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Biomedical subjects

G Krol

Publications and source records attributed to G Krol.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1988

Malignant extradural spinal tumors: MR imaging with Gd-DTPA.

Magnetic resonance (MR) imaging with gadolinium diethylenetriaminepentaacetic acid (DTPA) was performed in 12 patients with neoplasia of the spine and epidural space. Postcontrast images were compared with precontrast images. Gd-DTPA MR images did not improve the detection of tumors affecting the epidural space of the spine. In fact, many lesions were isointense when compared with the intensity of the surrounding bone marrow and were difficult to see. Because of this, contrast material-enhanced images were not sufficient; however, when they were combined with precontrast images, the use of Gd-DTPA improved the delineation and characterization of certain lesions. Gd-DTPA MR images were helpful in differentiating disk herniation from epidural tumors, indicating regions of more active tumor for biopsy, outlining areas of spinal cord compression, and demonstrating tumor response to therapy. Therefore, while it may be unlikely that Gd-DTPA will be used routinely in every case of suspected neoplasia of the epidural space, contrast-enhanced images will undoubtedly have an adjunctive role in certain clinical applications.

Adult↗
PubMed1988

Intraparenchymal brain metastases: MR imaging versus contrast-enhanced CT.

Prospective and retrospective studies of 75 patients were performed to assess the sensitivities of magnetic resonance (MR) imaging and computed tomography (CT) in the evaluation of suspected intraparenchymal brain metastases. The findings on MR images were equivalent to those on CT scans in 49 of the 75 patients; the remaining findings were discordant in 26 patients, and neither MR imaging nor CT was consistently superior. MR imaging demonstrated more metastases in nine of these 26 patients. However, contrast material-enhanced CT scans were superior in lesion depiction in eight of the 26 patients. Large enhanced lesions that were nearly isointense on MR images were seen well on CT scans. In several cases in which results were discordant, gadolinium-diethylenetriaminepentaacetic acid (DTPA)-enhanced MR images were obtained, and this agent behaved similarly to iodinated contrast agents. If indicated clinically, such as before surgery for a single metastasis, the authors perform both MR imaging and contrast-enhanced CT. Gd-DTPA-enhanced MR imaging may prove to be the method of choice for depiction of intraparenchymal metastases.

Adolescent↗
PubMed1988

Combined treatment of osteosarcoma of the spine.

We reviewed the clinical features and results of treatment in 24 patients with osteogenic sarcoma of the spine treated over a 35-year period. There were 14 male and 10 female patients 13 to 71 years old. The tumor arose de novo in 13 patients and was secondary to other conditions in 11. All patients presented with pain, and 16 (67%) had neurological deficits. Patients were divided into two treatment groups. Thirteen patients treated from 1949 to 1977 usually underwent limited tumor resection and external radiation therapy. The second group, 11 patients treated from 1978 to 1984, underwent more aggressive surgical resection and received combination chemotherapy as well as local radiation to the tumor bed. In the second group, there were 5 long term survivors, and only 1 patient developed metastatic disease while on therapy. Failure to obtain local control was the major cause of treatment failure. Complete surgical resection of the tumor by spondylectomy and combination chemotherapy offer the best prospect for cure of osteogenic sarcoma of the spine.

Adolescent↗
PubMed1988

Gadolinium-DTPA in the evaluation of intradural extramedullary spinal disease.

Gadolinium-DTPA was used in MR imaging of the spine to determine the ability of a contrast agent to increase the detection and characterization of disease in the intradural extramedullary space. Although MR imaging, especially with recent technological improvements, has been shown to be at least competitive with, and often superior to, myelography and postmyelography CT in the study of intramedullary and extradural disease, its use in the assessment of intradural extramedullary disease has been questioned. We selected 12 patients with intradural extramedullary disease as demonstrated by positive CSF cytology and/or myelographic findings and performed MR examinations on them before and after administering gadolinium-DTPA (0.1 mmol/kg). Gadolinium-DTPA was extremely effective in depicting intradural extramedullary disease of the spine. Small nodules of 3 mm, virtually invisible on noncontrast MR scans, enhanced strongly and were easily detected. In addition, leptomeningeal spread of tumor along nerve roots was also visualized, sometimes more readily than by myelography and postmyelography CT. The remarkable sensitivity of gadolinium-DTPA to intradural extramedullary disease assures its role in future MR examinations of the spine.

Adult↗
PubMed1988

MR of cranial and spinal meningeal carcinomatosis: comparison with CT and myelography.

Thirty-nine patients with histologically proved primary neoplasms, focal neurologic deficits, and positive CSF cytology were evaluated by enhanced cranial CT and MR, or complete myelography and MR of the spine. Intracranial abnormalities were noted on CT in 56% of cases and included abnormal enhancement of subarachnoid space and ventricular walls, ventricular dilatation, obliteration of cortical sulci, and enhancing nodules within the subarachnoid cisterns and lumen of the lateral ventricles. Although the degree of ventricular enlargement and intraventricular tumor deposits were equally well seen on CT and MR, involvement of ventricular walls, tentorium, subarachnoid cisterns, or subarachnoid space interpreted as abnormal enhancement on CT was not readily appreciated on routine T1- and T2-weighted spin-echo sequences. Forty-four percent of CT and 65% of MR studies were interpreted as normal. There was high correlation of myelographic findings with clinical diagnosis, and no false-negative myelograms. Nodular filling defects within the subarachnoid space, thickening and crowding of roots of the cauda equina, irregularity of individual roots, and scalloping of the subarachnoid membranes were demonstrated. MR was rather insensitive in detecting these changes, revealing a definite abnormality of the subarachnoid space in 27% of patients with positive myelograms. False-negative interpretation of MR of the spine was made in 44% of cases.

Brain Neoplasms↗