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D R Macdonald

Publications and source records attributed to D R Macdonald.

At least 37 records · Page 2Linked to original sources
PubMed1995

Primary diffuse leptomeningeal oligodendroglioma. Case report.

The authors describe a case of a diffuse primary leptomeningeal oligodendroglioma in a 17-year-old girl who presented with raised intracranial pressure and hydrocephalus. She underwent imaging studies and a left frontotemporal craniotomy that revealed a cystic oligodendroglioma in the suprasellar cistern and spread of neoplastic cells to the spinal leptomeninges. The tumor showed little response to maximum radiotherapy and chemotherapy, and the patient died from complications of high-dose chemotherapy 2 years after diagnosis. Postmortem examination of the brain and spinal cord revealed diffuse meningeal infiltration by neoplastic cells and no evidence of an intraparenchymal origin. Glial heterotopias were noted at several sites along the brain base, adding circumstantial support to the theory that leptomeningeal gliomas are derived from ectopic glial tissue in the subarachnoid space.

Adolescent↗
PubMed1994

A prospective study of short-course radiotherapy in poor prognosis glioblastoma multiforme.

PURPOSE: Older age and poor performance status at presentation are unfavorable prognostic factors for patients with glioblastoma multiforme. Some studies suggest a shorter, palliative course of radiotherapy may confer similar benefits as compared to a radical course in such patients. We report a prospective, single arm trial, describing the use of a short-course of radiation in patients with glioblastoma and poor prognostic features. METHODS AND MATERIALS: Twenty-nine patients with pathologically confirmed glioblastoma and age > or = 65 years or with initial KPS < or = 50 were treated with a short-course of whole brain radiotherapy (30 Gy/10 fractions/2 weeks). Computer tomography tumor volume, dexamethasone requirements, Spitzer quality of life index, and Karnofsky performance status were measured pre and 1 month postradiation. Overall survival for the study patients was compared with that of radically treated and supportive care only historical controls. RESULTS: Indices of tumor response were stable or improved in 60% of patients evaluable 1 month postradiotherapy. Median survival for all study patients was 6 months. Median survivals in similar groups of radically treated and supportive care only patients were 10 and 1 month(s), respectively. A survival advantage for the radical vs. short-course treatment was observed for the subset of patients with a pretreatment KPS > 50. CONCLUSION: Elderly patients with a low pretreatment KPS (< or = 50) may be treated adequately with a short, palliative course of radiotherapy. Elderly patients with a higher pretreatment KPS (> 50), however, may benefit from a higher dose radiotherapy regimen.

Aged↗
PubMed1994

Absence of hereditary mutations in exons 5 through 9 of the p53 gene and exon 24 of the neurofibromin gene in families with glioma.

Inherited mutations of the p53 and neurofibromin genes are thought to cause two distinct neoplastic disorders in which gliomas occur, the Li-Fraumeni syndrome and neurofibromatosis type 1. We investigated the possibility that inherited mutations in specific regions of these genes also contributed to the clustering of gliomas in otherwise normal families. Twenty-six members of 16 families with glioma were screened for germline mutations of exons 5 through 9 of the p53 gene and exon 24 of the neurofibromin gene using a polymerase chain reaction-single-strand conformation polymorphism method. No germline mutations were found, suggesting that the genetic basis of familial glioma is distinct from that of gliomas occurring in the Li-Fraumeni syndrome, and that inherited mutations of the catalytic domain of neurofibromin do not predispose affected glioma families to these tumors.

Adult↗
PubMed1994

Corticosteroid-induced magnetic resonance imaging changes in patients with recurrent malignant glioma.

PURPOSE: We studied corticosteroid-induced magnetic resonance (MR) scan changes in patients with recurrent malignant glioma to determine if corticosteroid therapy started concurrently with investigational treatment might yield false-positive responses. PATIENTS AND METHODS: Ten symptomatic patients not on corticosteroids when malignant glioma recurred had a baseline MR scan performed before corticosteroid treatment, followed by serial scans at weekly intervals for 1 month while on dexamethasone (16 mg/d). The maximum cross-sectional areas and volumes of the gadolinium-enhancing regions (tumor) and T2-weighted abnormalities (tumor plus edema) were compared quantitatively and qualitatively for each series of scans. RESULTS: Nine of 10 patients (90%) had a measurable reduction in the size of the gadolinium-enhancing region or T2-weighted abnormality with corticosteroid treatment. The maximum cross-sectional area and volume of the gadolinium-enhancing region decreased by at least 25% in three of 10 patients (30%). The maximum cross-sectional area and volume of the T2-weighted abnormality decreased by at least 25% in five of 10 patients (50%). Maximum measurable radiologic improvement was evident within 2 weeks in most patients. MR scans were judged improved by the reporting neuroradiologist in seven of 10 (70%). These subjective visual improvements were also evident within 2 weeks, but generally described as slight or modest. CONCLUSION: Corticosteroid-induced MR scan reductions in tumor size may confound the assessment of response of recurrent malignant gliomas to investigational agents. For patients who start corticosteroids for symptom control, investigational treatment should be delayed until a new baseline MR image is established 2 weeks later. Response is then judged by comparing subsequent MR scans with the new corticosteroid-influenced baseline image.

Adult↗
PubMed1994

Cognitive functioning in long-term survivors of high-grade glioma.

In a pilot study, two groups of patients with malignant glioma underwent sequential neuropsychological evaluations after successful tumor treatment. Group 1 included nine patients treated from 1981 to 1985; all patients received irradiation and eight underwent chemotherapy. The baseline neuropsychological assessment was performed 1 to 63 months after tumor diagnosis, with follow-up evaluations at irregular intervals over the next 3 to 7 years. Six patients in Group 1 exhibited impairment on most measures at baseline; subsequently, two patients developed profound cognitive impairment. Initially, three patients functioned in the average range on most tasks; thereafter, two deteriorated on one measure each. Group 2 was ascertained prospectively and included 16 patients treated from 1985 to 1987, all of whom received irradiation and chemotherapy. The first evaluation was performed 18 months after diagnosis, then every 6 months for 2 years, and then yearly. Compared to a control group, those in Group 2 had significant cognitive impairment at baseline. Cognitive performance did not change over the next 12 months in 10 patients who remained free of tumor, but within 2 years of baseline testing, deterioration on specific tasks was evident in two of seven disease-free survivors. When last tested, five of six disease-free survivors had deteriorated on one or more measures. Unlike Group 1, severe global cognitive impairment was not seen, perhaps because Group 2 was followed for a shorter time. Verbal and nonverbal composite scores derived from intelligence quotient (IQ) tests showed less impairment at baseline than did other measures and were more likely to remain stable subsequently. Verbal memory and sustained attention were the most impaired at baseline, and verbal learning and flexibility in thinking showed the greatest tendency to decline over time. Cognitive functioning in survivors of high-grade glioma is best measured and monitored by tests that probe a broader spectrum of abilities than IQ. Neuropsychological measures used in this analysis lacked sensitivity at the lower end of the impaired range. Future studies should use tests better able to discern cognitive differences at low performance levels. Based on this experience, the authors conclude that most long-term survivors of high-grade glioma will have significant cognitive difficulties, usually evident by the first assessment; some patients will develop profound impairment years later, and few are capable of fully independent living.

Adult↗
PubMed1993

Primary cerebral fibrosarcomas. Clinicopathologic study and review of the literature.

BACKGROUND: Primary of the brain and meninges are uncommon tumors. Information regarding optimum treatment is limited due to their rarity, and the best form of therapy is not yet known. METHODS: Nine patients between the ages of 22 and 61 years with primary fibrosarcomas confined to the brain and meninges were studied clinicopathologically. Tumors were superficially located in five patients and intracerebrally or deep in four patients. Treatment consisted of maximum feasible surgical resection (seven patients, gross total; one, subtotal; one, no surgery before death) and radiation therapy (45-60 Gy conventional fractionation) in eight of nine patients. RESULTS: Fibrosarcomas were moderate or high grade in seven of nine patients (78%). Immunohistochemical reactions with antisera to glial fibrillary acid protein (GFAP), cytokeratin, vimentin, desmin, and S-100 demonstrated vimentin positivity in five of nine patients and cytokeratin positivity in two of nine patients. Individual GFAP-positive cells were seen in two cases, thought to represent trapped reactive astrocytes. None were S-100-positive or desmin-positive. Eight patients have died, with a median survival time of 7.5 months (range, 1 day-96 months). Local recurrence developed in eight patients and distant recurrence in six patients. Systemic metastases developed in four patients (50%) and meningeal seeding in four patients (50%). Longer survival was observed in superficially located tumors (range, 7.5 months-96 months) compared with intracerebral tumors (range, 1 day-9 months). CONCLUSIONS: Primary fibrosarcomas of the brain are uncommon tumors, usually of high histologic grade, with a high rate of local recurrence. Their propensity for meningeal and distant relapse distinguishes them from tumors of glial origin. Immunohistochemistry is of limited diagnostic value, although it may facilitate exclusion of other diagnoses. Because the prognosis after conventional surgery with 50-60 Gy external beam radiation therapy is relatively poor, the authors recommend more aggressive therapy with maximal feasible resection followed by external beam radiation therapy to doses of 64-66 Gy. When effective chemotherapy is established for soft tissue sarcomas of the extremities, this should be evaluated in view of the high incidence of distant metastases.

Adult↗
PubMed1993

Phase II study of tiazofurin in gliomas in adults. A National Cancer Institute of Canada study.

The National Cancer Institute of Canada conducted a Phase II study of tiazofurin 1100 to 1375 mg/m2 IV daily x 5 days in adults with grade 2, 3, and 4 gliomas. No responses were seen. Five of sixteen evaluable patients had stable disease for 38 to 147 days (median, 75 days). Treatment was generally well tolerated, and hence the dose was escalated from 1100 mg/m2/day to 1375 mg/m2/day after the first twelve patients were entered. Treatment-induced hypertension requiring pharmacological intervention was seen in four patients. Gastrointestinal toxicity was generally mild. Treatment-related headache was seen in thirteen patients, and drowsiness or weakness was seen in seven patients. In summary, tiazofurin on this dose schedule does not have major activity against grade 2, 3, and 4 gliomas.

Adult↗
PubMed1993

Randomized comparison of diaziquone and carmustine in the treatment of adults with anaplastic glioma.

PURPOSE: We conducted a phase III trial comparing intravenous (IV) diaziquone (AZQ) and carmustine (BCNU) as single agents in patients with cerebral anaplastic gliomas who had received surgery and radiotherapy. Its purpose was to compare the efficacy of AZQ with that of BCNU, the standard agent for brain tumor chemotherapy. PATIENTS AND METHODS: Randomization between the two regimens occurred 8 weeks after completion of radiotherapy. A total of 251 patients were randomized to receive either AZQ or BCNU, and there were no significant differences between the two treatment arms in any of the known prognostic variables, including age, histologic grade, and Karnofsky performance status (KPS). RESULTS: There was no significant difference in either time to tumor progression or survival between the two treatment arms. Age and histology were strong predictors of outcome, whereas KPS had relatively less effect. Three groups of patients with distinctly different outcomes could be identified: (1) older age (45+) and glioblastoma/gliosarcoma (GBM/GS) patients had a median survival of 37 weeks after randomization; (2) patients with either older age or GBM/GS had a median survival of 61 weeks; and (3) younger age (< 45) and non-GBM/GS (usually anaplastic astrocytoma) patients had a median survival of 147 weeks. Toxicity was primarily hematologic, although acute gastrointestinal toxicity and chronic pulmonary toxicity were more common with BCNU. Patients randomized to AZQ who had significant hematologic toxicity that required dose reduction after the first treatment cycle had significantly longer time to tumor progression and survival than those who did not require dose reduction (P = .011 and .016, respectively). CONCLUSION: There was no significant difference in efficacy between AZQ and BCNU in patients with anaplastic gliomas as tested in this study, although AZQ was somewhat better tolerated.

Adult↗
PubMed1992

Supratentorial malignant glioma: patterns of recurrence and implications for external beam local treatment.

Pre- and postoperative computerized tomography scans, simulator films, and computerized tomography scans documenting tumor recurrence were analyzed on 70 patients with supratentorial malignant glioma treated with whole brain plus boost radiation therapy to determine sites of recurrence in relation to the boost. The boost was planned using the postoperative computerized tomography scan. Tumor recurred in 53 patients--within the boost in 38 (72%), partly outside the boost in 12 (23%), outside the boost but within the brain in one (2%), in the boost and in the spinal cord in one (2%), and in the spinal cord only in one (2%). All recurrences confined to the brain were found within 4 cm of the enhancing tumor as defined by the preoperative computerized tomography scan. Recurrences outside the boost were more common with inadequate boost margins, small boost volumes, temporal lobe tumors, and homolateral wedge pair technique. Survival was not adversely affected by recurrence outside the boost. We recommend that patients with malignant glioma be treated by parallel opposed fields with a margin that is 4 cm beyond the edge of the preoperative enhancing tumor, as seen on computerized tomography scan.

Adolescent↗
PubMed1992

Pedicle skin flaps in ponies: viable length is related to flap width.

The relationship between pedicle flap width and viable length was characterised for skin flaps of the flank in ponies. Four dorsally based, pedicle type skin flaps of 20 cm in length and 3, 6, 9 or 12 cm in width were created in a random sequence on one flank in each of 10 ponies. Flap survival length was assessed by skin texture and appearance, depilation of hair and wound healing at 14 days after surgery. There was considerable variation between animals in the viable length of flaps of the same width; however, a significant difference in the viable length of flaps of different widths was detected (P = 0.002). The viable length of the 3 cm flaps was significantly different from that of the 12 cm flaps (9.69 +/- 1.1 cm vs 12.97 +/- 1.0 cm, mean +/- se P less than 0.05). There was a positive correlation between flap width and viable length (r2 = 0.141, P = 0.017). There was no effect of flap order (cranial to caudal positioning relative to the other flaps) on viable length (P = 0.286). The results of this study demonstrate a significant relationship between flap width and viable length, confirming a previously unsupported assumption that flap width and viable length are related. These findings suggest that the clinician should employ broad pedicles when using local flaps to reconstruct skin defects on the flank of the horse.

Animals↗
PubMed1992

Aggressive oligodendroglioma: a chemosensitive tumor.

Aggressive oligodendrogliomas, tumors that are symptomatic, enlarging, enhancing, and usually but not always anaplastic, respond to chemotherapy. We have observed responses to chemotherapy in 18 of 19 consecutively treated patients with newly diagnosed or recurrent aggressive oligodendrogliomas. A regimen of procarbazine, CCNU (lomustine), and vincristine (PCV) is predictably effective, but other drugs have antioligodendroglioma activity. Cooperative group trials will be necessary to determine the most effective drug, or combination of drugs, and to explore fully the role of chemotherapy in the treatment of this uncommon glioma.

Antineoplastic Agents↗
PubMed1992

Selection bias, survival, and brachytherapy for glioma.

Interstitial irradiation is a promising treatment for malignant glioma. Longer than expected survival periods following treatment of recurrent tumor have led to the use of brachytherapy as an adjuvant treatment. The impact of patient selection on survival data was studied among candidates for this therapy. Consecutive, conventionally treated adults with newly diagnosed supratentorial tumors were identified retrospectively at a center where experience with glioma is population-based. Based on imaging and performance status, two surgeons and a radiation oncologist designated each patient as either eligible or ineligible for adjuvant brachytherapy. The survival and prognostic factors in the eligible and ineligible groups were analyzed. Overall, the patients eligible for brachytherapy (32% of the series) lived significantly longer than the ineligible patients (16.57 vs. 9.30 months), were younger, and had larger resections and better function. For glioblastoma, 40% of patients were eligible, and lived much longer than those who were ineligible (13.90 vs. 5.80 months). It is concluded that better outcome following adjuvant brachytherapy for glioma is at least in part the result of patient selection. Randomized trials of comparably selected patients will be necessary to demonstrate conclusively that longer survival is also a result of treatment.

Adolescent↗
PubMed1992

Gliomas in families.

This is a descriptive study of 19 families with glial tumors. Twelve were identified prospectively from 178 consecutive, unrelated adults and children with newly diagnosed gliomas seen at a regional cancer center between 01 Jan 89 and 31 Mar 91 (6.7%). There were 45 affected members (42 confirmed); 30 males, 15 females, ages 4 months-78 years (median, 44.5 years; mean, 38.9 years). Two families had four affected members, three families had three, and the others two. All confirmed tumors were supratentorial and all, save one, contained an astrocytic element. Three additional members of two families had other brain or neuroectodermal tumors. These families were not unusually cancer prone and did not appear to have neurofibromatosis, tuberous sclerosis, or colonic polyposis. There was no consistent pattern of inheritance.

Adolescent↗
PubMed1991

Primary leptomeningeal lymphoma: report of 9 cases, diagnosis with immunocytochemical analysis, and review of the literature.

We describe 9 patients who presented with a neoplastic meningitis of lymphomatous origin. No evidence of parenchymal central nervous system or systemic tumor was identified either at the time of presentation or throughout the course of their disease. We have chosen to call this entity "primary leptomeningeal lymphoma" (PLML). This unusual form of neurologic lymphoma must be differentiated from the more common clinical situations of primary parenchymal lymphoma with meningeal involvement and systemic lymphoma complicated by lymphomatous meningitis.

Adult↗
PubMed1991

Neurologic complications of chemotherapy.

Neurotoxicity is a common and potential dose-limiting complication of cancer chemotherapy. For most agents, high-dose therapy, combination chemotherapy, concomitant cranial radiotherapy, and intracarotid or intrathecal injection are more likely to produce neurologic complications than standard oral or intravenous therapy. Any portion of the nervous system can be damaged. Encephalopathies (either focal or diffuse) are produced by BCNU, cisplatin, cytarabine, 5-fluorouracil, ifosfamide, L-aspariginase, methotrexate, procarbazine, corticosteroids, and some biological response modifiers (interferon, interleukin-2). Cerebellar syndromes may follow the administration of cytarabine, 5-fluorouracil, and procarbazine. Myelopathy may complicate intrathecal methotrexate, cytarabine, thiotepa, and accidental intrathecal vincristine or doxorubicin injection. Peripheral neuropathy occurs from cisplatin, vincristine, and, sometimes, cytarabine or procarbazine. Myopathy is a common complication of corticosteroids. Strokelike syndromes may occur with L-aspariginase, high-dose methotrexate, and intracarotid BCNU or cisplatin. Differentiating the neurologic complications of chemotherapy from other neurologic complications of cancer is often difficult. As cancer patients are treated more aggressively, receive more chemotherapy, and live longer, and as new chemotherapeutic agents are developed and existing agents are used more intensively or in novel ways, neurologic complications of cancer chemotherapy will become more common, serious, and complex. The recognition and treatment of chemotherapy-induced neurotoxicity will become a frequent and important clinical problem for most neurologists.

Antineoplastic Agents↗