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Biomedical subjects

G Krol

Publications and source records attributed to G Krol.

At least 19 recordsLinked to original sources
PubMed1992

Spinal epidural tumor in patients with prostate cancer. Clinical and radiographic predictors of response to radiation therapy.

The authors retrospectively reviewed 50 episodes of spinal epidural tumor that occurred in 42 patients with metastatic prostate cancer and were treated with external-beam radiation. Treatment response was evaluated in terms of symptoms, neurologic status, and, in most cases, reduction of tumor on repeat myelography. At the completion of therapy, 92% of treated patients experienced pain relief and 67% had significant to complete improvement on neurologic examination. Thirty days after treatment, repeat myelography was performed in 40 of the 50 cases; compared with the initial findings immediately preceding radiation therapy (RT), the results of 58% of these studies had normalized completely, results were improved in 25%, and the results had not changed in 18%. The presence of a high-grade compression fracture of the vertebral body was an indicator of poor prognosis for tumor response on repeat myelography. The ability of a patient to walk before treatment and tumor response on repeat myelography were associated significantly with improved outcome of RT and with survival. The authors conclude that RT can effectively palliate epidural lesions from metastatic prostate cancer. The prognosis for the long-term response to therapy may be indicated by pretreatment ambulatory status and posttreatment imaging of the epidural space.

Adenocarcinoma↗
PubMed1992

Occult epidural chloroma complicated by acute paraplegia following lumbar puncture.

Acute paraplegia complicating lumbar puncture in a leukemic patient with an unsuspected epidural chloroma is described, including the postmortem findings. Lumbar puncture can precipitate irreversible injury to the spinal cord in the patient with an occult lesion causing subarachnoid block. This account, in addition to documenting this phenomenon, suggests a potential advantage to magnetic resonance imaging over myelography.

Acute Disease↗
PubMed1992

Binocular infrared oculography.

A new system of infrared oculography has been developed which provides binocular recordings and allows simultaneous measurement of horizontal and vertical eye movements. The sensitivity of the system is 1 minute of arc, and it has a horizontal range of +/- 30 degrees and a vertical range of +/- 20 degrees. Using this system for routine clinical evaluations, it was possible to record divergent spontaneous nystagmus and divergent thermally induced nystagmus. Rotatory nystagmus can also be recorded. The binocular infrared oculographic system (BIRO) satisfies nearly all the requirements of an ideal recording system.

Brain Ischemia↗
PubMed1991

Percutaneous radiofrequency neurolysis guided by computed tomography for the treatment of glossopharyngeal neuralgia.

The technique of radiofrequency neurolysis guided by computed tomography for the treatment of glossopharyngeal neuralgia is described. This technique has the advantage of being performed in a neutral head position, affording excellent visualization of the jugular foramen, and also of simulating radiographically the precise trajectory of the electrode. This procedure is of particular value in treating patients with neoplastic disease and those in whom the outlines of the jugular foramen are poorly visualized on fluoroscopy or plain radiography.

Aged↗
PubMed1990

Decompression of epidural metastases from germ cell tumors with chemotherapy.

Epidural cord compression from germ cell tumor metastases is not common. Treatment usually requires high dose corticosteroids with radiation therapy and/or surgical decompression. Three patients with epidural germ cell tumor metastases were treated with cisplatin-based chemotherapy and all three had complete neurologic recovery. Systemic chemotherapy should be considered as initial therapy with corticosteroids for epidural cord compression from metastatic germ cell tumor.

Adult↗
PubMed1990

Primary CNS lymphoma: combined treatment with chemotherapy and radiotherapy.

Primary central nervous system lymphoma (PCNSL), an uncommon tumor, is occurring with increasing frequency. Conventional therapy with corticosteroids and cranial radiotherapy (RT) usually gives a dramatic initial response, but median survival is only 10 to 18 months. Chemotherapy is more successful in comparable systemic lymphoma and has been employed for PCNSL at relapse, causing remission but not cure. Between June 1985 and June 1988, we prospectively staged 32 patients with PCNSL at Memorial Sloan-Kettering Cancer Center and treated 28 on a new protocol that combined chemotherapy and radiotherapy at diagnosis. None had occult systemic lymphoma, but 19% had ocular and 69% had definite or probable leptomeningeal lymphoma. There were no complications in 19 stereotactic biopsies, but 4/10 patients who had a complete resection suffered a severe postoperative deficit. Four patients received RT alone, and 28 received chemotherapy and cranial RT, 17 of whom (group A) received a combination regimen using pre-RT systemic (1 g/m2) and intra-Ommaya methotrexate (MTX), 4,000 cGy whole-brain RT with a 1,440 cGy boost, and 2 courses of post-RT high-dose cytosine arabinoside; 5 other patients received an identical regimen but with a decreased dose of MTX (200 mg/m2). Sixty-three percent of assessable patients had a response to MTX independent of corticosteroid and prior to RT. Eighteen of 26 (69%) assessable patients who received combined therapy are alive with a median follow-up of 25.4 months. Twelve of 16 (75%) assessable group A patients are alive in the same period. Chemotherapy-related toxicity was minimal, and no late toxicities have occurred to date.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The combined use of radiation therapy and lonidamine in the treatment of brain metastases.

Lonidamine is an indazole carboxylic acid that has been shown to be synergistic with radiotherapy (RT) in tissue culture and animal models. Clinical experience has shown that lonidamine is well-tolerated, and appears to potentiate the activity of conventional chemotherapy in the treatment of brain metastases. A prospective randomized trial was undertaken to evaluate the use of lonidamine in combination with RT in the treatment of brain metastases. All patients received 3000 cGy of whole brain radiotherapy (WBRT). Fifty eight patients were enrolled; 31 received lonidamine plus WBRT and 27 received WBRT alone. There was no significant difference in response rate or survival between the treatment groups. Lonidamine blood levels were measured in 30 of the 31 patients who received the drug, and were therapeutic (greater than or equal to 15 micrograms/ml) in 50%. Survival and response rate were unaffected by the presence or absence of a therapeutic lonidamine level. The most common side-effects of lonidamine were myalgia, testicular pain, anorexia, and ototoxicity; however, only 2 patients had to discontinue the drug because of intolerable myalgias. No serious organ toxicity or myelosuppression was observed.

Adult↗
PubMed1989

Patterns of failure following treatment for glioblastoma multiforme and anaplastic astrocytoma.

Recurrence patterns of glioblastoma multiforme (25) and anaplastic astrocytoma (9) were studied using CT scans of 34 patients who received all or a portion of their surgical treatment at Memorial Sloan-Kettering Cancer Center from January 1983 through February 1987. Thirty-two patients presented with unifocal tumors and two with multifocal tumors. All patients received radiation therapy following initial surgery. Eighteen patients who underwent re-operation following CT evidence of recurrence had histologic verification of recurrent tumor; sixteen patients had radiographic evidence of recurrence only. Seventy-eight percent (25/32) of unifocal tumors recurred within 2.0 cm of the pre-surgical, initial tumor margin, defined as the enhancing edge of the tumor on CT scan. Fifty-six percent (18/32) of tumors recurred within 1.0 cm of the initial tumor margin. Tumors for which a gross total resection was accomplished tended to recur closer to the initial tumor margin than did subtotally resected tumors (p greater than 0.1). Extensive pre-operative edema was associated with a decreased distance between initial and recurrent tumor margins. Large tumors were generally not more likely to recur further from the initial tumor margin than were smaller tumors. No unifocal tumor recurred as a multifocal tumor. Only one tumor (initially near the midline) recurred in the contralateral hemisphere. The findings support the use of partial brain irradiation for post-operative treatment of glioblastoma multiforme and anaplastic astrocytomas, and may help to determine the most appropriate treatment volume for interstitial irradiation.

Adult↗
PubMed1989

Effects of aluminum and magnesium antacids and ranitidine on the absorption of ciprofloxacin.

The effect of an antacid (Maalox) and ranitidine administration on the absorption of ciprofloxacin was evaluated in healthy male volunteers who were enrolled in three separate studies. Each study was designed at a three- or four-period crossover and included the administration of 750 mg ciprofloxacin alone as a control treatment. Treatments that were evaluated included the administration of ciprofloxacin 5 to 10 minutes, 2 hours, 4 hours, and 6 hours after a single 30 ml dose of antacid; the administration of antacid 2 hours after ciprofloxacin was given; and the administration of ciprofloxacin 2 hours after a 200 mg ranitidine tablet. Administration of antacid within 4 hours before ciprofloxacin dose resulted in a significant decrease in ciprofloxacin absorption (p less than 0.05). Percentages of relative bioavailability compared with control values were 15.1%, 23.2%, and 70% for the 5 to 10 minute, 2 hour, and 4 hour antacid pretreatments, respectively. Administration of antacid 6 hours before or 2 hours after the ciprofloxacin dose did not affect absorption. Ranitidine did not alter ciprofloxacin absorption. Antacids that contain magnesium and aluminum salts may reduce the absorption of ciprofloxacin. The extent of this interaction appears to increase as the time between administration of the two drugs decreases. Ranitidine is suggested as an alternative to antacids for patients receiving treatment with ciprofloxacin.

Adult↗
PubMed1989

The effect of cirrhosis on the steady-state pharmacokinetics of oral ciprofloxacin.

The pharmacokinetics of ciprofloxacin, a carboxyquinolone, was studied after oral administration of the drug to seven patients with biopsy-proved cirrhosis and to seven healthy volunteers. Serum concentrations of ciprofloxacin and its three metabolites--desethylene ciprofloxacin (M1), sulfociprofloxacin (M2), and oxociprofloxacin (M3)--were measured by an HPLC procedure. The pharmacokinetic parameters for ciprofloxacin were not significantly altered in cirrhotic patients. The elimination half-life (t 1/2) and the area under the serum concentration versus time curve (AUC) were, respectively, 3.71 hours and 16.18 microgram.ml-1.hr-1 in the normal subjects and 3.47 hours and 18.38 micrograms.ml-1.hr-1 in patients with cirrhosis. The formation of oxociprofloxacin was reduced by approximately one half in the cirrhotic subjects, as the Cmax was 0.29 micrograms/ml in normal subjects versus 0.14 micrograms/ml in cirrhotic patients and the mean AUC(0-t) was 1.54 micrograms.ml-1.hr-1 in normal subjects versus 0.70 micrograms.ml-1.hr-1 in cirrhotic patients. However, there appeared to be no significant difference between groups with respect to desethylene ciprofloxacin and sulfociprofloxacin. Therefore it appears from this study that no dosage adjustment is required in patients with hepatic cirrhosis.

Administration, Oral↗
PubMed1989

Spinal lesions: quantitative and qualitative temporal evolution of gadopentetate dimeglumine enhancement in MR imaging.

Seventy gadolinium-enhanced magnetic resonance imaging studies were reviewed, and 36 were selected for quantitative and qualitative analysis of the temporal evolution of contrast medium enhancement of spinal lesions. In the extradural space, lesions often showed mild increase of enhancement on delayed images, but enhancement was always visible on immediate postcontrast images. In the intradural extramedullary space, tumor nodules demonstrated most prominent enhancement on early images, although subtle, strandlike enhancement of the nerve roots showed some delayed uptake of contrast medium on later images. In the intramedullary space, enhancement often increased on delayed images, although this increase was usually mild. For clinical purposes, immediate postcontrast imaging should be sufficient to depict the majority of spinal lesions, regardless of location. However, selected cases, such as necrotic spinal cord tumors, will require delayed imaging.

Contrast Media↗
PubMed1989

Spondylectomy for malignant tumors of the spine.

Spondylectomy is the complete surgical removal of all parts of one or more vertebrae above the sacrum. We report our initial experience with spondylectomy in eight patients with malignant tumors of the spine operated on over a 7-year period (1980 to 1986). Four patients had primary neoplasms of the spine, and four others had solitary metastases to the vertebrae. Following surgery, five patients underwent radiation therapy (RT) and chemotherapy depending on histology of the tumor. Radiographic confirmation of tumor resection was obtained on all patients. Pain relief was noted in all patients, and six patients with preoperative neurological deficits improved. There was no surgical mortality, and one patient developed wound dehiscence following surgery. Six of the eight patients are alive with a median follow-up of 36 months, and local control was achieved in six of the eight patients. These preliminary data suggest that malignant tumors of the spine can be completely resected using a staged approach. In potentially responsive tumors, systemic chemotherapy is recommended between the two operations to reduce the risk of systemic dissemination.

Adult↗
PubMed1989

Inability of computed tomography appearance of recurrent malignant astrocytoma to predict survival following reoperation.

Computed tomographic (CT) scans of 39 patients who underwent reoperation for recurrent malignant astrocytoma at Memorial Sloan-Kettering Cancer Center from 1980 through 1987 were reviewed and correlated with the patients' clinical course. Histologic diagnosis (anaplastic astrocytoma v glioblastoma multiforme) had a statistically significant impact on survival following reoperation (P = .038). Patients with high preoperative performance status (P = .29), total resection by postoperative CT scan (P = .15), and frontal lobe tumors (P = .17) tended to survive longer following reoperation. The size of the tumor at the time of recurrence did not correlate with survival following reoperation. Patients with a small amount of peritumoral edema at the time of recurrence tended to survive longer, but the effect was small (P = .16). Prognosis following reoperation cannot be accurately predicted on the basis of tumor appearance on CT scan.

Adolescent↗
PubMed1989

MR imaging of hemorrhagic intracranial neoplasms.

Thirty patients with intracranial tumors containing hemorrhage of varying stages were examined with high-field-strength MR imaging and CT to determine what differences might exist between hemorrhagic tumor and pure hemorrhage. Pathology was obtained in the six patients with primary tumors and in 14 of the 24 patients with metastases. Similar to evolving intraparenchymal hematomas, hemorrhagic neoplasms undergo changes in their appearance that can be categorized into three distinct intensity patterns, or stages. Stage 1 is characterized as iso- or hypointensity on short TR sequences and as hypointensity on long TR sequences; stage 2 as developing hyperintensity on both short and long TR sequences, without evidence of a well-defined black rim; and stage 3 as a hyperintense lesion with a well-defined black rim on long TR sequences. An additional mixed-intensity pattern was identified, which contained areas corresponding to more than one stage. In all of the cases exhibiting this pattern, pathology confirmed that the appearance was due to recurrent bleeding. We found several characteristics on MR that, when present, suggest an underlying neoplasm. These include delay in evolution between stages, central or eccentric hyperintensity in stage 2, and a mixed-intensity pattern. In addition, the presence of a hemosiderin rim does not exclude an underlying neoplasm. We found that the MR patterns that characterize hemorrhagic intracranial neoplasms should help to determine the cause of the hemorrhage.

Adult↗
PubMed1989

MR imaging of the cranial meninges with emphasis on contrast enhancement and meningeal carcinomatosis.

MR imaging was used to investigate normal and abnormal meningeal enhancement, with an emphasis on meningeal carcinomatosis. Three groups of patients were studied on a 1.5-T system. In group 1, the normal meninges were examined in 20 patients and were found to show fine linear enhancement in short segments, especially in a parasagittal distribution. In group 2, all gadolinium-enhanced head scans were reviewed retrospectively. Abnormal meningeal enhancement was detected in 52 patients. In some of these, the enhancement was associated with pathologic conditions of the meninges, including leptomeningeal tumor and meningeal infections and other inflammatory conditions; in others the enhancement was adjacent to subdural hematomas, subacute infarcts, and skull lesions, such as metastases or postoperative defects. In group 3, 30 cases of meningeal carcinomatosis were studied prospectively. Enhancement was seen in approximately two-thirds of cases and usually was quite diffuse and applied to the inner table of the skull. Frank nodules were seen less often. Contrast-enhanced CT was equal to MR in the detection of nodules but was nearly always unable to show diffuse meningeal enhancement against the inner table of the skull. Contrast-enhanced MR was more sensitive than contrast-enhanced CT in the examination of normal and abnormal meninges. Abnormal findings, such as meningeal carcinomatosis, were demonstrated more often by MR than by CT.

Adolescent↗
PubMed1988

Distribution of brain metastases.

The number and site of brain metastases were identified on the computed tomographic scans of 288 patients. There was one brain metastasis in 49%, two in 21%, three in 13%, four in 6%, and five or more in 11% of scans. In patients with one metastasis, the posterior fossa was involved in 50% of patients when the primary tumor was pelvic (prostate or uterus) or gastrointestinal, but it was involved in only 10% of patients with other primary tumors. Hemispheral metastases preferred the anatomic "watershed areas" (29% of the brain surface contained 37% of the metastases), indicating that tumoral microemboli tend to lodge in the capillaries of the distal parts of the superficial arteries. The charts of 134 patients with brain metastases from a primary tumor originating outside the lung revealed that the incidence of lung and spine metastases was the same, whether the primary tumor was pelvic or gastrointestinal or from another site. These data suggest that the high incidence of subtentorial lesions in patients with pelvic and gastrointestinal primary tumors cannot be explained by arterial embolization alone, and that this peculiar distribution is probably not explained by seeding of the brain through Batson's plexus.

Brain Neoplasms↗
PubMed1988

Cerebral necrosis following neutron radiation of an extracranial tumor.

Radiation necrosis of the brain is a rare complication of irradiation for extracranial tumors. We present a patient who emphasizes the potential hazard of neutron therapy, the sensitivity of magnetic resonance imaging (MRI) which may detect white matter changes prior to the development of clinical symptoms, the potential diagnostic value of 18F-fluorodeoxyglucose/positron emission tomography, and the importance of a combined surgical and medical approach for proper treatment.

Brain↗