RESUMO
INTRODUCTION: Hypofractionated radiation therapy for breast cancer requires highly precise delivery through the use of image-guided radiotherapy (IGRT). Surface-guided radiation therapy (SGRT) is being increasingly used for patient positioning in breast radiotherapy. We aimed to assess the role of SGRT for verification of breast radiotherapy and the tumour bed. MATERIALS AND METHODS: Prospective study of 252 patients with early stage breast cancer. A total of 1170 determinations of daily positioning were performed. Breast surface positioning was determined with SGRT (AlignRT) and correlated with the surgical clips in the tumour bed, verified by IGRT (ExacTrac). RESULTS: SGRT improved surface matching by a mean of 5.3 points compared to conventional skin markers (98.0 vs. 92.7), a statistically significant difference (p < 0.01, Wilcoxon Test). For surface matching values > 95%, ≥ 3 clips coincided in 99.7% of the determinations and all markers coincided in 92.5%. For surface matching rates > 90%, the location of ≥ 3 clips coincided in 99.55% of determinations. CONCLUSIONS: SGRT improves patient positioning accuracy compared to skin markers. Optimal breast SGRT can accurately verify the localisation of the tumour bed, ensuring matching with ≥ 3 surgical clips. SGRT can eliminate unwanted radiation from IGRT verification systems.
Assuntos
Neoplasias da Mama/radioterapia , Posicionamento do Paciente/métodos , Radioterapia Guiada por Imagem/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Marcadores Fiduciais , Humanos , Mastectomia Segmentar , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Estudos Prospectivos , Hipofracionamento da Dose de Radiação , Estatísticas não Paramétricas , Instrumentos Cirúrgicos , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: To assess the pattern of treatment failure in patients with prostate cancer (PCa) treated with radiotherapy (76-80 Gy) ± hormone therapy (HT). We also evaluated the influence of treatment failure on survival outcomes. METHODS: Retrospective study of patients with PCa (n = 302) treated with radiotherapy (RT) ± HT at our centre between November 1999 and July 2007. The mean patient age was 70.2 years (range 51-87). Distribution by NCCN risk group was low (n = 80, 26.5%), intermediate (n = 86, 28.5%), high (n = 77, 25.5%), and very high (n = 49, 16.2%). Most patients (n = 273, 90.4%) received IMRT at a dose of 76-80 Gy. HT was administered in 237 patients (78.5%), in most cases (n = 167, 55.3%) for < 7 months RESULTS: Survival rates at 10 years were: overall survival (OS), 64.3%; biochemical disease-free survival, 83.9%; disease-free survival, 92.5%; and metastasis-free survival (MFS), 94.3%. Biochemical failure (BF) was observed in 55 cases (18.2%), 32 of whom subsequently developed clinical recurrence: metastasis (n = 17, 5.6%), local failure (n = 11, 3.6%), and regional failure (n = 4, 1.3%). The cause of death (n = 159) was intercurrent disease in 115 cases (72.3%), second cancer in 27 (17.0%), and PCa in 17 (10.7%). Biochemical failure-free survival ≤ 24 months was significantly associated with worse OS and MFS (p = 0.0001). Late genitourinary and gastrointestinal toxicity grade ≥ 3 (RTOG) was observed in 18 (6.0%) and 7 (2.3%) patients, respectively. CONCLUSIONS: The main type of treatment failure after 76-80 Gy of radiotherapy ± HT is local or metastatic. In all cases, biochemical failure occurred prior to treatment failure. BF within 24 months of treatment completion was significantly associated with worse OS and MFS.
Assuntos
Próstata/efeitos da radiação , Neoplasias da Próstata/radioterapia , Glândulas Seminais/efeitos da radiação , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Terapia Combinada , Intervalo Livre de Doença , Humanos , Calicreínas/sangue , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/mortalidade , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Taxa de Sobrevida , Falha de TratamentoRESUMO
PURPOSE: Total skin electron irradiation (TSEI) is a radiotherapy technique which consists of an homogeneous body surface irradiation by electrons. This treatment requires very strict technical and dosimetric conditions, requiring the implementation of multiple controls. Recently, the Task Group 100 report of the AAPM has recommended adapting the quality assurance program of the facility to the risks of their processes. MATERIALS AND METHODS: A multidisciplinary team evaluated the potential failure modes (FMs) of every process step, regardless of the management tools applied in the installation. For every FM, occurrence (O), severity (S) and detectability (D) by consensus was evaluated, which resulted in the risk priority number (RPN), which permitted the ranking of the FMs. Subsequently, all the management tools used, related to the TSEI process, were examined and the FMs were reevaluated, to analyze the effectiveness of these tools and to propose new management tools to cover the greater risk FMs. RESULTS: 361 FMs were identified, 103 of which had RPN ≥80, initially, and 41 had S ≥ 8. Taking this into account the quality management tools FMs were reevaluated and only 30 FMs had RPN ≥80. The study of these 30 FMs emphasized that the FMs that involved greater risk were related to the diffuser screen placement and the patient's position during treatment. CONCLUSIONS: The quality assurance program of the facility has been adapted to the risk of this treatment process, following the guidelines proposed by the TG-100. However, clinical experience continually reveals new FMs, so the need for periodic risk analysis is required.