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Biomedical subjects

R Guttenberger

Publications and source records attributed to R Guttenberger.

At least 19 recordsLinked to original sources
PubMed2001

[Xerostomia after radiotherapy. More effective treatment by a mucin-containing spray?].

INTRODUCTION: After radiotherapy (XRT) for head and neck tumors, xerostomia is observed as a chronic side effect. We investigated whether the topical use of a mucin-containing spray can help patients to cope with this problem. PATIENTS AND METHODS: A total of 73 patients with xerostomia post XRT received a bottle of the mucin spray (Saliva medac) and a questionnaire, 59 of which were completed and returned. RESULTS: All patients had received some form of prior treatment, which had been applied 16 times/day on average (median: 15 times/day). The mucin spray had to be used less frequently, i.e., 11 times/day (median: 5 times/day), (p < 0.001, Wilcoxon's rank test). Additionally, they reported being able to sleep significantly better when using the mucin spray (2.9 vs 3.9 in the German school grading system: 1 = very good, 6 = poor; p < 0.001, Wilcoxon's rank test). The spray was well accepted by the patients. CONCLUSIONS: The spray was useful against xerostomia in irradiated patients.

Administration, Oral↗
PubMed2001

Epithelial cells in the peripheral blood of patients with cancer of the head and neck: incidence, detection and possible clinical significance.

In this study amplification of cytokeratin-19 mRNA by Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect circulating tumor cells in the peripheral blood of patients with cancer of the head and neck before, during and after radiation therapy. Detection of cytokeratin-19-positive cells coincided with local failure, distant metastasis and anemia.

Adult↗
PubMed2001

Gliosarcoma: a clinical study.

BACKGROUND AND PURPOSE: Gliosarcomas are rare biphasic neoplasms of the central nervous system composed of a glioblastoma multiforme (GBM) admixed with a sarcomatous component. There are conflicting reports regarding their clinical aggressiveness. Four hundred and twenty-two consecutive patients with GBM were treated at our hospital between 1980 and 1999, among them 12 gliosarcomas. The goal of this study was to examine clinical features, treatment, survival and patterns of failure of gliosarcoma patients and to compare them with the entire group of GBM patients. This comparison was refined by a matched pair analysis with a group of 12 GBM patients selected for age, Karnofsky performance status, resection status, fractionation scheme and total dose (control GBM group). MATERIALS AND METHODS: Seven gliosarcoma patients were male, five female, with a median age of 56 years (range 37-76 years). The median tumor size was 4.5 cm (range 3-8 cm). The locations, all supratentorial, included temporal in six, parietal in five, frontal in four and occipital in one patient. All patients underwent tumor resection followed by postoperative radiation therapy. RESULTS: Median survival was 11.5 months for the gliosarcoma group, 8.1 months for the entire GBM group (log rank test, P=0.16) and 11.0 months for the control GBM group (log rank test, P=0.36). All gliosarcoma patients had local tumor recurrences and died due to neurologic causes within 19.3 months after radiation therapy. CONCLUSIONS: With regard to clinical features, survival and patterns of failure, gliosarcomas and GBM cannot be distinguished clinically. Therefore, the same principles should be applied for the treatment of these tumors.

Adult↗
PubMed2000

Anemia is associated with decreased local control of surgically treated squamous cell carcinomas of the glottic larynx.

PURPOSE: A strong association between hemoglobin levels and tumor control exists in head and neck cancer treated with radiotherapy. This retrospective study has been performed to determine whether or not this association can also be found in the surgical setting. METHODS AND MATERIALS: Between January 1970 and December 1990, 258 patients with glottic SCC received conventional surgery only (T1/T2/T3/T4 n = 188/31/37/2, respectively). Locoregional control was calculated by the Kaplan-Meier method. The influence of hemoglobin, T stage, age, gender, performance/nutritional status, and grading was evaluated using a Cox model. RESULTS: Five-year locoregional control for T1a/T1b/T2/T3/T4 tumors was 91%/85%/76%/62%/0%, respectively (log-rank test, p < 0.0001). Anemia (male < 13, female < 12 g/dL hemoglobin) was present in 27 patients. It was associated with significantly worse 5-year locoregional control, i.e., 60% vs. 85% (log-rank test, p = 0.003). In multivariate analysis stratified for T stage, two variables were of influence: positive margins (relative risk [RR], 3.8; 95% confidence interval [CI], 1.7-8.4), anemia (RR, 3.0; 95% CI, 1.4-6.2). The largest subgroup consisted of 162 patients characterized by male gender, T1, and complete resection. In this subgroup, the significant variables were T stage (T1b vs. T1a; RR, 3.5; 95% CI, 0.96-12.4) and hemoglobin with a RR of 1.4 (95% CI, 1.0-2.1) per g/dL less analyzed as a continuous variable. CONCLUSION: Anemia is associated with a high risk of treatment failure in surgically treated glottic cancer. Hemoglobin levels might be predictive even within the normal range as indicated by subgroup analysis.

Adolescent↗
PubMed2000

Blood hemoglobin level may affect radiosensitivity-preliminary results on acutely reacting normal tissues.

PURPOSE: To evaluate the influence of blood hemoglobin concentration on the radiosensitivity of acutely reacting normal tissues. METHODS AND MATERIALS: Weekly scores (EORTC/RTOG criteria) for acute reactions of skin and mucosa are available for 60 patients with cancer of the head and neck undergoing a standard conventional radiotherapy. The prognostic significance of blood hemoglobin levels on the development of acute reactions is studied by multivariate analysis (Cox Proportional Hazards Model). Further, the incidence and the time to development of these reactions is looked at in cohorts of patients with different mean blood hemoglobin concentrations during radiotherapy. Patients are therefore classified into a "severely anemic group" (hemoglobin < 11.0 g/100 mL), and into a cohort with a blood hemoglobin value equal or above 11.0 g/100 mL. RESULTS: Normal tissue scoring and monitoring of blood hemoglobin levels allows for a detailed analysis of possible correlations. A decrease in the mean blood hemoglobin value of 1 g/100 mL predicts a reduced risk to develop a skin reaction of Grade 2 or 3 (RR = 0.9; p = 0.08; RR = 0.8; p = 0.26, respectively) or a mucosa reaction of Grade 3 (RR = 0.8; p = 0.16), independent from the radiation dose, the treatment time and from previous surgery within the radiation volume (multivariate analysis). Likewise, patients with severe anemia develop grade 3 mucositis or dermatitis less often (0%; 13%) as compared to those with blood hemoglobin concentrations equal or above 11.0 g/100 mL (21%; 19%). Skin and mucosa reactions further tend to occur later in the course of radiation. The observations are not statistically significant and possible reasons will be discussed. CONCLUSIONS: A decreased blood hemoglobin concentration may-perhaps by an impaired tissue oxygenation-reduce the radiosensitivity of normal tissue such as skin and mucosa. However, the data is preliminary and needs further confirmation.

Adult↗
PubMed2000

Erythropoietin in radiation oncology - A review. 1st international conference, Freiburg, June 11-12, 1999.

The therapeutic potential of erythropoietin gains increasing attention among radiation oncologists because the prognosis is better for patients with high blood hemoglobin levels following radiotherapy. However, there is still a debate on how hemoglobin affects radiotherapy. Further, the means to manipulate the hemoglobin level, their indication and administration need to be clarified. Available experimental and clinical data on hypoxia, anemia and on their treatment with erythropoietin have been extensively discussed at an international conference in Freiburg, Germany, in June 1999. This report gives a summary reviewing the topic.

Anemia↗
PubMed1999

Erythropoietin for patients undergoing radiotherapy: a pilot study.

BACKGROUND AND PURPOSE: To evaluate the feasibility and efficacy of using recombinant human erythropoietin (rhEPO) to correct decreased hemoglobin levels in patients undergoing radiotherapy and to get an estimate of its influence on the efficacy of radiotherapy. MATERIALS AND METHODS: Fifty patients with cancer of the head and neck and the pelvis were randomized before radiotherapy to different rhEPO treatments (none, 3 x 150 U/kg per week i.v., 3 x 300 U/kg per week i.v. and 3 x 150 U/kg per week s.c.). Hematological parameters were evaluated weekly and the locoregional tumor control rates were determined in 38 patients with head and neck cancer. RESULTS: rhEPO-treated patients showed a significant increase in their hemoglobin values (0.7 g/100 ml per week). The rhEPO response was comparable for patients with cancer of the head and neck and the pelvis. A delayed recovery was seen when iron deficiency or impaired iron mobilization was present. No serious toxicity was observed. Locoregional tumor control was improved, although not statistically significantly, in those head and neck cancer patients who experienced a rapid rise of hemoglobin. CONCLUSIONS: Low hemoglobin levels can be safely and quickly corrected with rhEPO. This may improve the effectiveness of radiotherapy.

Adolescent↗
PubMed1999

Accelerated hyperfractionated radiotherapy in 149 patients with glioblastoma multiforme.

Between August 1986 and December 1997, 149 patients with glioblastoma were treated postoperatively with 1.5 Gy fractions three times daily to a total dose of 54 Gy with 4-h intervals. Median actuarial survival was 8.8 months. Survival was 31% at 12 months and 4% at 24 months. No severe acute toxicity occurred. Multivariate analysis revealed that only age < or = 60 years and lactate dehydrogenase levels < or = 240 U/l predicted significantly higher survival probabilities.

Adult↗
PubMed1998

The impact of blood hemoglobin content on the outcome of radiotherapy. The Freiburg experience.

BACKGROUND: Numerous publications have reported an impaired radiocurability when anemia is present. Tissue hypoxia and consecutive radioresistance are speculated to be the underlying causes. OWN EXPERIENCE: Our own retrospective data impressively confirm these observations: in an analysis of 889 patients homogeneously irradiated for head and neck cancer for locoregional tumor control and survival, anemia has proven to be a highly significant risk factor. Furthermore, hemoglobin content is an independent and, at least equally powerful predictor for outcome when compared to the known risk factors of site, treatment modality, resection status, T-, and N-stage. TREATMENT: In an attempt to improve therapeutic outcome, 50 anemic patients undergoing radiotherapy were treated with erythropoietin (rhEPO). A weekly increment in hemoglobin content of 0.7 g/dl was documented without any major side effects. Additionally, it seems that patients reacting sufficiently to rhEPO stimulation can expect better locoregional tumor control within the irradiation volume. This, however, awaits confirmation in an ongoing trial.

Anemia↗
PubMed1997

Radiation response of porcine RPE cells in vitro.

PURPOSE: To investigate the antiproliferative effect of ionizing radiation on retinal pigment epithelial (RPE) cells that are supposed to play a major role in the pathogenesis of proliferative vitreoretinopathy (PVR). METHODS: RPE cells from pig eyes were irradiated with doses ranging from 4 to 16 Gy (1 Gray = 1 Joule/kilogram). Cells were counted at 1, 2, 3, and 4 weeks (Experiment 1) or 1, 2, 4, and 6 weeks (Experiment 2) after treatment. In Experiment 3, cells were trypsinized 24 h after radiation and seeded again. Colonies were counted 10 days later, and the surviving fraction was determined. RESULTS: The numbers of cells and colonies were inversely correlated to the doses applied. In Experiment 2, cell numbers of radiated cultures remained stable during the time of follow-up, whereas, in Experiment 1, significant proliferation occurred in treated cultures as well as in controls. This may be due to the higher growing rate that was found in the cultures of Experiment 2, compared to those of Experiment 1, at the time of radiation. In Experiment 3, a D0 value of 0.72 Gy was found. CONCLUSIONS: Proliferation of RPE cells can be suppressed by irradiation in a dose-dependent manner. Therefore, radiotherapy may be useful in the treatment of PVR. Its effect probably depends on the stage or activity of PVR at the time of radiation.

Animals↗
PubMed1996

The kinetics of repair of sublethal radiation-induced damage in pig skin: studies with multiple interfraction intervals.

The kinetics of the repair of radiation-induced sublethal damage (SLD) was studied for the epidermis of the pig. A total of either 7 or 14 interfraction intervals with incomplete repair was achieved by giving 28 fractions either as 7 x 2 fractions/day plus a top-up dose of 17 Gy (half tolerance) or as 14 x 2 fractions/day. The dose per fraction ranged from 1.96-4.82 Gy. A total of 9 intervals ranging from 0.17 h up to 8 h between fractions was used. The incidence of moist desquamation, as an estimate of acute epidermal response, was used as an end point to establish dose-effect relationships. The data were analyzed using either the incomplete repair model of Thames, assuming mono-exponential repair kinetics, or a modified version of the incomplete repair model, assuming bi-exponential repair of sublethal damage. Both methods of analysis allowed for the longer overnight interval between fractions. Analysis assuming mono-exponential repair gave a T1/2 of 0.74 h for the combined data, although there was a trend toward a longer half-time when only the longer interfraction intervals ( > 1.0 h) were used in the analysis. A further analysis using the modified version of an incomplete repair model gave a fast and a slow component of repair with significantly different half-times of 0.09 and 4.5 h, respectively. Varying the number of incomplete repair intervals by replacing half the number of fractions with a single half-tolerance top-up dose did not modify the kinetics of repair significantly, in terms of either the repair half-times or the proportion of repair associated with a fast and slow component. Reanalysis of data published previously for 3 and 4 fractions using the modified incomplete repair model again resulted in two components of repair, represented by the significantly different half-times of 0.17 and 3.0 h. These values were similar to those obtained from the multiple-fraction experiment. These data clearly demonstrate that an acutely responding tissue is associated with a long T1/2 for the repair of SLD which is independent of the dose per fraction. For accelerated fractionation schedules in the clinic, using multiple fractions per day, these results suggest a need to control the intervals between fractions carefully and when appropriate to reduce the total dose to avoid serious normal-tissue complications.

Animals↗
PubMed1995

[Indications for percutaneous radiotherapy in carcinoma of the thyroid gland. Freiburg consensus].

At the University of Freiburg, a consensus was arrived at concerning the place of external radiotherapy in the management of thyroid cancer. External irradiation is always indicated in papillary and folliculary carcinoma in the pT4 stage of pTNM classification but not in those in pT1-3 pN0 stage. In the presence of lymph-node metastases and distant metastases, an individual treatment concept is recommended, which should be set up in an interdisciplinary conference regarding all risk factors, especially the age and sex of the patient, the histology and grading of the tumor and the completeness of tumor resection. Finally, radiotherapy is usually not indicated in medullary thyroid carcinoma, whereas it is always indicated in anaplastic carcinoma.

Adenocarcinoma, Follicular↗
PubMed1994

Radiation-induced injury to the visual pathway.

Radiation-induced injury to the visual pathway was reviewed in a cohort of patients treated for various cancers of the nasal cavity and paranasal sinuses between 1969 and 1985. The study subjects consisted of 219 patients, 137 men and 82 women, in whom detailed records were available on the extent of orbital shielding, treatment plan for estimating doses delivered to various optic structures, and visual acuity follow-up information. There was a wide range in doses administered to various optic structures because patients with different primary lesion types were included and the radiotherapy techniques used varied during this era. The endpoint of the study was visual acuity < 20/100. The Cox proportional hazard model was used to assess the influence of various factors on the latent time to visual impairment and to fit the LQ model to the failure-time data. Actuarial curves showing the proportion of patients with visual impairment as a function of dose and time were generated. Corneal injury occurred in 24 of the 49 patients treated with the 3-field technique without any orbital shielding; variables affecting the incidence of cornea injury were total radiation dose and chemotherapy. Symptomatic retinopathy was diagnosed in 7 of 77 patients who received irradiation to a relatively large retinal surface, but no variables were found to correlate with this complication. Eight patients developed ipsilateral blindness due to optic neuropathy and 11 patients had bilateral visual impairment secondary to chiasm injury. The total radiation dose was identified as the predominant determinant. None of patients receiving a dose of < 50 Gy developed optic neuropathy or chiasm injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Blindness↗
PubMed1992

Intrinsic radiosensitivity of normal human fibroblasts and lymphocytes after high- and low-dose-rate irradiation.

The existence of heritable radiosensitivity syndromes and clinical observations in radiotherapy patients suggests that human cellular radiosensitivity differs among individuals. We report here an in vitro study of radiosensitivity in 30 fibroblast and 29 lymphocyte cultures obtained from cancer patients and controls. In 25 cases, both fibroblasts and lymphocytes were obtained from the same donors. Fibroblasts were cultured from skin biopsy samples, and peripheral T-cell lymphocytes were cultured from blood. Clonogenic survival assays were performed by using high- and low-dose-rate irradiation; lymphocytes were in G0 phase and fibroblasts in confluent plateau phase. Various end points were calculated and compared (i.e., surviving fraction at 2 Gy, initial slope of the survival curve, and doses resulting in 10 and 1% survival, respectively). Depending on the end point, the coefficient of variation of the survival parameters ranged from 31 to 68% for lymphocytes and 21 to 41% for fibroblasts following high-dose-rate irradiation. Similar ranges were obtained after low-dose-rate irradiation. Variance analysis performed on replicate assays in cultures derived from the same patient showed that variation due to technical or sampling errors was significantly lower than variation between individuals (P = 0.00034 and 0.014 for fibroblasts and lymphocytes, respectively). No correlation was observed between the radiosensitivity of lymphocyte and fibroblast cultures derived from the same donors. We conclude that there is significant variation in normal cell radiosensitivity among individuals. On the other hand, comparisons of lymphocyte and fibroblast radiosensitivities suggest that tissue-specific characteristics, such as differentiation status, may variably modulate radiosensitivity.

Breast Neoplasms↗