Biomedical subjects

William A Friedman

Publications and source records attributed to William A Friedman.

24 records · Page 2Linked to original sources

PubMed2003

Oligodendroglioma: does deferring treatment compromise outcome?

This study reports the University of Florida experience treating oligodendrogliomas with the goal of identifying the factors that predict favorable outcome. Between 1958 and June 1998, 51 patients (aged 5-75 years) were diagnosed with pure oligodendroglioma at the University of Florida. Histologic grade was anaplastic in 19 patients, low-grade in 30 patients, and unknown in one patient. Twelve patients were treated with surgery alone (10 with low-grade tumors). Thirty-nine patients underwent postoperative radiotherapy after surgery (plus chemotherapy in four patients). A biopsy was performed in 10 patients, 40 underwent subtotal or gross total resection, and one had surgery of unknown extent. Thirteen patients with a radiographic abnormality consistent with a low-grade glioma had the initiation of definitive treatment (i.e., surgery with or without radiotherapy) deferred for a median of 4.5 years before undergoing treatment for worsening symptoms or radiographic progression. Absolute survival for the entire group (51 patients) at 5, 10, and 20 years from the date of initial treatment was 61%, 37%, and 31%, respectively, and at 5, 10, and 20 years from the date of initial diagnosis was 65%, 43%, and 34%, respectively. No patient died of intercurrent disease. Multivariate analysis for absolute survival from the time of initial treatment demonstrated young age (young patients fared better than older patients) and size (<5 cm better than > or =5 cm) to be significant variables. No patient under the age of 21 years (n = 8) at the time of diagnosis has died in this series. Deferring aggressive treatment did not alter survival. Multivariate analysis for favorable absolute survival based on the time from initial diagnosis demonstrated young age and presentation with seizures alone to be statistically significant for favorable outcomes. Approximately one third of patients with oligodendroglioma appear to be cured with aggressive treatment. Age is the most important predictor of long-term progression-free and absolute survival with young patients (especially aged <21 years) doing much better than older patients. Deferring aggressive treatment (surgery and/or radiation) until symptoms clearly indicate tumor progression does not compromise outcome for a select group of patients who are diagnosed at a young age with a nonenhancing mass on MR and seizures as the lone presenting symptom.

Adolescent↗

PubMed2003

Analysis of factors predictive of success or complications in arteriovenous malformation radiosurgery.

OBJECTIVE: This study was undertaken to determine which factors were statistically predictive of radiological and clinical outcomes in the radiosurgical treatment of arteriovenous malformations (AVMs). METHODS: The computerized dosimetric and clinical data for 269 patients were reviewed. The AVM nidus was hand-contoured on successive enhanced computed tomographic slices through the nidus, to allow detailed determinations of nidus volume, target miss, normal brain tissue treated, dose conformality, and dose gradient. In addition, a number of patient and treatment factors, including Spetzler-Martin grade, presenting symptoms, dose, number of isocenters, radiological outcome, and clinical outcome, were subjected to multivariate analysis. RESULTS: Two hundred twenty-five patients were treated with radiosurgery for the first time, and 44 patients underwent radiosurgical retreatment. One hundred forty-three patients had AVMs located in or near "eloquent" brain areas and 126 patients did not. Seventy patients demonstrated preoperative neurological findings related to the AVM and 199 did not. Twenty-six patients had previously undergone endovascular treatment and 10 patients had previously undergone surgical treatment of their AVMs. Of the 269 patients studied, 228 experienced no complication, 10 (3.7%) experienced a transient radiation-induced complication, 3 (1%) experienced a permanent radiation-induced complication, and 28 (10%) experienced posttreatment hemorrhage. CONCLUSION: None of the analyzed factors was predictive of hemorrhage after radiosurgery in this study. The 12-Gy volume was predictive of permanent radiation-induced complications. Eloquent AVM location and 12-Gy volume were correlated with the occurrence of transient radiation-induced complications. Better conformality was correlated with a reduced incidence of transient complications. Lower Spetzler-Martin grades, higher doses, and steeper dose gradients were correlated with radiological success.

Brain Damage, Chronic↗

PubMed2003

Salvage retreatment after failure of radiosurgery in patients with arteriovenous malformations.

OBJECT: The goal of this study was to evaluate the outcomes of patients who underwent repeated radiosurgery to treat a residual intracranial arteriovenous malformation (AVM) after an initial radiosurgical treatment failure. METHODS: The authors reviewed the cases of 52 patients who underwent repeated radiosurgery for residual AVM at the University of Florida between December 1991 and June 1998. In each case, residual arteriovenous shunting persisted longer than 36 months after the initial treatment; the mean interval between the first and second treatment was 41 months. Each AVM nidus was measured at the time of the original treatment and again at the time of retreatment, and the dosimetric parameters of the two treatments were compared. After retreatment, patients were followed up and their outcomes were evaluated according to a standard posttreatment protocol for radiosurgery for AVMs. The mean original lesion volume was 13.8 cm3 and the mean volume at retreatment was 4.7 cm3, for an average volume reduction of 66% after the initial treatment failure. Only two AVMs (3.8%) failed to demonstrate size reduction after the primary treatment. The median doses on initial and repeated treatment were 12.5 and 15 Gy, respectively. Five patients were lost to follow up and five refused neuroimaging follow up. One patient died of a hemorrhage shortly after retreatment. Of the remaining 41 patients, 24 had evidence of cure, 15 on angiographic studies and nine on magnetic resonance (MR) images. Seventeen had evidence of treatment failure, 10 on angiographic studies and seven on MR images. By angiographic criteria alone, the cure rate after retreatment was 60%, whereas according to angiographic and MR imaging results, the cure rate was 59%. CONCLUSIONS: Although initial radiosurgical treatment failed to obliterate the AVM in these 52 patients, it did produce a substantial therapeutic effect (volume reduction). This size reduction commonly allowed higher doses to be delivered during radiosurgical retreatment. The results show rates of angiographically confirmed cure comparable to primary treatment and a low incidence of complications, indicating that salvage radiosurgical retreatment is a safe and effective therapy in cases of failed AVM radiosurgery.

Adolescent↗

PubMed2002

Radiosurgery for paraganglioma of the temporal bone.

PURPOSE: To report the outcome of patients with paraganglioma of the temporal bone treated with stereotactic radiosurgery at the University of Florida. METHODS AND MATERIALS: Between January 1997 and June 1999, five patients with paraganglioma of the temporal bone were treated with Linac-based stereotactic radiosurgery at the University of Florida. The ages of the three female and two male patients were between 40 and 88 years (median, 49 years). Four patients were treated at initial presentation, and one had recurrent disease. Treatment volumes ranged from 4.9 cm3 to 18.4 cm3, with a mean of 10.84 cm3. The dose applied to the margin of the tumor varied from 12.5 to 15 Gy (median, 15 Gy). The treatment dose was specified to the 80% isodose shell in two cases and to the 70% isodose shell in three cases. The median follow-up time was 27 months, ranging from 14 to 50 months. RESULTS: One of four previously untreated patients had a relapse at the primary tumor site. Treatment failure occurred at the field margin 6 months after radiosurgery; the patient was subsequently treated with fractionated stereotactic radiotherapy and at the time of analysis had no evidence of disease, 21 months after initiation of salvage therapy. The patient treated at the time of recurrence after conventional radiotherapy had a local recurrence 40 months after radiosurgery. At the time of this recurrence, the patient had biopsy-proven metastatic disease in two cervical lymph nodes, and no salvage therapy was performed. All patients were alive at the time of the analysis, one with disease present. Presenting symptoms improved in two patients and stabilized in one. The two patients who had local recurrence develop had worsening of their symptoms. One patient had a cranial nerve V palsy develop 6 months after treatment, which resolved after a few months. CONCLUSIONS: In this series, the results with stereotactic radiosurgery are discouraging compared with our results with conventional fractionated radiotherapy in patients with paraganglioma of the temporal bone.

Adult↗

PubMed2002

Temporary ventricular drainage and emergency radiotherapy in the management of hydrocephalus associated with germinoma.

OBJECT: The authors used an alternative strategy to avoid shunt placement for hydrocephalus associated with germinoma, and the ensuing complications. METHODS: Between 1998 and 2000, five patients presenting with germinomas of the pineal area and symptomatic obstructive hydrocephalus were treated with a novel strategy. On arrival, they underwent ventriculostomy placement and one of several surgical procedures to obtain tissue for diagnosis. Within several days of the initial diagnosis, stereotactically guided fractionated radiotherapy was started. All patients experienced rapid tumor shrinkage and resolution of hydrocephalus, allowing discontinuation of external ventricular drainage without the need for permanent shunting of cerebrospinal fluid. To date, follow up reveals 100% radiographically and clinically confirmed tumor control. CONCLUSIONS: Prompt resolution of hydrocephalus and absence of complications make this a potentially valuable therapy for control of germinomas and their symptoms.

Adolescent↗

PubMedDate not supplied

Management of acoustic schwannoma.

PURPOSE: To discuss the optimal management for patients with acoustic schwannoma. MATERIALS AND METHODS: Review of the pertinent literature. RESULTS: Microsurgery, stereotactic radiosurgery, and fractionated radiotherapy result in cure rates that approximate 90% at 5 years. Depending on tumor extent and surgical approach, the morbidity of microsurgery may exceed that of stereotactic radiosurgery and fractionated radiotherapy. Patients with useful hearing before treatment may have a higher likelihood of hearing preservation after radiotherapy compared with radiosurgery. CONCLUSION: Both microsurgery and radiosurgery are good options for patients with tumors less than 3 cm. Depending on tumor extent and the surgical approach, the morbidity of microsurgery may exceed that of radiosurgery. Patients with useful hearing may have a higher likelihood of hearing preservation after radiotherapy. Microsurgery is preferred for patients in whom the disease progresses after initial irradiation and in patients with tumors larger than 3 cm.

Combined Modality Therapy↗