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Biomedical subjects

N Sundaresan

Publications and source records attributed to N Sundaresan.

At least 55 records · Page 3Linked to original sources
PubMed1984

Harrington rod stabilization for pathological fractures of the spine.

Nineteen patients with tumors involving the thoracolumbar spine were treated by Harrington rod stabilization following laminectomy. Sixteen patients had metastatic neoplasms, and three had primary tumors of the vertebral column. In five patients, extensive decompressive laminectomy and Harrington distraction rods to provide immediate stability were used as initial treatment; postoperative irradiation was then given. All five patients were ambulatory, and the four patients with preoperative pain all noted relief of pain following treatment. The remaining 14 patients had received radiation therapy to the spine prior to surgery; in these 14, indications for surgery included a combination of pain and weakness (10 patients), pain alone (two patients), or weakness alone (two patients). Of 12 patients with preoperative pain, after surgery pain relief was noted in nine patients, and eight were ambulatory. Major wound breakdowns occurred in two of the 14 patients who had received radiation prior to surgery. These results suggest that Harrington rod instrumentation is useful in providing postoperative stability and restoring alignment following laminectomy for tumors involving the spine, but carries an increased risk of wound-related complications if used in a previously irradiated region.

Adolescent↗
PubMed1984

Acute nonlymphocytic leukemia following treatment of malignant glioma. Report of two cases.

Two patients with malignant brain tumors who developed acute nonlymphocytic leukemia after treatment with radiation and chemotherapy are described. Both patients survived more than 2 years after diagnosis of the brain tumor. Survival following the diagnosis of leukemia was short, and both patients died of hemorrhage secondary to thrombocytopenia. A review of the literature reveals that leukemia after combined-modality treatment of malignant brain tumors is rare. A prolonged survival period from diagnosis of the primary tumor, treatment with nitrosoureas and radiation, plus the development of a preleukemic myelodysplastic syndrome are all important features of therapy-related nonlymphocytic leukemia.

Acute Disease↗
PubMed1984

An anterior surgical approach to the upper thoracic vertebrae.

Of the various anterior surgical approaches to the spine, exposure of the upper two thoracic vertebrae remains the most challenging. An operative approach to this region is described. The major features include resection of a portion of the clavicle and the manubrium sterni. Following resection of the tumor and involved vertebra, anterior fusion is performed using the clavicle as a strut graft. Immediate stabilization may also be achieved with methyl methacrylate replacement of the vertebral bodies. The operation is well tolerated, and requires minimal postoperative immobilization. The clinical presentation, radiological features, and results of treatment in a series of seven patients operated on during a 2-year period are presented.

Abscess↗
PubMed1983

Computed tomography of axial chordomas.

Preoperative computed tomography (CT) of 19 patients with axial chordomas was reviewed. These tumors characteristically feature a well-demarcated paraspinal soft tissue mass which is usually anterolaterally situated and has a homogeneous density comparable to that of muscle. The soft tissue component is disproportionately large compared to the area of bony involvement. Lytic or mixed vertebral lesions were noted. Amorphous calcifications that tended to occur at the periphery of the tumor were particularly common (89%) in chordomas of the sacrum. Epidural extension of tumor was noted in all spinal cases. Although it appears that CT studies will generally not enable a specific diagnosis of chordoma, the above features should alert the examiner to the possibility of this tumor.

Adult↗
PubMed1983

Radiation therapy for spinal epidural metastases with complete block.

Myelography was performed in 535 patients at the Memorial Sloan-Kettering Hospital from January 1979 to December 1979. In 110 cases a complete block was demonstrated and of these, 78 had epidural metastases. A uniform treatment was applied using radiation therapy and high dose steroid. The neurologic outcome for each patient was evaluated, correlating pre-treatment neurologic status, pathologic type, nature of block (level, structural versus tumoral), and result of repeat fluoromyelography. Only 2 patients improved, but 11 became completely paraplegic. The survival was influenced by the ambulatory status after treatment (median survival: 52.7 weeks in the ambulatory group and 4.6 weeks in the paraplegic). Based on this series, rational approach and management of complete block secondary to spinal epidural metastases are discussed.

Adolescent↗
PubMed1983

Preoperative chemotherapy and surgical resection in the management of posterior paraspinal tumors. Report of three cases.

Three patients with posterior paravertebral tumors are presented to illustrate the value of preoperative chemotherapy prior to surgical resection. All three had massive tumors adjacent to the spine, extending over several vertebral segments, with myelographic evidence of epidural involvement in one patient. Tissue diagnosis by incisional biopsy confirmed the diagnosis of extraosseous osteogenic sarcoma in one, extraosseous Ewing's sarcoma in the second, and embryonal rhabdomyosarcoma in the third. All patients were treated with chemotherapy preoperatively. Marked regression in tumor size was noted, and surgical excision of the tumor along with involved segments of spine was easily accomplished. Histological examination following surgery revealed completely necrotic tumor in two patients. Preoperative chemotherapy for fully malignant tumors offers the following advantages: 1) extremely bulky and otherwise unresectable tumors can be reduced in size to enable complete surgical resection; 2) systemic chemotherapy is instituted earlier in the course of disease to prevent more effectively the appearance of metastases; and 3) the information gained regarding the sensitivity of the tumor to a particular chemotherapy regimen allows postoperative adjuvant chemotherapy to be used on a more rational basis.

Adolescent↗
PubMed1983

Surgical treatment of brain metastases from lung cancer.

Thirty-five patients underwent surgical resection of brain metastases from non-oat-cell lung cancer between 1978 and 1981. Twenty-nine patients received postoperative radiation therapy to the brain. Twenty-three patients were male and 12 were female. Intracranial metastases occurred as the initial symptom of malignancy in 14 patients, and at varying periods following treatment of the primary tumor in 21 patients. The primary tumor and involved nodes were treated by definitive surgery in 18 patients, palliative resection and interstitial radiation in 10 patients, and by radiation therapy or chemotherapy alone in seven patients. The overall median survival time was 14 months. Favorable prognostic variables included: 1) absence of local or systemic disease at time of craniotomy (median 23 months survival time); 2) aggressive treatment of the primary tumor (median 18 months survival time); and 3) metachronous onset of brain metastases (median 15 months survival time). These survival data represent a considerable improvement over the historical 6 months median period of survival in such patients.

Adult↗
PubMed1982

Bronchogenic carcinoma with invasion of the spine. Treatment with combined surgery and perioperative brachytherapy.

A 64-year-old man with bronchogenic carcinoma was noted to have invasion of the chest wall and spine at time of diagnosis. Computed tomography and myelography demonstrated destruction of the vertebral body with epidural extension. After preoperative radiotherapy, resection of the involved lung, chest wall, and spine was accomplished. Afterloading catheters were placed for tumor-bed perioperative iridium 192 irradiation. The patient is free to disease two years after treatment. We describe the afterloading perioperative brachytherapy technique used and suggest this multidisciplinary approach for bronchogenic carcinoma invading the spine.

Brachytherapy↗
PubMed1981

Supratentorial recurrences in medulloblastoma.

Four children with medulloblastoma had massive supratentorial recurrences in the region of the cribriform plate after adequate craniospinal irradiation. The pathogenesis of these recurrences is probably related to underdosage to this region by shielding of the eyes. This hypothesis was corroborated by autopsy findings in two other patients in whom subfrontal implants were histologically different from recurrences elsewhere. Two possible solutions to avoid this problem in the future are suggested.

Brain Neoplasms↗
PubMed1981

Giant ossifying fibroma of the nasal cavity with intracranial extension.

A 12-year-old white male presented with an ossifying fibroma of the maxillary sinus. The tumour recurred following incomplete excision through a maxillary approach. Computerized tomography revealed an extensive tumour involving the paranasal sinuses, which extended intracranially through the cribriform plate. The tumour was successfully excised through a combined craniofacial approach. This approach should be used whenever there is radiological involvement of the base of the skull from paranasal sinus tumours. Accurate radiological delineation of the extent of the tumour is only possible by computerized tomography in the axial and coronal planes.

Brain Neoplasms↗
PubMed1981

Computerized tomography findings in multifocal glioma.

Six patients with multifocal glioma are presented. Computerized tomography revealed multiple, discrete, contrast-enhancing lesions in the cerebral hemispheres, suggestive of multiple intracranial metastases. The most accessible lesion was resected at craniotomy in each patient, confirming the diagnosis of primary malignant glioma. Postoperative radiation therapy and chemotherapy were instituted according to current protocols. Since neuroradiological studies may not allow distinction of multifocal glioma from multiple brain metastases, surgical biopsy is suggested in those patients who have no history of cancer.

Aged↗
PubMed1981

Malignant fibrous histiocytoma of the temporal bone with intracranial extension.

An 18-year-old male presented with a right temporal bone tumour; histology revealed malignant fibrous histiocytoma. Following surgical excision and radiation the tumour recurred. The patient was treated with Vindesine (desacetyl vinblastine amide sulphate) with marked response. Malignant fibrous histiocytomas of the temporal bone are extremely rare; this report suggests that the occasional dramatic response may be obtained by combined modality treatment.

Adolescent↗
PubMed1981

Radiation necrosis after treatment of solitary intracranial metastases.

During the period from July 1977 to June 1980, 75 patients underwent the surgical excision of solitary brain metastases, and 61 of these patients received whole brain radiation. Three patients developed chronic radiation necrosis. In the 3 patients with necrosis, computed tomography suggested recurrent tumor; the histological diagnosis of necrosis only was obtained at operation in 2 of these patients and by autopsy in the third. Radiation damage resulted in the death of 1 patient, a chronic vegetative state in another, and severe neurological deficit in the third. An additional 4 patients had neurological complications probably related to radiation therapy. As the survival of such patients is prolonged by aggressive treatment, the incidence of radiation-induced complications is likely to increase. The optimal dose of radiation necessary to destroy microscopic foci of tumor after the surgical resection of a single brain metastasis is unknown. Because of the significant incidence of damage after radiation as currently delivered, studies using graded, lower doses are indicated.

Adenocarcinoma↗
PubMed1981

Treatment of odontoid fractures in cancer patients.

A series of 18 patients with odontoid fractures due to metastatic cancer were treated at Memorial Sloan-Kettering Cancer Center between 1974--1980. The primary source of cancer was breast (12 cases), lung (two cases), nasopharynx (one case), multiple myeloma (one case), colon (one case), and rhabdomyosarcoma (one case). The clinical features consisted of severe neck pain and neck stiffness in 17 patients; signs of cord compression were noted in only four patients. Tomography and computerized tomography were useful in identifying both the osseous and soft-tissue involvement by tumor. Initial treatment in all patients except those with myelopathy consisted of high-dose steroids, and immobilization in a hard collar. Ten patients were treated with radiation therapy alone; six patients underwent surgical fusion (four before and two after radiation therapy); and two patients died before completion of treatment. Conservatively treated patients were allowed to walk with the support of only a collar following radiation therapy. We believe that the initial management of patients with odontoid fractures secondary to cancer should be high-dose steroids and radiation therapy, unless displacement is marked. Assessment for surgical fusion should be made following radiation therapy, since conservative treatment may suffice in most patients. Early recognition is important so that treatment can be instituted before C1--2 subluxation becomes severe.

Adolescent↗
PubMed1981

Hypothesis testing in neurosurgical trials.

Controlled clinical trials represent the most scientific methods of evaluating a new form of treatment. In designing such a trial, one must avoid committing two kinds of errors. The Type I error is defined as falsely concluding that a difference between two treatments exists, when they are equal. The Type II error is committed when one concludes that two treatments are the same, when a real difference exists. To reduce the probability of committing these errors, large sample sizes are required. A survey of neurosurgical trials showed that the majority of these trials have an unacceptably high probability of committing a Type II error because of inadequate sample size.

Clinical Trials as Topic↗
PubMed1980

Surgical treatment of single brain metastasis: factors associated with survival.

The results of surgical excision of solitary intracerebral metastases followed by whole-brain radiation therapy between 1972 and 1978 in a series of 78 patients were analyzed. The overall median survival of the series was 6 months with a 1-year survival rate of 29%. Statistical analyses of the data revealed that patients who presented with a cerebral metastasis 1 year or more after diagnosis of the primary cancer had a significantly longer survival than those in whom the metastasis was detected within 1 year (P less than .04). Patients with mild or no neurological deficits at time of craniotomy had a longer median survival and a 1-year survival of 44% (P less than .01). The presence of metastases at one or two other sites did not significantly affect overall survival except in those patients in whom the brain metastasis was detected more than 1 year after diagnosis of the primary tumor. Factors found to affect survival in this study may be useful in predicting survival of future patients similarly treated.

Brain Neoplasms↗