ABSTRACT
BACKGROUND: The effect of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT)-guided dose-painting intensity-modulated radiation therapy (IMRT) in locoregionally advanced nasopharyngeal carcinoma (NPC) is unclear. This study aimed to assess the efficacy and toxicity of such combination. METHODS: From 2012 to 2014, 213 patients with stage III-IVB NPC received chemoradiotherapy by PET/CT-guided DP-IMRT (group A, n = 101) or CT-based IMRT (group B, n = 112). In group A, subvolume GTVnx-PET (gross tumor volume of nasopharynx in PET images) was defined within GTVnx (gross tumor volume of nasopharynx) as the SUV50%max isocontour; the dose to GTVnx-PET was escalated to DT 75.2 Gy/32 and 77.55 Gy/33 Fx, respectively, for patients with T1-2 and T3-4 disease, respectively. In group B, PGTVnx was irradiated at DT 70.4-72.6 Gy/32-33 Fx in 2.2 Gy per fraction. RESULTS: Complete response rates were 99.0% (100/101) and 92.9% (104/112) in groups A and B, respectively (P = 0.037). Compared with CT-based IMRT, FDG-PET/CT guided DP-IMRT significantly improved 3-year local failure-free survival (LFFS, 98.8% vs. 91.3%; P = 0.032), locoregional failure-free survival (LRFFS, 97.2 vs. 91.2%; P = 0.049), distant metastasis-free survival (DMFS, 92.9% vs. 87.4%; P = 0.041), disease free survival (DFS, 87.9% vs. 82.4%; P = 0.02), and overall survival (OS, 91.8% vs. 82.6%; P = 0.049). No statistically significant differences in acute and late toxic effects were observed. Multivariate analysis showed that dose painting (PET/CT-guided DP-IMRT vs CT-based IMRT without DP) was a significant independent prognostic factor for LFFS and DFS. CONCLUSION: FDG-PET/CT guided DP-IMRT plus chemotherapy is associated with a considerable survival benefit, without increasing toxicity in patients with locoregional advanced NPC. Further randomized trials are needed to fully assess the role of PET/CT-guided DP-IMRT.
Subject(s)
Carcinoma/radiotherapy , Nasopharyngeal Neoplasms/radiotherapy , Positron Emission Tomography Computed Tomography/methods , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Image-Guided/methods , Radiotherapy, Intensity-Modulated/methods , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Carcinoma/diagnostic imaging , Carcinoma/pathology , Female , Fluorodeoxyglucose F18/metabolism , Follow-Up Studies , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/pathology , Prognosis , Radiotherapy Dosage , Retrospective Studies , Young AdultABSTRACT
OBJECTIVE: To identify molecular markers of lung squamous cell carcinoma by cDNA microarray technique. METHODS: cDNA expression profiles were examined by microarrays of 6 surgical specimens of stage I lung squamous cell carcinomas. Those genes, either up-regulated or down-regulated in every specimen studied, were identified. The expression levels of nm23 and BRCA2 by the squamous cell carcinoma of the lung were further examined by immunohistochemical techniques. RESULTS: A total of 107 genes were identified, of which 26 were up-regulated and 81 were down-regulated in all six specimens. Immunohistochemical staining showed that, compared with normal lung tissues, the intensity of nm23 expression by the squamous cell carcinoma of lung was significantly increased while that of BRCA-2 was decreased. CONCLUSION: cDNA microarrays can be used to identify gene expression profile of lung cancer, some of which may be used as markers of lung squamous cell carcinoma.