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Biomedical subjects

R Fietkau

Publications and source records attributed to R Fietkau.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Interstitial and percutaneous radiotherapy after limited surgery in carcinoma of the oral cavity].

From 1.1. 1986 to 31.12. 1990 50 patients with epidermoid carcinoma of the floor of the mouth and the mobile tongue (stage T1 18, stage T2 20, stage T3 eight and stage T4 four patients) were treated by surgery, 192-iridium implantation using the plastic tube technique and percutaneous irradiation. Surgery was performed as enoral resection (35 patients) or en bloc tumour resection with part of the mandible and flap reconstruction (15 patients). Interstitial therapy was considered as a boost to primary tumour region, the dose given ranged between 16 and 33 Gy. 50 to 60 Gy were applied with external beam radiotherapy. Management of the neck consisted of elective or radical neck dissection followed by external beam radiotherapy (50 to 60 Gy). At 2/1991 median follow-up was 17 (three to 53) months. 35 patients are alive and tumour-free, one patient lives with tumour. 14 patients died, eight patients tumour-related, four patients of intercurrent disease and two patients because of a second primary. Primary local control was 18/18 patients for stage T1, 19/20 patients for stage T2, 7/8 patients T3, 3/4 patients for stage T4. Three patients suffered from nodal recurrences, four patients from distant metastases. Complication rate was acceptable. Soft tissue necrosis occurred in 4/18 patients (T1); 5/20 patients (T2); 3/8 patients (T3) and 1/4 patients (T4). Three patients developed osteoradionecrosis. Our results show that combined modality treatment for tumours of the oral cavity yields high local control with acceptable complication rate.

Adult↗
PubMed1991

[A new applicator for the intraluminal high-dose-rate irradiation of esophageal carcinoma].

Within the framework of multimodal treatment (radiation, chemotherapy) of esophageal carcinoma high dose rate intracavitary irradiation is used either as a boost or with a palliative intention. By use of a set of four tubes of different thickness (diameter 6, 8, 10, 14 mm) it is possible to adapt the diameter of the applicator to the remaining esophageal lumen. Thereby the radioactive source is placed centrally in the esophagus. The distance between the source and the mucosa is maximized and the radiation dose to the mucosa is reduced in comparison to a normal tube with a diameter of 4 to 6 mm. Better depth penetration of the dose can be achieved in deeper parts of the esophageal wall. The applicators are placed using a guide wire during endoscopy. If the malignant stenosis is endoscopically impassable, an intraluminal reduction of the tumours mass is performed by laser therapy or bougienage.

Brachytherapy↗
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↗
PubMed1990

Spontaneous disruption of two Greenfield vena caval filters.

Two cases of fractured Kimray-Greenfield vena caval filter struts in patients with pulmonary embolism are reported. Both filters were inserted without complications by means of a jugular approach. Postoperative radiographs demonstrated correct positioning of the filter. During the follow-up period in both cases the devices migrated caudally and penetrated the caval wall; however, the patients remained asymptomatic. Radiographs should be obtained in the follow-up period to ensure proper positioning of the vena caval filter even in asymptomatic patients.

Equipment Failure↗
PubMed1990

Primary advanced and local recurrent head and neck tumors: effective management with interstitial thermal radiation therapy.

Thirty-seven patients with 18 primary advanced or persistent, 16 local recurrent, and three local metastatic tumors of the head and neck were treated with a combination of interstitial low-dose iridium-192 radiation therapy and interstitial 915-MHz microwave hyperthermia supplemented by external radiation therapy. Twenty-eight lesions received an additional external radiation dose of 21-61 Gy. Interstitial hyperthermia was applied immediately before Ir-192 was placed and after its removal for 45-60 minutes at 41 degrees C-44 degrees C. Follow-up ranged from 4 to 45 months. At 3 months, complete remission occurred in 25 lesions (68%); partial remission, in nine (24%); and no change or progressive disease, in three (8%). At 12 months of follow-up in 32 lesions, local control was achieved in 23 (72%), with the patients alive, and in four (12%), with the patients dead. There were five local recurrences, one of which occurred after complete response. Lesion type, tumor volume, radiation dose, and thermal quality at high minimum temperature were identified as prognostic factors influencing complete remission. The combined treatment was well tolerated.

Adolescent↗
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

[Nutrition of ENT tumor patients treated with radiotherapy. Comparison of oral and enteral nutrition using percutaneous gastrostomy].

The nutritional state of 99 patients with head and neck malignancies was assessed before, during and up to 18 weeks after radiotherapy (DXRT) using anthropometry, immunology and blood chemistry. 73 patients were fed orally during therapy, first with a normal diet and later, when the side effects of DXRT worsened, with a supplemental liquid formula diet. During the first two weeks 26 patients were treated with a PEG (percutaneous endoscopically controlled gastrostomy) and were fed mainly enterally with formula diets. The parameters of those patients fed orally during DXRT worsened rapidly and only recovered slowly and incompletely. On the contrary, in spite of their poor initial condition, the patients with PEG improved their state of nutrition, even during DXRT. Both the objective parameters of nutrition and the subjective condition of the patients were measured with the help of the "quality of life index". During DXRT the quality of life of both groups deteriorated equally. The objective parameters of nutrition showed that the patient's strength and the capacity for work remained constant. Unexpectedly, after DXRT only the orally fed patients were found to have an improved subjective condition, probably because the PEG patients were reminded of their disease by the tube, in spite of successful completion of tumor therapy. This undoubtedly impedes the return to normal family and working life. Early and consistent enteral diet with PEG helps to stabilize the state of nutrition of patients with head and neck cancer, and is recommended, especially for patients already suffering from malnutrition before starting an aggressive multimodal tumor therapy.

Body Mass Index↗
PubMed1989

[Comparison between oral nutrition and enteral nutrition using a percutaneous endoscopically guided gastrostomy (PEG) in patients undergoing radiotherapy for head and neck tumors].

The nutritional state of 99 patients with tumors in the head and neck area was determined prior to, during and after radiotherapy by anthropometric, laboratory-chemical and immunological parameters. In 73 orally nourished patients, the nutritional parameters deteriorated very quickly during radiotherapy and recovered slowly and incompletely after radiotherapy. In 26 patients treated prospectively by percutaneous endoscopically guided gastrostomy (PEG), however, an improved nutritional state was achieved already during the irradiation in spite of a less favorable starting point. The subjective feeling of patients was questioned by means of the "quality of life" index according to Padilla et al. (1983). The preliminary results show an identical deterioration of the subjective feeling in both groups, but - as opposed to the other patients - force and working capacity did not decrease during radiotherapy in the enterally nourished patients. This corresponds to the objective nutritional parameters. However, an improvement of the subjective feeling after the end of radiotherapy was observed only in the orally nourished patients. Possible reasons are discussed. We have the opinion that an early and constant enteral nutrition by PEG can stabilize the nutritional state of patients with tumors in the head and neck area. Therefore we recommend to establish a prophylactic, pretherapeutic PEG if an aggressive multimodal therapy is planned, especially in case of apparent primary malnutrition.

Body Mass Index↗
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

[DNA impulse cytophotometry measurements in head and neck tumors. Initial results of a correlation with clinical stage, therapeutic response and pattern of recurrence].

The DNA index and proliferation rate (percentage of S-phase cells) of 52 head and neck tumours were analysed by flow cytometry. Thirty-one (60%) of these tumours were aneuploid, 21 (40%) diploid. The distribution of aneuploid tumours was nearly equal in all T-stages. In contrast, the number of aneuploid tumours increased with higher N-stages. Locoregional recurrences developed more often (69%) in aneuploid tumours than in diploid tumours (54%). Furthermore, recurrence presented earlier (median 5 months) than in the latter (median 11 months). Regional recurrences were mainly observed in aneuploid tumours, local recurrences in diploid tumours.

DNA, Neoplasm↗
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

Malnutrition and the role of nutritional support for radiation therapy patients.

The nutritional status of a tumor patient can be negatively influenced by the local and systemic effects of the malignant tumor (tumor cachexia, anorexia, difficult oral food intake), by the effects of the various antitumoral therapy modalities (surgery, radiotherapy, chemotherapy), and by the complications associated with such modalities (anorexia, nausea, vomiting, mucositis, xerostomia, alterations of the smell and taste sensations, odynophagia, dysphagia, maldigestion, malabsorption, diarrhea, steatorrhea, conditioned aversions, radiogenic late effects), as well as by the psychological reactions of the patient to the real or feared existence of his tumor. The radiation-induced nutritional disorders depend on the tumor localization, the region irradiated, the dose and length of radiotherapy, the fractionation, the volume irradiated, and the combination with other therapeutic modalities ("combined modality therapy"). The acute radiation-induced reactions are usually of limited duration and for this reason tend to interfere with the nutritional status to a lesser extent than the permanent chronic consequences of irradiation. Weight loss and malnutrition tend to develop particularly in patients in whom segments of the gastrointestinal tract are subjected to irradiation. The incidence and severity of deficient nutrition depend not only on the region irradiated (head-neck region, thorax, abdomen, pelvis) but also, and most particularly, on the volume of the digestive tract irradiated. Chemotherapy and radiotherapy combined act very strongly on rapidly proliferating cell populations (skin, mucosa, epithelium of the gastrointestinal tract). In this context, actinomycin D and adriamycin act like real sensitizers, whereas the majority of the other drugs are likely to produce only an additive effect. The first named cytostatics give rise to the so-called recall phenomenon, i.e., the reactivation of latent radiation effects in response to the subsequent administration of the drug. Malnutrition impairs organ function and ultimately results in increased morbidity and mortality. For this reason it has proven mandatory and reasonable that the organism of all tumor patients suffering from malnutrition is provided with the missing essential nutrients (especially amino acids for protein synthesis). This tends to clearly improve the Karnofsky performance status, with a positive effect on response rates, toxicity, and survival rates in retrospective studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal Neoplasms↗
PubMed1988

[Experiences with percutaneous endoscopy controlled gastrostomy in patients with neck and otolaryngologic tumors].

Most patients with head and neck tumours need supportive long-term nutrition. To guarantee enteral food intake we implanted a nasogastric tube percutaneously without any complications in 108 patients. The advantage of this method of feeding is that the direct percutaneous route avoids any mechanical irritation of the upper gastro-intestinal tract; this could be important, for example, during radiotherapy, because the mucous membranes are already damaged. In addition the gastric tube is invisible below the patient's clothing so that he can move about without embarrassment.

Endoscopy↗
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↗
PubMed1988

[Induction of malignancies by radiotherapy: a retrospective study of 454 tumors].

On the basis of 98 case reports compiled from the literature of the years 1902 to 1984, a retrospective study was conducted on 454 tumors developed after radiotherapy within the irradiation field. 226 patients (49.8%) were treated for a benign primary disease and 222 (49.6%) for a malignant primary disease. In six cases the primary diagnosis was unknown. The histologic investigation of the tumors showed sarcomas in 52% of the cases, carcinomas in 38%, and leukemias in 8.5%. Cerebral tumors were described in two cases. The average latency was 7.1 years in leukemia, 12.1 years in sarcomas, and 19 years in carcinomas. Carcinomas were preponderantly found after a focal dose up to 30 Gy, sarcomas after higher doses up to 70 Gy. In leukemia, a dose-effect correlation was not evident. The influence of surgery, chemotherapy, the age of the patients at the moment of radiotherapy, as well as the dignity of the primary disease on latency and histology of the radiogenic tumor was also investigated.

Adolescent↗
PubMed1986

Cell kinetic studies of the effect of a combined therapy with 1-beta D-arabinofuranosylcytosine (Ara-C) and X-irradiation on the L1210 ascites tumour.

We studied the effect of combined therapy with X-ray and 1-beta-D-arabinofuranosylcytosine (Ara-C); firstly the effect of whole-body X-irradiation alone on the proliferation of the L1210 ascites tumour of the mouse was studied by autoradiographic and cytofluorometric (FCM) methods. The effect X-irradiation with 4 Gy was mainly a cytostatic one leading to an altered distribution of the cells throughout the cycle due to radiation induced mitotic delay. The cytocidal effect is negligible. As is known from previous studies (Fietkau, Friede & Maurer-Schultze, 1984) the effect of 200 mg/kg Ara-C consists of an inhibition of DNA synthesis and of killing a considerable portion of the L 1210 cells, predominantly of S phase cells. With respect to the importance for potential therapeutic regimens, the influence of the sequence and the time interval between the two therapeutic steps on the survival of tumour-bearing mice was studied. Most combination therapies significantly increase the survival of tumour-bearing mice compared to the single therapeutic steps; however, no significant differences between the various combined therapies were found. Whole-body X-irradiation with 4 Gy followed by the application of 200 mg/kg Ara-C 10 hr later resulted in the greatest increase of the mean survival time of tumour-bearing animals, from 13.2 to 17.4 days. It was shown that apart from the cytocidal effect on S-phase cells, Ara-C also kills cells sublethally damaged by a preceding X-irradiation.

Animals↗
PubMed1985

Cell kinetic studies of the effect of cytotoxic drugs on survival and proliferation of ascites and solid tumor cells of the mouse.

The three studies discussed show that the response of experimental ascites and solid tumors, as well as of the host organism, to a cytotoxic drug can be studied quantitatively with cell kinetic methods. Knowledge of this kind is necessary in the attempt to improve the application of cytotoxic drugs in chemotherapy of tumors which up to now has been based mainly on pure empiricism.

Adenocarcinoma↗