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P Schüller

Publications and source records attributed to P Schüller.

9 recordsLinked to original sources
PubMed2000

Results of prophylactic irradiation in patients with resected keloids--a retrospective analysis.

The data of 139 patients with 166 keloids treated postoperatively between 1962 and 1996 were evaluated for prognostic factors and outcomes. Treatment commenced within 48 h after surgery. Radiotherapy was carried out as brachytherapy, using an integrated radionuclide 90 Sr-90Y surface applicator. The median dose delivered to the subcutis amounted to 14 Gy (range 7.5-28.5 Gy). The overall recurrence-free response rate was calculated to be 80% for all keloids. Response rates differed significantly (p < 0.001) between the different anatomical regions. The recurrence rate was lowest (2%) with keloids of the face and neck and highest with keloids of the thorax (49%). Outcome also differed significantly, depending on the etiology. Keloids following burns had a poorer success rate than those developing after surgery or mechanical trauma (p < 0.001). We were unable to demonstrate any significance in outcome related to gender, age or size. No direct correlation was found between total doses and response rates. In our patients there were no signs of secondary malignancies in the irradiation area within a median follow-up period of 12 years. Two new prognostic factors have been identified: keloid etiology and localization of the disorder.

Adult↗
PubMed2000

Simultaneous radiochemotherapy versus concomitant boost radiation for advanced inoperable head and neck cancer.

In this prospective, non-randomized study we compare the results of simultaneous radiochemotherapy (RCT) with those of concomitant boost treatment (CBT) in advanced head and neck cancer. From January 1993 to March 1999, 77 patients were treated with cisplatin, 5-FU, and 70.2 Gy (accelerated split-course); from January 1995 to March 1999, a further 33 patients received CBT to a total dose of 72 Gy. Toxicities were prospectively recorded according to RTOG/EORTC criteria. Acute and subacute reactions did not differ significantly. Severe late effects (III/IV) remained anecdotal (one fistula). Therapy-associated mortalities were 3%(RCT) vs. 0% (CBT), most tumors responding well to therapy (CR + PR: RCT: 72%, CBT: 63%). The 2-year probabilities for freedom from locoregional progression amounted to 42% (RCT) and 31% (CBT); p > 0.05. Tumor-specific 2-year survival amounted to 40% (RCT) and 34% (CBT); p > 0.05. Both of the treatment concepts yield high remission rates with moderate toxicities. Nevertheless, median time to recurrence is still fairly short. We could not find any differences for local control and survival. For patients who are not able to complete the full three courses of radiochemotherapy, the concomitant boost schedule presents a good alternative.

Adult↗
PubMed1999

Radiotherapy for intracranial and spinal ependymomas. A retrospective analysis.

BACKGROUND: The low incidence of ependymomas results in limited treatment experience. While standard therapy consists of surgery and postoperative radiotherapy, irradiation techniques are still subject to discussion. We report the experience from Münster over the last 35 years. PATIENTS AND METHODS: Since 1961, 25 evaluable patients with ependymoma were irradiated in Münster: 17 intracranial and 8 spinal tumors. Fourteen of 25 patients underwent subtotal resection. Fifteen of 25 patients were treated by local irradiation, 10 of 25 with large-field techniques (whole-brain/cranio-spinal irradiation) and an additional tumor boost. The median tumor dose amounted to 50 Gy (16 to 65 Gy). Sites of recurrence were analyzed and correlated with the irradiated region. RESULTS: Twelve recurrences were observed. Six of 12 could be exactly related to the irradiation portals and were found well inside the local or boost fields. The remaining 6 tumors also recurred locally; whether they were in-field or field margin recurrences was not to be discerned by the imaging available at the time. No out-field recurrences or spinal seeding were observed. For 8 of 17 locally irradiated patients with intracranial ependymomas, 5 local recurrences were recorded. In 9 of 17 patients receiving whole-brain or cranio-spinal irradiation, 6 local recurrences were found. Two of 8 spinal tumors recurred locally. CONCLUSIONS: All tumors recurred within the former tumor bed. In the remaining cranio-spinal axis no recurrences or metastases were found. Similar results are reported from current literature. The value of large-field techniques (whole brain/spinal irradiation) is to be questioned. Modern methods like IORT or stereotactic radiotherapy might be able to deliver a higher tumor dose without increasing toxicity.

Adolescent↗
PubMed1995

[Intraoperative radiotherapy (IORT) in malignant brain tumors].

PURPOSE: Feasibility and morbidity of IORT for malignant brain tumors as well as value of innovative imaging for diagnosis of rest tumors and recurrences were examined. METHODS AND MATERIALS: Between May 1992 and November 1993, 23 patients with malignant brain tumors were treated in Münster with IORT. The patient collective was heterogeneous and negatively selected, i.e. beside of primary treatments, also patients with extensive previous treatment, recurrent tumors or metastases were included. Therapy consisted of radical surgical resection and intraoperative electron radiotherapy using total doses from 15 Gy to 25 Gy relative to the 90% isodose. Afterwards, patients without prior treatment underwent percutaneous irradiation with a maximum dose of 60 Gy, related to the small volume of the tumor area plus a safety margin of 2 cm. RESULTS: No increase of peri-operative morbidity or subacute sequelae was observed. Overall 1-year survival was 67% for grade III gliomas (WHO), and 56% for glioblastoma multiforme. When the Matsutani selection criteria (primary therapy of a supratentorial, peripheral astrocytoma grade III or glioblastoma smaller than 5 cm in diameter with a Karnofsky performance index of more than 60% and possible wide resection) were applied, 1-year survival increased to 75%. Nuclear medical diagnostics using 123I-alpha-methyltyrosin SPECT proved a valuable method for imaging of non-resectable tumor tissue and diagnosis of recurrences. CONCLUSIONS: The results of this study indicate that IORT can contribute to successful tumor treatment while neither increasing peri-operative morbidity nor subacute sequelae.

Adult↗
PubMed1989

Analysis of urinary stones by computerized infrared spectroscopy.

The computerized assessment of infrared spectra of urinary stones with existing programmes such as SEARCH (Lehmann, C. A. et al. (1988) Clin. Chim. Acta 173, 107-116), TWIN or CIRCOM (Hesse, A. et al. (1988) Fresenius Z. Anal. Chem. 330, 372-373) has proved to be unreliable when used for routine urinary stone analysis. A more refined method has to be used in place of simple comparison algorithms. STONES is a new programme for computerized analysis of urinary stones developed with the intention of simulating the former non-computerized analysis procedure. STONES is a rule-based system, which interprets the infrared spectra qualitatively by its rules. A quantitative result is obtained by means of library search. Combining these two methods 93% of the tests were correct with regard to clinical relevance.

Evaluation Studies as Topic↗
PubMedDate not supplied

Fast neutron irradiation in advanced pre-irradiated head and neck tumors.

AIMS AND BACKGROUND: Radiotherapy with fast neutrons offers radiobiological advantages in the treatment of hypoxic and slowly proliferating tumors. Tumors recurring in pre-irradiated areas of the head and neck usually exhibit a low radiation sensitivity that seems to promise little success for a repeated irradiation with photons. In such a situation, radiotherapy with fast neutrons may offer an alternative treatment option. To evaluate the question, the Muenster patients were retrospectively analyzed. METHODS: During the period July 1986 to January 1994, 26 patients with local-regional recurrences of pre-irradiated head and neck tumors were treated with fast neutrons at our department. RESULTS: Median survival calculated by the Kaplan-Meier method was 7.4 months. The 1-year survival probability was 29.3% and the 2-year survival probability 5.9%. The objective tumor remission (complete + partial) was 50%. A subjective improvement of symptoms was reported by 42.3% of all patients. CONCLUSIONS: Despite relatively unfavorable survival rates produced by the therapy, good remission rates and thereby a good palliative effect can be attained with a short treatment time and tolerable side effects.

Adult↗
PubMedDate not supplied

Results of fast neutron therapy of adenoid cystic carcinoma of the salivary glands.

BACKGROUND: Adenoid cystic carcinomas (ACC) seem to have a better response to fast neutron irradiation than to photon beam therapy because of the higher relative biological effectiveness of neutron radiation. METHODS: Between 1986 and 1995, 72 patients with ACC of the salivary glands were treated in Münster with fast neutrons. The median age was 54 years. All the patients had either recurrent or macroscopic rest tumor prior to neutron therapy. The median total dose was 15.03 Gy. Median follow-up was 50 months. RESULTS: 39.1% of the patients achieved a complete remission and 48.6% a partial remission. The survival probability was 86% after one year, 73% after two years and 53% after five years. The recurrence-free survival was 83% after one year, 71% after two years and 45% after five years. CONCLUSION: Neutron beam therapy seems to have been an effective treatment in these selected patients.

Adolescent↗