Biomedical subjects

D A Gorman

Publications and source records attributed to D A Gorman.

13 recordsLinked to original sources

PubMed2001

High-dose trigeminal neuralgia radiosurgery associated with increased risk of trigeminal nerve dysfunction.

OBJECTIVE: Stereotactic radiosurgery is being used with more frequency in the management of patients with trigeminal neuralgia. To improve facial pain outcomes, many centers have increased the prescribed radiation dose to the trigeminal nerve. METHODS: Between April 1997 and December 1999, 68 patients underwent radiosurgery for trigeminal neuralgia with use of the Leksell gamma knife (Elekta Instruments, Norcross, GA) and a single 4-mm isocenter of radiation. Twenty-seven patients (40%) received 70 Gy (low dose) of irradiation and 41 patients (60%) received 90 Gy (high dose). The groups were similar with regard to age, sex, duration of pain, number of prior surgeries, and preexisting trigeminal deficits. The primary facial pain outcomes for analysis were excellent (pain-free, no medications) and good (pain-free, reduced medications). The mean length of follow-up after radiosurgery was 14.4 months (range, 2-36 mo). RESULTS: At last follow-up examination, 11 (41%) of the 27 patients with low-dose radiosurgery remained pain-free compared with 25 (61%) of the 41 patients with high-dose radiosurgery (P = 0.17). Additional surgery was performed in 12 low-dose patients (44%) and 8 high-dose patients (20%) (P = 0.05). High-dose radiosurgery was associated with an increased rate of permanent trigeminal nerve dysfunction (54% versus 15%, P = 0.003). Bothersome dysesthesias occurred in 13 high-dose patients (32%), whereas only 1 low-dose patient had this complication (P = 0.01). Three high-dose patients (8%) developed corneal numbness after radiosurgery. Pain recurred with more frequency in patients not developing trigeminal nerve dysfunction after radiosurgery (9 of 22 patients, 41 %) compared with those who sustained facial numbness, paresthesias, or dysesthesias (4 of 27 patients, 15%); however, the difference was not statistically significant (P = 0.08). CONCLUSION: Higher doses of radiation may correlate with better facial pain outcomes after radiosurgery for trigeminal neuralgia. However, the incidence of significant trigeminal nerve dysfunction is markedly increased after radiosurgery for patients receiving high-dose radiosurgery. Because of the nonselective nature of this ablative technique, dose prescription should be limited to less than 90 Gy.

Aged↗

PubMed2001

Results of combined stereotactic radiosurgery and transarterial embolization for dural arteriovenous fistulas of the transverse and sigmoid sinuses.

OBJECT: Most dural arteriovenous fistulas (DAVFs) of the transverse and sigmoid sinuses do not have angiographically demonstrated features associated with intracranial hemorrhage and, therefore, may be treated nonsurgically. The authors report their experience using a staged combination of radiosurgery and transarterial embolization for treating DAVFs involving the transverse and sigmoid sinuses. METHODS: Between 1991 and 1998, 25 patients with DAVFs of the transverse and/or sigmoid sinuses were treated using stereotactic radiosurgery; 22 of these patients also underwent transarterial embolization. Two patients were lost to follow-up review. Clinical data, angiographic findings, and follow-up records for the remaining 23 patients were collected prospectively. The mean duration of clinical follow up after radiosurgery was 50 months (range 20-99 months). The 18 women and five men included in this series had a mean age of 57 years (range 33-79 years). Twenty-two (96%) of 23 patients presented with pulsatile tinnitus as the primary symptom; two patients had experienced an earlier intracerebral hemorrhage (ICH). Cognard classifications of the DAVFs included the following: I in 12 patients (52%), IIa in seven patients (30%), and III in four patients (17%). After treatment, symptoms resolved (20 patients) or improved significantly (two patients) in 96% of patients. One patient was clinically unchanged. No patient sustained an ICH or irradiation-related complication during the follow-up period. Seventeen patients underwent follow-up angiographic studies at a mean of 21 months after radiosurgery (range 11-38 months). Total or near-total obliteration (> 90%) was seen in 11 patients (65%), and more than a 50% reduction in six patients (35%). Two patients experienced recurrent tinnitus and underwent repeated radiosurgery and embolization at 21 and 38 months, respectively, after the first procedure. CONCLUSIONS: A staged combination of radiosurgery and transarterial embolization provides excellent symptom relief and a good angiographically verified cure rate for patients harboring low-risk DAVFs of the transverse and sigmoid sinuses. This combined approach is a safe and effective treatment strategy for patients without angiographically determined risk factors for hemorrhage and for elderly patients with significant comorbidities.

Adult↗

PubMed2000

Stereotactic radiosurgery for recurrent ependymoma.

BACKGROUND: Patients with recurrent intracranial ependymomas were evaluated to assess local control, overall survival, and complications from stereotactic radiosurgery (SRS). METHODS: Twelve patients (with a total of 17 tumors) with recurrent ependymoma underwent SRS. Local failure was defined as tumor progression within the prescription isodose volume, and marginal failure was defined as tumor progression adjacent to the SRS prescription isodose volume. Tumor progression away from the prescription volume was considered distant failure. Eleven of the 12 patients had undergone previous resection and external beam radiation therapy (46-56 Grays [Gy]; median, 54 Gy) before radiosurgery, and 1 patient had failure after complete resection alone. Age at SRS ranged from 5-56 years (median, 29 years). Three patients were female. The marginal tumor dose was 12-24 Gy (median, 18 Gy). One to 14 isocenters (median, 4 isocenters) were utilized to irradiate volumes of 0.3-15.5 cm(3) (median, 3.2 cm(3)). RESULTS: The duration of follow-up ranged from 2.5-60 months (median, 22.5 months). The median overall survival after SRS was 3.4 years (range, 1.4-5 years). In-field local control was achieved in 14 of the 17 tumor sites and estimated 3-year local control was 68%. There were two in-field failures and one marginal failure. Distant failure occurred in two patients. Two patients developed treatment-related complications after SRS. CONCLUSIONS: SRS provides good local tumor control for patients with recurrent intracranial ependymoma and may have a favorable impact on survival. SRS should be evaluated more extensively in the initial treatment of patients with ependymoma to minimize local failure after surgical management.

Adolescent↗

PubMed2000

Stereotactic radiosurgery for tumor-related trigeminal pain.

OBJECTIVE: Between 1 and 6% of patients who are diagnosed with facial pain syndromes have tumors that involve the trigeminal nerve. We report the effects of stereotactic radiosurgery on tumor-related trigeminal pain. METHODS: We reviewed results, from a prospective database, for 24 consecutive patients with cranial base tumors and either trigeminal neuralgia (n = 9) or painful trigeminal neuropathy (n = 15) who underwent stereotactic radiosurgery during an 8-year period. The tumor was the radiosurgical target for these patients (not the trigeminal nerve or ganglion). The median clinical follow-up period after radiosurgery was 45 months (range, 12-90 mo); the median neuroimaging follow-up period was 36 months (range, 5-86 mo). RESULTS: There were 20 women and 3 men, with an average age of 57 years (range, 33-79 yr). One patient had bilateral facial pain and underwent staged radiosurgery. Pathological classification indicated 16 meningiomas and 8 malignant cranial base tumors (adenoid cystic carcinoma, n = 6; squamous cell carcinoma, n = 2). Twelve of 24 patients (50%) were initially free of pain, and another 11 patients (46%) reported that they experienced significant improvements in their trigeminal pain syndromes after radiosurgery. The tumor histological type, quality of facial pain, preexisting facial numbness, and marginal and maximal radiation doses were not related to postradiosurgical facial pain outcomes. Three patients with malignant cranial base carcinomas developed recurrent facial pain, 1 to 9 months after radiosurgery, which was related to tumor progression outside the irradiated volume. One patient (4%) developed new partial V2 numbness after radiosurgery. CONCLUSION: Radiosurgery proved to be effective in improving tumor-related trigeminal pain for the majority of patients with either benign or malignant cranial base tumors. Recurrence of trigeminal pain is frequent for patients with malignant cranial base carcinomas and is related to tumor progression.

Adult↗

PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗

PubMed1999

A multi-institutional analysis of complication outcomes after arteriovenous malformation radiosurgery.

PURPOSE: To better understand radiation complications of arteriovenous malformation (AVM) radiosurgery and factors affecting their resolution. METHODS AND MATERIALS: AVM patients (102/1255) who developed neurological sequelae after radiosurgery were studied. The median AVM marginal dose (Dmin) was 19 Gy (range: 10-35). The median volume was 5.7 cc (range: 0.26-143). Median follow-up was 34 months (range: 9-140). RESULTS: Complications consisted of 80/102 patients with evidence of radiation injury to the brain parenchyma (7 also with cranial nerve deficits, 12 also with seizures, 5 with cyst formation), 12/102 patients with isolated cranial neuropathies, and 10/102 patients with only new or worsened seizures. Severity was classified as minimal in 39 patients, mild in 40, disabling in 21, and fatal in 2 patients. Symptoms resolved completely in 42 patients for an actuarial resolution rate of 54% +/- 7% at 3 years post-onset. Multivariate analysis identified significantly greater symptom resolution in patients with no prior history of hemorrhage (p = 0.01, 66% vs. 41%), and in patients with symptoms of minimal severity: headache or seizure as the only sequelae of radiosurgery (p < 0.0001, 88% vs. 34%). CONCLUSION: Late sequelae of radiosurgery manifest in varied ways. Further long-term studies of these problems are needed that take into account symptom severity and prior hemorrhage history.

Adrenal Cortex Hormones↗

PubMed1999

Decrease in cranial nerve complications after radiosurgery for acoustic neuromas: a prospective study of dose and volume.

PURPOSE: To determine whether tumor control can be maintained, and cranial nerve complications decreased by reducing the radiosurgical dose to acoustic neuromas. METHODS AND MATERIALS: Forty-two consecutive patients with acoustic neuromas were treated prospectively using an initial standard-dose protocol in which the tumor-margin dose (50% isodose) was 20, 18, and 16 Gy for tumor diameters < or =2 cm, 2.1-3 cm, and 3.1-4 cm, respectively. After analysis of tumor control and complications, the next 40 patients were treated using a reduced-dose protocol in which the tumor-margin dose was 16, 14, and 12 Gy for tumor volumes < or =4.2 cm3, 4.2-14.1 cm3, and > or =14.1 cm3, respectively. RESULTS: Median follow-up was 2.3 years (range 0.1-6) for 80 of 82 patients. The actuarial incidence (Kaplan-Meier) of facial neuropathy at 2 years was 38% (95% confidence interval [CI], 23-53%) for the standard-dose protocol and 8% (95% CI, 0-17%) for the reduced-dose protocol (p = 0.006). Univariate analysis revealed an association between risk of facial neuropathy and use of CT planning, higher radiosurgical dose, and neurofibromatosis, type 2. Multivariate analysis revealed that the only factor associated with increased risk of post-treatment facial neuropathy was a tumor margin dose > or =18 Gy. The incidence of trigeminal neuropathy at 2 years was 29% (95% CI, 15-43%) for the standard-dose protocol and 15% (95% CI, 3-27%) for the reduced-dose protocol (p = 0.17). Univariate analysis revealed an association between maximal tumor diameter and increased risk of trigeminal neuropathy; multivariate analysis revealed no additional statistically significant associations between tumor and dosimetric and patient characteristics and risk of trigeminal neuropathy. Two tumors in the standard-dose protocol required salvage surgery for progression. To date, no tumor in the reduced-dose protocol has shown progression. CONCLUSION: Our analysis suggests that a tumor margin dose of > or =18 Gy is the most significant risk factor for facial nerve complications after acoustic neuroma radiosurgery. Patients receiving a minimal tumor dose of < or =16 Gy are at significantly lower risk for permanent facial neuropathy after radiosurgery. Longer follow-up is required before definitive conclusions can be made about the ultimate rate of tumor control using reduced radiosurgical doses.

Adult↗

PubMed1999

Stereotactic radiosurgery and particulate embolization for cavernous sinus dural arteriovenous fistulae.

OBJECTIVE: To evaluate the safety and efficacy of stereotactic radiosurgery, either with or without transarterial embolization, in the treatment of patients with dural arteriovenous fistulae (DAVFs) of the cavernous sinus. METHODS: We reviewed the findings, from a prospectively established database, for 20 patients with cavernous sinus DAVFs who were treated with either radiosurgery alone (n = 7) or radiosurgery and transarterial embolization (n = 13) in a 7-year period. The median follow-up period after radiosurgery was 36 months (range, 4-59 mo). RESULTS: Nineteen of 20 patients (95%) experienced improvement of their clinical symptoms. Fourteen of 15 patients (93%) experienced either total (n = 13) or nearly total (n = 1) obliteration of their DAVFs, as documented by angiography performed a median of 12 months after radiosurgery. No patient experienced a recurrence of symptoms after angiography showed DAVF obliteration. Two patients developed new neurological deficits after embolization procedures. One patient exhibited temporary aphasia secondary to a venous infarction; another patient exhibited permanent VIth cranial nerve weakness related to acute cavernous sinus thrombosis. Two patients experienced recurrent symptoms and underwent repeat transarterial embolization at 7 and 12 months; both patients achieved clinical and angiographic cures (5 and 10 mo later, respectively). One patient experienced recurrent visual symptoms and underwent transvenous embolization 4 months after radiosurgery. CONCLUSION: Staged radiosurgery and transarterial embolization provided both rapid symptom relief and long-term cures for patients with cavernous sinus DAVFs. Radiosurgery alone was effective for patients with DAVFs whose arterial supply was not accessible via a transarterial approach, although the time course of symptom improvement was longer, compared with patients who also underwent embolization.

Adult↗

PubMed1999

The Mayo Clinic gamma knife experience: indications and initial results.

OBJECTIVE: To review the results and expectations of contemporary stereotactic radiosurgery. MATERIAL AND METHODS: We conducted a retrospective analysis of 1,033 consecutive patients who underwent gamma knife radiosurgery at Mayo Clinic Rochester between January 1990 and January 1998. RESULTS: The number of patients undergoing radiosurgery increased from 57 in 1990 to 216 in 1997. Of 97 patients with arteriovenous malformations who underwent follow-up angiography 2 years or more after a single radiosurgical procedure, 72 (74%) had complete obliteration of the vascular malformation. Of 209 patients who underwent radiosurgery for benign tumors (schwannomas, meningiomas, or pituitary adenomas) and had radiologic studies after 2 years or more of follow-up, tumor growth control was noted in 200 (96%). Tumor growth was also controlled in 90% of brain metastatic lesions at a median of 7 months after radiosurgery. Of 20 patients with trigeminal neuralgia and follow-up for more than 2 months, 14 (70%) were free of pain after radiosurgery. CONCLUSION: Radiosurgery is a safe and effective management strategy for a wide variety of intracranial disorders. Use of radiosurgical treatment should continue to increase as more data become available on the long-term results of this procedure.

Arteriovenous Fistula↗

PubMed1997

The role of stereotactic radiosurgery in the treatment of malignant skull base tumors.

PURPOSE: To determine the efficacy and toxicity of stereotactic radiosurgery in the treatment of malignant skull base tumors. METHODS AND MATERIALS: Thirty-two patients with 35 newly diagnosed or recurrent malignant skull base tumors < or = 33.5 cm3 were treated using the Leksell Gamma unit. Tumor histologies included: adenoid cystic carcinoma [12], basal cell carcinoma [1], chondrosarcoma [1], chordoma [8], nasopharyngeal carcinoma [3], osteogenic sarcoma [2], and squamous cell carcinoma [8]. RESULTS: After a median follow-up of 2.3 years, 83% +/- 15% (+/-95% confidence interval) of patients experienced a symptomatic response to treatment. Local control at the skull base was 95 +/- 9% at 2 years and 78 +/- 23% at 3 years. Local-regional control above the clavicles was 75 +/- 15% at 1 year and 51 +/- 20% at 2 years. Overall and cause specific survival were identical, 82 +/- 13% at 1 year, 76 +/- 14% at 2 years, and 72 +/- 16% at 3 years. One patient developed a radiation-induced optic neuropathy 12 months after radiosurgery. CONCLUSION: Stereotactic radiosurgery using the Leksell Gamma Unit can provide durable tumor control and symptomatic relief with acceptable toxicity in the majority of patients with malignant tumors 4 cm or less in size involving the skull base. Further evaluation of more patients with longer follow-up is warranted.

Adolescent↗

PubMed1997

Stereotactic radiosurgery for glomus jugulare tumors: a preliminary report.

PURPOSE: This study was conducted to evaluate the toxicity and efficacy of stereotactic radiosurgery treatment of glomus jugulare tumors. METHODS AND MATERIALS: Between March 1990 and January 1995, nine patients underwent stereotactic radiosurgery with the Leksell Gamma Knife Unit for glomus jugulare tumors. Previous treatment had failed in four patients. The seven female and two male patients had a median age of 67 years. RESULTS: The median time from stereotactic radiosurgery to the most recent clinical follow-up was 20 months (range 7-65 months). Subjectively, 7 of 9 patients noted a decrease in the intensity of their symptoms. Objectively, 8 of 9 tumors remained stable in size by serial magnetic resonance imaging scans and one was smaller. There was no acute or chronic toxicity. CONCLUSION: This early experience suggests that stereotactic radiosurgery is a promising treatment for glomus jugulare tumors.

Adult↗

PubMed1996

The role of radiosurgery and particulate embolization in the treatment of dural arteriovenous fistulas.

Over the past 5 years 29 patients with dural arteriovenous fistulas (AVFs) were treated by the authors using the Leksell radiosurgical gamma knife unit. Within 2 days after radiosurgery, 17 patients with AVFs that exhibited retrograde pial or cortical venous drainage (12 patients) and/or produced intractable bruit (eight patients) underwent particulate embolization of external carotid feeding vessels. The rationale for this treatment strategy was that radiosurgery was expected to cause obliteration of most fistulas after 12 to 36 months. In patients with bruit, ocular symptoms, or in those at risk for hemorrhage, treatment with embolization after radiosurgery kept the fistulas angiographically visible for radiosurgical targeting yet offered palliation of symptoms and temporary, partial protection from hemorrhage during the latency period. In 12 patients, preobliteration embolization immediately reduced (10 patients) or eliminated (two patients) retrograde pial venous drainage. To date, no lesion has hemorrhaged after treatment. Angiography 1 to 3 years posttreatment in 18 patients showed total obliteration of 13 fistulas (72%) and partial obliteration of five (28%). Radiosurgery, followed by embolization when retrograde pial venous drainage, intractable bruit, and/or major external carotid artery supply is present, appears to be a promising treatment for selected patients with symptomatic dural AVFs.

Adult↗

PubMed1995

Nimodipine as an add-on therapy for intractable epilepsy.

OBJECTIVE: To analyze the effect of nimodipine in patients with intractable epilepsy. DESIGN: We conducted a double-blind placebo-controlled crossover study in 95 patients. MATERIAL AND METHODS: The dihydropyridine calcium antagonist nimodipine was used as add-on therapy (60 mg four times a day) in a 1-year placebo-controlled crossover study in 71 patients with localization-related epilepsy and 24 with generalized seizure disorders. Of the 95 patients, 81 were receiving two or more antiepileptic drugs. Patients diaries were used to record the number of seizures and any side effects. RESULTS: Nimodipine seemed to be well tolerated during the study; only two patients were unable to complete the study because of probable adverse effects. The trial demonstrated no significant crossover effect and no significant effect of nimodipine on either the mean or the median number of seizures or seizure days. The peak median serum nimodipine level was less than 5 ng/mL in the 78 patients who completed the study. CONCLUSION: This clinical trial found no beneficial effect with use of nimodipine as add-on therapy for intractable epilepsy. Potential reasons for the absence of efficacy of nimodipine may be the inclusion of patients with very refractory seizure disorders or the relatively low serum nimodipine concentrations related to the pharmacokinetic effect of concurrent antiepileptic medication.

Adult↗