Search PubMed⌕ Search

Biomedical subjects

M D Prados

Publications and source records attributed to M D Prados.

At least 55 records · Page 3Linked to original sources
PubMed1997

Age and the risk of anaplasia in magnetic resonance-nonenhancing supratentorial cerebral tumors.

BACKGROUND: It is often assumed that a cerebral lesion that is nonenhancing on a magnetic resonance imaging study with gadolinium contrast is a low grade tumor. Some physicians recommend observation rather than biopsy for such lesions. METHODS: The authors prospectively evaluated the incidence of anaplastic tumor histology in a consecutive series of patients who presented to a neuro-oncology service with a nonenhancing mass of the cerebral hemisphere. RESULTS: During a 5-month period, the authors evaluated 31 patients who had a nonenhancing lesion in the cerebral hemisphere on initial magnetic resonance images. Thirty patients underwent stereotactic biopsy (27%) or open resection (73%). The median patient age was 36 years (range, 6-63 years). There was no mortality or permanent neurologic morbidity from surgery. Twenty-eight patients had pathologic confirmation of diagnosis while their lesions were still nonenhancing. Of these patients, 9 (32%) had Grade 3 lesions (anaplastic astrocytoma or oligoastrocytoma), 13 (43%) had Grade 2 lesions (astrocytoma, oligodendroglioma, or oligoastrocytoma), and 2 (7%) had Grade 1 lesions (dysembryoplastic neuroepithelial tumors). Two additional patients (ages 33 and 59 years) who developed enhancement within their lesions during preoperative periods of observation had glioblastomas at surgery. Logistic regression was used to relate patient age to the risk of anaplasia in a nonenhancing cerebral mass lesion. Older age predicted a significantly higher risk of anaplasia (P = 0.025). The model predicted that nonenhancing cerebral masses in patients older than 44 years were more likely to be anaplastic tumors than low grade tumors. There was no "safe" age below which low grade histology could be confidently assumed. CONCLUSIONS: Magnetic resonance-nonenhancing cerebral lesions may be histologically anaplastic, even in young patients. The risk of anaplasia in magnetic resonance-nonenhancing lesions increases significantly with patient age.

Adolescent↗
PubMed1997

Neuropsychological sequelae of medulloblastoma in adults.

PURPOSE: To investigate the neuropsychological consequences of medulloblastoma in adults. METHODS: Patients 18 years of age or older who had medulloblastoma and at least 3 years of disease-free survival were eligible. A battery of tests was conducted to assess global intellectual functioning, verbal ability, visuospatial ability, memory, reasoning, and academic proficiency. For the verbal memory performance, each patient was matched with two normal controls selected on the basis of age, sex, and level of education. RESULTS: Review of the Neuro-Oncology database revealed 24 patients eligible for the study. Of these, 10 patients (6 good-risk and 4 poor-risk) agreed to participate; 7 patients were lost to follow-up; 5 lived too far away to come to the testing site, and 2 refused testing. There were four men and six women; their mean age was 36.5 years at testing and 29.9 years at surgical diagnosis. Mean dose of whole brain radiation was 34.5 Gy. Mean interval between diagnosis and testing was 79.1 months. Test results demonstrated below average intelligence quotients (mean intelligence quotient 90.2; range 67-103) and specific deficits in memory, reasoning, visuospatial ability, and arithmetic. CONCLUSION: Adults with medulloblastoma in a prolonged disease-free status may suffer significant cognitive deficits. We recommend further controlled, prospective studies to evaluate cognitive outcomes in this patient population in the hope that interventional strategies could be developed, or treatment modified to minimize such toxicities.

Adult↗
PubMed1997

18-Fluorodeoxyglucose uptake and survival of patients with suspected recurrent malignant glioma.

BACKGROUND: After intensive initial radiation therapy for malignant glioma, magnetic resonance imaging (MRI) and computerized tomography (CT) cannot distinguish tumor progression from radiation injury. METHODS: The authors studied the prognostic value of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in 55 patients with malignant glioma for whom MRI obtained after initial surgery and radiation therapy demonstrated enlarging, enhancing lesions consistent with either tumor progression or radiation necrosis. Forty patients (73%) had an initial diagnosis of Grade 4 malignant glioma and 15 (27%) had Grade 3 malignant glioma. The FDG-PET scans were graded visually on a four-level scale at the time of acquisition. RESULTS: In univariate analysis, the FDG-PET score was a significant predictor of survival time after FDG-PET scanning (P = 0.005). Median survival was 10 months for patients with FDG-PET scores of 2 or 3 (glucose uptake > or = adjacent cortex) and 20 months for those with scores of 0 or 1 (glucose uptake < adjacent cortex). In multivariate proportional hazards analysis, the FDG-PET score was a significant predictor of survival (P = 0.019) in a model that included patient age, recurrence number, and FDG-PET score. There was no significant difference in the FDG-PET score hazard ratio for patients with Grade 3 or 4 tumors at initial diagnosis, first or later suspected recurrence, initial photon irradiation given with standard fractions or hyperfractionation, or stereotactic irradiation prior to FDG-PET scanning. CONCLUSIONS: This analysis demonstrates that FDG-PET scanning has prognostic value in a cohort limited to patients with suspected recurrent high grade glioma.

Adolescent↗
PubMed1997

Treatment of pediatric low-grade gliomas with a nitrosourea-based multiagent chemotherapy regimen.

Between March 9, 1984 and January 29, 1992, 42 children with newly diagnosed symptomatic or previously diagnosed progressive low-grade gliomas received outpatient chemotherapy as their primary treatment. This study was a single arm, phase II trial designed to estimate the time to tumor progression and toxicity of this regimen. Procarbazine, 6-thioguanine, and dibromodulcitol were given before lomustine (CCNU) and vincristine was given 1 and 3 weeks after CCNU. Patients were treated for six treatment cycles or until the tumor progressed, whichever came first. Twenty-three patients had juvenile pilocytic astrocytomas, 11 had astrocytomas, one had oligodendroglioma, one had ganglioglioma, and six had radiographically diagnosed low-grade gliomas. The mean age of the patients was 5 years (median, 3 years). The median time to treatment failure was 132 weeks (95% confidence interval: 106, 186 weeks). Only eight patients have died the estimated 5-year survival rate is 78% (95% confidence interval, 60% 87%). There were two episodes of grade 4 neutropenia, and three episodes of grade 4 thrombocytopenia. This regimen was safe, able to be delivered in the outpatient setting, and produced prolonged periods of disease stabilization in children with low-grade gliomas.

Adolescent↗
PubMed1997

Serial proton magnetic resonance spectroscopy imaging of glioblastoma multiforme after brachytherapy.

The utility of three-dimensional (3-D) proton magnetic resonance spectroscopy (1H-MRS) imaging for detecting metabolic changes after brain tumor therapy was assessed in a serial study of 58 total examinations of 12 patients with glioblastoma multiforme (GBM) who received brachytherapy. Individual proton spectra from the 3-D array of spectra encompassing the lesion showed dramatic differences in spectral patterns indicative of radiation necrosis, recurrent or residual tumor, or normal brain. The 1H-MRS imaging data demonstrated significant differences between suspected residual or recurrent tumor and contrast-enhancing radiation-induced necrosis. Regions of abnormally high choline (Cho) levels, consistent with viable tumor, were detected beyond the regions of contrast enhancement for all 12 gliomas. Changes in the serial 1H-MRS imaging data were observed, reflecting an altered metabolism following treatment. These changes included the significant reduction in Cho levels after therapy, indicating the transformation of tumor to necrotic tissue. For patients who demonstrated subsequent clinical progression, an increase in Cho levels was observed in regions that previously appeared either normal or necrotic. Several patients showed regional variations in response to brachytherapy as evaluated by 1H-MRS imaging. This study demonstrates the potential of noninvasive 3-D 1H-MRS imaging to discriminate between the formation of contrast-enhancing radiation necrosis and residual or recurrent tumor following brachytherapy. This modality may also allow better definition of tumor extent prior to brachytherapy by detecting the presence of abnormnal metabolite levels in nonenhancing regions of solid tumor.

Aspartic Acid↗
PubMed1996

Demonstration of brachytherapy boost dose-response relationships in glioblastoma multiforme.

PURPOSE: To evaluate brachytherapy dose-response relationships in adults with glioblastoma undergoing temporary 125I implant boost after external beam radiotherapy. METHODS AND MATERIALS: Since June 1987, orthogonal radiographs using a fiducial marker box have been used to verify brain implant source positions and generate dose-volume histograms at the University of California, San Francisco. For adults who underwent brachytherapy boost for glioblastoma from June 1987 through December 1992, tumor volumes were reoutlined to ensure consistency and dose-volume histograms were recalculated. Univariate and multivariate analysis of various patient and treatment parameters were performed evaluating for influence of dose on freedom from local failure (FFLF) and actuarial survival. RESULTS: Of 102 implant boosts, 5 were excluded because computer plans were unavailable. For the remaining 97 patients, analyses with adjustment for known prognostic factors (age, KPS, extent of initial surgical resection) and prognostic factors identified on univariate testing (adjuvant chemotherapy) showed that higher minimum brachytherapy tumor dose was strongly associated with improved FFLF (p = 0.001). A quadratic relationship was found between total biological effective dose and survival, with a trend toward optimal survival probability at 47 Gy minimum brachytherapy tumor dose (corresponding to about 65 Gy to 95% of the tumor volume); survival decreased with lower or higher doses. Two patients expired and one requires hospice care because of brain necrosis after brachytherapy doses > 63 Gy to 95% of the tumor volume with 60 Gy to > 18 cm3 of normal brain. CONCLUSION: Although higher minimum tumor dose was strongly associated with better local control, a brachytherapy boost dose > 50-60 Gy may result in life-threatening necrosis. We recommend careful conformation of the prescription isodose line to the contrast enhancing tumor volume, delivery of a minimum brachytherapy boost dose of 45-50 Gy in conjunction with conventional external beam radiotherapy, and reoperation for symptomatic necrosis.

Adolescent↗
PubMed1996

Necrosis as a prognostic factor in glioblastoma multiforme.

BACKGROUND: Many pathologists require the presence of tumor necrosis within an astrocytic neoplasm to establish the diagnosis of glioblastoma multiforme (GM). Two new grading systems for astrocytic neoplasms allow a tumor to be diagnosed at the highest level of anaplasia without requiring the presence of tumor necrosis. METHODS: To determine whether GMs without necrosis had biologic behavior most compatible with a diagnosis of GM or of anaplastic astrocytoma (AA), we examined the survival of 299 patients whose tumors were diagnosed as GM because they contained endothelial proliferation and who were treated according to prospective clinical protocols. Multivariate proportional-hazards survival analysis was used to assess the importance of tumor necrosis after adjustment for other prognostic factors. RESULTS: Of 275 patients with GMs containing endothelial proliferation, 88% had tumor necrosis. Absence of necrosis was associated with younger age and with less extensive surgical resection. The absence of necrosis predicted longer survival in univariate analysis (P = 0.02) and after adjustment for age, Karnofsky performance score, and extent of resection in a multivariate analysis (P = 0.04). However, the magnitude of the survival difference was not clinically important: patients without tumor necrosis had a median survival of 12.5 months, and those with tumor necrosis had a median survival of 10.9 months. Kaplan-Meier survival rates two years after diagnosis were 13.0% for patients with necrosis and 27.1% for patients without necrosis; the difference in 2-year survival was not statistically significant (difference in survival rates = 14.1%, 95% confidence interval -2.2% to 30.4%). CONCLUSIONS: The survival of patients with astrocytic neoplasms containing endothelial proliferation and no necrosis conforms best to the pattern expected for patients with GM rather than AA. This supports the classification of these tumors as GM in the revised World Health Organization grading system and as grade 4 astrocytomas in the St. Anne-Mayo grading system.

Adolescent↗
PubMed1996

Bromodeoxyuridine labeling index in glioblastoma multiforme: relation to radiation response, age, and survival.

PURPOSE: Various measures of the rate of tumor cell proliferation have been found to predict survival in patients with intracerebral gliomas. We correlated the bromodeoxyuridine labeling index (BrdUrd LI) with the response to radiation therapy, survival, and known prognostic factors in a series of patients with glioblastoma multiforme (GM) to test its utility as a prognostic factor. METHODS AND MATERIALS: The BrdUrd LI was determined in 200 newly diagnosed intracranial GMs. Age and sex were known for all patients. The response to radiation therapy was determined in 116 patients by comparing neuroimaging studies obtained before and after external beam radiation therapy. Survival was analyzed in 64 patients who were treated according to two consecutive prospective clinical protocols. RESULTS: The median BrdUrd LI was 6.5% (mean, 7.2%; range, 1.1-25.4%). The BrdUrd LI did not correlate significantly with age, sex, radiation response, or survival. Age and Karnofsky performance score were independent prognostic factors in our cohort. CONCLUSION: The proliferative rate as measured by BrdUrd LI was not a prognostic factor in our GM cohort. The BrdUrd LI did not correlate significantly with known prognostic factors in GM. There was no significant relationship between BrdUrd LI and radiation response.

Adolescent↗
PubMed1996

Intravenous carboplatin for recurrent gliomas. A dose-escalating phase II trial.

In a Phase II trial, 63 evaluable patients with recurrent glioma received i.v. infusions of carboplatin every 3 weeks beginning at a dose of 400 mg/m2. The dose was increased by 50 mg/m2 at each subsequent infusion until the maximum tolerated dose reached, as defined by a platelet count < 25,000/mm3 or an absolute neutrophil count (ANC) < 500/mm3. Treatment was then resumed at the previous dose level and continued until tumor progression occurred. There were 43 men and 20 women studied (mean age, 41 years; range, 6 months to 70.6 years). The combined response and stabilization rate was 29% for 31 patients with glioblastoma and 71.9% for 32 patients with other tumors; median time to tumor progression was 8.2 and 20.3 weeks and median survival was 25.9 and 58.3 weeks, respectively. Twenty patients had level 4 platelet toxicity and nine had level 4 ANC toxicity. Most tumors progressed before the maximum tolerated dose was reached. These results were not better than those from a previous trial of carboplatin at an initial dose of 350 mg/m2, which was escalated by 25 mg/ m2 after every two infusions. Therefore, an optimal dosing schedule was not achieved in this trial.

Adolescent↗
PubMed1996

Radiologic classification of brain stem tumors: correlation of magnetic resonance imaging appearance with clinical outcome.

Although tumors of the brain stem have traditionally been classified as a single entity, these tumors are increasingly being recognized as a heterogeneous group, with some subgroups having better prognoses for long-term survival. Although several systems for classification of brain stem tumors have been proposed, none have been based on data derived from contrast-enhanced magnetic resonance (MR) imaging. In this review, we present a classification scheme based on our review of the literature and of the MR scans of 64 patients with brain stem tumors. In addition, we assess the contribution of gadolinium to the classification of brain stem tumors and correlate the various tumor subtypes, based on MR appearance, with prognosis. Our results suggest that the most important factor in determining prognosis based on MR characteristics is whether the tumor is diffuse or focal. Focal tumors have an excellent prognosis regardless of the site of tumor origin. Diffuse tumors of the mesencephalon and pons have a significantly poorer prognosis than focal tumors (p = 0.0013), with diffuse pontine tumors having the worst prognosis. Differentiation of diffuse and focal medullary tumors was difficult, possibly explaining the lack of significant difference in the survival of patients with diffuse versus focal medullary tumors. The presence or absence of enhancement after the administration of paramagnetic contrast has no significant relation with outcome, overall or within specific tumor subgroups.

Adolescent↗
PubMed1996

Long-term follow-up after high-activity 125I brachytherapy for pediatric brain tumors.

A retrospective review including long-term follow-up (4.6-12.0 years) was performed of all 28 pediatric patients who underwent high-activity 125I brachytherapy at the University of California, San Francisco, for primary or recurrent brain tumors from 1980 until 1991. There were 4 glioblastomas, 11 high-grade nonglioblastoma multiforme (NGM) malignant gliomas, 10 contrast-enhancing low-grade NGM, 2 choroid plexus carcinomas, and 1 rhabdomyosarcoma. The 13 survivors included 7 of 8 patients with primary high-grade NGM, 2 of 3 patients with primary low-grade NGM, and 3 of 7 patients with recurrent low-grade NGM. Necrosis (with or without tumor) was identified in 17 of 22 reoperated patients. The mean Karnofsky performance status was 88 +/- 9 at the time of brachytherapy, 87 +/- 7 at 3 years, and 87 +/- 9 in 11 patients alive at 6-12 years. Brachytherapy is a useful modality for treating selected pediatric brain tumors, and although focal necrosis is a common sequela, it does not tend to have a major impact on the Karnofsky performance status, if the implant site is amenable to reoperation.

Adolescent↗
PubMed1996

Treatment of high-risk medulloblastoma and other primitive neuroectodermal tumors with reduced dose craniospinal radiation therapy and multi-agent nitrosourea-based chemotherapy.

PURPOSE: To investigate toxicity, and progression-free survival (PFS) of children and adults with newly diagnosed medulloblastoma, pineoblastoma, and other primitive neuroectodermal tumors (PNET) with a combined modality regimen of radiation therapy and adjuvant nitrosourea-based chemotherapy. PATIENTS AND METHODS: Between 1984 and 1992, 34 evaluable patients with newly diagnosed tumors were treated with chemotherapy and radiotherapy according to a single-arm phase II study. One cycle of chemotherapy was given prior to and for 6 cycles following craniospinal radiotherapy (CSA). Procarbazine, 6-thioguanine, and dibromodulcitol were given before lomustine (CCNU) to enhance CCNU-induced tumor cell kill and to reduce alkyltransferase repair of ethylated DNA. Vincristine was given 1 and 3 weeks after CCNU to kill cells that began to cycle after the challenge of the first four drugs. Chemotherapy was given in the outpatient setting. CSA radiation was planned to deliver a dose of 54 Gy to the primary tumor site and 24 Gy to the rest of the neuroaxis. Additional radiation was given to bulky disease outside the primary site if present. Hydroxyurea was used during radiotherapy as a radiosensitizer. RESULTS: Patients treated included 27 with medulloblastoma, 5 with pineoblastoma, and 2 with supratentorial PNET. All but 3 medulloblastoma cases were considered high risk either because of bulky residual disease remaining after surgery and/or metastatic disease detected during staging. For the 34 patients, 24 have progressed, 20 have died. Overall estimated PFS was 55% at 3 years and 35% at 5 years. The 5-year survival estimate is 56%. One patient had inadequate staging to determine M stage. Of the remaining 33 patients, there were 19 patients who had metastatic disease at diagnosis (M1 or higher stage) who had a 3- and 5-year PFS of 42 and 21% respectively and 5-year survival of 42%. There were 14 patients who had negative staging (M0 stage) who had a 3- and 5-year PFS of 69 and 52% respectively and 5-year survival of 71%. Of the 27 patients with medulloblastoma, 15 had M1 or higher stage. These 15 patients had a 5-year PFS and overall survival of only 20 and 40% respectively. Medulloblastoma patients with M0 staging had a 5-year PFS and overall survival of 52 and 73% respectively. Overall toxicity was primarily due to mild hematological toxicity and related to the use of the chemotherapy. CONCLUSIONS: The results using this therapy in high-risk groups of patients does not offer any improvement over results reported in other recent studies. The reason for these results may be due to the lowered craniospinal radiation dose.

Adolescent↗
PubMed1996

Phase II study of paclitaxel in patients with recurrent malignant glioma.

PURPOSE: To assess the efficacy and toxicity of paclitaxel administered as a 3-hour infusion to patients with recurrent malignant glioma. PATIENTS AND METHODS: Adult patients with recurrent malignant glioma following radiation therapy, who had received no more than one prior chemotherapy regimen and who had a Karnofsky performance status (KPS) > or = 60, were treated with a 3-hour infusion of paclitaxel every 3 weeks. The initial dose was 210 mg/m2; dose escalation to 240 mg/m2 was allowed. Tumor response was assessed at 6-week intervals using radiographic and clinical criteria. Treatment was continued until documented tumor progression or a total of 12 paclitaxel infusions. RESULTS: Of 41 eligible patients, all were assessable for treatment toxicity and 40 (98%) were assessable for response. The response rate (disease stabilization or better) was 35%. Twenty-nine patients (71%) underwent dose escalation to 240 mg/m2 without the use of growth factors. Toxicities included alopecia (98%), nausea (22%), arthralgias (32%), CNS toxicity (24%), peripheral neuropathy (15%), cardiac toxicity (7%), and myelosuppression (10% grade 3 or 4 hematologic toxicity). No patient developed febrile neutropenia. There was one allergic reaction (2%). CONCLUSION: Paclitaxel is well tolerated at this dose schedule in patients with recurrent malignant glioma, and affords a modest response rate. Because minimal myelotoxicity was encountered in our patients, a dose-escalating phase I/II study of paclitaxel is planned to determine the maximal-tolerated dose (MTD).

Adult↗
PubMed1996

Radiation response and survival time in patients with glioblastoma multiforme.

The determine the value of radiographically assessed response to radiation therapy as a predictor of survival in patients with glioblastoma multiforme (GBM), the authors studied a cohort of 301 patients who were initially treated according to uniform clinical protocols. All patients had newly diagnosed supratentorial GBM and underwent the maximum safe resection followed by external- beam radiation treatment (60 Gy in standard daily fractions or 70.4 Gy in twice-daily fractions of 160 cGy). The radiation response and survival rates were assessable in 222 patients. The extent of resection and the immediate response to radiation therapy were highly correlated with survival, both in a univariate analysis and after correction for age and Karnofsky performance scale (KPS) score in a multivariate Cox model (p< 0.001 for radiation response and p=0.04 for extent of resection). A subgroup analysis suggested that neuroimaging obtained within 3 days after surgery served as a better baseline for assessment of radiation response than images obtained later. Imaging obtained within 3 days after completion of a course of radiation therapy also provided valid radiation response scores. The impact of the radiographically assessed radiation response on survival time was comparable to that of age or KPS score. This information is easily obtained early in the course of the disease, may be of value for individual patients, and may also have implications for the design and analysis of trials of adjuvant therapy for GBM, including volume-dependent therapies such as radiosurgery or brachytherapy.

Adolescent↗
PubMed1995

Medulloblastoma in adults.

PURPOSE: To examine the relationship between extent of disease and outcome in adults with medulloblastoma. METHODS AND MATERIALS: We reviewed the records of all patients over 15 years old with newly diagnosed or recurrent medulloblastoma treated by or referred to the University of California, San Francisco, and recorded demographic characteristics, clinical symptoms, radiographic findings, extent of resection, staging, myelography, computerized tomography (CT) scans or magnetic resonance (MR) images of the spine, histopathological assessment, treatment received, treatment response, recurrence patterns, and survival duration. RESULTS: A total of 47 patients were identified, 26 of whom were designated "poor-risk" because they had < 75% removal of tumor, metastatic disease, or brain-stem or leptomeningeal invasion. All patients had radiation therapy; 32 had adjuvant chemotherapy. Twenty-two patients (47%) died of tumor progression, 19 are progression-free, and 6 are alive with disease. The median survival time was 282 weeks in poor-risk patients and has not been reached in good-risk patients. Overall and disease-free 5-year survival rates differed significantly between the two groups (81% vs. 54%, p = 0.03 and 58% vs. 38%, p = 0.05, respectively). Tumors most often recurred in the posterior fossa. The median survival time from recurrence was 77 weeks (range 44 to 89 weeks). CONCLUSION: These findings are similar to those reported for children. Therefore, staging and treatment in adults should be approached the same way as in children: staging should include cerebrospinal fluid assessment and spinal imaging. Treatment should be based on staging, and should include craniospinal irradiation; additional chemotherapy should probably be reserved for poor-risk patients.

Adolescent↗
PubMed1995

Radiation therapy for primary intracranial germ-cell tumors.

PURPOSE: To evaluate the diagnosis, therapy, and survival of patients with intracranial germ-cell tumors. To define the role of prophylactic craniospinal irradiation and chemotherapy necessary to impact on survival. METHODS AND MATERIALS: Forty-eight patients with surgically confirmed or suspected primary intracranial germ-cell tumors treated at UCSF between 1968-1990 were reviewed. Thirty-four patients had a pathologic diagnosis, including 24 germinomas, 3 malignant teratomas, 2 choriocarcinomas, 1 embryonal carcinoma, 1 endodermal sinus tumor, and 3 mixed tumors. Information obtained included histology, location, cerebrospinal fluid (CSF) cytology, alpha-fetoprotein (AFP), and beta-human chorionic gonadotropin (B-HCG), metastatic evaluation, radiation details, survival, and sites of failure. Minimum follow-up time was 2 years and ranged to a maximum of 24 years, with a median of 8 years. RESULTS: Median age at diagnosis was 16 years with 36 males and 12 females. Ten of 32 patients had elevated B-HCG at diagnosis; 6 of 29 had elevations of AFP. Cerebrospinal fluid cytology was negative in 35 of 36 patients evaluated; myelography or spinal MRI was positive in only 1 of 31 patients studied. Five-year actuarial disease-free survival after irradiation was 91% for germinomas, 63% for unbiopsied tumors, and 60% for nongerminoma germ-cell tumors with doses of 50-54 Gy to the local tumor site with or without whole-brain or whole-ventricular irradiation. Routine prophylactic cranio-spinal axis irradiation was not given with a spinal only failure rate of 2%. Eleven of 48 patients have expired, with an actuarial 5-year survival rate of 100% for germinomas, 79% for nonbiopsied tumors, and 80% for nongerminoma germ-cell tumors. CONCLUSION: With complete diagnostic craniospinal evaluation, spinal irradiation is not necessary. Cure rates for germinomas are excellent with irradiation alone. Multidrug chemotherapy is necessary with irradiation for nongerminoma germ-cell tumors. Histology is the most important prognostic factor; therefore, all patients should have surgical conformation of their diagnosis so that appropriate treatment can be given.

Adolescent↗
PubMed1995

Fetal dose estimates for radiotherapy of brain tumors during pregnancy.

PURPOSE: To determine clinically the fetal dose from irradiation of brain tumors during pregnancy and to quantitate the components of fetal dose using phantom measurements. METHODS AND MATERIALS: Two patients received radiotherapy during pregnancy for malignant brain tumors. Case 1 was treated with opposed lateral blocked 10 x 15 cm fields and case 2 with 6 x 6 cm bicoronal wedged arcs, using 6 MV photons. Fetal dose was measured clinically and confirmed with phantom measurements using thermoluminescent dosimeters (TLDs). Further phantom measurements quantitated the components of scattered dose. RESULTS: For case 1, both clinical and phantom measurements estimated fetal dose to be 0.09% of the tumor dose, corresponding to a total fetal dose of 0.06 Gy for a tumor dose of 68.0 Gy. Phantom measurements estimated that internal scatter contributed 20% of the fetal dose, leakage 20%, collimator scatter 33%, and block scatter 27%. For case 2, clinical and phantom measurements estimated fetal dose to be 0.04% of the tumor dose, corresponding to a total fetal dose of 0.03 Gy for a tumor dose of 78.0 Gy. Leakage contributed 74% of the fetal dose, internal scatter 13%, collimator scatter 9%, and wedge scatter 4%. CONCLUSIONS: When indicated, brain tumors may be irradiated to high dose during pregnancy resulting in fetal exposure < 0.10 Gy, conferring an increased but acceptable risk of leukemia in the child, but no other deleterious effects to the fetus after the fourth week of gestation. For our particular field arrangements and linear accelerators, internal scatter contributed a small component of fetal dose compared to leakage and scatter from the collimators and blocks, and 18 MV photons resulted in a higher estimated fetal dose than 6 MV photons due to increased leakage and collimator scatter. These findings are not universal, but clinical and phantom TLD measurements estimate fetal dose accurately for energies < 10 MV and should be taken for each pregnant patient considered for treatment to confirm and document acceptable dose.

Adult↗