RESUMO
PURPOSE: To investigate development of radiation pneumonitis (RP) in relation to pulmonary function, dosimetric factors, and transforming growth factor beta-1 (TGFß1) expression in irradiated breast cancer patients. METHODS: A total of 49 breast cancer patients who received post-operative radiotherapy (RT) were evaluated in terms of pulmonary function tests (PFTs), quality of life (QoL), development of RP, dosimetric factors, cytokine levels, and lung high-resolution computed tomography (HRCT) before and after RT. ROC analysis was performed for performance of dosimetric factors in predicting RP, while frequencies of single nucleotide polymorphisms (SNPs) genotyped for TGFß1 (rs11466345 and rs1800470) were also evaluated. RESULTS: All cases with RP (10.2%) recovered clinically at the end of third post-RT month. PFT and HRCT parameters were similar before and after RT overall, as well as by RP and the radiation field subgroups. ROC analysis revealed the significant role of the ipsilateral V5 (cutoff value of 45.9%, p = 0.039), V10 (29.4%, p = 0.015), V20 (23%, p = 0.017), and MLD (1200 cGy, p = 0.030) in predicting RP. Higher post-RT TGFß1 levels (p = 0.037) were noted overall and in patients with RP. Patient and control groups were similar in terms of frequencies of SNPs genotyped for TGFß1 (rs11466345 and rs1800470). EORTC QLQ-C30 and QLQ-BR-23 scores were similar in patients with vs. without RP. CONCLUSION: Our findings revealed significant role of dosimetric factors including MLD, V20 as well as the low dose-volume metrics in predicting the risk of RP among breast cancer patients who received post-operative RT. Implementation of RT, extent of radiation field or the presence of RP had no significant impact on PFTs.
Assuntos
Neoplasias da Mama , Pulmão , Pneumonite por Radiação , Radioterapia Adjuvante , Feminino , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Seguimentos , Pulmão/fisiopatologia , Pulmão/efeitos da radiação , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Qualidade de Vida , Pneumonite por Radiação/etiologia , Pneumonite por Radiação/genética , Pneumonite por Radiação/fisiopatologia , Dosagem Radioterapêutica , Radioterapia Adjuvante/efeitos adversos , Testes de Função RespiratóriaRESUMO
OBJECTIVE: To study the predictive value of functional and biologic metrics for predicting radiation pneumonitis (RP) in locally advanced non-small cell lung cancer (LANSCLC) patients treated with chemoradiotherapy. METHODS: Between March 2006 and April 2010, 57 LANSCLC patients were enrolled in a prospective study. Fusion of SPECT and computed tomography scans provides perfusion-weighted functional dose-volume histogram (DVH) and associated functional dosimetric parameters. Blood for serum biomarkers-interleukin-6 (IL-6), transforming growth factor-beta1, and superoxide dismutase (SOD)-was drawn pre-RT and then 40 Gy/4 weeks during the treatment. The incidence of RP was related to the functional and biologic metrics. The predictability of predictors was calculated and compared based on the area under receiver-operating characteristic (ROC) curve (AUC). RESULTS: Relative volumes of functional lung receiving more than a threshold dose of 5-50 Gy at increments of 5 Gy and elevated levels of serum SOD after delivery of 40 Gy/4 weeks were associated with RP (p < 0.05). The best predictive efficacy of SOD was observed for a cutoff value of 56 U/ml, with a sensitivity of 0.80 (95 % CI 0.28-0.99) and a specificity of 0.67 (95 % CI 0.43-0.65) (p = 0.040). Functional DVH provided better predictive outcome (AUC 0.76-0.98) than standard DVH (AUC 0.62-0.86) for patients with poor baseline lung function. CONCLUSION: Functional metrics were identified to be better predictors for RP in patients with poor baseline lung function. SOD seemed to be a potential predictor for RP; however, it will need to be further verified using a larger sample size.