Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]
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We report a case of suspected radiation-induced myelitis after twice-daily irradiation with a cord dose of 45.8 Gy. The 48-year old patient had been irradiated with two daily fractions of 1.8 Gy up to 70.2 Gy for oropharyngeal cancer T4 N2 G3 M0 and achieved a complete remission. ⋯ A complete neurological diagnostic procedure revealed no other causes than suspected radiation damage. This is the only case of radiation myelitis among 90 patients treated twice daily and over 2000 patients irradiated with conventional fractionation in the same technique and doses.
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In radiotherapy to ensure that appropriate tumor lethal dose is delivered without exceeding normal tissue tolerance, concepts like NSD and its derivatives were used in the past. Due to their short coming these concepts are now replaced by a linear quadratic model. ⋯ For most of the tumors and normal tissues, values of the parameters are not yet accurately known. We have estimated alpha/beta value for mucosal reactions, i.e. normal tissue early reactions in head neck cases treated with twice daily fractionation schedules and observed it to be 7.90 Gy for slight mucositis whereas it is 7.68 and 8.11 Gy for patchy and confluent mucositis, respectively.
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Clinical Trial Controlled Clinical Trial
Fast neutron therapy for malignant gliomas--results from NIRS study. National Institute of Radiological Sciences.
The results of combined radiotherapy with fast neutrons and photons for 39 malignant gliomas were analyzed. The patients consisted of 16 astrocytoma grade 3 and 23 glioblastoma multiforme. There were two kinds of combination methods which were either "boost therapy" or "mixed beam therapy" with a localized fast neutron field. ⋯ This result seems to have no impact on survival compared to other reports. Patients' ages, surgical debulking procedures, and photon doses were listed as significant prognostic factors, but doses of fast neutrons had no prognostic significance for survival. Because there were no moderate or severe complications for the brain except permanent epilation in all cases, neutron dose escalation study with a localized field will be recommended.
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Comparative Study
[Medulloblastomas--the results after postoperative radiotherapy with and without adjuvant chemotherapy].
Between 1975 and 1991, 40 patients with newly diagnosed medulloblastoma were treated at the authors' institutions. After aggressive surgical resection 39/40 (98%) received craniospinal radiation therapy with a local boost to the posterior fossa and other macroscopically involved areas. A group of 29 patients was treated with adjuvant chemotherapy. ⋯ Survival was significantly better for patients treated after 1981 as compared to those treated between 1975 and 1980 (p = .02). Younger age (two to four years) was associated with a better prognosis (p = .02). The extend of resection, Chang-stage, radiation dose to posterior fossa and the use of chemotherapy did not significantly impact on survival and relapse-free survival.
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Clinical Trial Controlled Clinical Trial
[Atypical fractionation in advanced squamous-cell carcinomas of the head-neck area].
From May 1990 to May 1991, 23 patients with advanced, inoperable squamous cell cancers, clinically staged as III or IV, were treated by unconventional fractionation radiotherapy. Treatment consisted of a continuous hyperfractionated accelerated radiotherapy, delivering a total dose of 55.3 Gy within 17 consecutive days. In ten patients radiation therapy was combined with chemotherapy; 20 mg mitomycin C/m2, administered by intravenous bolus injection on day 5 of treatment. ⋯ After a median follow-up of 18 months, ten of 23 patients have survived (8/23 without evidence of disease). Eleven patients have died due to local tumour progression and one patient died with distant metastases, being without evidence of local tumour. The advantage of this unconventional fractionation, which takes the described short potential tumour doubling time for head and neck cancers into account, is discussed.