Biomedical subjects
Publications and source records attributed to M Wannenmacher.
The interaction of cisplatin and irradiation was studied in vitro in four human cell lines. Additive effects were observed for the combination given either simultaneously or sequentially. No influence on recovery was seen in split-dose experiments. It is concluded that radiosensitization cannot be presumed in every clinical setting of combined treatment with radiation and cisplatin.
Despite a very successful interdisciplinary therapy regimen for pediatric solid tumors dominated by surgery and chemotherapy, the role of radiotherapy might become again more important if new techniques will allow a better dose localization to the target volume combined with a better protection of the normal tissue. This characteristic is known for charged particle beams. In a field study based on German cooperative trials, the possibility of a charged particle radiotherapy to retroperitoneal tumors of childhood will be discussed regarding indications in risk groups and recurrences. Absolute patient numbers are estimated from the clinical experiences and the incidences of the diseases. A stepwise introduction of this new therapy modality is proposed.
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In a prospective, nonrandomized study 43 patients with inoperable oesophageal carcinoma were treated with a combined therapy of external and intracavitary irradiation according to the Heidelberg protocol adjusted to tumor stage, general condition and age. The proportion of external beam to afterloading doses was 2/3:1/3. The reference doses were between 50 and 75 Gy. Intracavitary radiotherapy was carried out with a HDR-afterloading device in single doses of 5 Gy. In a median follow-up of 23 months 46% had a complete remission and 42% had a partial remission. Within ten months 17 patients (39.5%) showed local tumor progression or recurrence. Presently the estimated median survival time of the whole collective is eleven months. The median survival was significantly influenced by achievement of complete remission (17.7 months in comparison to 8.7 months by missing complete remission). After completion of therapy 90% had sufficient oral nutrition. During long-term follow-up in 44% of the cases repeated measures had to be taken to eliminate initial or recurrent dysphagia. Almost all postradiogenic stenoses were caused by tumor progression. Radiogenic side-effects caused by HDR-afterloading boosts, exceeding the acceptance, were not found. The combined therapy reduces the period of hospitalisation and has the same palliative effects as an exclusively external radiotherapy.
In the Department for Gynecology and the Department for Gynecologic Radiology, University of Heidelberg, breast conserving therapy was carried out in 1,330 patients with breast cancer between 1975 and 1990. The tumor size was up to 3 cm, 28% showed positive nodes. The medium age was 47.6 years, segmental resection was the standard operation, whole breast irradiation with 50 Gy and an additional boost of 10 Gy was standard irradiation schedule. After five years (n = 307) the following results were observed: local failure 6.8%, regional lymph node recurrence 2.1%, overall survival 88.3%, disease-free survival 81.2%. Five out of 36 of the death-cases died without recurrence. Significant factors for local failure were following: 1. lymphangiosis of more than 1 cm in size around the tumor (p = 0.03); 2. intra-ductal non-invasive cancer of more than 1 cm in size around the primary (p = 0.01); 3. intra-ductal non-invasive cancer reaches the margin of resection (p less than 0.00001). With segmental resection (2 cm margin macroscopically free of tumor) showed in 19% histologically tumor beyond the margins so-called residuals. In the other three quadrants additional second primaries of (multicentric cancers) macroscopical size could be confirmed in an additional study. In case of high risk for local failure more radicality in operation as well as in irradiation is recommended.
21 patients were followed by positron-emission-tomography (PET) FDG (18Flourdeoxyglucose) uptake, physical examination, CT and CEA levels after combined photon-neutron irradiation for inoperable recurrent rectal carcinoma. In order to evaluate the response to radiotherapy symptomatic relief, CEA levels, decrease of tumor volume measured by CT analysis were correlated with the FDG-uptake. The objective of this study was also to investigate if the level of FDG-uptake prior to radiotherapy or the early decrease after therapy can be used as a prognostic factor. Prior to radiotherapy sacral pain was the predominant symptom. All malignancies showed measurable tumor masses, evaluation of CEA levels and enhanced tracer accumulation of FDG in the PET cross section. The mean FDG-uptake before radiotherapy was 2.3 +/- 1.1 (range 1.1 to 5.0) in 21 patients in contrast to 1.9 +/- 0.7 (range 0.8 bis 4.0) three months after radiotherapy. In six patients FDG concentration values decreased to the range of normal soft tissue, moreover, two of them relapsed after six and 22 months. Elevated FDG-uptake of the sacral bone was noted in PET cross sections in two patients, while there was no evidence of osseous alterations in CT. Normal levels of CEA were achieved in 14 patients and complete or partial pain relief in 20 of 21 patients. A decrease of tumor volume of more than 50% was detected in the follow-up CT scans of three patients but no complete remission was found. The result suggests that enhanced glucose uptake is associated with recurrent rectal cancer. However, enhanced glycolytic activity is related not only to malignant cells but also to all proliferating cells. To distinguish between proliferation, repair, inflammation, and residual viable tumor cells is not possible and may be responsible for an unchanged or elevated FDG-uptake after radiotherapy.
Subdiaphragmatic radiation therapy in malignant lymphoma requires complete irradiation of retroperitoneal lymph nodes, spleen and splenic pedicle and optimal shielding of radiosensitive structures. The aim of our study was to develop a new method for individual field definition by using MR tomography and MR angiography. In 38 patients with malignant lymphoma coronal MR tomograms and MR angiograms of the abdominal vessels were obtained and superimposed by a specially created computer program. By using a Subtraskop the MRT/MRA superposition was geometrically projected onto the simulation film in correct scale. The target volume could individually be defined and was compared to standard treatment planning according to the definition by Abbatucci. In all patients an exact irradiation of the spleen, the splenic pedicle and prominent lymphatic masses was possible. Furthermore, this resulted in a 32% reduction of treated kidney volume in the average of patients. Noninvasiveness, acceptable costs and high accuracy support the application of this new method in clinical routine.
"Radiosurgery" is the term for a special concept in radiotherapy. It describes a percutaneous, stereotactically guided irradiation delivering a single high dose with collimated narrow beams. The precise stereotactic localization of the target point and a steep dose gradient outside the target volume allow the administration of high doses to a lesion without damage to adjacent normal tissue. Risk of necrosis, due to a dose volume relationship represents the limits of radiosurgery. Units for radiosurgery were designed at Stockholm using multiple external cobalt-60-gamma sources, at Boston operating with protons of a cyclotron, at Berkeley operating with helium ions accelerated by a synchrocyclotron. An attractive alternative to these complicated and expensive facilities is the use of a modified linear accelerator. At the German Cancer Research Center in Heidelberg such a system was developed and has been available for the treatment of patients since 1984. Though, data of over 100,000 patients with vascular malformations and cancer disease are available worldwide, the indication for this therapy is validated only for a minority of entities. In cases of inoperable arteriovenous malformations favourable results in achieving obliteration range between 60% and 100% were obtained. Median survival for solitary brain metastases with controlled, extracerebral tumor diseases were between nine and twelve months. Up to now, advantages of stereotactic irradiation for benign tumor masses could not be proven. Therefore, randomized trials should be initiated in this field, considering decisive improvements in local tumor control with techniques of microsurgery and fractionated, postoperative radiotherapy during the last few years.
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From 1948 through 1977, 151 patients with an epipharyngeal tumor underwent radiation therapy at our department. A retrospective analysis was made reviewing treatment results and prognostic features. The 5-year survival rate of the total group amounted to 39%, the 10-year survival to 27%. Tumor stage and histology were confirmed as the preponderant factors in prognostication. Stage T1--2 cases had a 5-year survival rate of 57%, which decreased to 46% if unilateral lymph node metastases had occurred, and down to 17% in case of bilateral metastasition to the lymph nodes. Of stage T3--4 patients, 45% survived during 5 years. Lymphoepithelial carcinoma, with a 5-year survival rate of 54%, had a better prognosis than squamous cell carcinoma (47%), transitional cell carcinoma (30%) and reticulum cell sarcoma (30%). A review of the results other authors have obtained since 1956 with combinations of surgical and irradiation methods gives evidence that the efficiency of techniques confined to local or regional treatment has reached its limits. At present, further improvement may be achieved mainly by means of systematically applied adjuvant chemotherapy complementary to the general thérapeutic concept.
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The authors describe the frequency, clinical features and methods of diagnosis of venous malformations of the orbits based on their own experience and on the relevant literature. Special attention is paid to plain film diagnosis and angiographic methods of investigation. Orbital phlebography is the most suitable method for demonstrating cavernous haemangiomas and orbital varices and for demonstrating the anatomy of the supplying vessels. For this, special apparatus and skills are necessary in order to obtain adequate, or optimal, phlebograms. The radiological features of venous malformation are described and a selection of typical phlebographic findings are illustrated. An attempt is made to evaluate other forms of examination. Possible aetiological factors in the development of venous malformation in the head and neck region are discussed.
The nearly exclusive metastatic spread of the radiosensitive medulloblastoma into the fluid spaces of the liquor system allows a curative therapeutic attempt by a systemic radiation. The actual 5-years survival rate is about 40%. It should be possible to improve it to up to 50% by consequently applicating radiotherapy. A prospective study concerning the possibilities of chemotherapy presently underway, does not yet permit a definite statement. The most essential complication after radiotherapy of children concerns the symmetric reduction of growth.
A review of 82 cases of adenoid cystic carcinoma in the head and neck is given. Radical surgery was carried out in 33 patients and yielded the best long-term results. Radiation therapy was given to 43 patients for inoperable tumour, local recurrence or, postoperatively, for sub-clinical disease. It proved especially valuable in obtaining remissions from local recurrence.
Therapeutic results of Hodgkin's disease could be significantly improved by the introduction of megavoltage radiotherapy equipment and more profound knowledge about this disease. By this way, five year survival rates of 70% can be achieved for all stages and up to 100% for the early stages. The wide field technique enables the coverage of all lymph nodes with protection of non involved organs. Simultaneously, these improved technical conditions make optimal radiation planning necessary which demands numerous technical auxiliaries. Radiation type and radiation energy are important preconditions for the therapy; production and usage of shilding blocks are necessary for individual performance. The principle for optimal radiation dose distribution are measurements and calculations on the phantom which are now included in computer programs. Nevertheless, radiation of large volumes represent a high stress for the patient. Despite the improvement of the therapeutic results there are except the acute radiation side effects, also irreversible alterations. These can be analysed only after long time observations and has to be balanced with the therapeutic results. The knowledge of these side effects is very important for the radiologist. Beside that, the risk of induction of a second tumor has to be considered. The present possibilities of absolute control of this disease enables the overtreatment of lesions in the early stages. Therefore it has to be postulated to regard the present therapy concepts with attention and to consider the possible side effects.
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