RESUMO
INTRODUCTION: The aim of this study is to determine the interobserver variability (IV) between radiation oncologists (RO) in target volume delineation for postoperative gastric cancer (GC) radiotherapy planning. MATERIALS AND METHODS: Four physicians were asked to delimitate clinical target volume (CTV) on the same 3D CT images in 9 postoperative radiochemotherapy GC patients. Instructions were given to include tumour bed, remaining stomach, anastomosis, duodenal loop and local lymph nodes. The principal variable was spatial volume discrepancy between the main observer (called "A") and other observers (all called "B"), which were compared using the mathematical formula Aâ£B/Aâ¢B, applied to the 3D CT images using Boolean operators. Analysis of variance with two random effects (observers and patients) was performed. RESULTS: Mean volumes were 1410 cm(3) for OBA, 1231 cm(3) for OB2, 734.6 cm(3) for OB3 and 1350 cm(3) for OB4. Discrepancies were 519.9±431.6 cm(3) for OB2, 652.1±294.36 cm(3) for OB3 and 225.90±237.07 cm(3) for OB4. Standard deviation ascribed to patients as random effect was 898.6 cm(3) and that ascribed to observers was 198.10 cm(3), considered as a statistically significant difference. CONCLUSIONS: A significant IV in target delineation that can be attributed to many factors depends more on patients' characteristics than RO delineating decisions.
Assuntos
Quimiorradioterapia , Variações Dependentes do Observador , Padrões de Prática Médica , Radioterapia (Especialidade) , Planejamento da Radioterapia Assistida por Computador , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/terapia , Projetos Piloto , Prognóstico , Estudos Prospectivos , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVES: The aim of this study was to retrospectively evaluate clinical characteristics, local control, acute and late toxicity, and prognostic factors of patients with anal canal carcinoma treated with brachytherapy. METHODS: From 1989 to 2009, 38 patients were treated with iridium 192 low-dose-rate (N = 26) or pulsed-dose-rate (N = 12) interstitial brachytherapy at a single institution. The median age was 62 years (range, 38-86 years). The TNM classification was as follows: 10 T1, 22 T2, 5 T3 and 1 T4; 32 N0, 3 N1 and 3 N2. Most patients (32/38) received either a first course of radiochemotherapy (N = 22) or radiotherapy alone (N=10) consisting of a total delivered dose of 45 Gy to the pelvis (range, 32-50) followed by a boost a median of 18 days later of 15-35 Gy (median 20 Gy) to the anal canal. The remaining 6 cases were treated with brachytherapy alone (dose range, 60-65 Gy). RESULTS: With a median follow-up of 30 months (range, 4-200), 2- and 5-year local control rates were 91% and 87%, respectively. Preservation of the anal sphincter was achieved in 32 patients (84%). Three patients experienced incontinence after brachytherapy. Only 2 patients showed chronic mucositis grade 3/4. Age proved to be a statistically significant prognostic factor for overall survival in the univariate (p = 0.033) and multivariate analyses (p = 0.018). Concurrent chemotherapy with external beam radiotherapy was a statistically significant prognostic factor for disease-free survival in the univariate and multivariate analyses (p = 0.007 and p = 0.044, respectively). CONCLUSIONS: Interstitial brachytherapy appears to be an effective and well tolerated treatment for anal carcinoma offering both high local tumour control and anal sphincter preservation.