Prostate specific antigen after external beam radiotherapy for prostatic cancer: followup

Between 1986 and 1989, 117 patients with pretreatment and serial posttreatment prostate specific antigen values received external beam radiotherapy at our hospital. Followup ranged from 0.6 to 5.9 years (mean 2.7). No patient had hormonal manipulation before distant recurrence. Biochemical relapse, defined as an increasing prostate specific antigen level after treatment, was observed in 44 patients. To date 30 of these 44 patients (68%) have had clinical relapse. The prognostic factors of advanced local stage, high Gleason score and high elevations of pretreatment prostate specific antigen values predicted for biochemical relapse and subsequent clinical failure. The interval between biochemical and clinical relapse was 156 +/- 46 days. Biochemical relapse is an important end point that can be used to determine the effect of treatment in prostatic cancer research.

Correlation of thermal parameters with outcome in combined radiation therapy-hyperthermia trials

Many studies utilizing combined hyperthermia (HT) and radiation therapy (XRT) in the treatment of advanced or recurrent malignancies have reported a correlation between some measure of the minimum temperature achieved and outcome. Previous reported studies at Stanford have demonstrated a statistically significant correlation between the duration of local control and Tmin, the mean over treatments of the minima of (a) measured intratumoral temperatures in fields which contained diffuse or nodular tumours, or (b) measured interstitial temperatures in fields treated for microscopic residual disease. Recently, T90, the mean of the temperatures above which 90% of all measured intratumoral temperatures fall, has been proposed as an alternative characterization of the efficacy of the HT treatment that reportedly has a superior correlation with outcome. To test this hypothesis, T90 was computed by two different methods for three groups of patients treated at Stanford with XRT-HT for superficially located tumor recurrences. Tmin was found to be strongly correlated with T90 calculated by both methods. All three thermal parameters correlated with complete response at 3 weeks and with local control, although Tmin usually demonstrated the strongest correlation.

Stereotactic radiosurgical treatment of brain metastases

In a series of 33 patients with reasonably controlled primary cancers, stereotactic radiosurgery was used to treat 52 brain metastases. After a mean radiological follow-up time of 5.5 months, six lesions (12%) had stabilized in size, 26 (50%) were significantly reduced, and 15 (29%) had disappeared. One large melanoma metastasis progressed relentlessly despite treatment. Five lesions (9%) had decreased in size slightly before enlarging. In two of these lesions, biopsy revealed only necrosis. In almost all cases, treatment was associated with decreased peritumoral edema. However, a group of patients with large metastases and extensive prior brain irradiation has been identified in whom prolonged symptomatic cerebral edema poses a problem. It is concluded that radiosurgery is a viable alternative to surgical resection for some cases of brain metastasis.

The importance of local control in the treatment of prostatic cancer

In a retrospective analysis of 946 patients with prostatic carcinoma treated with external beam radiotherapy between 1958 and 1989 at Stanford University Hospital the 15-year actuarial clinical local control rate was 77.8 +/- 3.3% for Stanford stage T1, 61.3 +/- 4.4% for stage T2 and 64.9 +/- 4.8% for stage T3 disease. Overall, there was improvement in disease-specific survival without a significant alteration in survival in patients who achieved clinical local control. For the 50 Stanford stage T1 cases with local control on clinical examination and a positive post-treatment biopsy a decrease in disease-specific survival was observed. There was no difference in disease-specific survival for comparable stage T2 or T3 cases. In an analysis of patients who underwent ultrasound guided prostatic biopsy performed after irradiation the trend of prostate specific antigen was more important than biopsy results in predicting which patients would have relapse.

Critical reassessment of second-look exploratory laparotomy for epithelial ovarian carcinoma. Minimal diagnostic and therapeutic value in patients with persistent cancer

From 1979 to 1984, 88 women with epithelial ovarian cancer were treated with surgery and chemotherapy, achieved a clinical complete response, and then had "second-look" exploratory laparotomy to assess the pathologic status of their disease. Persistent cancer was found in 50 (57%) patients: 34 of 50 (68%) had gross tumor, which was larger than 2 cm in 12 (24%) and smaller than 2 cm in 22 (44%), and 16 (32%) had microscopic disease. Salvage therapy was as follows for these patients: whole abdominal irradiation, 29 (58%); chemotherapy, 17 (34%); intraperitoneal chromic phosphate, 1 (2%); and no further therapy, 3 (6%). With a follow-up time of 4 to 8 years, 7 (14%) patients are alive without evidence of cancer, 7 (14%) are alive with disease, 35 (70%) are dead of disease, and 1 (2%) has died of treatment complications. At 5 years, the relapse-free rate was 18% and the survival rate was 25%. Seventy-two parameters of suspected prognostic significance and 64 potential sites of tumor involvement were correlated with survival in a univariate analysis. The factors favorably affecting survival included the following: lower grade; microscopic tumor versus gross disease at second-look laparotomy; removal of the uterus; removal of the omentum; pelvic and paraaortic lymph node biopsy; negative results of a right diaphragm biopsy; and radiation therapy at Stanford University Medical Center, Stanford, California. There was no survival advantage for whole abdomen irradiation compared with chemotherapy or for the patients who had their disease successfully debulked at second-look laparotomy. The above factors and others were evaluated by multivariate regression. The best model (P = 0.000004) for predicting survival included largest tumor mass (P = 0.0002), operative blood loss (P = 0.002), perioperative blood transfusion (P = 0.003), and grade (P = 0.004). The detection of persistent ovarian cancer by second-look exploratory laparotomy should identify a subgroup of patients whose conditions can be salvaged by a second-line therapy. Unfortunately, that subgroup is small (8%) and an effective salvage therapy remains to be identified.

Second cancers in long-term survivors of Ewing's sarcoma

Previous reports suggest an increased risk of a second cancer, primarily osteosarcoma, in survivors of Ewing's sarcoma. In a retrospective review of 25 long-term irradiated survivors of Ewing's sarcoma, the incidence of second cancers was determined. The patients were free of disease for more than three years (except for one patient who developed a second cancer 2.5 years after diagnosis), with a median follow-up period of 7.6 years. All received megavoltage radiation to the primary tumor. Twenty-four of the 25 patients were treated with chemotherapy. Second cancers developed in two patients. Acute myelogenous leukemia (AML) developed in a seven-year-old 15 months after treatment. An osteosarcoma developed within an irradiated field in a 13-year-old three years after treatment. The actuarial risk of developing a second cancer at five years is 8% whereas the actuarial risk of developing a bone sarcoma is 4%. Genetic factors may play a role in the development of AML in patients with Ewing's sarcoma. Megavoltage radiation, particularly doses greater than 60 Gy, as well as alkylating agent chemotherapy may contribute to the risk for bone sarcoma. The risk of a second cancer after successful treatment of Ewing's sarcoma is similar to that expected for survivors of all childhood cancers.

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)

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.

Stereotaxic radiosurgery for brain metastases: the importance of adjuvant whole brain irradiation

Stereotaxic radiosurgery delivered from a modified 4 MV linear accelerator was used to treat 47 brain metastases in 27 patients at Stanford. Response was assessed in 41 lesions. Histopathologies included adenocarcinoma (24 lesions), renal cell carcinoma (9 lesions), melanoma (6 lesions), and squamous cell carcinoma (2 lesions). Follow-up ranged from 1.0-16.5 months, with a median of 5.0 months. Radiographic local control was achieved in 88% of the lesions. Three patients developed enlarging contrast-enhancing lesions in the radiosurgical field; one of these was biopsied and revealed necrosis with no viable tumor. Adjuvant whole brain irradiation (10 patients) was associated with regional intracranial control in 80% of patients. This was statistically superior (p = 0.0007) to the regional intracranial control rate achieved when radiosurgery alone was employed (6 patients). Most patients reported resolution of their neurologic symptoms, and were able to discontinue dexamethasone without impairment of neurologic function.

External beam radiotherapy for incidental adenocarcinoma of the prostate discovered at transurethral resection

This paper updates the results of 89 patients treated between 1967 and 1989 for incidental carcinoma discovered at transurethral resection of the prostate (Stanford stage T0 or AJC-UICC stage T1) with external beam irradiation. Twenty-two patients had Stanford T0 focal (less than 5% involvement of the prostatic chips) and 67 presented with Stanford T0 diffuse (5% or more involvement). Follow-up ranges from 4 months to 25.1 years, with a mean follow-up of 9.8 years. The actuarial local control for Stanford T0 focal is 100%, and 70% for Stanford T0 diffuse at 15 years. There was no difference in survival between Stanford T0 diffuse and T0 focal and the expected survival of an age-matched control population. Patients who were treated when younger than 65 had a similar local control and distant relapse when compared to those treated when 65 or older. There was no difference in local control, freedom from relapse, or disease-specific survival when the 38 patients who received irradiation to the prostate only are compared with the 29 who also received pelvic irradiation for Stanford T0 diffuse carcinoma. Patients with a Gleason score of 6 or more, when compared with those with a score of 5 or less, experienced more distant relapses and similar local control, suggesting that patients with a high grade tumor have occult metastases at presentation.

Radiation treatment of prostate bone metastases and the biological considerations

This contribution on the biology and management of bone metastases from prostatic cancer is divided into three parts. The first details a study conducted at Stanford University on the prevention of bone metastases in the lumbar spine, in patients in whom the lumbar spine has been irradiated coincidental to the radiation treatment of the paraaortic lymph nodes. The incidence of metastases was significantly reduced in 71 patients in whom the apparently normal lumbar spine was irradiated, as compared to the incidence of metastases in 65 patients who received no lumbar irradiation. The implications of these observations on developing strategies for early, or preemptive, irradiation for bone metastases are discussed. In the second part, the optimum radiation dose and fractionation scheme for the palliation of overt bone metastases is addressed. Drawing largely from the work of Arcangeli et al., a total dose of 40-50 Gy*, fractionated at 2 Gy per day, seems to be the regimen of choice for enduring pain relief for most patients with prostatic metastases to bone. Finally, the recent utilization of strontium-89 in the palliation of advanced bone metastases is addressed. *The Gy is the current international unit of radiation. 1Gy = 100 Rad; 1cGy (centigray) = 1 Rad.

The clinical significance of a positive post-irradiation prostatic biopsy without metastases

To define the prognostic value of a post-irradiation prostatic biopsy, the outcome of 203 previously irradiated patients who underwent post-treatment biopsy was analyzed. The majority of patients were selected for biopsy based on an abnormal digital rectal exam or elevated prostate specific antigen. Patients with distant metastases found at the time of biopsy were excluded from further analysis. One hundred thirty-nine (139) of these had a positive biopsy and 64 were negative. Those with a positive biopsy tended to present with more locally-advanced (Stage B2/C) tumors (61%) compared to those with negative biopsies (42%). The 10- and 15-year survival and cause-specific survival from the time of initial presentation were similar for both groups. However, those with a negative biopsy had a more favorable survival and cause-specific survival from the time of post-treatment biopsy and were less likely to develop distant metastases than the positive biopsy group. These data suggest that a positive prostatic biopsy is associated with a greater likelihood of subsequent distant relapse and decreased survival following biopsy relative to patients with negative biopsies. Since a positive post-treatment biopsy is more likely among patients presenting with locally-advanced disease, perhaps more aggressive initial therapy (i.e., interstitial boost or hyperthermia) would benefit this subgroup.

Medulloblastoma: freedom from relapse longer than 8 years--a therapeutic cure?

Seventy-seven patients presenting with medulloblastoma between 1958 and 1986 were treated at Stanford University Medical Center and studied retrospectively. Multimodality therapy utilized surgical extirpation followed by megavoltage irradiation. In 15 cases chemotherapy was used as adjunctive treatment. The 10- and 15-year actuarial survival rates were both 41% with an 18-year maximum follow-up period (median 4.75 years). There were no treatment failures after 8 years of tumor-free survival. Gross total removal of tumor was achieved in 22 patients (32%); the surgical mortality rate was 3.9%. No significant difference was noted in the incidence of metastatic disease between shunted and nonshunted patients. The classical form of medulloblastoma was present in 67% of cases while the desmoplastic subtype was found in 16%. Survival rates were best for patients presenting after 1970, for those with desmoplastic tumors, and for patients receiving high-dose irradiation (greater than or equal to 5000 cGy) to the posterior fossa. Although early data on freedom from relapse suggested a possible beneficial effect from chemotherapy, long-term follow-up results showed no advantage from this modality of treatment. The patterns of relapse and survival were examined; 64% of relapses occurred within the central nervous system, and Collins' rule was applicable in 83% of cases beyond the period of risk. Although patients treated for recurrent disease could be palliated, none were long-term survivors. The study data indicate that freedom from relapse beyond 8 years from diagnosis can be considered as a cure in this disease. Long-term follow-up monitoring is essential to determine efficacy of treatment and to assess survival patterns accurately.

Non-small cell lung cancer: treatment results at a USAF referral center

The treatment results of 197 consecutive patients with non-small cell carcinoma of the lung managed at David Grant USAF Medical Center between January 1978 and September 1985 were reviewed. Patients were staged according to 1983 AJCC criteria as follows: 52 stage I, 28 stage II, and 117 stage III. Five-year survival and freedom from relapse (FFR) were 24% and 32%, respectively, for the entire population. Survival and FFR by stage were: stage I, 68% and 77% (5-year); stage II, 32% and 43% (5-year); and stage III, 10% and 10% (3-year), respectively.

Thyroid diseases after treatment of Hodgkin's disease

BACKGROUND AND METHODS

Thyroid disease, especially hypothyroidism, is common in patients with Hodgkin's disease who have been treated with irradiation. We reviewed the records of 1787 patients (740 women and 1047 men) with Hodgkin's disease who were treated with radiation therapy alone (810 patients), radiation and chemotherapy (920 patients), or chemotherapy alone (57 patients) at Stanford University between 1961 and 1989. Among these patients, 1533 were alive at the last follow-up, and 254 had died of causes other than Hodgkin's disease. (Four other patients were excluded from the analysis because they had undergone thyroidectomy before treatment for Hodgkin's disease. The thyroid was irradiated in 1677 patients. Follow-up averaged 9.9 years.

RESULTS

A total of 573 patients had clinical or biochemical evidence of thyroid disease. Among the 1677 patients whose thyroid was irradiated, the actuarial risk of thyroid disease 20 years after treatment was 52 percent, and it was 67 percent at 26 years. Hypothyroidism was found in 513 patients. A total of 486 patients received thyroxine therapy for elevated serum thyrotropin concentrations and either low free thyroxine (208 patients) or normal free thyroxine values (278 patients); 27 had transient elevations of the serum thyrotropin level that were not treated. Graves' hyperthyroidism developed in 30 patients (2 of whom had not undergone thyroid irradiation), and ophthalmopathy developed in 17 of these patients. Ophthalmopathy developed in four other patients with Graves' disease during a period of hypothyroidism (n = 3) or euthyroidism (n = 1). The risk of Graves' disease was 7.2 to 20.4 times that for normal subjects. Silent thyroiditis with thyrotoxicosis developed in six patients. Forty-four patients were found to have single or multiple thyroid nodules, 26 of whom underwent thyroidectomy. Six of the 44 had papillary or follicular cancers. Among the patients who did not undergo operation, 12 had small functioning nodules, 4 had cysts, and 2 had multinodular goiters. The actuarial risk of thyroid cancer was 1.7 percent. The risk of thyroid cancer was 15.6 times the expected risk.

CONCLUSIONS

High risks of thyroid disease persist more than 25 years after patients have received radiation therapy for Hodgkin's disease, reinforcing the need for continued clinical and biochemical evaluation. Prolonged follow-up confirms an elevated risk of thyroid cancer and Graves' disease as well as hypothyroidism in these patients.

A model of prostatic carcinoma tumor kinetics based on prostate specific antigen levels after radiation therapy

Serial prostatic specific antigen values (PSA) were determined on 42 patients receiving definitive radiation therapy for localized adenocarcinoma of the prostate. The PSA declined exponentially in 25 patients. None of these patients experienced metastases. The PSA initially declined then increased exponentially in 17 patients. The rate of decline was similar to the rate of rise in all 17 patients. Five of these patients had distant metastases (P less than 0.02) within 2 years of treatment. The PSA values after radiation therapy were employed to formulate a model of tumor kinetics. This model predicts the mean duration of G0. This parameter is correlated with the development of distant metastases within 2 years of treatment. For those patients at low risk for relapse, the mean G0 is calculated to be 22.5, and 13.6 weeks for those who have relapsed or are at high risk for relapse.

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)

Computer-assisted work station timing analysis of instrument labor efficiency

Labor use ratings assigned to instruments by the Workload Recording Method (WRM) do not change with batch size or walk-away time use. The authors evaluated the effect of both on the labor use of the analyzers Paramax B6100 (Baxter Paramax, Irvine, CA) and Ektachem 700 (Eastman Kodak, Rochester, NY) by timing all worked and walk-away intervals on both instruments. Extrapolation of the data to a workload of slightly more than 1.1 million tests showed that reapportionment of tests to various batch sizes caused Paramax-Ektachem labor cost differences to fluctuate between $37,254 and $34,995. When the minimum usable walk-away interval length was varied from 1 to 20 minutes, Ektachem savings over Paramax increased from $8,700 to $61,400. The WRM predicted a constant $29,050 labor cost advantage for Ektachem over Paramax. If other instruments show similar labor use characteristics with respect to batch size and walk-away utility, laboratory managers who do not consider these factors may fail to select the most cost-effective instruments for their laboratories.

Interleukin 1 beta initially sensitizes and subsequently protects murine intestinal stem cells exposed to photon radiation

Interleukin 1 (IL-1) has been shown to prevent early bone marrow-related death following total-body irradiation, by protecting hematopoietic stem cells and speeding marrow repopulation. This study assesses the effect of IL-1 on the radiation response of the intestinal mucosal stem cell, a nonhematopoietic normal cell relevant to clinical radiation therapy. As observed with bone marrow, administration of human recombinant IL-1 beta (4 micrograms/kg) to C3H/Km mice 20 h prior to total-body irradiation modestly protected duodenal crypt cells. In contrast to bone marrow, IL-1 given 4 or 8 h before radiation sensitized intestinal crypt cells. IL-1 exposure did not substantially alter the slope of the crypt cell survival curve but did affect the shoulder: the X-ray survival curve was offset to the right by 1.01 +/- 0.06 Gy when IL-1 was given 20 h earlier and by 1.28 +/- 0.08 Gy to the left at the 4-h interval. Protection was greatest when IL-1 was administered 20 h before irradiation, but minimal effects persisted as long as 7 days after a single injection. The magnitude of radioprotection at 20 h or of radiosensitization at 4 h increased rapidly as IL-1 dose increased from 0 to 4 micrograms/kg. However, doses ranging from 10 to 100 micrograms/kg produced no further difference in radiation response. Animals treated with saline or IL-1 had similar core temperatures from 4 to 24 h after administration, suggesting that thermal changes were not responsible for either sensitization or protection. Mice irradiated 20 h after IL-1 had significantly greater crypt cell survival than saline-treated irradiated controls at all assay times, which ranged from 54 to 126 h following irradiation. The intervals to maximum crypt depopulation and initiation of repopulation were identical in both saline- and IL-1-treated groups, suggesting that IL-1 altered absolute stem cell survival but not the kinetics of repopulation.

Two or six hyperthermia treatments as an adjunct to radiation therapy yield similar tumor responses: results of a randomized trial

From March 1984 to February 1988, 70 patients with 179 separate treatment fields containing superficially located (less than 3 cm from surface) recurrent or metastatic malignancies were stratified based on tumor size, histology, and prior radiation therapy and enrolled in prospective randomized trials comparing two versus six hyperthermia treatments as an adjunct to standardized courses of radiation therapy. A total of 165 fields completed the combined hyperthermia-radiation therapy protocols and were evaluable for response. No statistically significant differences were observed between the two treatment arms with respect to tumor location; histology; initial tumor volume; patient age and pretreatment performance status; extent of prior radiation therapy, chemotherapy, hormonal therapy, or immunotherapy; or concurrent radiation therapy. The means for all fields of the averaged minimum, maximum, and average measured intratumoral temperatures were 40.2 degrees C, 44.8 degrees C, 42.5 degrees C, respectively, and did not differ significantly between the fields randomized to two or six hyperthermia treatments. The treatment was well tolerated with an acceptable level of complications. At 3 weeks after completion of therapy, complete disappearance of all measurable tumor was noted in 52% of the fields, greater than or equal to 50% tumor reduction was noted in 7% of the fields, less than 50% tumor reduction was noted in 21% of the fields, and continuing regression (monotonic regression to less than 50% of initial volume) was noted in 20% of the fields. No significant differences were noted in tumor responses at 3 weeks for fields randomized to two versus six hyperthermia treatments (p = 0.89). Cox regression analyses were performed to identify pretreatment or treatment parameters that correlated with duration of local control. Tumor histology, concurrent radiation doses, and tumor volume all correlated with duration of local control. The mean of the minimum intratumoral temperatures (less than 41 degrees C vs. greater than or equal to 41 degrees C) was of borderline prognostic significance in the univariate analysis, and added to the power of the best three covariate model. Neither the actual number of hyperthermia treatments administered nor the hyperthermia protocol group (two versus six treatments) correlated with duration of local control. The development of thermotolerance is postulated to be, at least in part, responsible for limiting the effectiveness of multiple closely spaced hyperthermia treatments.

Radiation therapy for localized prostate cancer. Justification by long-term follow-up

In the series presented here, survival patterns at 15 years after radiotherapy for patients with clinical stage A carcinoma of the prostate did not deviate significantly from those of an age-matched peer group. For patients with clinical stage B disease (nodular disease that did not exceed involvement of one lateral lobe), survival was only 5% less at 15 years than for the age-matched group of California men. This was in spite of the fact that the lymph node status and the true incidence of capsular penetration were unknown. Moreover, the patients were not stratified by histopathologic grade or by either acid phosphatase or prostate-specific antigen values. If one were to restrict the patients to those with intermediate and low Gleason scores, normal acid phosphatase, and low prostate-specific antigen values, it is likely that there would have been no difference between the survival of those with prostatic cancer and their age-matched peers. As one deviates from these conservative selection criteria and includes patients with more advanced stages, the likelihood of achieving 15-year survival diminishes. With radiation treatment, however, patients whose disease, by clinical examination, extends beyond the prostate and who seem too advanced for radical prostatectomy still may have a 20 per cent to 30 per cent chance of 15-year survival.

Prostate specific antigen after irradiation for prostatic carcinoma

The clinical significance of serum prostate specific antigen after primary irradiation for adenocarcinoma of the prostate is uncertain. Between September 1986 and December 1987 serial prostate specific antigen values were determined in 43 patients before and after definitive radiation therapy. The study group included 6 patients with stage T0d, 10 with stage T1, 11 with stage T2 and 16 with stage T3 disease, with a mean pre-treatment prostate specific antigen level of 49.2 +/- 10.8. For all patients the first post-treatment prostate specific antigen level was less than the pre-treatment level. One patient failed locally with recurrent prostatic cancer that invaded the rectum. The 6 patients who failed with symptomatic metastases had an increasing prostate specific antigen level 2 to 7 months before detection of recurrence. Based on the absolute value and trend of the prostate specific antigen, patients were described as being at high, intermediate or low risk for distant metastases. Of 9 high, 6 intermediate and 28 low risk patients 4 (44%), 2 (33%) and 0 (0%) have experienced recurrent disease (p = 0.0025). We conclude that serial post-irradiation prostate specific antigen values may be useful in the early identification of patients at risk for treatment failure.

Reduction of spinal metastases after preemptive irradiation in prostatic cancer

For this study, 136 patients treated at Stanford University Hospital for prostatic cancer between 1971 and 1980 were selected for review. The patients had received no prior therapy, and had no evidence of bone metastases at time of radiation treatment based on radiographic studies and bone scan. Of this group, 71 patients received extended-field irradiation (paraaortic and pelvic fields), and 65 patients received pelvic irradiation. The pelvic field was treated to 50 Gy and the paraaortic field received 45 Gy to 60 Gy. All patients subsequently underwent routine follow-up examinations and studies at Stanford University Hospital: 1,513 follow-up X rays, bone scans, and CT-scans were analyzed for site-specific recurrence. The follow-up ranged from 14 months to 16 yrs from the time of initial treatment, with a mean follow-up of 7 yrs. Lower extremities and ribs were found to be the most common sites of bone metastases. Irradiation of the lumbar spine to a dose of 35 to 60 Gy, coincidental to irradiation of the paraaortic lymph nodes prevented or delayed the development of lumbar spine metastases. The potential mechanism and clinical implications are discussed.

Development of total-skin electron therapy at two energies

Total-Skin Electron Therapy (TSET) modalities have been developed at two energies on a Varian Clinac 1800. The physical criteria for the beams were determined mainly from the requirement of continuing the Stanford treatment technique, which was 12 Total-Skin Electron Therapy portals combined in six pairs. The penetration of the lower energy mode matches that previously obtained at Stanford on the Varian Clinac 10, (about 4 mm for the 80% isodose contour in the 12-field treatment). The penetration of the higher energy mode is about 8 mm at the 80% contour. The Total-Skin Electron Therapy modes necessarily use electrons produced by the two standard electron-beam modes of lowest energy, nominally 6 and 9 MeV. Measurements to verify the beam specifications were carried out with diodes, a variety of ionization chambers, and a specially constructed circular phantom for film dosimetry. Initially, the penetration of the Total-Skin Electron Therapy beams was too large to match our criteria, so two methods of reducing it were explored: (a) the energies of the electron beams produced by the machine were reduced (which also reduced the energies of the corresponding standard electron modes) and (b) a large polymethylmethacrylate degrader (2.4 m X 1.2 m) 1 cm thick was placed just in front of the patient plane. Acceptable Total-Skin Electron Therapy beams could be produced by either method and the latter was finally used. The use of the standard dose monitoring system for the Total-Skin Electron Therapy modes considerably simplifies the daily treatment delivery as well as the implementation. However, the need for reasonable dose rates at the treatment plane (3.5 meters beyond the isocenter) requires dose rates of 24 Gy/min at the isocenter. Nevertheless, it is possible to use the internal dose monitor provided the problems associated with high dose rates (recombination and amplifier saturation) are addressed. Solutions to these problems involved switching the primary and back-up dose monitors, increasing the collecting voltage on the ion chambers, and calibrating the dose monitor so that 1 unit = 1 cGy at the patient rather than at the isocenter.