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M Bamberg

Publications and source records attributed to M Bamberg.

At least 127 records · Page 7Linked to original sources
PubMed1996

Radiotherapy in the treatment of uterine sarcomas. A retrospective analysis of 54 cases.

BACKGROUND: In the general population, uterine sarcoma (US) is an uncommon tumor, which accounts for approximately 1-3% of all uterine neoplasms. Its biological behavior is characterized by hematogenous metastases and local recurrent growth including the pelvis and peritoneal cavity. In the management of US, surgery is the primary form of treatment. Up to now the role of adjuvant radiotherapy has not been clearly established. PATIENTS AND METHODS: We report about 54 patients with US treated from 1954 to 1994 by surgical resection alone (22) or a combination of surgery and irradiation (32) and evaluate the influence of histology, stage and different treatment options on survival. RESULTS AND CONCLUSIONS: Our data indicate an increased disease-free survival for patients treated with adjuvant radiotherapy, especially if poor prognostic factors are present (advanced tumor stage, histopathological grade II or III of leiomyosarcoma and mixed mesodermal sarcoma). Postoperative irradiation using doses between 50 and 60 Gy is recommended, in selected cases brachytherapy should be added. Prospective multicentric trials including a statistically evaluable number of patients are necessary to further clarify the role of multimodality treatment programs for US.

Disease-Free Survival↗
PubMed1996

[Stereotaxic convergent-beam irradiation. Initial experiences with the SRS 200 system].

BACKGROUND: The system SRS 200 for the stereotactic convergent beam irradiation described in this paper has a stereotactic floor stand, which allows the high precision rotation of a secondary collimator around an isocenter. This system is used since 1991 at the University Hospital of Tübingen for the treatment of patients with solitary brain metastases, acoustic neurinomas and arteriovenous malformations. PATIENTS AND METHODS: The attainable accuracy of the mechanics and dosimetry was studied within the scope of extensive quality assurance measures during its installation and before each patients' irradiation. The individual treatment steps from radiotherapy planning to irradiation were evaluated by means of a specially developed head phantom. Since the installation of the SRS 200 a total of 50 patients (21 solitary brain metastases, 12 acoustic neurinomas, 17 arteriovenous malformations) has been treated with the system. RESULTS: With 0.3 mm +/- 0.2 mm an excellent accuracy of the target point transfer and isocenter stability during irradiation was attained. The difference between calculated dose and dosimetric control measurements was smaller than 3%. The physical accuracy, however, is limited by the imaging resolution (CT and digital subtraction angiography). Of the patients 15% with solitary brain metastases developed complete remission, 20% partial remission and with 50% no further neurological deterioration was observed. Imaging revealed for 88% of the patients a reduced uptake of contrast medium or a regression of the tumor size. Six patients with acoustic neurinoma had anacusis already before radiotherapy. Regarding the other patients in the follow-up, hearing improved in 1 patient, 1 patient showed hearing deterioration, and all other patients hearing remained constant. MR and CT imaging revealed in 10 patients with acoustic neurinoma a reduced uptake of contrast medium and in 1 patient a tumor diminution. From the patients with arteriovenous malformation only 4 have been followed for more than 2 years after treatment. Therefore, statements about the rate of obliteration are not possible yet. Concerning pretherapeutic symptoms (headache 22%, convulsion 28%, neurological deficits 11%) 8/17 (47%) of the arteriovenous malformation patients showed an improvement, in 8 patients clinical findings were unchanged and 1 patient showed neurological deterioration. CONCLUSION: The stereotactic system SRS 200 allows an excellent mechanical accuracy in the radiosurgery with linear accelerators.

Adolescent↗
PubMed1996

[Acute gastrointestinal side effects of radiotherapy. What is certain in the treatment?].

PURPOSE: Radiotherapy, especially in the abdominal region, is frequently associated with gastrointestinal side effects. METHODS: The article reviews the current knowledge about pathophysiological background, clinical symptoms and the treatment strategies of the major gastrointestinal side effects. RESULTS: Several basics are investigated and depending on this knowledge some special treatment strategies have been developed (5-HT3-receptor-antagonists in the treatment of nausea, Figure 1, Table 2). The treatment of stomatitis, esophagitis, enteritis and proctitis still remains symptomatic and is not yet standardized (Tables 3 to 6). There are some promising results with smectit (enteritis) and sucralfat. Special dental attendance should be performed before initiating radiotherapy of the head and neck region. Technical improvement in radiotherapy will also help to reduce side effects. CONCLUSION: In order to minimize gastrointestinal side effects, it is necessary to further investigate the pathophysiology of acute and late toxicity.

Abdominal Neoplasms↗
PubMed1996

The underlying cellular mechanism of fibrosis.

Fibrosis is a common sequela of various exogenous insults to a variety of parenchymal tissues. The underlying mechanisms of the induction and progression of fibrosis both at the molecular and cellular level have not been clarified so far. In the present study the cellular processes that ultimately may lead to interstitial fibrosis are described using the model of radiation-induced terminal differentiation in the fibroblast/fibrocyte cell system. The data reported herein will provide evidence that exogenously induced changes in the proliferation and differentiation pattern of the fibroblast/fibrocyte cell system based on either autocrine and/or paracrine mediators represent the underlying cellular mechanism of fibrosis. Using co-culture systems of parenchymal cells (fibroblasts and type II pneumocytes), the intercellular communication via cytokines, which may lead to fibrosis have been studied. TGF beta 1 could be described as one key modulator of these cellular processes.

Animals↗
PubMed1995

Is the standardized helmet technique adequate for irradiation of the brain and the cranial meninges?

PURPOSE: To evaluate whether the standardized helmet technique is adequate to reliably cover the clinical target volume (whole brain including cranial meninges) during treatment planning and treatment delivery. METHODS AND MATERIALS: In 21 patients undergoing irradiation of the brain in acute lymphoblastic leukemia or primary cerebral lymphoma, the coverage of the clinical target volume was checked with a repeat computed tomography (CT) in the treatment position (head fixation with face mask). The accuracy of field alignment was quantitatively assessed with sequential verification films. For each patient, linear and rotational discrepancies were measured between the simulation and first check film, and between five consecutive verification films. RESULTS: Coverage of clinical target volume. In 11 cases (52%), the CT examinations showed that parts of the subfrontal region and midcranial fossa were not included by the field assigned under simulation. Accuracy of field alignment. For the total group of patients, all deviations were normally distributed with mean values between -1.2 mm and 1.5 mm and standard deviations of 2.9 mm to 3.7 mm for linear discrepancies, and 0.3 degrees +/- 3.2 degrees for rotational discrepancies. For all patients, deviations were similar for the transition from simulation to the treatment machine and for subsequent treatment delivery, with 50% and 95% of absolute differences being less than 2.0 mm and 6.5 mm, respectively. Maximum linear deviations were less than 9.5 mm. CONCLUSIONS: The currently used helmet technique is inadequate to cover the clinical target volume. Repeat CT examinations are a useful method to delineate the clinical target volume on an individual patient basis. In addition, statistical fluctuations of field displacements up to 1.0 cm have to be considered when prescribing safety margins for reliable coverage of the clinical target volume during treatment planning and delivery.

Adolescent↗
PubMed1995

Stereotactic convergent beam radiosurgery versus stereotactic conformation beam radiotherapy.

By means of preliminary results in the treatment of patients with acoustic neurinoma the achievable accuracies, dose distributions and time consumption of stereotactic LINAC-based convergent beam radiosurgery are compared to those achieved with fractionated stereotactic conformation beam radiotherapy. Characteristics of both techniques are described. With the Tübingen radiosurgery system a good adaptation of the dose distribution to spherical or oval target volumes with a steep dose gradient was achieved, whereas homogeneity and adaptation of the dose distribution to irregularly shaped targets were better with the Heidelberg conformation technique. The mechanical accuracy of the Tübingen floorstand system was 0.3 mm +/- 0.2 mm, and that of the Heidelberg mask fixation system < 1 mm. Both methods require similar total treatment times. Nine patients were treated by the Tübingen radiosurgery system. The results are compared with 12 patients treated by conformation radiotherapy in Heidelberg. In both patient groups no further tumour growth occurred. Four of 9 single dose treated patients developed side-effects, such as temporary trigeminal and facial paraesthesia hearing deterioration and oedema. In contrast, patients treated by fractionated radiotherapy showed no side-effects. Relating to the short follow-up the results indicate that single dose application has certain drawbacks for special indications. Further studies have to work out which method gives the best treatment results.

Adolescent↗
PubMed1995

Abdominal wall metastasis following percutaneous endoscopic gastrostomy.

Percutaneous endoscopic gastrostomy (PEG) has become a widely used method for nutritional support, particularly in patients with advanced head and neck carcinomas. Since the method is easy and widely established it is necessary to assess possible complications, even rare ones. In this paper we report on two patients with vaccination metastasis following PEG insertion. Both patients had advanced squamous cell carcinoma of the head and neck or the upper esophagus. In three patients previous bougienage was performed, because of considerable stenosis of the pharynx and/or esophagus. Fast-growing metastases were found at the site of PEG insertion, with and without involvement of the gastric wall. In neither case was abdominal wall metastasis the cause of death. There is a small but definite risk of tumor seeding into the abdominal wall after PEG insertion for obstructive malignant tumors. The clinical impact of this finding, however, is still undefined and needs further investigation.

Abdominal Muscles↗
PubMed1995

Atypical and anaplastic meningiomas--does the new WHO-classification of brain tumours affect the indication for postoperative irradiation?

We retrospectively analysed 13 patients (pts.) treated at the University of Tübingen from 1985 to 1993 to evaluate the results of radiation therapy (XRT) given as an adjuvant to totally or subtotally resected meningiomas. The overall survival was 38% at five years with a probability of relapse of 50% at this time. Reclassification of the tumours according to the new WHO-classification of brain tumours [14] revealed 10 grade-II-tumours (atypical meningioma) and 3 grade-III-tumours (anaplastic meningioma). Radiotherapy failed in all 3 pts. with macroscopically incomplete resection (Simpson's grade IV), who died with relapse between 4 and 51 months after radiotherapy. 5 out of 10 pts. with grade-II-tumours relapsed. All 3 pts. with grade-III-tumours died with relapse between 6 and 21 months after XRT. Morbidity was seen in 2 pts. after irradiation with 60 GY (ICRU dose specification). Complete surgical exstirpation offers the best possibility of tumour control. Grade-III-tumours should be irradiated whatever the extent of the primary surgery was. Our results might indicate a possible indication for XRT in pts. with atypical grade-II-tumours especially when radical surgery must be in doubt. Prospective multicentre trials are warranted to prove the prognostic value of the new WHO-classification for atypical and anaplastic meningiomas and to define the ultimate role of radiotherapy in this setting.

Adult↗
PubMed1995

Bowman-Birk proteinase inhibitor (BBI) modulates radiosensitivity and radiation-induced differentiation of human fibroblasts in culture.

The radiosensitivity and differentiation pattern of cultured normal human fibroblasts was analysed as a function of treatment of the cells with the Bowman-Birk proteinase inhibitor (BBI). Upon irradiation with doses from 0 to 8 Gy normal human fibroblasts are induced to a premature terminal differentiation within 14-21 days of postirradiation incubation. Treatment of the cells with 10 microM BBI for 2 h prior to the irradiation procedure resulted in a significant shift of the radiation survival curve, increased SF2 values 0.63 vs. 0.84 and the cell type composition of the test fibroblast cultures. Upon pretreatment with BBI the radiation-induced premature terminal differentiation of progenitor fibroblasts to postmitotic fibrocytes could significantly be inhibited. Based on this data, it can be postulated that BBI may serve as a radioprotector of normal fibroblasts which are involved in radiation-induced tissue injuries like radiation fibrosis.

Cell Differentiation↗
PubMed1995

Accuracy of field alignment in radiotherapy of head and neck cancer utilizing individualized face mask immobilization: a retrospective analysis of clinical practice.

Deviations between simulation and first check films were quantitatively assessed for 95 unselected head and neck cancer patients. All measured deviations--calculated on the basis of a total of 190 simulation and 380 verification films--were normally distributed, with mean values of 0-3 mm and standard deviations of 3-5 mm. Of the absolute deviations, 50% and 95% were within 3 mm and 9 mm, respectively. These results should be considered in clinical practice when prescribing safety margins and adequate cut off doses for sparing critical organs in head and neck cancer.

Head and Neck Neoplasms↗
PubMed1995

Cellular basis of radiation-induced fibrosis.

Fibrosis is a common sequela of both cancer treatment by radiotherapy and accidental irradiation and has been described in many tissues including skin, lung, heart and liver. The underlying mechanisms of the radiation-induced fibrosis still remain to be resolved. In the present review we tried to illustrate the basic cellular mechanisms of radiation-induced fibrosis based on the newest findings arising from molecular radiobiology and cell biology. Based on these findings the cellular mechanism of radiation-induced fibrosis can be seen as a multicellular process involving various interacting cell systems in the target organ resulting in the fibrotic phenotype of the fibroblast/fibrocyte cell system.

Animals↗
PubMed1995

[Treatment options in early-stage testicular seminoma. Review of the literature with initial results of a prospective multicenter study on radiotherapy of clinical-stage I, IIA and IIB seminomas].

BACKGROUND: Testicular seminoma in the early stages is treated with orchiectomy and radiotherapy to the retroperitoneal nodes. Despite the high cure rates of this treatment, there is an ongoing controversy concerning the extent of the radiation fields and the radiation doses to be given in the clinical stages I, IIA and IIB. In the following literature review, these controversial issues are discussed. Recent reports emphasize, that the irradiation of the paraaortic nodes seems to be adequate in stage I disease. The "wait and see" strategy avoids an overtreatment in 80% of the patients in stage I. The application of 1 or 2 cycles of carboplatinum chemotherapy induced comparable results to adjuvant radiotherapy. In the stages IIA and IIB radiotherapy to the paraaortal and ipsilateral iliacal nodes, with a prescribed dose of 30 Gy and 36 Gy respectively, has been the standard treatment. The treatment of the upper contralateral iliacal nodes has been a matter of controversy. PATIENTS AND METHODS: Four hundred and ninety-one patients in stage I testicular seminoma received adjuvant paraaortic irradiation with a total dose of 26 Gy. Forty-one patients in stage IIA, and 19 patients in stage IIB received 30 Gy or 36 Gy respectively to the paraaortic and ipsilateral iliacal nodes. RESULTS: Paraaortic radiotherapy in stage I disease was associated with low acute side effects and a disease-free survival in 97.1% of the patients after a median observation of 13 months. In stage IIA the disease-free survival was 100%, in stage IIB 94.7%. CONCLUSIONS: The literature review and preliminary results of the reported ongoing trial are indicating that paraaortic irradiation in stage I and paraaortic with ipsilateral iliacal irradiation in stages IIA and IIB seem to be a sufficient treatment in early stage testicular seminoma with low treatment associated morbidity.

Carboplatin↗