RESUMO
Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination.
Assuntos
Contaminação Radioativa do Ar/estatística & dados numéricos , Acidente Nuclear de Chernobyl , Monitoramento Ambiental/estatística & dados numéricos , Neoplasias Induzidas por Radiação/prevenção & controle , Proteção Radiológica/estatística & dados numéricos , Liberação Nociva de Radioativos/estatística & dados numéricos , Agricultura , Contaminação Radioativa do Ar/prevenção & controle , Exposição Ambiental/estatística & dados numéricos , Contaminação Radioativa de Alimentos/prevenção & controle , Humanos , Neoplasias Induzidas por Radiação/epidemiologia , Proteção Radiológica/métodos , Liberação Nociva de Radioativos/prevenção & controle , Ucrânia , Gerenciamento de Resíduos/estatística & dados numéricosRESUMO
OBJECTIVE: To evaluate the cosmetic outcome of brachytherapy after lumpectomy in the management of carcinoma of the previously irradiated breast. MATERIALS AND METHODS: Between January 1998 and April 2008, 26 patients with TIS or T1 breast carcinoma were offered interstitial or intracavitary brachytherapy after lumpectomy in a previously irradiated breast as an alternative to salvage mastectomy. Twenty-five of 26 patients had prior lumpectomy followed by standard postoperative external beam radiotherapy for early stage carcinoma of the breast [dose range 5000-6040 cGy]. One patient developed breast cancer after full mantle irradiation [4500 cGy to the mediastinum and axillae] for Hodgkin Lymphoma 27 years earlier. All tumors were excised with final margins of resection free of disease per National Surgical Adjuvant Breast and Bowel Project definition. After lumpectomy, tumor bed implantation was carried out utilizing a low dose rate interstitial technique in 22 patients, whereas 3 patients were treated with high dose rate brachytherapy using the MammoSite brachytherapy catheter and 1 patient was treated with high dose rate brachytherapy using the Contura catheter. The low dose rate treatment consisted of 4500 to 5000 cGy at 35 to 50 cGy per hour to the tumor bed plus a 1.0 cm margin, whereas the high dose rate treatment consisted of 3400 cGy in twice daily fractions of 340 cGy currently used in National Surgical Adjuvant Breast and Bowel Project B-39. Cosmesis was graded according to the B-39 cosmesis scale for de novo treatments: grade I as excellent, grade II as good, Grade III as fair, and Grade IV as poor. RESULTS: Eighteen patients were scored as grade I, 6 as grade II, and 2 as grade III. No patient received a Grade IV score. All 4 balloon brachytherapy patients were scored as Grade I. Twenty-five of 26 patients remained free of local failure with a median follow-up of 38 months (range 6-75 months). The only patient to develop a second local recurrence was graded as grade I before salvage mastectomy. Two patients developed wound dehiscence after immediate postlumpectomy implantation. Two have succumbed to metastatic breast carcinoma at 17 and 24 months after salvage implant therapy. An additional patient has succumbed to chronic obstructive pulmonary disease. All patients, regardless of cosmesis grade were satisfied with their decision for repeat conservation therapy. Factors affecting cosmesis were distance from the implant to the skin, the type of device used, and the amount of residual breast tissue after repeat lumpectomy. CONCLUSIONS: The cosmetic effect of brachytherapy after lumpectomy in the management of recurrent carcinoma of the previously irradiated breast is acceptable in highly selected patients. Intracavitary technique may provide superior cosmetic results for patients retreated with brachytherapy for salvage.