Biomedical subjects
Publications and source records attributed to E Schnepper.
In 37 brain, head and neck tumors, sagittal and coronal MR-images were superimposed on lateral and AP simulator radiographs for target definition using a subtrascope. The accurate, reproducible and efficient integration of sagittal and coronal images led to individualized delineation of target and normal tissue on simulator radiographs.
The left kidneys of Wistar rats were irradiated with a single dose of 20 Gy percutaneously and the local tissue partial oxygen saturation was measured with the multi wire surface electrode (Kessler and Lübbers). The rats were sacrificed at various intervals post irradiation and the pO2-measurements were compared with control values from the unirradiated contralateral kidneys in each animal. Beforehand "normal histograms" were obtained in unirradiated rats. 24 hours post irradiation hyperemia and local perfusion changes were observed, which nearly turned to normal in the course of four weeks. The histograms after 16 weeks proved persisting damage. After a short delay the nonirradiated right kidneys showed similar significant injuries. Further studies are required to clarify these alterations. The multi wire surface electrode render it possible to conceive early functional disturbances in organ microcirculation after high energy irradiation.
For rectal recurrent cancer and macroscopic residual disease after surgery neutron radiotherapy has been suggested to be superior to photon radiotherapy. At the d,T generator in Münster (14 MeV) 20 patients have been treated with a combined photon-/neutron-radiotherapy: two patients with residual disease after surgery: among the 18 patients with rectal recurrence 15 for pain relief; all for tumor control. Tumor resection had been carried out in five recurrent tumors. Six patients presented with distant metastases. 30 to 40 Gy photons for tumor region and potential microscopic spread with 2 Gy per fraction and 5 to 10 Gy neutrons for macroscopic tumor volume with 0.7 to 1.6 Gy per fraction were applied using multiple fields (three to five). The mean follow-up period is nine months. Pain relief was achieved in eleven of 15 patients (73%), the onset of pain was fast, the probability for a pain-free period is 46% for nine months and for survival 56% for twelve months. Side-effects were slight to moderate beside a severe subcutaneous fibrosis in two patients. The superiority of neutrons to photons in rectal recurrent cancer remains questionable and is to be proven in a prospective trial comparing different schedules for frequency, onset and duration of pain relief, tumor control, survival and side-effects.
A case report on a 27 year old woman with an inoperable angiosarcoma of the right atrium is presented. The tumor localization was established by echocardiography, computed tomography and cinecardiography. There was no evidence of distant metastases at diagnosis. After exploratory thoracotomy with surgical biopsy a radiotherapy was started covering the whole heart and the mediastinum. Superior Vena Cava Syndrome was improved quickly and reducing the target volume to the right atrium after 40 Gy radiotherapy was continued up to a total dose of 60 Gy. A complete remission was documented by echocardiography and computed tomography. Chemotherapy ("VAPAC") for distant metastases led to partial remission. The patient died 15 months after diagnosis from brain metastases. Autopsy revealed no macroscopic evidence of tumor in the right atrium. A combined modality approach with surgical tumor mass reduction followed by high dose locoregional radiotherapy (60 Gy) and combination chemotherapy (e.g. "VAPAC") is suggested.
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In ambitious radiotherapy with individually shaped irradiation fields, high-contrast field radiography is necessary for fine adjustment, control and field documentation. If intensification foils made of materials with medium or high atomic numbers such as copper, iron and lead are used, the film lying between the foils is mainly darkened by the secondary electrons released from the material of the front foil. Within the range of 1 MeV to 15 MeV, high-contrast radiographs are produced by means of copper or steel foils which are clearly superior to lead foils. Steel foils are to be preferred to copper foils because of their rigidity and the firmness of the polished surface. Usual X-ray diagnosis films with steep graduation can be used as film material for field control radiography performed in double exposure technique. A new insensitive film not applied hitherto in X-ray diagnosis allows to prepare field documentation images of high quality which are exposed during the whole irradiation time. This is also important for perpetuation of evidence.
The results in 164 patients receiving radiotherapy for humeroscapular periarthritis were evaluated on the basis of questionnaires. In all, 76% of the patients reported an improvement. A long-term study over an average of 5 years showed 61 patients (49%) to have experienced long-lasting freedom from pain. However, 38 patients (24%) noticed no improvement. Criteria affecting the success of therapy seem to include the length of the history of the disease as well as inadequate differential diagnosis. No influence is attributed to age, sex or previous types of treatment.
The indications and possibilities of radiotherapy in carcinomas of the renal pelvis and the ureter are demonstrated. Based on the literature and our own experience in 22 cases, postoperative radiotherapy should be performed in cases of deep infiltrating carcinomas, after subtotal surgery, and in cases with lymph node metastases. The radiation dose applied should be 50-55 Gy to the tumor bed and 45 (-50) Gy to the regional lymph nodes. Local recurrences can be greatly diminished without severe complications. Therefore, postoperative radiotherapy in carcinomas of the renal pelvis and the ureter can be recommended.
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Twelve osteosarcomas treated according to the COSS 80 protocol (preoperative chemotherapy, resection) were studied by light and electron microscopic, histochemical, and autoradiographic methods. Evidence of regressive and necrotic changes was found in many tumor cells, but the alterations were unspecific. Viable tumor cells of high malignancy were also observed regularly, often at the S phase. As the tumor regression continued, a strong reaction of the mononuclear phagocyte system was manifested by the presence of macrophages and giant cells.
If the irradiation field of a megavoltage therapy extends over one kidney or a part of it, blood pressure reactions suggest in some cases an affection of the kidney. These reactions may already occur after doses of 5 to 20 Gy. After higher doses, a number of symptoms may appear which have been classified into three clinical groups by Sarre and Moser and even into five groups by Luxton and Kunkler. They show histologic manifestations in the glomeruli and tubuli and are mostly progressive. In case of radiotherapy alone, the threshold doses are 20 to 25 Gy. After a latent time of several months, these patients may present renal insufficiency and hypertonia, leading eventually to death in an acute stage, chronic development with preponderant renal insufficiency, hypertonia, or incomplete healing. These doses are considerably lower in children. It has been proved recently that these threshold doses are considerably reduced by combined chemotherapy, too even if the cytostatic drugs alone have no nephrotoxic potential. This is verified by our experimentations on animals. If only a little part of the kidney is situated within the irradiation field, e.g. the upper renal pole in case of an irradiation of the spleen, a significantly reduced activity in the upper pole of the left kidney can be proved by scintigraphy after a period of eight months. After about 18 months, tomography shows a cortical atrophia in this region. However, as far as clinical or technical examinations are concerned, no abnormal parameters could be found.
Contrary to other tumors in children, e.g. leukemia and Wilms tumor the prognosis of which has been considerably improved by the application of surgery, radiotherapy, and chemotherapy, the treatment results of one of the most frequent tumors, namely the neuroblastoma, have not essentially ameliorated during the last few years. The authors present 28 own case records of irradiated patients and describe the clinical symptoms, diagnosis and therapy, especially radiotherapy of the neuroblastoma. A prolongation of the survival time by several months could be achieved in a small group of eight patients treated additionally with an aggressive chemotherapy. The overall long-term prognosis, however, could not be improved hitherto.
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102 patients entered a multicentric randomized study from May 1978 till December 1980. After an operative removal of a supratentorial astrocytoma grade 3 or 4 all patients were treated by radiotherapy of the whole brain with 40 Gy, and after a rest of 1 to 2 weeks with a boost dose of 20 Gy to the tumor region. By randomization the patients got misonidazole (400 mg/m2) to each of the 30 fractions or a placebo. The overall tolerance was good. A mild transient peripheral neuropathy was seen only in 2 patients. The median of survival time was not significantly different for both groups with 16 months (grade 3) and 10 months (grade 4). Thus a radiosensitizing effect of misonidazole was not proven.
A report is given about the results of radiotherapy in 139 patients with vulvar carcinomas treated at the Radiologic University Hospital in Münster. This group of patients had undergone a very heterogenic preliminary treatment. Radiotherapy carried out mainly with 18 MeV electrons brought about a five-year survival rate of 58%. Due to the favorable action of the split course method, the incidence of side effects was very low regarding the total focal dose of 60 Gy (27% exudative reactions, 11% superficial ulcerations). Taking into account the unsurmountable difficulties caused by the high age of the patients and the numerous accompanying risk factors, the treatment results achieved during the last few years can probably only be gradually improved. After an operation performed as radically as possible, radiotherapy should aim at a low recurrence rate.
So-called nipple-preserving operations were performed as primary treatment of mammary carcinoma, predominantly in stage T1, in 135 women. The operation consisted of subcutaneous mastectomy, axillary lymphadenectomy, nipple biopsy and X-ray therapy. Most of the patients in whom more than two lymph nodes had carcinomatous changes also received chemotherapy. Survival of more than five years was achieved in 48 patients in stage T1. One woman died of carcinoma; in six there was further growth with metastases. In no case was there further growth in the nipple region. Although the numbers are small one can already state that the results are no worse than after more radical operations.
Eighty-three patients with prostatic cancer, who underwent megavoltage therapy of the carcinoma or of its metastases, are reported. The majority of the patients had advanced disease (Stage C or D according to Flocks) when they came to be treated, and thus the general prognosis was bad. Radiation therapy, however, represents on the whole an important constituent of therapy in prostatic cancer, with regard to the practicability as well as to palliative treatment of metastases to the skeleton.
The radiograph is usually the first step in diagnosis of tumorous bone lesions. Although definitive diagnosis depends on biopsy in many instances the radiograph allows the most essential decision on malignancy or benignity. This radiological grading of neoplastic bone disease is based on various criteria in particular the pattern of bone destruction and behaviour of the cortex. 3 main types of bone destruction predicting tumour behaviour can be differentiated: 1. the geographic well-defined destruction which is characteristic of static or slowly growing lesions; 2. moth-eaten pattern with scattered and confluent holes reflecting a highly aggressive lesion; 3. most aggressive permeative pattern characterized by multiple tiny holes. The cortex also reflects the response of normal bone against destruction. Depending on the activity of the process, the cortex will either remain intact, or will be expanded, or is even penetrated. The characteristic features of the different destruction patterns are illustrated by radiographs and corresponding pathologico-anatomical slices.