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K Schnabel

Publications and source records attributed to K Schnabel.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Brain metastases of colon and rectum carcinomas].

We analyzed 20 cases with brain metastases from colon or rectum carcinoma. Fourteen were treated with radiotherapy alone (total dose 30-60 Gy), six with neurosurgery plus radiotherapy (total dose 30-40 Gy). All patients had advanced primary tumours (T3 and T4), most of which were poorly differentiated; lymph node metastases were common. In 5 patients (25%) the brain was the first site of distant metastases. Ten patients (50%) had a solitary brain metastasis. As a tendency, the results of surgery plus radiotherapy were superior to those of radiotherapy alone, with respect to palliation of symptoms as well as to local tumour remission and survival. Overall median survival was only 51 days. The 1-year survival rate was 6%. In 5 of 14 cases (36%) symptomatic improvement was observed after radiotherapy alone. Partial remission of the brain metastases occurred in 3 of 14 cases (21%). The presence of extracerebral metastases was the most important prognostic factor. Selected patients considered to have a favourable prognosis may profit from combined treatment, i.e. neurosurgery plus radiotherapy. Despite the short survival time, stereotactic irradiation should be evaluated as an alternative to conventional radiotherapy in the remaining patients because the palliative effect of fractionated external irradiation is relatively disappointing.

Adult↗
PubMed1997

Accelerated radiotherapy for brain metastases.

BACKGROUND AND PURPOSE: Two novel fractionation schedules for whole-brain irradiation were applied to patients with brain metastases. Both schedules were aimed at reduction of treatment time, whereby tumour control should be increasing with the application of a higher total dose (schedule 2). MATERIALS AND METHODS: We applied 2 x 2.5 Gy/day to a total dose of 30 Gy (schedule 1) or 2 x 1.8 Gy/day to a total dose of 50.4 Gy (schedule 2). The interval between daily fractions was 6 h. Treatment was interrupted on weekends. The 30 Gy schedule was also used in adjuvant treatment for resected brain metastases. We compared the results of 15 patients who underwent the 50.4 Gy schedule and 47 patients who were treated up to 30 Gy with those of a historical patient group, treated with one daily fraction of 3 Gy up to 30 Gy (n = 283). RESULTS: Local result, clinical course and survival were similar for the 30 Gy groups, whereby prognostic factors were equally distributed. Despite a favourable patient selection no therapeutic gain was seen for the 50.4 Gy group. Patients treated with the accelerated 30 Gy schedule had a significantly worse progression-free survival and a higher rate of late radiation toxicity than the historical group. In contrast, no severe acute toxicity was observed. CONCLUSIONS: Considering progression-free survival and late toxicity, the accelerated 30 Gy schedule can not be recommended without hesitation. Radiotherapy with a higher total dose (50.4 Gy) showed no advantage.

Adult↗
PubMed1997

Enzyme-linked immunosorbent assay for detection of antibody to human herpesvirus 6.

The results obtained with an enzyme-linked immunosorbent assay (ELISA) for detection of human herpesvirus 6 (HHV-6) immunoglobulin G using a single 1:100 dilution of serum correlated well with those found by an indirect fluorescence microscopic assay (IFA) (r = 0.71). Concordant results were found in all 7 paired serum samples obtained from patients with acute primary infections and in 37 of 41 (90.24%) single serum samples. Fourteen serum samples (25%) which yielded nonspecific results by IFA were evaluable by ELISA. In a serologic survey using the ELISA, a disproportionate number of 12-month-old infants had low difference-of-optical-density values, suggesting that maternal antibody might persist beyond a year of age. This finding and the rises in antibody to HHV-6 found in patients with primary cytomegalovirus infections might lead to overestimation of HHV-6 infection rates in young children in seroprevalence studies. Other herpesvirus infections produced lesser effects on anti-HHV-6.

Adolescent↗
PubMed1996

Rapid course radiation therapy vs. more standard treatment: a randomized trial for bone metastases.

PURPOSE: In a prospective randomized trial we examined whether radiotherapy of painful bone metastases can be shortened using larger single doses without impairing effectivity. METHODS AND MATERIALS: One hundred patients with painful bone metastases having no prior surgical intervention or treatment with x-ray therapy and had a median follow-up of 12 months were analyzed. The primary tumor was located in the breast in 43%, in the lung in 24%, and in the prostate in 14%. The most frequent sites of metastases were the pelvis (31%), the vertebral column (30%), and the ribs (20%). Further percentages of sites were: lower extremity 11%, upper extremity 6%, and skull 2%. Fifty-one patients received a short course radiotherapy with a total dose of 20 Gy in 1 week (daily dose 4 Gy), and 49 patients received 30 Gy in 3 weeks (daily dose 2 Gy). RESULTS: There were no significant differences in frequency, duration of pain relief, improvement of mobility, recalcification, frequency of pathologic fractures nor survival. There was a light trend favoring 30 Gy in frequency of pain relief and recalcification. Survival was mostly influenced by primary tumor site, Karnofsky performance status, and possibly by the response to radiotherapy (pain relief). CONCLUSIONS: Because of the very short life expectancy of patients with metastatic bone disease, we now use 20 Gy in 1 week as our standard to reduce hospital stay.

Adult↗
PubMed1996

Ten years disease-free survival after solitary brain metastasis from breast cancer.

The unique case of a 51-year-old woman who developed a solitary brain metastasis as the first site of systemic disease 11 months after a total mastectomy for an undifferentiated infiltrating ductal carcinoma of her right breast is described. After surgery for the pT2pN0 carcinoma, the patient received radiotherapy of the internal mammary and supraclavicular lymph nodes. The brain metastasis was treated with surgery and adjuvant whole-brain radiotherapy to a total dose of 30 Gy in December 1984 and January 1985. Afterwards a hormonal treatment with tamoxifen was initiated, which still continues. Since then no further distant or lymph node metastases have developed. The patient is under regular after-care and undergoes various apparative examinations every 6 months. She is generally well and suffers only from a postoperatively persistent hemianopsia. This is the first case in which a disease-free survival for more than 10 years after brain metastases from breast cancer has been reported. It illustrates the specific biological behaviour of this tumour type and the chance of achieving long-term survival in very selected cases.

Antineoplastic Agents, Hormonal↗
PubMed1996

Dynamic snapshot gradient-echo imaging of head and neck malignancies: time dependency and quality of contrast-to-noise ratio.

The purpose of this study was to evaluate the time dependency of the contrast-to-noise ratio (CNR) of head and neck malignancies during contrast-enhanced MR imaging. Then we would compare the CNR of dynamic snapshot gradient-echo (SGE) images with conventional spin-echo (SE) and fast spin-echo (FSE) sequences. Fifteen patients with squamous cell carcinomas were examined with T1W-SE, T2W-FSE, contrast-enhanced Gd-T1W-SE, and T1W-SGE sequences, the latter statically and contrast-enhanced dynamically. The CNR for all sequences and adjacent tissues was computed and the time to reach maximal CNR (Tmax) was determined for dynamic studies. The CNR was time dependent with two distinct Tmax at 6-18 and 60-160 s which corresponded to two different tumor enhancement patterns. Neither enhancement pattern correlated with distinct histologic findings or tumor grading. The CNR improved for the Gd-T1W-SE images. The improvement was statistically significant in relation to T1W-SE and Gd-T1W-SE images at the floor of the mouth and at the tongue base. The good CNR of the dynamic Gd-T1W-SGE measurements justifies further investigations of this method in order to improve tumor delineation.

Adult↗
PubMed1996

A palliative accelerated irradiation regimen (PAIR) for advanced non-small-cell lung cancer (NSCLC).

In order to avoid overtreatment in advanced NSCLC we developed a palliative accelerated irradiation regimen (PAIR) applying a total dose of 32 Gy in 10 days with two daily fractions of 2 Gy. This paper reports on a 1-year pilot study carried out in preparation of a randomised trial. Data for the 34 patients receiving PAIR were compared to 179 conventionally irradiated historical controls selected from a pre-existing database according to identical inclusion criteria. Statistical analysis showed that PAIR patients had a significantly longer survival than controls (P = 0.0029). Median survival was 11.8 and 5.8 months, respectively, while 1-year survival was 45.6% vs. 21.2%. Compared to the subgroup of controls who had received the full planned dose of 60 Gy (n = 104) PAIR patients showed no significant difference in survival. In order to adjust for possible imbalances we used a comprehensive blinded prognostic rating design creating one score value per patient out of several known prognostic factors. After adjustment for the resulting prognostic score by means of the Cox proportional hazards model PAIR patients still showed significantly longer survival. We conclude that in advanced NSCLC survival after a palliative short-term regimen appears to be at least equivalent to that following conventional high-dose irradiation.

Carcinoma, Non-Small-Cell Lung↗
PubMed1996

Solitary pulmonary nodules: MR evaluation of enhancement patterns with contrast-enhanced dynamic snapshot gradient-echo imaging.

PURPOSE: To evaluate the enhancement patterns of solitary pulmonary nodules (SPNs) with dynamic contrast-material-enhanced magnetic resonance (MR) imaging to differentiate between benign and malignant SPNs. MATERIALS AND METHODS: Twenty-eight patients with SPNs 30 mm or smaller in diameter were examined with pre- and postcontrast, electrocardiographically gated, T1-weighted spin-echo (SE) sequences and a snapshot gradient-echo (GRE) sequence after bolus injection of a paramagnetic contrast agent. For all SPNs (20 malignant, eight benign), the percentage increase in signal intensity (%SI) on the postcontrast T1-weighted SE images and the enhancement curves (%SI/sec) for the snapshot GRE measurements were established from regions of interest. RESULTS: Malignant nodules showed a higher increase of signal intensity during the first transit of the bolus of contrast material on the dynamic snapshot GRE images (malignant: median, 18.1 %SI/sec; range, 6.7-95.2 %SI/sec; benign: median, 2.3 %SI/sec; range, 0.1-8.1 %SI/sec) (P < .0001). Static T1-weighted SE measurements did not allow differentiation between malignant (median, 53.4 %SI; range 12.5-110.0 %SI) and benign (median, 33 %SI; range, 0.8-85.5 %SI) (P > .2) nodules on the basis of the degree of contrast enhancement. CONCLUSION: Dynamic contrast-enhanced MR measurements of tumor enhancement can provide additional information about the nature of SPNs.

Adult↗
PubMed1996

Treatment of brain metastases from hypernephroma.

UNLABELLED: Considering the relative radioresistance of hypernephroma, the optimum treatment schedule for its metastases is a matter of debate. This study evaluated the effects of surgery as well as different irradiation schedules in cases with brain metastases from hypernephroma. Seven patients received surgery plus radiotherapy, 2 patients fractionated stereotactic radiotherapy, and 13 patients whole-brain irradiation in either conventional or accelerated fractionation to a total dose of 30 Gy. Local results, clinical course, and survival were most favorable in the group of patients who were treated with surgery plus radiotherapy. The patients treated by stereotactic radiotherapy had a better outcome than those treated by whole-brain irradiation to a total dose of 30 Gy. Accelerated fractionation was not associated with better local control or clinical improvement. Only 4/13 patients with whole-brain irradiation improved. CONCLUSION: In patients with brain metastases from hypernephroma standard palliative whole-brain irradiation led to unsatisfactory results. Stereotactic radiotherapy and surgery seem to be superior, but are not always available and/or indicated. Therefore, the use of higher total doses should be investigated for patients whose local disease extent makes whole-brain irradiation the treatment of choice.

Brain Neoplasms↗
PubMed1996

Risk factors and dose-effect relationship for osteoradionecrosis after hyperfractionated and conventionally fractionated radiotherapy for oral cancer.

A high frequency of osteoradionecrosis after hyperfractionated radiotherapy (RT) of head and neck tumours led to a detailed analysis of risk factors in the dental, surgical, and radiotherapeutic areas. 168 patients with oral cancer were analysed retrospectively. 19% of them had been irradiated primarily and 81% postoperatively. 116 patients received a total dose mostly ranging from 60 Gy to 70 Gy to the ICRU 29 reference point (daily single dose 2 Gy). 52 patients were treated hyperfractionally with two daily fractions of 1.2 Gy per day, 4 h minimum apart and a total dose 82.8 Gy. Dental findings could be evaluated in 126 patients. Factors were checked for prognostic significance for osteoradionecrosis (ORN). Dose dependency was computed using a PROBIT analysis. Dental status before radiotherapy was generally poor (mean 11/32 teeth present, of these 1 was dead, 2.4 carious, 2.4 loose, 0.3 destroyed). On average, six teeth (range 0-27 teeth) had to be extracted. In one-third of the patients bone surgery was necessary. ORN occurred in 8.6% of the patients treated conventionally but in 22.9% of those treated hyperfractionally (p = 0.029). Biologically effective dose (p = 0.032) and deep paradontitis (p = 0.034) proved to be significant risk factors for ORN. PROBIT analysis showed a steadily rising dose dependency of the ORN frequency after conventional radiotherapy. Using total doses up to 70 Gy the frequency of ORN was 8.6%. Dose escalation using hyperfractionation led to an intolerable ORN frequency (22.9%) where a short interfraction interval was a significant factor. The use of this dose fractionation was therefore discontinued in 1992.

Dose-Response Relationship, Radiation↗
PubMed1996

[Primary cerebral non-Hodgkin's lymphomas. The results of radiotherapy].

BACKGROUND: In the last years many therapeutic attempts were made to improve the poor prognosis of primary cerebral non Hodgkin's lymphoma. The aim of this study was to report on own experiences concerning this rare disease. PATIENTS AND METHODS: In 1986 to 1994 26 patients were treated for primary cerebral non Hodgkin's lymphoma. 15% were HIV-positive. High-grade non-Hodgkin's lymphomas were diagnosed in 62%. 46% of all cases showed multiple lesions. 23% of our patients received a dose less than 25.5 Gy, 27% received 37.5 Gy (whole brain) and 39% were treated with 51 Gy (37.5 Gy whole brain and 13.5 Gy boost dose). Radiation technique included regular and irregular fields (single dose: 1.5 Gy). RESULTS: 62% of patients achieved a complete or partial remission directly after irradiation, in 4% no change or progression was seen. 31% could not be examined due to their bad status or death. The mean follow-up time for all patients was 19.6 months, the median survival was 3.6 months. The 1-year-survival rate was 41%, 3-year survival rate was 28%. Patients who received a tumor dose of 51 Gy had better survival times in comparison to patients who received less (p = 0.01). Prognostic parameters (Cox regression analysis) were: tumor dose, grading and local result after irradiation. The Karnofsky performance status was not an independent parameter (p = 0.12). Side effects were low. Long-term survivors had relatively good quality of life. CONCLUSION: Taking into consideration the small numbers of patients in all studies all results or conclusions have to be made with great reservations. Despite the high proportion of HIV-positive patients our results are in compliance with other authors using similar therapy protocols. Reports dealing with combined radio-chemotherapy have published good results concerning survival time. But long-term morbidity due to these protocols needs further investigation and has to be awaited.

Adult↗
PubMed1995

Relation between local result and total dose of radiotherapy for brain metastases.

PURPOSE: Some studies published recently focused on the improvement of the treatment results of patients with brain metastases who underwent radiation therapy. They evaluated survival as a measure for the expected improvement, but failed to demonstrate a significant benefit from an increased total dose of radiotherapy. This study was targeted to investigate the effect of dose escalation with a different endpoint, the local response. METHODS AND MATERIALS: As a first step, a retrospective analysis of 164 patients treated with a standard regimen of 10 x 3 Gy was performed to find factors correlating with the local result. All patients were systematically followed and underwent regular computed tomography (CT) examinations of the brain after irradiation. The second step was to compare, with respect to local control and survival, 39 patients treated with a total dose of 40-60 Gy with 39 patients treated with the standard regimen selected by means of a matched cohort pairs method. RESULTS: The retrospective analysis showed a dependence of the local result after irradiation on three parameters: diameter of brain metastases, primary tumor, and tumor histology. Small-cell and adenocarcinoma were found to be more radiosensitive than squamous-cell carcinoma. The highest radiosensitivity was found in breast cancer metastases. The matching procedure was performed with respect to those parameters and also the number of brain metastases and total cerebral tumor volume. The resulting groups were absolutely equivalent and differed only with regard to the total dose applied. The local response (complete or partial remission) was 48-52% after 30 Gy vs. 77% after 40-60 Gy (p < or = 0.05). Survival was not significantly different. A further analysis of the dose-response relationships showed the tendency of control probability to increase with total dose. CONCLUSION: This study suggests that there is a rationale for dose escalation in the treatment of brain metastases with radiotherapy, when local control is the aim. However, it seems questionable whether an improvement in survival results.

Brain Neoplasms↗
PubMed1995

Low-dose radiotherapy for stage I seminoma: early results.

One hundred and one patients with stage I seminoma were irradiated with total doses of 30, 25.5 and 20 Gy to gradually reduced target volumes (paraaortic, pelvic, and inguinal regions to paraaortic only). Low doses and small target volumes resulted in excellent survival and freedom of recurrence but in more frequent nausea.

Adult↗
PubMed1995

Spin-echo and 3D gradient-echo imaging of the knee joint: a clinical and histopathological comparison.

OBJECTIVE: A clinical and histopathological comparison of 2D spin-echo (SE) and 3D gradient-echo (3DGE) sequences was undertaken for the knee joint. The purpose of the study was to evaluate the clinical results and to explain the different appearances of meniscal abnormalities on both 2DSE and 3DGE images. PATIENTS, MATERIALS AND METHODS: The clinical study comprised 45 patients with arthroscopically correlated MR imaging results. For the histopathological correlation, seven cadaveric knee joints were examined with the same 2DSE and 3DGE (FISP) imaging protocol and sliced in sagittal sections according to the MR images. Different stainings were used. RESULTS: For the detection of meniscal tears, accuracy (82.2%) and positive predictive value (70.7%) of the 3DGE sequence were limited due to a high number of false positive findings. Cartilaginous lesions were more easily visible on 3DGE than on 2DSE images (sensitivity: 63.1% vs. 52.6%, respectively). As in the clinical study, the meniscal signal abnormalities of the cadaveric knee joints were much more extensive on the 3DGE images than on the 2DSE images. The 3DGE findings correlated better with degenerative meniscal changes which were visible microscopically. CONCLUSION: The high sensitivity of the 3DGE sequence for degenerative meniscal changes explains the lack of specificity for the differentiation between meniscal degeneration and tears with this sequence. The MR grading system for meniscal lesions is of limited value for the evaluation of 3D FISP images.

Adult↗
PubMed1995

[The outcome of surgery and radiotherapy in treatment of brain metastases of breast carcinoma].

In a group of 45 patients who had been conventionally irradiated, a multivariate analysis of prognostic factors was performed to find criteria for patient selection for surgery and radiotherapy or radiotherapy only. Nine patients underwent resection of metastases before irradiation. In most cases 10 x 3 Gy over 2 weeks were administered. 28 patients received concomitant hormonal treatment. Complete remission was seen in 30% of the non-operated cases (partial remission 25%). Symptomatic relief was seen in 67% of all cases. Median survival was 4 months (9.5 months after surgery) (p = 0.02). Survival of patients having had simultaneous extracerebral metastases and low Karnofsky performance status was disappointing. All long-time survivors received either hormonal treatment or chemotherapy. Karnofsky performance status and interval between the diagnosis of the primary tumour and the development of brain metastases were the most important prognostic factors. The influence of age and extracerebral metastases was less pronounced. In case of favourable prognostic factors and solitary metastases surgical treatment should be considered. Primary irradiation seems to be appropriate for the majority of patients. In any case an additional hormonal or chemotherapy must be considered. It seems to be questionable if patients with poor Karnofsky performance status and extracerebral metastases should be irradiated.

Adult↗
PubMed1995

[The results of the radiotherapy of brain metastases in patients at an advanced age].

BACKGROUND: To evaluate which patients older than 70 years will benefit by radiotherapy for their brain metastases. PATIENTS AND METHODS: The data of 35 patients in this age-group who were treated between 1983 and 1994 were retrospectively analyzed. All patients were previously untreated and received a whole-brain irradiation and concomitantly corticosteroids. The median total dose was 30 Gy (fractionation: 10 times 3 Gy in 2 weeks). Six patients each received lower or higher total doses with 50.4 Gy at maximum. RESULTS: Six patients failed to complete their prescribed treatment (17%). The median survival of all patients who completed their radiotherapy course was 67 days only. Patients with extracerebral metastases had a median survival of 31 days. Survival was not dependent on total dose of radiotherapy. In 56% of all cases the general condition of the patients improved or remained stable at a high level. Karnofsky-performance status was the most important prognostic factor. CONCLUSIONS: Advanced age is an unfavourable prognostic factor. Only patients in good general condition without extracerebral metastases had survival times which justify radiotherapy for their brain metastases. It seems to be extremely doubtful whether the other cases surviving 1 to 2 months should undergo radiotherapy. In each case a short and easily tolerable course of radiotherapy should be preferred.

Age Distribution↗