Histologic subtypes of breast cancer following radiotherapy for Hodgkin lymphoma.

BACKGROUND: The purpose of the study was to determine whether breast cancers (BCs) that develop in women previously irradiated for Hodgkin lymphoma (HL) are biologically similar to sporadic BC. MATERIALS AND METHODS: We retrospectively reviewed the charts of patients who developed BC after radiotherapy (RT) for HL. Tumors were classified as ductal carcinoma in situ (DCIS) or invasive carcinoma. Invasive carcinomas were further characterized according to the subtype: hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)-, HR+/HER2+, HR-/HER2+, and HR-/HER2-. BCs after HL were compared with four age-matched sporadic, non-breast cancer (BRCA) I or II mutated BCs. RESULTS: One hundred forty-seven HL patients who were treated with RT between 1966 and 1999 and subsequently developed BCs were identified. Of these, 65 patients with 71 BCs had complete pathologic information. The median age at HL diagnosis was 23 (range, 10-48). The median age at BC diagnosis was 44 (range, 28-66). The median time to developing BC was 20 years. Twenty cancers (28%) were DCIS and 51 (72%) were invasive. Of the 51 invasive cancers, 24 (47%) were HR+/HER2-, 2 (4%) were HR+/HER2+, 5 (10%) were HR-/HER2+, and 20 (39%) were HR-/HER2-. There were no differences in BC histologic subtype according to the age at which patients were exposed to RT, the use of chemotherapy for HL treatment, or the time from RT exposure to the development of BC. In a 4 : 1 age-matched comparison to sporadic BCs, BCs after HL were more likely to be HR-/HER2- (39% versus 14%) and less likely to be HR+/HER2- (47% versus 61%) or HR+/HER2+ (4% versus 14%) (P = 0.0003). CONCLUSION(S): BCs arising in previously irradiated breast tissue were more likely to be triple negative compared with age-matched sporadic invasive cancers and less likely to be HR positive. Further studies will be important to determine the molecular pathways of carcinogenesis in breast tissue that is exposed to RT.

Breast cancer after treatment of Hodgkin's disease.

BACKGROUND: Most studies of survivors of Hodgkin's disease have shown a low risk for subsequent breast cancer, even though much lower doses of radiation than those used for Hodgkin's disease have been shown to induce breast cancer in other settings. PURPOSE: This study quantifies the risk of breast cancer following Hodgkin's disease treatment according to age at treatment and type of treatment. METHODS: To evaluate the risk of breast cancer from irradiation, we reviewed records of 885 women treated for Hodgkin's disease between 1961 and 1990 (mean follow-up, 10 years). Risks for breast cancer incidence and mortality were calculated by comparison with expected rates for a general female population matched by age and race. RESULTS: Twenty-five patients have developed invasive breast cancer, yielding a relative risk (RR) of 4.1 (95% confidence interval [CI] = 2.5-5.7). An additional patient developed multifocal carcinoma in situ. Age at irradiation strongly influenced risk: RR was 136 for women treated before 15 years of age (95% CI = 34-371). RR declined with age at irradiation (P for trend < .0001), but the elevation remained statistically significant for subjects less than 30 years old at the time of irradiation (for those 15-24, RR = 19 [95% CI = 10.3-32]; for those 24-29, RR = 7 [95% CI = 3.2-14.4]). In women above 30 years of age, the risk was not elevated (RR = 0.7; 95% CI = 0.2-1.8). Risk of breast cancer increased significantly with time since treatment (P for trend < .0001). The RR was 2.0 (95% CI = 1.0-3.5) with follow-up under 15 years and 13.6 (95% CI = 7.9-18.2) with follow-up equal to or exceeding 15 years. The addition of mechlorethamine, vincristine, procarbazine, and prednisone chemotherapy to irradiation increased the risk within the first 15 years. Most breast cancers (22 of 26) arose within or at the margin of the radiation field and were infiltrating ductal carcinomas. Stage distribution and outcome suggest that the increased incidence was not solely attributable to vigilant screening. RR of death from breast cancer was 5.1 (95% CI = 2.2-10.0). CONCLUSIONS: Women treated for Hodgkin's disease with radiation before 30 years of age are at markedly increased risk for breast cancer, with risk increasing dramatically more than 15 years after therapy. IMPLICATIONS: The high RR for development of breast cancer in women exposed to therapeutic radiation under 30 years of age raises important issues about optimal treatment strategies for patients with Hodgkin's disease, breast cancer, and other cancers.

The effect of stem cell factor on irradiated human bone marrow.

This study evaluates the effect of recombinant human stem cell factor (SCF) on the in vitro response of human bone marrow progenitor cells to irradiation. Light density nonadherent mononuclear cells were isolated from human bone marrow and resuspended in either semisolid culture or liquid culture with or without 100 ng/ml SCF. After 24 h in culture, cells were irradiated and assessed for survival of erythroid burst-forming unit, granulocyte colony-forming unit(s), or granulocyte-macrophage colony-forming unit precursors in the presence of erythropoietin, granulocyte colony-stimulating factor, or granulocyte-macrophage colony-stimulating factor, respectively. Incubation with SCF prior to irradiation (0-300 cGy) resulted in an increase in both absolute colony number and surviving fraction for erythroid burst-forming units, granulocyte colony-forming units, and granulocyte-macrophage colony-forming units as compared to cultures that did not contain SCF. The mean surviving fraction enhancement ratio after 100 cGy ranged from 1.2 to 3.7. An increased fraction of CD34+ progenitors in S-phase after exposure to SCF may explain in part the apparent radioprotective effect of SCF on human bone marrow progenitor cells.

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.

Cardiac disease following treatment of Hodgkin's disease in children and adolescents.

PURPOSE: Cardiac disease is second only to neoplastic disease as a cause of death after treatment for Hodgkin's disease. This study evaluates the risks of cardiac disease following treatment of Hodgkin's disease during childhood and adolescence. PATIENTS AND METHODS: We reviewed records of 635 patients treated for Hodgkin's disease before 21 years of age at Stanford University between 1961 and 1991. Mean age was 15.4 years; mean follow-up duration was 10.3 years, representing 6,564 person-years of observation. Relative risks (RRs) of death from cardiac diseases were calculated by comparison with age-, sex-, and race-matched general population rates from United States decennial life-tables. RESULTS: Twelve patients have died of cardiac disease (RR, 29.6; 95% confidence interval [CI], 16.0 to 49.3), including seven deaths from acute myocardial infarction ([AMI] RR, 41.5; 95% CI, 18.1 to 82.1), three from valvular heart disease, and two from radiation pericarditis/pancarditis. Thus far, the risk of AMI death was comparable after radiation alone (RO) or after chemotherapy and radiation (CM) (RO-AMI RR, 52.2; 95% CI, 21.1 to 108.7; CM-AMI RR, 21.1; 95% CI, 0.0 to 104.4; P = .6). The risk for other cardiac death (CD) tended to be higher after combined treatment (RO-non-AMI RR, 7.4; 95% CI, 0.0 to 36.5; CM-non-AMI RR, 45.8; 95% CI, 14.4 to 110.6; P = .1). Deaths occurred 3 to 22 years after patients received 42 to 45 Gy to the mediastinum between 9 and 20 years of age. There have been no deaths among patients treated to lower mediastinal radiation doses or without mediastinal radiation. There are no clear trends in the latency of risk. One hundred six nonfatal abnormalities have also been diagnosed. CONCLUSION: Mediastinal radiation of 40 to 45 Gy increases the risk of death from coronary artery and other cardiac diseases. The risk increases within 5 years of irradiation. These observations support combined-modality, low-dose irradiation regimens in children and adolescents and suggest the need for careful cardiac screening of treated patients.

Vinblastine, bleomycin, and methotrexate: an effective adjuvant in favorable Hodgkin's disease.

Sixty-seven patients with favorable pathologic stage (PS) I and IIA or B or IIIA Hodgkin's disease were randomized to receive subtotal or total lymphoid irradiation (STLI/TLI) alone or involved field irradiation (IF) plus six cycles of a novel adjuvant chemotherapy containing vinblastine, bleomycin, and methotrexate (VBM). With a follow-up from 6 to 72 months (median, 37 months), the actuarial freedom-from-progressive disease (FFP) at 5 years is 70% after STLI/TLI and 95% after IF plus VBM. One death has occurred in the irradiation-only treatment group. The data for IF plus VBM are significantly superior to previous actuarial results at 5 years using IF alone (FFP = 35%, P less than .00001) and compare favorably with prior results with IF plus nitrogen mustard, vincristine, procarbazine, +/- prednisone (MOP[P]) chemotherapy (FFP = 80% at 5 years, P = .10). VBM is well tolerated with greater than 90% of calculated doses delivered. As anticipated, VBM has had relatively little adverse effect on male or female fertility. Selected pulmonary functions are reduced early after IF plus VBM to a greater degree than with irradiation of the mediastinum alone, but the differences are modest. Based upon our current numbers and follow-up, we can be 90% confident that VBM as an adjuvant to irradiation in favorable Hodgkin's disease is as effective, or even superior, to MOP(P) chemotherapy. Because of its lesser toxicity, adjuvant VBM may have a broader role in the management of Hodgkin's disease.

Linear accelerator-based stereotaxic radiosurgery for brain metastases:the influence of number of lesions on survival.

PURPOSE: To evaluate the influence of the number of brain metastases on survival after stereotaxic radiosurgery and factors that affect the risk of delayed radiation necrosis after treatment. MATERIALS AND METHODS: Between March 1989 and December 1993, 120 consecutive patients underwent linear accelerator-based stereotaxic radiosurgery for brain metastases identified by computed tomography (CT) or magnetic resonance imaging (MRI) scans. The influence of various clinical factors on outcome was assessed using Kaplan-Meier plots of survival from the date of radiosurgery, and univariate and multivariate analyses. RESULTS: The median survival time was 32 weeks. Progressive brain metastases, both local and regional, caused 25 of 104 deaths. Patients with two metastases (n = 30) or a solitary metastasis (n = 70) had equivalent actuarial survival times (P = .07; median, 37 weeks; maximum, 211+ weeks). Patients treated to three or more metastases (n = 20) had significantly shorter survival times (P < .002; median, 14 weeks; maximum, 63 weeks). Prognostic factors associated with prolonged survival included a pretreatment Karnofsky performance status > or = 70% and fewer than three metastases. Delayed radiation necrosis at the treated site developed in 20 patients and correlated with prior or concurrent delivery of whole-brain irradiation and the logarithm of the tumor volume. CONCLUSION: Survival duration is equivalent for patients with one or two brain metastases and is similar to that reported for patients with a solitary metastasis managed by surgical resection and whole-brain irradiation. Survival after radiosurgery for three or more metastases was similar to that reported for whole-brain irradiation.

Brief chemotherapy, Stanford V, and adjuvant radiotherapy for bulky or advanced-stage Hodgkin's disease: a preliminary report.

PURPOSE: Although survival rates have improved for patients with bulky and advanced-stage Hodgkin's disease (HD), current treatments entail substantial acute morbidity and risks for late effects such as infertility, second malignancies, and cardiopulmonary toxicities. A novel, brief chemotherapy regimen (doxorubicin, vinblastine, mechlorethamine, vincristine, bleomycin, etoposide, and prednisone [Stanford V]) was designed to shorten the duration of treatment, significantly reduce cumulative doses of alkylating agents, doxorubicin, and bleomycin, and maintain dose-intensity (DI). This brief chemotherapy was combined with radiation therapy (RT) to bulky disease sites. METHODS: Since May 1989, 65 previously untreated patients were treated for stage II HD with bulky mediastinal involvement (n = 21) or for stage III or IV HD (n = 44). Patients received weekly chemotherapy for 12 weeks. Consolidative RT was given to the first 25 patients to sites of initial bulky disease or radiographic abnormalities that persisted after chemotherapy; in the remaining 40 patients, RT was limited to bulky disease (adenopathy > or = 5 cm and/or macroscopic splenic nodules defined by computed tomography [CT]). RESULTS: With a median follow-up period of 2 years, actuarial 3-year survival rate is 96% and failure-free survival (FFS) rate is 87%. The 3-year FFS rate is 100% for stage II patients with bulky mediastinal disease and 82% for patients with stage III to IV disease. There were no treatment-related deaths. In a preliminary analysis on a subset of patients, female and male fertility appears to be preserved. CONCLUSION: These preliminary results indicate that the Stanford V chemotherapy regimen with or without RT is well-tolerated and effective therapy for bulky, limited-stage, and advanced-stage HD. Less cumulative exposure to alkylating agents, doxorubicin, and bleomycin and limited use of radiation is expected to decrease risks for second neoplasms and late cardiopulmonary toxicity. Based on these results, the Stanford V chemotherapy with or without RT regimen deserves further study in the context of a randomized clinical trial.

Stanford-Kaiser Permanente G1 study for clinical stage I to IIA Hodgkin's disease: subtotal lymphoid irradiation versus vinblastine, methotrexate, and bleomycin chemotherapy and regional irradiation.

PURPOSE: We have demonstrated that a relatively mild chemotherapy regimen, vinblastine, methotrexate, and bleomycin (VBM), and involved-field radiotherapy (IFRT) could substitute for extended-field radiotherapy in patients with favorable Hodgkin's disease (HD) who have been laparotomy-staged. The purpose of this study is to determine if VBM and regional radiotherapy can substitute for extended-field radiotherapy in favorable clinical stage (CS) I and II HD. PATIENTS AND METHODS: Seventy-eight patients with favorable CS I to II HD were randomly assigned to subtotal lymphoid irradiation (STLI) or VBM chemotherapy and regional radiotherapy. Randomization was stratified on the basis of age, sex, number of Ann Arbor sites, histology, and institution. Patients were evaluated for freedom from progressive HD, survival, and toxicity. Results were compared with the predecessor trial in pathologically staged patients. RESULTS: With a median follow-up period of 4 years, the rate of freedom from progressive HD was 92% (95% confidence interval [CI], 88% to 96%) for patients treated with STLI and 87% (95% CI, 81% to 93%) for patients treated with VBM and regional radiotherapy. Six of seven patients who relapsed are alive and in remission following successful second-line therapy. CONCLUSION: Given the caveat of a small number of patients, the results of extended-field radiotherapy and VBM and regional radiotherapy are comparable with a median follow-up period of 4 years. VBM serves as a paradigm to reduce late effects in favorable early-stage HD. We do not advocate its routine use in clinical practice, but instead encourage participation in clinical trials with the objective of maintaining efficacy while reducing toxicity in CS I and II HD.

Management of breast cancer after Hodgkin's disease.

PURPOSE: To evaluate the incidence, detection, pathology, management, and prognosis of breast cancer occurring after Hodgkin's disease. PATIENTS AND METHODS: Seventy-one cases of breast cancer in 65 survivors of Hodgkin's disease were analyzed. RESULTS: The median age at diagnosis was 24.6 years for Hodgkin's disease and 42.6 years for breast cancer. The relative risk for invasive breast cancer after Hodgkin's disease was 4.7 (95% confidence interval, 3.4 to 6. 0) compared with an age-matched cohort. Cancers were detected by self-examination (63%), mammography (30%), and physician exam (7%). The histologic distribution paralleled that reported in the general population (85% ductal histology) as did other features (27% positive axillary lymph nodes, 63% positive estrogen receptors, and 25% family history). Although 87% of tumors were less than 4 cm, 95% were managed with mastectomy because of prior radiation. Two women underwent lumpectomy with breast irradiation. One of these patients developed tissue necrosis in the region of overlap with the prior mantle field. The incidence of bilateral breast cancer was 10%. Adjuvant systemic therapy was well tolerated; doxorubicin was used infrequently. Ten-year disease-specific survival was as follows: in-situ disease, 100%; stage I, 88%; stage II, 55%; stage III, 60%; and stage IV, zero. CONCLUSION: The risk of breast cancer is increased after Hodgkin's disease. Screening has been successful in detecting early-stage cancers. Pathologic features and prognosis are similar to that reported in the general population. Repeat irradiation of the breast can lead to tissue necrosis, and thus, mastectomy remains the standard of care in most cases.

Radiation therapy of esophageal cancer.

Radiation therapy has been used extensively in the management of patients with cancer of the esophagus. It has demonstrated an ability to cure a small minority of patients. Cure is likely to be limited to patients who have lesions less than 5 cm in length and have minimal, if any, involvement of lymph nodes. Esophagectomy is likely to cure a similar, small percentage of patients with the same presentation of minimal disease but has a substantial acute postoperative mortality rate and greater morbidity than irradiation. Combining surgery and either preoperative or postoperative irradiation may cure a small percentage of patients beyond the number cured with either modality alone. Radiation has demonstrated benefit as an adjuvant to surgery following the resection of minimal disease. However, radiation alone has never been compared directly with surgery for the highly select, minimal lesions managed by surgery. Radiation provides good palliation of dysphagia in the majority of patients, and roughly one third may have adequate swallowing for the duration of their illness when "radical" doses have been employed. Surgical bypass procedures have greater acute morbidity but appear to provide more reliable, prolonged palliation of dysphagia. They constitute the best approach for patients with persistent or recurrent dysphagia following esophageal irradiation. Several approaches to improving the efficacy of irradiation are currently under investigation. Fewer large fractions appear to be equivalent to conventionally fractionated radiotherapy in terms of local control and survival but produce more prompt palliation and shorten courses of palliative therapy. Multiple-daily-fractionation schedules and hyperfractionation have theoretical appeal and clear basis for investigation from the early suggestions of improved response rates in advanced squamous-cell cancer of the head and neck. Hypoxic-cell radiosensitizers, neutron-beam, and helium-ion therapy results have not been overly encouraging in esophageal cancer, thus far. However, the new generation of particle beams and the new radiation-sensitizer drugs require further evaluation. Better means of dealing with the high incidence of disseminated disease are clearly needed. It is clear that combined-modality approaches using both local and systemic therapy will ultimately be desirable in esophageal-cancer treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Anterior eye protection with orbital neoplasia.

The administration of adequate doses of radiation to tumors involving the orbit and surrounding facial structures and sinuses is often complicated by the need to protect the sensitive ocular components, the lens and cornea. A technique has been devised that uses four photon beam fields and an optional electron field to treat the contents of both orbits and adjacent sinuses with effective, reproducible protection of cornea and lens. Essential features include: alignment of the corneal surfaces with the central plane of rotation of the treatment machine, use of a narrow eye block across the entire beam to shield a strip equal to the width of the cornea, positioned symmetrically across the central plane of rotation, fine alignment of the eye block with both corneal surfaces by altering pedestal angle, treatment with paired, wedged, anterior oblique fields to encompass desired orbital and sinus volumes with additional blocking placed as needed, and complementary, lateral strip fields using collimators set to eye block thickness to equalize dose in the posterior orbit shielded by the strip eye block. A similar anterior electron beam strip field may be added to boost the medial orbit and ethmoid regions covered by the eye block. Bite block head immobilization and easy, direct daily visualization of block position assures eye protection for each treatment and provides substantial reduction in dose to the cornea, lens and iris. Additional blocking may be incorporated to provide partial lacrimal and parotid sparing.

Thyroid abnormalities after therapeutic external radiation.

The thyroid gland is the largest pure endocrine gland in the body and one of the organs most likely to produce clinically significant abnormalities after therapeutic external radiation. Radiation doses to the thyroid that exceed approximately 26 Gy frequently produce hypothyroidism, which may be clinically overt or subclinical, as manifested by increased serum thyrotropin and normal serum-free thyroxine concentrations. Pituitary or hypothalamic hypothyroidism may arise when the pituitary region receives doses exceeding 50 Gy with conventional, 1.8-2 Gy fractionation. Direct irradiation of the thyroid may increase the risk of Graves' disease or euthyroid Graves' ophthalmopathy. Silent thyroiditis, cystic degeneration, benign adenoma, and thyroid cancer have been observed after therapeutically relevant doses of external radiation. Direct or incidental thyroid irradiation increases the risk for well-differentiated, papillary, and follicular thyroid cancer from 15- to 53-fold. Thyroid cancer risk is highest following radiation at a young age, decreases with increasing age at treatment, and increases with follow-up duration. The potentially prolonged latent period between radiation exposure and the development of thyroid dysfunction, thyroid nodularity, and thyroid cancer means that individuals who have received neck or pituitary irradiation require careful, periodic clinical and laboratory evaluation to avoid excess morbidity.

Effect of combined transient androgen deprivation and irradiation following radical prostatectomy for prostatic cancer.

PURPOSE: To evaluate whether transient androgen deprivation improves outcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence. METHODS AND MATERIALS: Records of 105 consecutive patients who were treated with pelvic irradiation after radical retropubic prostatectomy between August 1985 and December 1995 were reviewed. Seventy-four patients received radiation alone (mean follow up: 4.6 years), and 31 received transient androgen blockade with a gonadotropin-releasing hormone agonist (4) androgen receptor blocker (1) or both (24) beginning 2 months prior to irradiation (mean follow-up 3.0 years) for a mean duration of 6 months. Two of these patients were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dose of 60-70 Gy at 2 Gy per fraction; 48 patients also received pelvic nodal irradiation to a median dose of 50 Gy. Survival, freedom from clinical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml. RESULTS: At 5 years after irradiation, actuarial survival for all patients was 92%, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during radiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p = 0.004). FFCR was also superior for the combined treatment group (100 vs. 70% at 5 years, p = 0.014). Potential clinical prognostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic score, lymph node status, indication for treatment, and PSA levels before surgery or subsequent treatment. Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure. CONCLUSION: This retrospective study of irradiation after radical prostatectomy suggests that transient androgen blockade and irradiation may improve freedom from early biochemical and clinically evident relapse compared to radiotherapy alone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates.

Computed tomography assessment of splenic size as a predictor of splenic weight and disease involvement in laparotomy staged Hodgkin's disease.

PURPOSE: To evaluate how well splenic size predicts the risk of splenic Hodgkin's disease and to assess how accurately splenic dimensions on computerized tomographic scans predict spleen size and involvement by Hodgkin's disease. METHODS AND MATERIALS: Splenic weights were obtained from laparotomies performed on 897 patients who presented with Hodgkin's disease and were compared with histologic involvement using logistic regression. Splenic dimensions were measured from preoperative computerized tomographic scans in 94 of these patients, and unidimensional splenic measurements [length (L), width (W), thickness (T)] and their products were compared with splenic weight at laparotomy using linear regression. RESULTS: Hodgkin's disease involved 42% of the spleens at laparotomy and 31% of those assessed by computerized tomography. Splenic weight averaged 198 +/- 5 g (range 40-2000 g). Weight and involvement were greater with "unfavorable" histologies (mixed cellularity, lymphocyte depletion, and unclassified Hodgkin's disease: 229 +/- 12 g; 62.7% involved) than with "favorable" histologies (nodular sclerosing, lymphocyte predominant, and interfollicular Hodgkin's disease: 191 +/- 5 g; 37.8% involved). Splenic weight was the strongest independent risk factor correlated with Hodgkin's disease in univariate and multivariate analyses in all patients and the only identifiable univariate risk factor among those with computerized tomographic scans. For most patients, however, splenic weight poorly predicted involvement: The probability of involvement never fell below 20% and exceeded 80% when splenic weight exceeded 270 g with unfavorable histologies or 685 g in favorable histologies. Spleens of average weight had a probability of involvement of 36% with favorable histologies, 70% with unfavorable histologies. Unidimensional measurements of the spleen on computed tomography correlated poorly with splenic weight, but their product correlated well (Correlation coefficients: L: 0.73; W: 0.65; T: 0.78; [0.344485 x L x W x T]: 0.94). CONCLUSIONS: Splenic weight is the strongest factor correlating with the risk of splenic involvement by Hodgkin's disease and can be accurately estimated from three-dimensional measurements on computed tomographic scans, but not from unidimensional measurements. However, splenic weight is not a sensitive predictor of involvement of the spleen by Hodgkin's disease. Therefore, treatment approaches to Hodgkin's disease must be based upon intermediate risks of splenic involvement for most clinically staged patients.

Gastrointestinal cancer after treatment of Hodgkin's disease.

PURPOSE: This study aimed to quantify the risk of gastrointestinal cancer following Hodgkin's disease treatment according to age at treatment, type of treatment, and anatomic sites. METHODS AND MATERIALS: Cases were identified from the records of 2,441 patients treated for Hodgkin's disease between 1961 and 1994. Follow-up averaged 10.9 years, representing 26,590 person-years of observation. Relative risks (RR) for gastrointestinal cancer incidence and mortality were computed by comparison with expected annualized rates for a general population matched for age, sex, and race. RESULTS: Gastrointestinal cancers developed in 25 patients. The incidence RR was 2.5 [95% confidence interval (CI), 1.5-3.5] and mortality RR was 3.8 (CI, 2.4-4.7). Sites associated with significantly increased risks included the stomach [RR 7.3 (CI, 3.4-13.8)], small intestine [RR 11.6 (CI, 1.9-38.3)], and pancreas [RR 3.5 (CI, 1.1-8.5)]. Risk was significantly elevated after combined modality therapy, RR 3.9 (CI, 2.2-5.6). The risk after radiotherapy alone was 2.0 (CI, 1.0-3.4), not a statistically significant elevation. The RR for gastrointestinal cancer was greatest after treatment at young age and decreased with advancing age. It was significantly elevated within 10 years after treatment [RR 2.0 (CI, 1.1-3.5)] and increased further after 20 years [RR 6.1 (CI, 2.5-12.7)]. Risk assessed by attained age paralleled risk according to age at treatment. Fifteen cases of gastrointestinal cancers arose within the irradiation fields. CONCLUSION: Patients treated for Hodgkin's disease are at modestly increased risk for secondary gastrointestinal cancer, especially after combined modality therapy and treatment at a young age. Risk was highest more than 20 years after treatment, but was significantly elevated within 10 years. Gastrointestinal sites with increased risk included the stomach, pancreas, and small intestine.

Muscle cramping in phase I clinical trials of tirapazamine (SR 4233) with and without radiation.

PURPOSE: Tirapazamine (SR 4233) is a benzotriazine di-N-oxide which acts as a hypoxic cytotoxic agent and as a radiation enhancer when given shortly before or after radiation. Three Phase I clinical trials were designed to determine the maximum tolerated dose, toxicities, pharmacokinetics, and effects on irradiated tumors and normal tissues. METHODS AND MATERIALS: Tirapazamine 9 mg/m2 to 21 mg/m2 was given i.v. 1/2 to 1 h prior to irradiation on a multiple dose schedule of 10 consecutive doses. This was later revised to a three times-per-week schedule for 12 doses. In a second clinical trial, tirapazamine was given in a single dose of 18 mg/m2 to 293 mg/m2 i.v. after irradiation. In a third trial, tirapazamine was administered without irradiation in single doses of 36 mg/m2 to 250 mg/m2, with an option for retreatment. RESULTS: Subjects reported muscle cramping of varying degrees of severity on all three dose schedules. One patient experienced Grade 3 cramping and treatment was discontinued. The most frequent site of cramping were the lower extremities. Creatine phosphokinase (CPK) values were elevated in three patients with associated muscle soreness in one patient. MB (cardiac) isoenzymes were elevated in one patient with no evidence of cardiac muscle damage, and returned to baseline at drug completion. No consistent abnormalities in clinical laboratory values were found. Stretching of the muscle was most effective in relieving the cramping. CONCLUSION: Muscle cramping has been the most frequently reported toxicity in Phase I studies of tirapazamine, though it does not appear to be dose limiting. Dose escalation on the three clinical trials continues. In vitro studies to investigate the cramping are ongoing.

Role of beam orientation optimization in intensity-modulated radiation therapy.

PURPOSE: To investigate the role of beam orientation optimization in intensity-modulated radiation therapy (IMRT) and to examine the potential benefits of noncoplanar intensity-modulated beams. METHODS AND MATERIALS: A beam orientation optimization algorithm was implemented. For this purpose, system variables were divided into two groups: beam position (gantry and table angles) and beam profile (beamlet weights). Simulated annealing was used for beam orientation optimization and the simultaneous iterative inverse treatment planning algorithm (SIITP) for beam intensity profile optimization. Three clinical cases were studied: a localized prostate cancer, a nasopharyngeal cancer, and a paraspinal tumor. Nine fields were used for all treatments. For each case, 3 types of treatment plan optimization were performed: (1) beam intensity profiles were optimized for 9 equiangular spaced coplanar beams; (2) orientations and intensity profiles were optimized for 9 coplanar beams; (3) orientations and intensity profiles were optimized for 9 noncoplanar beams. RESULTS: For the localized prostate case, all 3 types of optimization described above resulted in dose distributions of a similar quality. For the nasopharynx case, optimized noncoplanar beams provided a significant gain in the gross tumor volume coverage. For the paraspinal case, orientation optimization using noncoplanar beams resulted in better kidney sparing and improved gross tumor volume coverage. CONCLUSION: The sensitivity of an IMRT treatment plan with respect to the selection of beam orientations varies from site to site. For some cases, the choice of beam orientations is important even when the number of beams is as large as 9. Noncoplanar beams provide an additional degree of freedom for IMRT treatment optimization and may allow for notable improvement in the quality of some complicated plans.

Stem cell factor enhances the survival of murine intestinal stem cells after photon irradiation.

Recombinant rat stem cell factor (SCF) has been shown to decrease lethality in mice exposed to total-body irradiation (TBI) in the lower range of lethality through radioprotection of hematopoietic stem cells and acceleration of bone marrow repopulation. This study evaluates the effect of SCF on the survival of the intestinal mucosal stem cell after TBI. This non-hematopoietic stem cell is clinically relevant. Gastrointestinal toxicity is common during and after abdominal and pelvic radiation therapy and limits the radiation dose in these regions. As observed with bone marrow, the administration of SCF to mice prior to TBI enhanced the survival of mouse duodenal crypt stem cells. The maximum enhancement of survival was seen when 100 micrograms/kg of SCF was given intraperitoneally 8 h before irradiation. This regimen increased the survival of duodenal crypt stem cells after 12.0 Gy TBI from 22.5 +/- 0.7 per duodenal cross section for controls to 30.0 +/- 1.7 after treatment with SCF (P = 0.03). The TBI dose producing 50% mortality at 6 days (LD50/6) was increased from 14.9 Gy for control mice to 19.0 Gy for mice treated with SCF (dose modification factor = 1.28). These findings demonstrate that SCF has radioprotective effects on a non-hematopoietic stem cell population and suggest that SCF may be of clinical value in preventing radiation injury to the intestine.

Treatment of hemangioblastomas in von Hippel-Lindau disease with linear accelerator-based radiosurgery.

OBJECTIVE: Stereotactic radiosurgery is increasingly being used to treat hemangioblastomas, particularly those that are in surgically inaccessible locations or that are multiple, as is common in von Hippel-Lindau disease. The purpose of this study was to retrospectively evaluate the effectiveness of radiosurgery in the treatment of hemangioblastomas. METHODS: From 1989 to 1996, 29 hemangioblastomas in 13 patients with von Hippel-Lindau disease were treated with linear accelerator-based radiosurgery. The mean patient age was 40 years (range, 31-57 yr). The radiation dose to the tumor periphery averaged 23.2 Gy (range, 18-40 Gy). The mean tumor volume was 1.6 cm3 (range, 0.07-65.4 cm3). Tumor response was evaluated in serial, contrast-enhanced, computed tomographic and magnetic resonance imaging scans. The mean follow-up period was 43 months (range, 11-84 mo). RESULTS: Only one (3%) of the treated hemangioblastomas progressed. Five tumors (17%) disappeared, 16 (55%) regressed, and 7 (24%) remained unchanged in size. Five of nine patients with symptoms referable to treated hemangioblastomas experienced symptomatic improvement. During the follow-up period, one patient died as a result of progression of untreated hemangioblastomas in the cervical spine. Three patients developed radiation necrosis, two of whom were symptomatic. CONCLUSION: Although follow-up monitoring is limited, stereotactic radiosurgery provides a high likelihood of local control of hemangioblastomas and is an attractive alternative to multiple surgical procedures for patients with von Hippel-Lindau disease.