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Biomedical subjects

M Deutsch

Publications and source records attributed to M Deutsch.

At least 199 records · Page 11Linked to original sources

Manual reconstruction of tumor volumes from CT scans for radiotherapy planning.

Using a computed tomographic scan to construct a tumor volume on a simulation film has become an important part of radiation therapy treatment planning. Techniques for reconstruction of brain tumor volumes from computed tomographic scans onto simulation films are discussed. A technique for reconstructing by hand the tumor volume projection at a different angle from the plane of the computed tomographic scan is outlined. Ignoring beam divergence simplifies reconstruction, allowing it to be done by hand but introduces an additional error of at most 0.06, 0.15, 0.26 and 0.42 cm for tumors with maximum diameters of 5, 7.5, 10 and 12.5 cm, respectively. This technique provides the capability for limited 3-dimensional volume reconstruction of small tumors without the use of the computer.

Brain↗

Repeat megavoltage irradiation of pituitary and suprasellar tumors.

From 1965 to 1984, ten patients with suprasellar or pituitary tumors received repeat courses of radiation therapy at the Joint Radiation Oncology Center of the University of Pittsburgh. The radiation doses varied between 36.00 to 53.65 Gy for the first treatment course and from 35.00 to 49.60 Gy for retreatment. Six patients were treated for pituitary tumors, two for germinoma, one for optic glioma, and one for craniopharyngioma. One died of disease progression 19 years after a second course of radiation. Two patients were dead of intercurrent disease 0.2 and 1.5 years after repeat radiation. The remainder are free of disease progression 1.6 to 20.5 years after repeat irradiation. Optic neuropathy developed in one patient 1.3 years following a second course of treatment to 40 Gy in 20 fractions administered 7.5 years after initial treatment to 46 Gy in 23 fractions. Neither the Nominal Standard Dose nor the Neuret formula provided an adequate estimate of the repair of radiation. An estimation that 40% of the original radiation dose effect is still present appears to be a reasonable "rule of thumb" guideline to account for prior radiotherapy.

Adolescent↗

Verification of electron beam therapy with conventional and storage phosphor images: preliminary experience.

Portal verification images were generated by the photon contamination in electron beams produced by a linear accelerator during treatment of patients receiving high-energy electron radiation therapy. Both conventional and storage phosphor methods yielded projection radiographs in which anatomy of the irradiated and surrounding tissue was demonstrated. Exposed phantoms were used to confirm that the images represent a true projection of the radiation field. A preliminary series of 22 cases was evaluated by two radiotherapists and judged subjectively to be of clinical value. Geometric error, or more importantly, the lack thereof, during high-energy electron treatments was easily confirmed with this method. In three cases, the treatment protocol was corrected based on the images obtained. Because the readout process of storage phosphor images allows for gain adjustments and post-processing, the images obtained with this method were found to delineate anatomy in the treated and surrounding tissues somewhat more consistently than could conventional images.

Electrons↗

Results of a randomized trial comparing BCNU plus radiotherapy, streptozotocin plus radiotherapy, BCNU plus hyperfractionated radiotherapy, and BCNU following misonidazole plus radiotherapy in the postoperative treatment of malignant glioma.

In Brain Tumor Cooperative Group Study 77-02, eleven institutions randomized 603 adult patients with supratentorial malignant glioma to one of four treatment groups following surgery: conventional radiotherapy (6000 cGy in 30-35 fractions) + BCNU, conventional radiotherapy + streptozotocin, hyperfractionated (twice daily) radiotherapy (6600 cGy in 60 fractions) + BCNU, and conventional radiotherapy with misonidazole followed by BCNU. Data were analyzed for the total randomized population and for the 557 patients (86% with glioblastoma multiforme) who met protocol eligibility specifications (including confirmed histopathology on central review). Median survival was approximately 10 months following randomization. Overall there was no statistically significant difference in survival among the four groups. Among non-glioblastoma patients, the misonidazole group appeared to have poor survival. Peripheral neuropathy was a dose-limiting toxicity with misonidazole. It is concluded that neither the addition of misonidazole nor hyperfractionated radiotherapy as given in this protocol offered any advantage over conventional radiotherapy plus either BCNU or streptozotocin for treatment of malignant glioma.

Adolescent↗

Human endothelial cell seeding: evaluation of its effectiveness by platelet parameters after one year.

Platelet parameters were assessed in patients after implantation of polytetrafluoroethylene (PTFE) grafts, either nonseeded or seeded with autologous endothelial cells or reversed saphenous vein grafts, during the follow-up period of 1 year. The objective of this investigation was to compare the sensitivity of different noninvasive platelet parameters with the assessment of the result of endothelial cell seeding. Scanning electron microscopic investigation of circulating blood platelets showed a significantly higher incidence of activated platelets in patients with seeded or nonseeded PTFE grafts, compared with patients after reversed vein graft implantation. "Shape-changed" platelets, as well as membrane-perforated thrombocytes, were found exclusively in the circulating blood of patients after seeded or nonseeded PTFE graft implantation, indicative of platelet trauma by the artificial graft surface. Plasma levels of platelet factor IV and beta-thromboglobulin, as well as the uptake of indium-111-labeled platelets, failed to show statistically significant differences after 1 year of follow-up. The similar results for seeded and nonseeded grafts indicate the failure of endothelial cell seeding to induce the development of a nontraumatizing surface, comparable to that of saphenous vein grafts.

Blood Platelets↗

Current neurosurgical treatment of medulloblastomas in children. A report from the Children's Cancer Study Group.

To determine the current neurosurgical treatment of children with medulloblastomas, we reviewed the operative reports and neurosurgical report forms from 141 children with posterior fossa medulloblastomas treated on two current Children's Cancer Study Group (CCSG) protocols, CCG-921 for high-stage and CCG-923 for low-stage medulloblastoma. Most medulloblastoma operations were performed in major medical centers: 61% of the operations were performed in CCSG member institutions, 23% in CCSG affiliates and 16% in other institutions. The tumor T stage distribution was as follows: T1-4%, T2-15%, T3A-35%, T3B-36%, and T4-10%. Tumors infiltrated the brainstem in 38% of cases and were associated with hydrocephalus in 91% of cases. Hydrocephalus was managed by external ventricular drains in 50% and by shunts in 60%. Adjunctive instruments (e.g., microscope, ultrasonic aspirator) were used in 93% of the operations. Tumor removals were as follows: biopsy only 3%, partial removals 13%, subtotal removals 13%, near total removals 41% and gross total removals in 40%; 90% or more of the tumor was removed in 81% of the operations. Forty-seven percent of the operations were performed by pediatric neurosurgeons. Near total and gross total removals were performed significantly more often (p less than 0.05) by pediatric neurosurgeons than by general neurosurgeons. Postoperative morbidity was reported in 46% of cases, including neurologic morbidity in 26% of cases. There was no significant difference in patient morbidity between pediatric and general neurosurgeons.

Biopsy↗

Use of fibrin glue as a substrate for in vitro endothelialization of PTFE vascular grafts.

The shear stress resistance of cultured human endothelium was investigated on 6 mm polytetrafluoroethylene vascular grafts. Endothelial cell attachment was promoted by precoating the grafts with fibrin glue, which contained human fibronectin and inhibitors of fibrinolysis (aprotinin and tranexam acid). To evaluate the possible effect of fibrinolysis on cell detachment, seven grafts were lined with adult human saphenous vein endothelial cells (AHSVEC) and 11 with fibrinolytically almost inactive human umbilical vein endothelial cells (HUVEC). Endothelial cell seeding was performed in a microprocessor-controlled rotation device, allowing a low inoculum of 12 X 10(4) endothelial cells/cm2. Grafts were then cultivated for 9 days to enable the maturation of the cytoskeleton, before they were exposed to pulsatile shear stress for 48 hours. A mock circulation simulated the flow patterns and the wall shear forces of the femoral artery. After a 3-hour seeding process, 45% of AHSVEC and 43% of HUVEC were attached to the fibrin matrix, forming a confluent monolayer. After 24 hours of perfusion, a cell loss of 23% in AHSVEC- and of 42% in HUVEC-lined grafts was encountered. In spite of a further cell loss during the following 24 hours of perfusion, the majority of the graft surface was still covered by endothelial cells. Therefore we conclude that fibrin glue is a suitable substrate for the formation of a shear stress-resistant endothelial cell monolayer on polytetrafluoroethylene vascular grafts.

Aprotinin↗

Precoating substrate and surface configuration determine adherence and spreading of seeded endothelial cells on polytetrafluoroethylene grafts.

Primary adherence and attachment area of seeded human endothelial cells (EC) were determined on differently coated polytetrafluoroethylene (PTFE) grafts. Cell counts and morphometric analyses were done immediately after 60 minutes of electronically controlled seeding of 3 x 10(4) EC/cm2, as well as after 3 hours of subsequent incubation. Cell adherence and cell spreading were distinctly superior on two surface-covering substrates: fibronectin-treated type I/III collagen and fibrinolytically inhibited fibrin glue. Uncovered, purely fibronectin- or laminin-coated PTFE or type IV collagen treated with the specifically binding glycoprotein laminin showed a far lower EC attachment rate and less pronounced cell spreading. It appears that not only a high surface content of fibronectin but also a smooth PTFE-covering matrix are prerequisites for optimal primary adherence and cell spreading. Because fibrin glue might be fibrinolytically degraded despite its plasmin-inhibiting epsilon-amino-caproic acid compound, type I/III collagen plus fibronectin could provide an optimal precoating substrate for EC lining of PTFE grafts.

Aprotinin↗

Postoperative adjuvant chemotherapy or radiation therapy for rectal cancer: results from NSABP protocol R-01.

Information is presented from 555 patients with Dukes B and C rectal cancers treated by curative resection who were entered into the National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol R-01 between November 1977 and October 1986. Their average time on study was 64.1 months. The patients were randomized to receive no further treatment (184 patients), postoperative adjuvant chemotherapy with 5-fluorouracil, semustine, and vincristine (MOF) (187 patients), or postoperative radiation therapy (184 patients). The chemotherapy group, when compared with the group treated by surgery alone, demonstrated an overall improvement in disease-free survival (P = .006) and in survival (P = .05). Employing the proportional hazards model, a global test was used to determine the presence of treatment interactions. Investigation of stratification variables employed in this study indicated that sex, and to a lesser extent age and Dukes stage, made individual contributions to the disease-free survival and the survival benefit from chemotherapy. When evaluated according to sex, the benefit for chemotherapy at 5 years, both in disease-free survival (29% vs. 47%; P less than .001; relative odds, 2.00) and in survival (37% vs. 60%; P = .001; relative odds, 1.93), was restricted to males. When males were tested for age trend with the use of a logistic regression analysis, chemotherapy was found to be more advantageous in younger patients. When the group receiving post-operative radiation (4,600-4,700 rad in 26-27 fractions; 5,100-5,300 rad maximum at the perineum) was compared to the group treated only by surgery, there was an overall reduction in local-regional recurrence from 25% to 16% (P = .06). No significant benefit in overall disease-free survival (P = .4) or survival (P = .7) from the use of radiation has been demonstrated. The global test for interaction to identify heterogeneity of response to radiation within subsets of patients was not significant. In conclusion, this investigation has demonstrated a benefit from adjuvant chemotherapy (MOF) for the management of rectal cancer. The observed advantage was restricted to males. Postoperative radiation therapy reduced the incidence of local-regional recurrence, but it failed to affect overall disease-free survival and survival.

Aged↗

Management of low-grade gliomas of the optic nerve and chiasm.

Thirty-six patients were evaluated between 1965 and 1983 for glioma of the optic nerves and/or chiasm. Median follow-up was 10.2 years. Pathologic verification was obtained in 32 patients. Tumor initially confined to the optic nerve recurred in one of five patients after complete resection. The actuarial survival for 25 patients irradiated for biopsy-proven glioma of the optic chiasm was 96%, 90%, and 90% at 5, 10, and 15 years, respectively, and the progression-free survival was 87% at 5, 10, and 15 years. Vision stabilized or improved in 86% of patients after radiotherapy. Patients irradiated to a dose greater than a NSD of 1385 ret had a significantly improved progression-free survival (P = 0.015). One serious complication occurred after a dose of 1533 ret. The recommended radiation dose for optic glioma is 45 to 50 Gy with 1.8 Gy fractions.

Adolescent↗

An evaluation of the SCM test for the diagnosis of cancer of the breast.

The SCM test (structuredness of the cytoplasmic matrix) consists of measuring the fluorescence polarization of fluorescein which is introduced into a particular sub-group of peripheral lymphocytes. The test has a non-specific part for the general detection of cancer and a specificity procedure which is based on the use of specific cancer extracts. In this article we deal only with the latter in relation to breast cancer. Blood samples from 94 patients have been tested; six of these had mastectomy performed previously; 83 underwent consecutively a surgical procedure and histology was obtained; five were only clinically examined. In 45/49 (92%) patients, correlation between a positive specificity test and tissue malignancy was found. Out of 35 patients with non-malignant proliferative lesions (as found by histology), 25 reacted positively in the test. Two out of five patients with non-malignant, non-proliferative lesions reacted positively in the test. Five patients who were defined as normals by clinical examination reacted negatively in the test. These results indicate the potential of the SCM test for detecting breast malignancy. The clinical implications of the test for cancer diagnosis are discussed.

Adolescent↗

Medulloblastoma: staging and treatment outcome.

Fifty-two newly diagnosed patients with medulloblastoma were prospectively staged with myelography. Fifty also had at least one CSF cytology study. Twenty-four patients (46%) had evidence of dissemination beyond the posterior fossa at diagnosis. Patients under age 5 years were more likely to have dissemination at diagnosis than older patients (61% vs 38%). The 5-year disease-free survival for 45 patients diagnosed at least 1 year ago and treated with craniospinal irradiation was 62.6%. Overall 5-year survival for this group was 76.7%. Patients without evidence of dissemination at diagnosis had a 5-year disease-free survival of 73.3% compared to 49.1% for patients with M1-3 disease. Eighteen patients relapsed, 16 within 3 years of diagnosis. Eight patients had recurrent tumor in the posterior fossa, eight in the supratentorial compartment, seven in the cord, and five had systemic metastasis. Patients with initial cord involvement were more likely to develop systemic metastasis (4/12) than patients without initial cord involvement (1/33).

Cerebellar Neoplasms↗

Split course radiation therapy for adenocarcinoma of the pancreas.

Ninety-five patients with biopsy proven adenocarcinoma of the pancreas were treated with split course radiation therapy. Fifty-five patients had disease confined to the peripancreatic tissues and lymph nodes. Forty patients had metastatic disease. The intended radiation therapy scheduled consisted of two courses of 25 Gy in 10 fractions each followed by a 3 to 4 week rest period. Depending on the response and the patient's clinical status, another 10 Gy in 5 fractions was administered as a final boost. The median survival in patients with metastatic disease was 3 months and the median survival in patients with localized disease was 8 months. Twenty-seven of the fifty-five patients with localized disease received chemotherapy (5 FU or FAM) combined with radiotherapy. There was no significant difference in median survival between the patients treated with radiation alone and those with combined radiation and chemotherapy. The median survival for patients with localized disease receiving 25, 50, and 60 Gy were 3, 7, and 12 months respectively. After a dose of 50 Gy in 20 fractions, CT scan showed no evidence of tumor in 6%, smaller tumor size in 31%, stable tumor size in 41%, and tumor growth in 22% of patients. The split course radiation therapy was well tolerated and no late complications were detected. The medical and economic advantages of using split course radiation therapy and in using CT scan response to plan boost therapy are discussed.

Adenocarcinoma↗

An 11-year follow-up study of 110 depressed patients.

In 1972 the World Health Organization organized a cross-cultural five-centre study of depressive disorders. This report is concerned with data collected, after an 11-year follow-up period, in the sample of 110 depressed patients in Montreal, Canada. Eighty-five percent were traced and 59% were interviewed. Of 93 patients, 20 were dead at the follow-up date, 11 by suicide. Fifty-two percent of patients were receiving psychiatric treatment at follow-up, but there was no relation between psychiatric morbidity and treatment-seeking. Moderate or severe impairment of social functioning was present in 32%; in women, a trend linking the presence of social impairment and the time spent in episodes was observed. Of the episodes of psychiatric illness recorded after the index episode, 86% were diagnosed as depressive, 14% as unspecified affective disorder. The mean durations of the index and four subsequent episodes were 10, 11, 7, 11, and 2 months respectively. At least one recurrence after the index episode was reported by 78%, at least four recurrences by 19%. Episodes lasted at least one year in 5%, 4%, 6%, and 6% in the first, second, third and fourth episodes respectively. Sixteen percent were depressed for at least one year and 31% for at least 2 years. There was a marked trend from inpatient to outpatient treatment and from ECT to drug therapy over time. Twenty-two percent reported either moderate or severe problems with alcohol or substance abuse. There was a statistically significant association between the amount of time patients spent in depressive episodes and the number of life events they reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Whole blood aggregometry and platelet adenine nucleotides during cardiac surgery.

The influence of extracorporeal circulation (ECC) on human platelet adenine nucleotides has been studied in 28 coronary bypass patients before, during and after operation. An oscillating pattern of transient increases and decreases in total platelet ATP was observed following the sternotomy until the end of the operation. A highly significant increase in platelet ATP (20% +/- 14 of the pre-anaesthesia values) occurred during the first 24 h after surgery. Total platelet ADP however, did not show this oscillation nor was there any significant release of ADP from the platelets during ECC. Following collagen activation, increased amounts of 'releaseable ATP' were found after protaminization (124% +/- 38 of pre-anaesthesia values) (p less than 0.05), although whole blood aggregability was slightly reduced (89% +/- 18 of pre-anaesthesia values). This study indicates that 1) the metabolic ATP pool of circulating platelets underwent rapid changes during open heart surgery; 2) the majority of platelets did not release inert ADP during ECC; 3) there may be a compensatory enhancement of platelet function by other blood cells, which could explain the discrepancy between our aggregatory results in whole blood and those reported in platelet rich plasma (PRP) aggregometry.

Adenosine Diphosphate↗