RESUMO
We have applied the cytokinesis-block micronucleus assay to peripheral blood lymphocytes of patients undergoing radiotherapy in pelvic and pulmonary sites, in order to evaluate the individual cytogenetic response. Our cytogenetic data correlated with the equivalent whole-body dose are homogeneous and compare well with the data presented by other authors. We have used an exponential mathematical formula to calculate the attenuation of the cytogenetic effect with time. The k coefficient (cytogenetic recovery factor) in the formula expresses the degree of attenuation. In lymphocytes from patients after radiotherapy, the trend of the micronucleus frequency observed after 2 Gy of in vitro X-irradiation demonstrates that the cytogenetic effect obtained in vitro is added to that obtained in vivo. The k coefficient is inversely proportional to the micronucleus frequency observed after 2 Gy in vitro. The micronucleus assay and the cytogenetic recovery factor are proposed as suitable diagnostic tools for application in the field of radiotherapy.
Assuntos
Linfócitos/efeitos da radiação , Testes para Micronúcleos , Radioterapia , Relação Dose-Resposta à Radiação , Humanos , Linfócitos/ultraestrutura , Tolerância a RadiaçãoRESUMO
In several bone disorders, including those with metastatic involvement, changes in procollagen type I C-terminal and type III N-terminal peptides are detected, as indications of altered bone metabolism. Assessment of bone turnover could play a role in the evaluation of response to Strontium-89 used as palliative treatment in symptomatic bone metastases from various primary tumors. A correlation between bone formation rate markers procollagen I and III and efficacy of ionic Strontium-89 was shown in a group of 13 patients who underwent treatment with 4 mCi of Strontium-89 for painful bone metastases: 5 from breast, 7 from prostate, and 1 from lung carcinoid cancer. Assessed as a modification of analgesic intake, pain, and ambulation, there were 6 complete remissions, 3 partial remissions, and 4 nonresponders. The duration of the response was from 2 to 11 months. Procollagen I and III levels were found to be highly abnormal in those with no benefit from Strontium-89 administration but were in the normal range or only slightly elevated in those achieving complete or partial pain control, thus correlating with the clinical response.
Assuntos
Densidade Óssea/efeitos da radiação , Neoplasias Ósseas/radioterapia , Cuidados Paliativos/métodos , Radioisótopos de Estrôncio/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/fisiopatologia , Neoplasias Ósseas/secundário , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The paper reports the historical origins of remote afterloading systems in intracavitary radiotherapy, together with the results and complications of high dose rate brachytherapy in gynecological tumours. High dose rate therapy achieves the same results as low dose rate therapy but has the advantage of making treatment more comfortable for patients.