long-term complications. This combined modality treatment approach appear to offer a significant survival advantage compared with treatment programs using chemotherapy alone.

Glioblastoma multiforme: treatment by large dose fraction irradiation and metronidazole

In an attempt to overcome the possible radioresistance of glioblastoma multiforme related to the large shoulder on the in vitro survival curves and to sensitize hypoxic tumor cells, a treatment protocol was instituted at Yale University Medical Center and affiliated hospitals, using large dose fraction irradiation therapy in conjunction with the hypoxic cell sensitizer metronidazole. Nineteen patients with biopsy-confirmed, previously untreated, cerebral grade IV glioblastoma multiforme were, following surgery, irradiated once a week at 600 rad per fraction, 3.5 to 4 hours after ingestion of metronidazole, 6 gm/m2. A total of 7 treatments were employed, with all patients maintained on antiseizure medications and corticosteroids. Metronidazole levels were determined prior to each treatment and patients were followed closely clinically and with serial computerized tomography (CT) scans. The treatment was well tolerated, in general, with no untoward side effects related to the high dose fraction irradiation. The majority of the patients experienced varying degrees of gastrointestinal upset lasting up to several hours following metronidazole administration. Three patients died of pulmonary emboli. One patient experienced moderately severe ototoxicity. A median survival of 9.4 months was obtained for all 19 patients, suggestive of a prolongation of survival compared to historical controls treated with conventionally fractionated radiation or with unconventional radiation fractionation schemes and metronidazole or misonidazole.

Subsequent malignancies associated with carcinoma of the uterine cervix: including an analysis of the effect of patient and treatment parameters on incidence and sites of metachronous malignancies

The incidence and sites of metachronous malignancies were retrospectively determined from the records of 763 patients seen at Yale University medical Center and affiliated hospitals with previously untreated, invasive carcinoma of the uterine cervix from 1953-1972. These patients were treated predominantly with radiation therapy; follow-up status was known for periods of 5-25 years or until time of death in over 96% of the patients. Forty-four patients had second malignancies noted at least 6 months after the initial cervical cancer was diagnosed. The expected incidence of second malignancies was determined from the Connecticut State Tumor Registry data controlling for year of diagnosis of the cervical cancer, patient age, sex, and time at risk (person-years exposure). To correct for any error in estimation of second malignancies introduced by the existence of a latency period for the development of a second cancer, the expected incidence of malignancies was also computed for 5-year time intervals following the cervical cancer. No significant increase in second malignancies was found (observed/expected-44/36) for the entire follow-up period nor for any individual 5-year interval. However, a statistically significant increase in lung cancer and vulva-vaginal cancer was noted and a significant decrease in breast cancer was observed. Cox regression analyses were performed to study the effect of total radium exposure and total external beam treatment, adjusting for other factors. No statistically significant increased risks were found.

Anaplastic carcinoma following well-differentiated thyroid cancer: etiological considerations

Most cases of anaplastic thyroid carcinoma can be pathologically and often historically associated with the presence of low-grade (differentiated) cancer in the thyroid. That radiation therapy to the differentiated tumor plays an etiologic role in the transformation of a differentiated to an undifferentiated tumor has been suggested. If such therapy can be implicated, is there a difference in risk between external radiotherapy or radioactive iodine? Review of the literature discloses that more anaplastic carcinoma of the thyroid develop in patients without a history of prior radiation than in individuals who have received radiation. We report our recent experience with two patients who demonstrated the sequence of well-differentiated followed by anaplastic thyroid cancer subsequent to radiation and review the question.

Histologic variants of cervical involvement by endometrial carcinoma

Examination of histologic material from 54 patients with endometrial carcinoma, in whom the pretreatment fractional curettage showed adenocarcinoma in the endocervical specimen, demonstrated 4 main patterns. These were designated as tumor separate from endocervical tissue (13 patients), true stage II (23 patients), tumor in stroma (12 patients), and tumor only (6 patients). Patients with tumor separate from endocervical tissue had a better survival rate (expressed as survival to first recurrence) than did patients in the other 3 groups, and this difference was statistically significant. No statistically significant difference between the survival of patients in the true stage II, tumor in stroma, and tumor only groups could be demonstrated. It is therefore suggested that the treatment protocol used for these 3 groups of patients be similar. Among the true stage II groups, only 3 patients had superficial endocervical involvement, whereas 15 had stromal involvement without surface tumor. Therefore, spread to the cervix in endometrial carcinoma appears to be more frequent by tissue spaces or lymphatic channels than by contiguous surface extension.

Epithelial carcinoma of the ovary: current strategies

Epithelial ovarian cancer is usually diagnosed late in its biologic course (70% of cases are diagnosed as stage III or IV). Recent advances in chemotherapy and radiation therapy offer the possibility of long-term disease-free survival and the potential for cure. The selection of treatment for disease confined to the pelvis (stage I or II) remains controversial. After total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy, high risk patients probably should receive abdominopelvic irradiation or chemotherapy; the relative roles of these two modalities are currently under study. Stage III consists of cases of minimal residual disease at surgery, minimal residual disease after debulking surgery, and residual large bulky tumor masses. Patients with minimal residual disease are best treated with either abdominopelvic radiation or chemotherapy; patients with stage IV or bulky stage III disease, with chemotherapy. Despite the multiplicity of active single agents, only one study to date has shown a statistically significant improvement in survival for patients with advanced disease utilizing combination chemotherapy.