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Biomedical subjects

R Sauer

Publications and source records attributed to R Sauer.

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

[Radiobiologic in-vivo investigation of angiogenesis in the yolk sac vascular system of chicken embryos].

PURPOSE: The aim of this study was to investigate whether the yolk sac blood vessel system of chick embryos represents a useful model of in-vivo measurements of angiogenesis in radiobiology. MATERIAL AND METHODS: The fertilized eggs of the crossbreeding White Plymouth Rox X Sussex were used for the study of the extraembryonic vascularisation after irradiation with different fractionation and dosage. On day 3 of incubation an oval window was cut into the shell and then the area vasculosa was irradiated with 1.0 cm in diameter. Forty-eight hours after irradiation in-vivo photographs were taken for quantitative evaluation of blood vessel density. RESULTS: Irradiation from 2.0 to 8.0 Gy in a single fraction leads to a slight decrease in vascular density. After a single fraction of 10.0 Gy a distinct increase in vascular density occurs. Fractionated irradiation leads to a considerable clear increasing of vascular density in comparison with the single fraction and same total dose. CONCLUSION: Our model of the fertilized egg enables in-vivo measurements of angiogenesis in radiobiology.

Animals↗
PubMed1996

[Role of percutaneous radiotherapy in male breast carcinoma].

PURPOSE: Breast cancer in men is a very rare malignancy. Current knowledge about its natural history, diagnostic management and overall prognosis is poor and usually relies on reviews and a few retrospective studies. Herein we report about our past 20-year-clinical experience. PATIENTS AND METHODS: From 1972 to 1993, 21 men with histologically verified tumors were irradiated for operable primary (n = 17) or recurrent (n = 4) breast cancers at our institution. Patients received surgery and post-operative radiotherapy to the chest wall and ipsilateral lymph nodes. Additionally hormones and chemotherapy were applied in only a few cases (n = 5). RESULTS: The follow-up ranged from 18 to 184 months (median 46 months). At last follow-up (11/94), 9 patients were alive and 8 without disease. The median overall survival of all patients was 69 (mean: 106) months and the 5-year survival rate 59%. In univariate analysis, a relapse- and disease-free survival advantage was observed for patients with stage I/II disease, with negative lymph nodes, central tumor location, patients younger than 60 years and short interval (less than 3 months) from first symptoms and diagnostic verification of the malignancy. None of these factors, however, was statistically significant due to the low case number. CONCLUSION: Postoperative adjuvant radiotherapy is an essential part of the treatment strategy of advanced node-negative and node-positive cancer of the breast in men. With respect to locoregional tumor control it is a necessary treatment, while it does not influence the rate of distant metastases. The role of adjuvant hormones and chemotherapy management remains unclear from our scarce patient data.

Adenocarcinoma↗
PubMed1996

[Radiotherapy of plantar heel spurs: indications, technique, clinical results at different dose concepts].

BACKGROUND: In a retrospective study the efficacy of orthovoltage radiotherapy for refractory painful plantar heel spur was analyzed for 3 different radiation dose concepts. PATIENTS AND METHODS: From 1.1 1984 through 1.3.1994, 182 patients with refractory painful heel symptoms and radiologically proven plantar heel spur received radiotherapy. A total of 141 patients and 170 heels (due to double-sided symptoms) were completely documented in long-term follow-up. Clearly defined semi-quantitative criteria (9-point score) were used to analyze heel pain and ankle function prior to RT, 6 to 12 weeks post-radiation, and at last follow-up. The treatment outcome, i.e. (un)favourable response, of 3 radiation dose concepts were compared: Group A (n = 72 heels) received 12 Gy total radiation dose in 3 fractions per week and 2 series (6 x 1 Gy per series) separated by 6 weeks; group B (n = 98 heels) received 3 Gy total radiation dose in 10 fractions of 0.3 Gy (n = 50) or 5 Gy (10 x 0.5 Gy) (n = 48) with conventional fractionation in 1 series. RESULTS: Radiotherapy was very effective: at last follow-up 67% (group A) and 71% (group B) remained completely free of pain. The rate of "complete pain relief" (i.e. free of any pain symptoms) was not different between the 3 radiation concepts. However, significant differences were observed with regard to "incomplete or insufficient pain relief", i.e. a subjective pain relief of less than 80%, a delayed pain relief after more than 4 weeks or a relapse of pain symptoms in long-term follow-up. More favourable results were achieved in patients receiving 5 Gy or 12 Gy total dose, while patients with 3 Gy total dose had significantly worse results. Prognostic factors for "complete pain relief" were short duration of pain symptoms and acute pain symptoms prior to radiotherapy; with regard to "in-complete or insufficient pain relief" the total dose was found to be a prognostic parameter. CONCLUSIONS: Patients with refractory heel pain can yield a high response to radiotherapy even after failing various conventional treatments previously. Thus, radiotherapy should not be solely regarded as a last resort due to its low costs and high efficacy at low radiation doses.

Adult↗
PubMed1996

[Supportive treatment with megestrol acetate during radio(chemo)therapy in patients with tumors in the head-neck area. A randomized study].

BACKGROUND: The value of megestrol acetate in treating tumor anorexia and cachexia of terminal patients is well known. However, the supportive effect of megestrol acetate during intensive radio-(chemo-)therapy was not investigated up to now. Therefore a randomized trial was performed including patients with advanced tumors in the head and neck region. PATIENTS AND METHODS: From June 1991 to December 1993 a total of 64 patients were admitted to a randomized, double-blind placebo-controlled study. During and up to 6 weeks following radiotherapy patients received 160 mg/d megestrol acetate or placebo. The nutritional status (anthropometric and laboratory parameters) and the quality-of-life index according to Padilla et al. [24] were determined prior to therapy, 1, 4, 6 weeks later during radiotherapy and 12, 18 weeks after completion. RESULTS: Sixty-one out of 64 patients were evaluable (control group: n = 30; megestrol acetate patients: n = 31). One patient refused further participation after randomization. One patient in each arm was excluded due to side effects (impotence, diarrhoea). Further side effects were not observed. In the control group the nutritional parameters (body weight, triceps skinfold) and the subjective feeling of the patients deteriorated during radiotherapy and did not restore following radiotherapy. By contrast, the patients of the megestrol acetate group were able to stabilize these parameters. This difference was most prominent in the orally nourished patients (weight loss during therapy: control group: -4.1 kg; megestrol acetate group: -0.8 kg; p = 0.004); but not in the patients fed by percutaneous endoscopically guided gastrostomy (weight loss control group: -2.4 kg; megestrol acetate group: -0.8 kg; p = 0.14). CONCLUSION: In patients on radiochemotherapy megestrol acetate prevents patients from further deterioration of the nutritional status and quality of life.

Anthropometry↗
PubMed1996

[Hypoxyradiotherapy: changes in the oxygen partial pressure distribution in the tumor and in the healthy tissue under acute respiratory hypoxia].

PURPOSE: Based on the oxygen effect a new therapeutic modality has been developed to protect healthy tissues while breathing hypoxic gas mixture during irradiation. MATERIAL AND METHODS: The effect of breathing hypoxic gas mixture (8.1% O2) on pO2 in Yoshida sarcoma and muscle was studied using rats of Wistar strain. Different fractionation schedules were used: 10 x 3 Gy, 6 x 5 Gy and 3 x 10 Gy. Tissue oxygenation was assessed with a polarographic electrode system. RESULTS: The median pO2 in Yoshida sarcoma was 10 mm Hg. 21% of pO2-values were lower than 5 mm Hg. During breathing of hypoxic gas mixture no significant changes in median tumor pO2 or radiobiologic hypoxic values (< or = 5 mm Hg) were recorded. The median pO2 in muscle was 30 mm Hg. During breathing of gas hypoxic mixture a significant decrease of the median to the value 12 mm Hg and an increase of the radiobiologic hypoxic values (p < 0.00001) were observed. The changes of pO2-values were constant independent from fractionation. CONCLUSIONS: Between tumor and healthy tissue exists a significant difference regarding changes in the radiobiologic fraction during breathing of hypoxic gas mixture. This fact explains the experimental and clinical experience, that the breathing hypoxic gas mixture protects the healthy tissue without changes in the radiosensibility of chronic hypoxic tumor tissue.

Acute Disease↗
PubMed1996

Concurrent Taxol and split-course accelerated radiotherapy for advanced head and neck cancer.

AIM: The aim of this study was to investigate feasibility and toxicity of fractionated paclitaxel administration concurrently with accelerated radiotherapy in the treatment of advanced head and neck cancer. PATIENTS AND METHODS: Patients with a proven histology of inoperable head and neck carcinoma were eligible for this study. Between July 1994 and August 1995, 12 patients with stage IV (UICC) tumors were treated. Patients were required to have normal end-organ function. Exclusion criteria included: age > 70 years, metastatic disease, performance status (Karnofsky < 70), major intercurrent medical disorders, and previous chemotherapy. External radiation was delivered twice a day at 1.5 Gy per fraction, specified to the reference point (ICRU 50), with a minimum interfraction interval of 6 hours. The accelerated scheme was split into 2 courses by a rest period of 9 days (including weekends) after administration of 30 Gy within 2 weeks. After 39 days a total dose of 72 Gy was reached. Paclitaxel (30 mg/m2/d) was administered as a continuous intravenous infusion over a period of 3 hours on days 1 to 5 and 29 to 33 of radiation therapy. All patients received premedication to avoid allergic reactions and circulatory monitoring was used routinely. RESULTS: Radiochemotherapy was completed in 10 patients with 8 complete and 2 partial remissions. Most important toxicity was a short period of neutropenia, which occurred 3 to 6 days after chemotherapy and was associated with fever in 9 cases. During paclitaxel infusion there was a significant but clinically not relevant increase in blood pressure and a decrease in heart rate. No acute cardiac effects occurred and no hypersensitivity reaction was seen. CONCLUSIONS: This regimen demonstrates a high activity in locally advanced head and neck cancer. Neutropenia associated with fever was the major dose limiting toxicity.

Aged↗
PubMed1996

[Reoxygenation in Yoshida sarcoma during different fractionated radiotherapy].

PURPOSE: Tumor reoxygenation is one of the most important factors determining the tumor control probability after radiotherapy. In experimental studies reoxygenation has been measured preferably after single dose irradiation. Only few data exist about changes in the hypoxic tumor fraction during fractionated radiotherapy. MATERIAL AND METHODS: The changes in the pO2 during fractionated radiotherapy were studied in Yoshida sarcoma transplanted to Wistar rats. Tissue oxygenation was assessed using a polarographic electrode system at the beginning, in the middle and at the end of radiation therapy. Different fractionation schedules were used: 10 x 3 Gy, 6 x 5 Gy and 3 x 10 Gy. RESULTS: In the statistical analysis significant changes emerged in the mean, median, 10%-percentile and 0 to 2.5 mm Hg and 0 to 5.0 mm Hg values dependent on time. The tumors were significantly more hypoxic at the end of therapy. This trend became more pronounced with decreasing dose per fraction. CONCLUSIONS: The Yoshida sarcoma has no effective reoxygenation during fractionated radiotherapy.

Animals↗
PubMed1995

[Adjuvant radiochemotherapy of rectal carcinoma].

Adequate surgical treatment is the basis for any adjuvant therapy. However, even in case of optimal surgery local recurrence rates of 20 to 30% are to be expected for stage II/III patients with 5-year-survival figures in the range of 40 to 60%. In some series, e.g. the results of the Surgical Department of the University of Erlangen, a significant correlation between local control and survival does exist. Postoperative radio-therapy decreases the risk of local recurrence but has--as postoperative chemotherapy--only marginal impact on survival. Combined adjuvant treatment (radio-therapy plus 5-FU-chemotherapy) has significantly increased the 5-year survival figures by 10 to 15% in two randomized trials and is considered as standard adjuvant treatment. From a radio-oncological point of view, most studies may be criticized at least in part because of low preoperative doses, inadequate technique without individual treatment planning and shielding, unfavourable fractionation, or dose reductions of radiotherapy in case of chemotherapy. Further improvement of local efficacy of radiotherapy and reduction of therapy-related toxicity seems, therefore, possible. Innovative approaches in radiation oncology mainly include preoperative strategies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Radiation therapy in Ewing's sarcoma: an update of the CESS 86 trial.

PURPOSE: We present an update analysis of the multiinstitutional Ewing's sarcoma study CESS 86. METHODS AND MATERIALS: From January 1986 through June 1991, 177 patients with localized Ewing's sarcoma of bone, aged 25 years or less, were recruited. Chemotherapy consisted of four 9-week courses of vincristine, actinomycin D, cyclophosphamide, and adriamycin (VACA) in low-risk (extremity tumors < 100 cm3), or vincristine, actinomycin D, ifosfamide, and adriamycin (VAIA) in high-risk tumors (central tumors and extremity tumors > or = 100 cm3). Local therapy was an individual decision in each patient and was either radical surgery (amputation, wide resection) or resection plus postoperative irradiation with 45 Gy or definitive radiotherapy with 60 Gy (45 Gy plus boost). Irradiated patients were randomized concerning the type of fractionation in either conventional fractionation (once daily 1.8-2.0 Gy, break of chemotherapy) or hyperfractionated split-course irradiation simultaneously with the VACA/VAIA chemotherapy (twice daily 1.6 Gy, break of 12 days after 22.4 Gy and 44.8 Gy, total dose and treatment time as for conventional fractionation). For quality assurance in radiotherapy, a central treatment planning program was part of the protocol. RESULTS: Forty-four patients (25%) received definitive radiotherapy; 39 (22%) had surgery, and 93 (53%) had resection plus postoperative irradiation. The overall 5-year survival was 69%. Thirty-one percent of the patients relapsed, 30% after radiotherapy, 26% after radical surgery, and 34% after combined local treatment. The better local control after radical surgery (100%) and resection plus radiotherapy (95%) as compared to definitive radiotherapy (86%) was not associated with an improvement in relapse-free or overall survival because of a higher frequency of distant metastases after surgery (26% vs. 29% vs. 16%). In irradiated patients, hyperfractionated split-course irradiation and conventional fractionation yielded the same results (5-year overall survival of definitively irradiated patients 63% after conventional fractionation and 65% after hyperfractionation; relapse-free survival 53% vs. 58%; local control 76% vs. 86%, not significant). The six local failures after radiotherapy did not correlate with tumor size or response to chemotherapy. Radiation treatment quality (target volume, technique, dosage) was evaluated retrospectively and was scored as unacceptable in only 1 out of 44 patients (2%) with definitive radiotherapy. Grade 3-4 complications developed in 4 out of 44 (9%) patients after definitive radiotherapy. CONCLUSIONS: Under the given selection criteria for local therapy, radiation therapy yielded relapse-free and overall survival figures comparable to radical surgery. Hyperfractionated split-course irradiation simultaneously with multidrug chemotherapy did not significantly improve local control or survival.

Adolescent↗
PubMed1995

Historical essentials influencing the development of radiooncology in the past 100 years.

An overview of the development in the recent 100 years is given. The work of the most important pioneers is described. Both technical preconditions and radiobiological fundamentals influencing advances in radiotherapy are lined out. It is shown that many modern techniques and therapeutical strategies have their origin in the beginning of radiotherapy and that this is the case for many unsolved problems as well.

Brachytherapy↗
PubMed1995

[Adjuvant radiotherapy of breast carcinoma].

Adjuvant postoperative radiotherapy for breast conserving treatment is well established. Contraindications against breast conservation are macroscopic tumor residues, multicentric disease, diffuse microcalcifications or inflammatory carcinoma because of the necessary radiation (dose) which exceeds the tolerance of the breast. Treatment results are comparable for skillful excision and quadrantectomy or segmentectomy. The impact of postoperative radiotherapy is debated for very favourable situations--clinical evidence of significant prognostic factors is the aim of prospective randomized studies. Postoperative radiotherapy after mastectomy diminishes five fold the local recurrence rate. This strategy does improve the quality of life. Prognostic factors for local relapse are T3-, T4-tumors, extensive axillary involvement, multifocal or multicentric disease, extensive lymphangiosis and extensive intraductal carcinoma. New clinical protocols confirm the value of radiotherapy of the regional lymph nodes. The results show a promising impact not only on the regional but also on the distant relapse free time and the overall survival.

Breast Neoplasms↗
PubMed1995

[Periarthritis humeroscapularis (PHS). Indications, technique and outcome of radiotherapy].

BACKGROUND: Radiation treatment for patients with acute or subacute tendonitis or bursitis of the shoulder once commonplace has been mostly supplanted by antiinflammatory drug treatment. PATIENTS AND METHODS: 106 patients with clinically evident disease of PHS were treated between January 1987 and May 1991. 73/106 patients had a continuous follow-up. 16/73 patients showed typical symptoms on both shoulders: therefore a total of 89 shoulders were examined in this investigation. A daily dose of 0.5 Gy was given for 3 times a week and a total dose of 3.0 Gy. After 8 weeks a second treatment course was performed. In follow-up the subjective (pain) and objective (limitation of abduction) symptoms were classified in 3 grade scales. RESULTS: A marked pain reduction and an improved mobility (abduction of at least 20 degrees more than before radiation) could be observed in 72/89 shoulders (81%). 44/89 shoulders (49%) showed an excellent response and were completely free of pain and impairment of motion. CONCLUSION: Radiotherapy of acute or subacute Periarthritis humeroscapularis is a very effective treatment if radiation starts within the first year of symptoms and if it is supported by physiotherapy.

Adult↗
PubMed1995

[Preoperative radiochemotherapy in primary non-resectable rectal cancer].

PURPOSE: In a pilot-study patients with primarily non-resectable rectal cancer received a pre-operative radiochemotherapy to assess the tolerance and efficacy of this treatment protocol. PATIENTS AND METHOD: Twenty patients with non-resectable rectal cancer (Mason CS III-IV) have been irradiated from September 1989 through February 1994. The total dose, calculated at the isocenter, was 50.4 Gy with 5 fractions of 1.8 Gy per week with a small volume boost in selected cases. Chemotherapy was administered on 5 consecutive days in week 1 and 5 with 1000 mg/m2 5-FU per day as continuous infusion over 120 hours. RESULTS: The treatment was well tolerated. Acute toxicity included 1 grade III-dermatitis, 7 grade II-enteritis, 1 grade III- and 3 grade II-leucopenia. Seventeen out of 20 patients were resected 6 weeks after radiochemotherapy, 3 patients had no surgery (1 toxic death due to septicemia, 1 refusal of surgery after complete remission, 1 thrombocytopenia due to liver cirrhosis), all 3 had at least partial remission of their tumors. Fourteen out of 17 (82%) resections were curative (R0) with 1 additional R1- and 2 R2-resections. Ten out of 14 (71%) curative resected patients had no lymph node metastasis. A detailed histological examination showed regression in 15/16 tumors with fibrosis and vascular wall changes. Nine out of 16 patients had only minimal residual tumor. CONCLUSIONS: In this pilot study, pre-operative radiochemotherapy was well tolerated. The relatively high rate of curative resections and marked histological tumor regressions of this approach requires further investigations in a randomized trial.

Adenocarcinoma↗
PubMed1995

[Simultaneous radiochemotherapy in recurrent and metastatic breast neoplasm. Clinical experience].

BACKGROUND: To improve the quality of life for patients with recurrent and metastatic breast cancer, palliation of pain, skin and soft tissue metastases and complicating lymph node relapses are mandatory. Toxicity and efficacy of 2 simultaneous radiochemotherapy regimens was tested in this study. PATIENTS AND METHODS: From October 1989 to March 1993, 48 patients with locoregional relapse of breast carcinoma after primary mastectomy and no option for curative resection were entered in the study. Seventeen patients had additional distant metastases. Two different radiochemotherapy regimens were applied: Group A (28 patients) received a "split course" radiotherapy within 10 weeks (1.8 to 2 Gy single dose) on day 1 to 12, 29 to 40 and 57 to 68 up to a total dose of 54 Gy. Chemotherapy with 5-FU, methotrexate and cyclophosphamide was applied simultaneously with radiation. After the second and fourth week the treatment was interrupted for 2 weeks. Group B (20 patients) received "conventional" radiotherapy over 6 weeks with 1.8 to 2 Gy single and 54 Gy total dose. 5-FU and mitomycin C was applied in the first and fifth week of radiotherapy. Treatment toxicity was analyzed in 48 patients, while treatment efficacy was assessed in 44 patients with a minimum follow-up of at least 1 year. RESULTS: Overall treatment response (CR+PR) was 82% in group A (CR 21%). Five of 28 patients developed toxicities of grade 3 to 4 (EORTC/RTOG/WHO). The overall response rate in group B was 87% (CR 19%). In this group 6 of 20 patients experienced toxicities of grade 3 to 4. In both groups, the local response rate was remarkably reduced in patients with additional visceral metastases. CONCLUSIONS: Both treatment concepts achieved similar response rates. Group B patients experienced a higher toxicity rate, but treatment duration was considerably shorter. The local response rate correlated well with the extent of systemic metastatic disease.

Antibiotics, Antineoplastic↗