Biomedical subjects
M G Malkin
Publications and source records attributed to M G Malkin.
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.
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.
Cerebrospinal fluid tumor markers for the diagnosis and management of leptomeningeal metastases.
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Detection of DNA abnormalities by flow cytometry in cells from cerebrospinal fluid.
To evaluate the diagnostic utility of flow cytometry (FCM) as compared to cytology, DNA and RNA content of cells were measured in 233 samples of cerebrospinal fluid (CSF) from 147 patients with solid tumors or lymphomas and 17 controls with nonmalignant disorders. All control specimens were normal. Twenty-eight samples were abnormal: 20 showed an aneuploid peak and 8 an increased number of cells with DNA content in the S and G2M phases of the cell cycle. Of these 28, cytologic results were positive in 18, suspicious in 3, and negative in 7. All but one of the suspicious and negative cases had confirmatory laboratory and/or radiographic evidence of leptomeningeal metastasis within one week of FCM examination. Cytologic results were positive in eight samples negative by FCM. Compared with cytology, the sensitivity of FCM was 69% and the specificity 95%. Abnormal DNA content by FCM can be a useful adjunct to cytologic examination.
[Analysis of the injuries in road traffic accidents in a provincial center].
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A versatile method for planning stereotactic brain implants.
Our approach to planning stereotactic 125I brachytherapy of brain tumors has involved least-squares optimization of individual seed positions within the target contour, followed by repeated combining of seeds from nearest-neighbor catheters in order to achieve an acceptably low number of catheters and an acceptable-separation of entry points. In one option, the catheters diverge from an extra-cranial point that can be close to the skull if all catheters are to be placed through a small craniectomy to treat a larger-diameter target. In another option, catheters converge toward a point beyond the target, to facilitate perpendicularity at the skull surface if a separate opening is to be drilled for each catheter. In either case, the fact that seed orientations are known, permits including anisotropy in dose calculations. Trial seed locations are constrained to a target region defined on a 1-mm mesh, both in the initial optimization of single-seed catheters and in subsequent combinations followed by tune-up optimizations. In the optimization process, sum-of-squares contributions are weighted more heavily when the dose rate is lower than the target dose rate; the weighting imbalance falls short of keeping all target points above the target dose rate and requires targeting on a dose rate about 25% higher than the desired minimum dose rate.