ABSTRACT
Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200 with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study.
Subject(s)
Brachytherapy/methods , Radioisotopes , Calibration , Coloring Agents , Humans , Phantoms, Imaging , Polymethyl Methacrylate , Radiometry/methods , WaterABSTRACT
Dose-dependent damage to Fc and C3 receptors on leukocytes by ionizing radiation was obtained with monocytes in peripheral blood leukocytes (M-PBL) as well as granulocytes in bone marrow cells (G-BMC) from total body irradiated mice. G-BMC from these mice took more than 4 months after irradiation to present normal levels of Fc and C3 receptors. Evidence is provided that albumin can protect Fc and C3 receptors from the damage of ionizing radiation in a dose-dependent way, and that this radioprotection can last for several days after albumin administration. In general, M-PBL from cervical cancer patients under radiotherapy maintained normal values of C3 receptors as compared to non-albumin-treated patients where an important decrease was found.
Subject(s)
Granulocytes/radiation effects , Macrophage-1 Antigen/radiation effects , Monocytes/radiation effects , Radiation-Protective Agents/pharmacology , Receptors, Fc/radiation effects , Serum Albumin/pharmacology , Uterine Cervical Neoplasms/blood , Adult , Animals , Blood Cells/drug effects , Blood Cells/metabolism , Blood Cells/radiation effects , Bone Marrow Cells , Cobalt Radioisotopes/therapeutic use , Female , Gamma Rays , Granulocytes/drug effects , Granulocytes/metabolism , Humans , Macrophage-1 Antigen/drug effects , Mice , Monocytes/drug effects , Monocytes/metabolism , Radioisotope Teletherapy , Receptors, Fc/drug effects , Uterine Cervical Neoplasms/radiotherapy , Whole-Body IrradiationABSTRACT
Using a probabilistic model with parameters from four radiotherapy protocols used in Mexican hospitals for the treatment of cervical cancer, we have calculated the distribution of dose to cells in peripheral blood of patients. Values of the mean dose to the lymphocytes during and after a 60Co treatment are compared to estimates from an in vivo chromosome aberration study performed on five patients. Calculations indicate that the mean dose to the circulating blood is about 2% of the tumor dose, while the mean dose to recirculating lymphocytes may reach up to 7% of the tumor dose. Differences up to a factor of two in the dose to the blood are predicted for different protocols delivering equal tumor doses. The data suggest mean doses higher than the predictions of the model.
Subject(s)
Lymphocytes/radiation effects , Uterine Cervical Neoplasms/radiotherapy , Chromosome Aberrations , Female , Gamma Rays , Humans , Lymphoid Tissue/radiation effects , Radiotherapy DosageABSTRACT
The effect that ionizing radiation has in vitro on Fc and C3 receptors was evaluated at various doses and measured by means of erythrocytes coated with antibody (EA) and erythrocytes coated with antibody and complement (EAC) rosettes on human peripheral blood leukocytes (PBL) and on mouse bone marrow cells (BMC) and PBL. We found that the number of cells with either EA and EAC rosettes decreased as the radiation doses increased, and that they were almost absent when the highest doses were employed. We obtained evidence that albumin is a natural source of radio-protection for Fc and C3 receptors, and we showed that by increasing the amount of this molecule we could completely protect receptors for EA and EAC in vitro. Finally, the possible therapeutic value of the administration of human albumin to patients undergoing radiotherapy is discussed.
Subject(s)
Leukocytes/radiation effects , Radiation-Protective Agents , Receptors, Complement/metabolism , Receptors, Fc/metabolism , Serum Albumin , Animals , Bone Marrow/metabolism , Bone Marrow Cells , Dose-Response Relationship, Radiation , Gamma Rays , Humans , In Vitro Techniques , Leukocytes/metabolism , Mice , Rosette FormationSubject(s)
Neoplasms/therapy , Combined Modality Therapy , Female , Humans , Male , Neoplasms/drug therapy , Neoplasms/radiotherapyABSTRACT
Leuprolide (Lupron, TAP Pharmaceuticals, North Chicago), a gonadotropin-releasing hormone analogue, was administered to 26 premenopausal women with metastatic breast cancer. Of 25 evaluable patients, 11 (44%) had a partial response with a median duration of 39 weeks and five (20%) remained stable. Six patients showed early rapid progression of their disease. Toxicity was mild and included hot flashes, nausea, vomiting, and headache. Leuprolide induced amenorrhea in all patients who received treatment for ten weeks or longer. We conclude that this GnRH analogue provides a safe and effective means of producing medical castration in premenopausal patients with metastatic breast carcinoma.
Subject(s)
Antineoplastic Agents/therapeutic use , Breast Neoplasms/drug therapy , Gonadotropin-Releasing Hormone/analogs & derivatives , Adult , Antineoplastic Agents/adverse effects , Breast Neoplasms/blood , Combined Modality Therapy , Drug Evaluation , Female , Gonadotropin-Releasing Hormone/adverse effects , Gonadotropin-Releasing Hormone/therapeutic use , Hormones/blood , Humans , Leuprolide , Mastectomy , Menstruation , Middle Aged , Neoplasm Metastasis , Ovary/drug effects , Receptors, Estrogen/analysisSubject(s)
Medical Oncology/trends , Neoplasms/therapy , Adolescent , Adult , Aged , Antineoplastic Agents/therapeutic use , Child , Child, Preschool , Combined Modality Therapy , Female , Forecasting , Humans , Immunotherapy , Infant , Infant, Newborn , Male , Middle Aged , Neoplasms/drug therapy , Neoplasms/radiotherapy , Neoplasms/surgery , Pregnancy , Preventive MedicineABSTRACT
The basic biological aspects in relation to cancer are reviewed and how this concepts has influenced the rational treatment of this disease. The best results achieved in the treatment of cancer are obtained because of the use of a more radical treatment. And for the patients with not very advanced stages, the results have been improved with the prophylactic treatment on those areas where the tumor usually gives metastases. However, an early diagnosis and the proper treatment are the best way to obtain relieve in this group of patients.
