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Biomedical subjects

M Herbst

Publications and source records attributed to M Herbst.

At least 37 records · Page 2Linked to original sources
PubMed1990

Digital tumor fluoroscopy (DTF)--a new direct imaging system in the therapy planning for brain tumors.

Digital Tumor Fluoroscopy is an expanded x-ray video chain optimized to iodine contrast with an extended Gy scale up to 64000 Gy values. Series of pictures are taken before and after injection of contrast medium. With the most recent unit, up to ten images can be taken and stored. The microprogrammable processor allows the subtraction of images recorded at any moment of the examination. Dynamic views of the distribution of contrast medium in the intravasal and extravasal spaces of brain and tumor tissue are gained by the subtraction of stored images. Tumors can be differentiated by studying the storage and drainage behavior of the contrast medium during the period of examination. Meningiomas store contrast medium very intensively during the whole time of investigation, whereas astrocytomas grade 2-3 pick it up less strongly at the beginning and release it within 2 min. Glioblastomas show a massive but delayed accumulation of contrast medium and a decreased flow-off-rate. In comparison with radiography and MR-imaging the most important advantage of Digital Tumor Fluoroscopy is that direct information on tumor localization is gained in relation to the skull-cap. This enables the radiotherapist to mark the treatment field directly on the skull. Therefore it is no longer necessary to calculate the tumor volume from several CT scans for localization. In radiotherapy Digital Tumor Fluoroscopy a unit combined with a simulator can replace CT planning. This would help overcome the disadvantages arising from the lack of a collimating system, and the inaccuracies which result from completely different geometric relationships between a CT unit and a therapy machine.

Astrocytoma↗
PubMed1990

Initial results of phase I/II interstitial thermoradiotherapy for primary advanced and local recurrent tumors.

Since January 1986 in a phase I/II study, 45 lesions (30 head and neck, 11 pelvic, and 4 other lesions) in 44 patients (24 men, 20 women; age 18-81 years) received a combination of interstitial Ir-192 radiotherapy (IRT) and interstitial 915 MHz MW hyperthermia (IHT) supplemented by external radiation (ERT). In June 1989, evaluation was performed for lesions with minimum follow-up (FU) of 6 months and FU periods between 6 and 39 months (mean: 16 months, SD +/- 9). The tumors comprised 21 advanced primary (AP) lesions without prior ERT, 18 local recurrent (LR) and 6 local metastatic (LM) lesions with variable prior treatment modes; 24 lesions had received prior ERT between 40 and 70 Gy, 23 chemotherapy and 30 prior surgery. The mean dimensions of 42 lesions were 4.5 X 4.0 X 3.0 (cm3) with tumor volumes ranging from 12 to 135 cm3 (mean: 54 cm3, SD +/- 35); 3 lesions had extensive tumor volumes greater than 225 cm3. IHT was applied immediately prior to and/or after low-dose Ir-192 IRT (20-30 Gy) for 60 min at temperatures between 41 and 44 degrees C. ERT (40-50 Gy) was always given for AP and LM lesions, but variably applied for previously irradiated LR lesions, thereby avoiding the cumulative radiation dose exceeding 110 Gy per site. IRT doses ranged from 17-48 Gy (mean: 26.8 Gy, SD +/- 8) at a dose rate of 25-70 cGy/h (mean: 42 cGy/h, SD +/- 12). Thirty-three lesions received additional ERT of 30-56 Gy (mean: 46.5 Gy, SD +/- 9). Total radiation dose (IRT + ERT dose) ranged from 31 to 82 Gy (mean: 61 Gy, SD +/- 18). The hyperthermia systems of Lund/Buchler 4010 and Clini-Therm Mark VI/IX with thermistor or fiber-optic thermometry devices were employed. Initial response at 3 months FU showed 31 (69%) lesions complete response (CR), 10 (22%) partial response (PR), and 4 (9%) no change (NC). Long-term response of 30 lesions at 12 months FU revealed a total of 27 (90%) with local control (LC) and 3 (10%) in-field recurrences. Six patients died prior to 12 months FU, three with LC and three with progressive disease. So far 10 (22%) patients have developed distant metastases. Acute side-effects occurred in 15 lesions (33%) resulting in 12 (27%) long-term complications with 3 lesions (7%) requiring surgery.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

A comparison of amplitude-modulated and frequency-modulated ambulatory monitoring systems.

To compare the results of monitoring for ischemia with amplitude-modulated (AM) and frequency-modulated (FM) ambulatory recorders, 22 patients with coronary artery disease were monitored during exercise and during 24 to 48 hours of daily activities. Simultaneous recordings were obtained with Oxford Medilog 4000-II and Medilog MR-35 systems from the same 2 bipolar leads. Each potential ischemic episode was interpreted blindly by 2 investigators. Significant ST depression was strictly defined as greater than or equal to 1 mm of horizontal or down-sloping ST depression persisting for 0.06 second beyond the J point and lasting greater than or equal to 1 minute. Of 82 episodes reviewed, 63 (77%) were either positive (37) or negative (26) for ischemia by both systems. However, 17 episodes were interpreted as positive on AM tracings but negative on FM tracings; the converse was true for only 2 episodes (p less than 0.01). For episodes read as positive with both systems, there were close correlations between recorders for duration (r = 0.80) and magnitude (r = 0.90) of ST depression. Because of the greater number of positive AM events, however, the mean total duration of ST depression for patients with ischemia during daily activities was greater on AM than on FM recordings (74 +/- 77 vs 39 +/- 42 minutes, p less than 0.10). Discrepancies between AM and FM tracings were invariably due to small differences in ST-segment morphology or in the magnitude of ST-segment depression. In summary, AM monitors generate complexes similar in appearance to those produced by FM devices in most instances.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1989

Superficial chest wall recurrences of breast cancer: prognostic treatment factors for combined radiation therapy and hyperthermia.

Forty-nine patients with chest wall recurrences of breast carcinoma received radiation therapy and 915-MHz microwave hyperthermia for 95 lesions. Follow-up ranged from 3 to 39 months, with five patients dying before 6 months follow-up. At 1 month follow-up, 49 (52%) of 95 lesions showed complete response; 28 (29%), partial response; and 18 (19%), no change. At 6 or more months follow-up, 54 (67%) of 81 lesions demonstrated local control; 10 (12%), partial response; six (7%), no change; and 11 (14%), local-regional recurrences. Superficial blisters occurred in 24 (25%) of 95 lesions, whereas long-term complications (deep necrosis, subcutaneous burns) occurred in seven (7%) lesions. Relapse occurred in 16 (17%) lesions, seven after initial complete response and nine after partial response. Several prognostic treatment factors were identified: applied radiation dose (greater than 30 Gy, P less than .01), size of tumor (less than 6 cm diameter, P less than .001), minimum tumor temperature (greater than 41 degrees C, P less than .001), and status of disease (M0 or M1 vs M2, P less than .001). Treatment complications were correlated with maximum temperatures (greater than 45 degrees C, P less than .001). In summary the palliative treatment concept proved to be safe and effective.

Adult↗
PubMed1989

[Results of temporary interstitial iridium 192 implantation in head and neck tumors].

In order to improve local tumor control in advanced head and neck tumors, a temporary interstitial iridium-192 implantation (40 to 50 cGy/h) was performed as a boost therapy (20 to 30 Gy at the surface of the target volume). This treatment was part of a multimodal therapy conception for primary tumors (N = 55) as well as for recurrences (N = 22). Local control was achieved in 89% (49/55) of patients treated for primary tumors. Complications appeared in the form of soft tissue necroses in 55% (30/55) and in the form of osteoradionecrosis of the mandible in 7% (4/55) of the patients. The authors discuss as possible reasons for this high complication rate: implantation volume too large or total activity too high, activities of the individual iridium-192 seeds to high, setting of radiation sources too close together, total dose too high, disturbed reparation capacity of sound tissues due to preceding operation and chemotherapy, premature test biopsies in the area of implantation, lacking oral hygiene and dental care by uncooperative patients. A local control rate of 50% was achieved by the treatment of recurrences, but this has no importance for the course of this tumor disease which is fatefully determined by the formation of remote metastases.

Adult↗
PubMed1989

[A new multi-channel LDR/MDR-afterloading-system (Inter-Pal-C38)].

The methods of temporary interstitial implantation of iridium-192 seed chains have been applied in Erlangen for two years in many cases of squamous cell carcinoma in the head and neck area, the cervix uteri or the anal duct. The afterloading procedure which at the beginning had to be performed manually involved partially considerable radiation-exposures of medical and nursing staff. Therefore we have developed a 38-canal machine for remote control afterloading with iridium-192 seed chains in LDR and MDR therapy which is working in a similar way as the already established methods of remote control afterloading in HDR therapy. Special technical features are the automatic afterloading procedure, the disconnecting of patient and machine for any length of time, the possibility to use the machine for several succeeding patients, and the modern computer control by an IBM PC with color monitor and alpha-numerical keyboard. The new machine is fast and easy to handle, protects the staff completely against radiation and, due to the possibility of disconnection and free mobility, makes it easier and more comfortable for the patient to stay within the radioprotection room.

Anus Neoplasms↗
PubMed1989

[Flow cytophotometric measurements before and during radiotherapy of head and neck tumors].

The DNA index and proliferation activities were determined by flow cytophotometry in 59 tumors of the head and neck area. 35 tumors (59%) were aneuploid, 24 (41%) were diploid. Aneuploid tumors showed a tendency to increased formation of lymph node metastases, an increased risk of relapse as well as a shorter relapse-free interval. No correlation was found between the primary tumor stage and the incidence of aneuploid tumors. Whereas aneuploid tumors developed frequently regional recurrences, only local recurrences were observed in diploid tumors. A number of biopsies was additionally performed during radiotherapy in twelve tumors. After 10 or 20 Gy, aneuploid tumors showed a considerably increased number of S and S2 + M phase cells. In diploid tumors, substantial modifications of the cell cycle phases were not found, because it is not possible in these cases to distinguish between normal cells and tumor cells.

Aneuploidy↗
PubMed1988

[Evaluation of the tolerance of the intra-ocular injection of hydroxypropyl methylcellulose in animal experiments].

Hydroxy-propyl-methyl-cellulose (HPMC) was injected into the anterior chambers or vitreous bodies of rabbit eyes in order to test local and systemic tolerance. In doing so the typical intraoperative complication of capsule rupture, which, in anterior segment surgery in man, allows HPMC to enter the vitreous body, was simulated. Neither clinically, nor in laboratory workup, nor histopathologically could any difference be shown between the local and systemic reactions of HPMC and those of DRSS. The data obtained in the study admit the conclusion that HPMC can be used in surgery of the anterior segment without any risk of adverse reactions.

Animals↗
PubMed1988

[Individual collimators as an aid in improving the accuracy of positioning, the reproducibility of irradiation and the sparing of critical organs].

Despite the technical progress regarding radiotherapeutic facilities, the positioning and fixation of the patient and the reproduction of the daily irradiation geometry is still the critical point in planning and performance of radiotherapy treatments. Besides the use of irradiation masks, an improved adjustment precision and reproducibility as well as an individualization of the target volume is achieved above all by individual collimators. The use of individual absorbers offers a precise and fast adjustment of irradiation fields at the therapy unit, an optimum adaptation of the irradiation volumes to the anatomical features of the patient and the loco-regional tumor extent as well as a selective protection of radiosensitive structures. The historical method of field-shaping by standard absorbers should be abandoned.

Humans↗
PubMed1987

[Demonstration of brain tumors using a computer-assisted x-ray image enhancement technic].

It is possible to distinguish cerebral tumours from brain tissue after the injection of contrast by using an x-ray-video chain. Weak contrast situated behind strongly absorbing bone can be demonstrated by a nontomographic method by reducing the noise level and by using a special subtraction technique designed for optimal iodine contrast. For this examination, four series of images are prepared and stored (one before the administration of contrast and three subsequently). Dynamic studies of the distribution of contrast in the intra- and extra-vascular spaces of brain and tumour are produced by subtracting the stored images. The demonstration of blood-flow dynamics improves the differentiation of the tumour and, in particular, makes it possible to distinguish the tumour from cerebral oedema. The current input into the x-ray tube is low and the skin dose on the entry side is less than 0.6R for each series. The usefulness of the method in complementing computer tomography for surgical and radiation treatment is illustrated from various types of tumour. Up to the present 35 patients have been examined by this method.

Brain Neoplasms↗
PubMed1987

[Combined treatment of hypopharyngeal carcinoma].

From 1978 through 1984, 120 patients with hypopharyngeal carcinomas were treated cooperatively by the University Hospitals of Erlangen. 120 out of these patients were men and 6 women. 96 patients (80%) suffered from cervical lymph node metastases, 91 (76%) were already in UICC stage IV. There were two cases with stage I, eight cases (7%) with stage II, and 19 cases (16%) with stage III. Among the 116 patients treated by causal therapy, 70 (60%) reached complete remission (CR), 34 (29.5%) partial remission (PR), and 12 (10.5%) were non-responders (NC,P). The cumulative survival at five years was 14% in 120 patients and 24% in 70 patients after CR. None of the patients with PR or NC survived more than two years. 111 patients were irradiated. Group 1: radiotherapy alone (41 patients), group 2: surgery and radiotherapy (47 patients), group 3: chemotherapy and radiotherapy (19 patients). The medium treatment period was 76, 107, and 141 days, respectively. The cumulative survival at five years was 3% in group 1, 28% in group 2, the survival at three years in group 3 was 14%. The results of postoperative radiotherapy, amounting to 36%, were better than the rate of 20% achieved by preoperative radiotherapy and surgery. A survival at five years of 46% was obtained after transoral microlaryngoscopic laser resection and postoperative irradiation, which was therefore superior to conventional operation techniques combined with radiotherapy (16%). Moreover, better functional and cosmetic results were achieved with this method. The prognosis is unfavorably influenced by a high stage, lymph node manifestations, and dedifferentiated tumor histology.

Adult↗
PubMed1987

[Reversible functional disorders of the intestinal tract caused by abdominal radiotherapy].

In 20 patients with malignancies receiving abdominal radiotherapy, tests for disturbed intestinal functions were performed at the beginning and at the end of the therapy and after 6 to 12 month following radiation. Four noninvasive tests were performed: 75Se-homotaurocholate (75SeHCAT) test for estimation of bile acid malabsorption; Schillings test for quantification of vitamin B12 absorption; H2-breath analysis before and after a test meal containing lactose as a parameter of lactose malabsorption; and 51Cr-EDTA test for estimation of intestinal permeability. Both bile acid and vitamin B12 absorption decreased significantly towards the end of abdominal radiotherapy in more than 50% of patients. Only one patient developed lactose malabsorption. After 6 to 12 month, these abnormalities had completely disappeared. In contrast, small intestinal permeability did not increase during radiotherapy but was significantly elevated 6 to 12 month following treatment as the only indication of chronic injury of small intestinal mucosa. During radiotherapy, a significant correlation existed between the severity of diarrhea and the degree of bile acid malabsorption.

Diarrhea↗
PubMed1986

Distribution of synaptophysin immunoreactivity in guinea pig heart.

The distribution of synaptophysin, an integral polypeptide of presynaptic vesicle membranes, was investigated in guinea pig heart by immunohistochemistry using monoclonal antibodies. Synaptophysin immunoreactivity was found in varicose nerve terminals in all regions of the heart. Dense networks of immunoreactive varicosities were found to surround the vasculature and to be located within the subendocardial layers of the atria and ventricles, the highest levels being seen in the innervation of the conductive system. As synaptophysin is probably a component of the presynaptic vesicles of all synapses, its use as a marker of all nerve terminals within the heart is proposed.

Animals↗
PubMed1986

Total lymphoid irradiation of intractable rheumatoid arthritis.

Eleven patients with intractable rheumatoid arthritis were treated with fractionated total lymphoid irradiation at a total dose of 20 Gy. Lasting improvement in clinical symptoms was found in four patients during treatment and the remaining patients experienced a similar benefit within 2 months of irradiation. There was marked reduction in exacerbations and the number of joints involved. Morning stiffness, joint swelling and tenderness decreased. Complications included severe fatigue during treatment and acute bacterial arthritis in multiple joints in one patient. Four of the patients have since died, one of renal failure and another of cardiogenic shock following surgery 3 and 24 months after total lymphoid irradiation. Both had generalised amyloidosis. The third patient developed joint empyema and died of toxic cardiac failure. The fourth died 3 months after resection of a Kaposi's sarcoma complicated by wound infection which responded to treatment. Immunologically, total lymphoid irradiation resulted in suppression of the absolute lymphocyte count and a reduction in T-helper cells, while the number of T-suppressor cells remained unchanged. These data provide evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis. Total lymphoid irradiation can induce sustained improvement in clinical disease activity, but severe, possibly fatal, side-effects cannot be ignored.

Aged↗