ABSTRACT
In patients with metallic dental fillings radiation therapy to the oral cavity can cause mucous membrane lesions, which are more severe than expected. They appear as circumscribed erosions, opposite to metallic fillings and are caused by an increase in radiation dose through secondary radiation due to the higher density and atomic number of the filling material. This dose increase can be directly measured with 0.1 mm thin sheets of graphite-loaded TLD's (LiF, Vinten). For Co-60 gamma rays a commercial amalgam filling caused a dose increase by a factor of 1.7. The half value layer for this additional radiation was measured to be approximately 0.4 mm tissue. In order to avoid painful mucous membrane ulcerations which are even more a problem if hyperfractionated treatment schedules are used, we constructed individual dental shields for each patient. As shielding material we used a dental impression material (Optosil P+1 Bayer). This method was tested in 35 patients, in all of them circumscribed mucous membrane ulcerations could be avoided. The method proved to be fast and simple and was very well tolerated by all patients.
Subject(s)
Dental Restoration, Permanent , Mouth Mucosa/radiation effects , Oropharynx/radiation effects , Radiation Injuries/prevention & control , Radiation Protection/instrumentation , Dental Amalgam/radiation effects , Dental Impression Materials/radiation effects , Dose-Response Relationship, Radiation , Humans , In Vitro Techniques , Radiation Injuries/etiology , Silicones/radiation effects , Thermoluminescent DosimetryABSTRACT
We examined the lungs of 35 women following postoperative radiotherapy for breast cancer by using high-resolution computed tomography (HR-CT). Radiotherapy was performed on a cobalt 60 unit using a five-field technique. The average interval between the end of radiotherapy and HR-CT examinations was 23.8 months. HR-CT was limited to those lung areas that were at risk for radiation-induced changes. In 40% of patients minimal interstitial damage (e.g. thickened septal lines, curvilinear densities) invisible on chest x-ray was demonstrated by HR-CT. Massive fibrosis as reported by others was not seen in our study. We conclude that in case lung involvement is suspected clinically during or after radiotherapy, HR-CT is the method of choice for demonstrating these morphological changes.
Subject(s)
Breast Neoplasms/radiotherapy , Lung/diagnostic imaging , Radiography, Thoracic , Tomography, X-Ray Computed , Adult , Aged , Aged, 80 and over , Breast Neoplasms/surgery , Cobalt Radioisotopes/therapeutic use , Combined Modality Therapy , Evaluation Studies as Topic , Female , Humans , Middle Aged , Postoperative Care , Pulmonary Fibrosis/diagnostic imaging , Pulmonary Fibrosis/etiology , Radiotherapy/adverse effects , Radiotherapy DosageABSTRACT
Purpose of this study was to compare the results of two different modalities of palliative radiation i.e. conventional fractionated (group I: 35 patients) vs. hyperfractionated radiation (group II: 20 patients). Group I received 1.8 to 2.3 Gy one time a day (total dose 30 to 40 Gy), with an average treatment duration of 20 days. Group II received 1.8 to 2 Gy two times a day (total dose 25 to 35 Gy), with an average treatment duration of ten days. Regression of complaints occurred in 80% of group I, with an average of twelve days, and in 95% of group II, with an average onset of four days after beginning of treatment. Neither acute nor long term complications did occur in any group. The advantages of the hyperfractionated radiation modality therefore are on one hand a higher regression-rate of subjective complaints, with equal good recovery of clinical and radiological findings and lack of side-effects especially those of the myelon, and on the other hand are resulting in a shortening of hospitalisation.
