Influence of emphysema distribution on pulmonary function parameters in COPD patients / Influência da distribuição do enfisema nos parâmetros de função pulmonar em pacientes com DPOC

ABSTRACT OBJECTIVE: To evaluate the impact that the distribution of emphysema has on clinical and functional severity in patients with COPD. METHODS: The distribution of the emphysema was analyzed in COPD patients, who were classified according to a 5-point visual classification system of lung CT findings. We assessed the influence of emphysema distribution type on the clinical and functional presentation of COPD. We also evaluated hypoxemia after the six-minute walk test (6MWT) and determined the six-minute walk distance (6MWD). RESULTS: Eighty-six patients were included. The mean age was 65.2 ± 12.2 years, 91.9% were male, and all but one were smokers (mean smoking history, 62.7 ± 38.4 pack-years). The emphysema distribution was categorized as obviously upper lung-predominant (type 1), in 36.0% of the patients; slightly upper lung-predominant (type 2), in 25.6%; homogeneous between the upper and lower lung (type 3), in 16.3%; and slightly lower lung-predominant (type 4), in 22.1%. Type 2 emphysema distribution was associated with lower FEV1, FVC, FEV1/FVC ratio, and DLCO. In comparison with the type 1 patients, the type 4 patients were more likely to have an FEV1 < 65% of the predicted value (OR = 6.91, 95% CI: 1.43-33.45; p = 0.016), a 6MWD < 350 m (OR = 6.36, 95% CI: 1.26-32.18; p = 0.025), and post-6MWT hypoxemia (OR = 32.66, 95% CI: 3.26-326.84; p = 0.003). The type 3 patients had a higher RV/TLC ratio, although the difference was not significant. CONCLUSIONS: The severity of COPD appears to be greater in type 4 patients, and type 3 patients tend to have greater hyperinflation. The distribution of emphysema could have a major impact on functional parameters and should be considered in the evaluation of COPD patients.

RESUMO OBJETIVO: Avaliar o impacto que a distribuição do enfisema tem na gravidade clínica e funcional em pacientes com DPOC. MÉTODOS: A distribuição do enfisema foi analisada em pacientes com DPOC, que foram classificados de acordo com um sistema de classificação visual de cinco pontos a partir de achados de TC de tórax. Avaliou-se a influência do tipo de distribuição do enfisema na apresentação funcional e clínica da DPOC. Hipoxemia após o teste da caminhada de seis minutos (TC6) foi também avaliada e a distância percorrida (DTC6) foi determinada. RESULTADOS: Foram incluídos 86 pacientes. A média de idade foi de 65,2 ± 12,2 anos, 91,9% eram homens, e todos menos um eram fumantes (média de carga tabágica, 62,7 ± 38,4 anos-maço). A distribuição do enfisema foi categorizada como obviamente predominante no pulmão superior (tipo 1), em 36,0% dos pacientes; levemente predominante no pulmão superior (tipo 2), em 25,6%; homogêneo entre o pulmão superior e inferior (tipo 3), em 16,3%; e levemente predominante no pulmão inferior (tipo 4), em 22,1%. A distribuição do enfisema do tipo 2 foi associada a menores valores de VEF1, CVF, relação VEF1/CVF e DLCO. Em comparação com os pacientes do tipo 1, os do tipo 4 apresentaram maior probabilidade de ter VEF1 < 65% do previsto (OR = 6,91, IC95%: 1,43-33,45; p = 0,016), DTC6 < 350 m (OR = 6,36, IC95%: 1,26-32,18; p = 0,025),e hipoxemia após o TC6 (OR = 32,66, IC95%: 3,26-326,84; p = 0,003). Os pacientes do tipo 3 tiveram uma relação VR/CPT maior, embora sem diferença significativa. CONCLUSÕES: A gravidade da DPOC parece ser maior nos pacientes do tipo 4, e os do tipo 3 tendem a apresentar maior hiperinsuflação. A distribuição do enfisema pode ter um impacto importante nos parâmetros funcionais e deve ser considerada na avaliação de pacientes com DPOC.

T2-weighted endorectal magnetic resonance imaging of prostate cancer after external beam radiation therapy

PURPOSE: To retrospectively determine the accuracy of T2-weighted endorectal MR imaging in the detection of prostate cancer after external beam radiation therapy and to investigate the relationship between imaging accuracy and time since therapy. MATERIAL AND METHODS: Institutional review board approval was obtained and the study was HIPPA compliant. We identified 59 patients who underwent 1.5 Tesla endorectal MR imaging of the prostate between 1999 and 2006 after definitive external beam radiation therapy for biopsy-proven prostate cancer. Two readers recorded the presence or absence of tumor on T2-weighted images. Logistic regression and Fisher’s exact tests for 2x2 tables were used to determine the accuracy of imaging and investigate if accuracy differed between those imaged within 3 years of therapy (n = 25) and those imaged more than 3 years after therapy (n = 34). Transrectal biopsy was used as the standard of reference for the presence or absence of recurrent cancer. RESULTS: Thirty-four of 59 patients (58 percent) had recurrent prostate cancer detected on biopsy. The overall accuracy of T2-weighted MR imaging in the detection cancer after external beam radiation therapy was 63 percent (37/59) for reader 1 and 71 percent for reader 2 (42/59). For both readers, logistic regression showed no difference in accuracy between those imaged within 3 years of therapy and those imaged more than 3 years after therapy (p = 0.86 for reader 1 and 0.44 for reader 2). CONCLUSION: T2-weighted endorectal MR imaging has low accuracy in the detection of prostate cancer after external beam radiation therapy, irrespective of the time since therapy.