Comparison of predictive powers of functional and anatomic dosimetric parameters for radiation-induced lung toxicity in locally advanced non-small cell lung cancer. Issue 2 (November 2018)

• Record Type: Journal Article
• Authors: Xiao, Linlin; Yang, Guoren; Chen, Jinhu; Yang, Yuchen; Meng, Xue; Wang, Xiaohui; Wu, Qingwei; Huo, Zongwei; Yu, Qingxi; Yu, Jinming; Kong, Feng-Ming (Spring); Yuan, Shuanghu
• Is Part Of: Radiotherapy and oncology. Volume 129:Issue 2(2018)
• Page Start: 242
• Page End: 248
• Publication Date: 2018-11
• Subjects: NSCLC -- Radiation-induced lung toxicity -- Q-SPECT -- DVH -- DFH; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2018.09.005
• Languages: English
• ISSNs: 0167-8140

Abstract

Highlights: Conventionally, metrics of pre-radiotherapy (RT) pulmonary function or post-RT pulmonary function changes have been used to predict outcomes in lung cancer patients receiving RT, but we hypothesized that parameters evaluated mid-treatment and used for replanning could provide accurate prediction of subsequent radiation-induced lung toxicity (RILT). In the presented study, we tested this hypothesis in 42 patients receiving RT for high-risk, locally advanced non-small cell lung cancer (NSCLC) Perfusion (Q)-single-photon emission computed tomography (SPECT) and Q-SPECT-CT were performed prior to RT and mid-treated after delivery of 40–50 Gy RT. Our findings suggest that the mid-Tx dose–function histogram (DFH) parameters based on Q-SPECT were significantly elevated in patients who experienced grade 2 and above RILT. Mid-Tx DFH seemed to be better for predicting RILT than traditional anatomical metrics in locally advanced NSCLC patients with significant functional lung changes mid-RT, though the difference did not reach a significant level, likely due to the limited sample size in this study. Abstract: Purpose: To investigate the predictive value of the perfusion (Q) single-photon emission computed tomography (SPECT)-weighted dose–function histogram (DFH) obtained mid-treatment (mid-Tx) with radiotherapy (RT) for radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC). Materials and methods: The study population consisted of NSCLC patients who were undergoing RT treatment and enrolled in prospective imaging studies. Q-SPECT was performed prior to and during RT (at ∼40–45 Gy). A baseline dose–volume histogram (DVH) and mid-Tx DVH based on simulation CT as well as a baseline DFH and mid-Tx DFH based on Q-SPECT were calculated. Only patients with stage III NSCLC and visible functional lung (FL) changes on the mid-Tx scan were eligible for this enriched analysis. RILT was graded according to a reported scale. Results: Forty-two stage III NSCLC patients met the criteria for inclusion. The accumulative incidence of grade ≥2 RILT was 31% in this high-risk population. Significant differences in functional metrics such as functional lung volume FV5–FV20 at increments of 5 Gy and functional MLD (FMLD) were observed between patients with and without grade ≥2 RILT ( p < 0.05). Similar results were also obtained for anatomical metrics from V5–V20 and MLD ( p < 0.05). The areas under the receiver operating characteristic curves (AUCs) ranged from 0.724to 0.812 for baseline DVH parameters, from 0.745 to 0.830 for mid-Tx DVH parameters, from 0.764 to 0.878 for baseline DFH parameters, and from 0.767 to 0.891 for mid-Tx DFH parameters. Further principal components analysis showed that the AUCs were 0.814/0.817 and 0.790/0.857 for baseline/mid-Tx DVH and baseline/mid-Tx DFH, respectively. Conclusions: Mid-Tx DFH parameters based on Q-SPECT were significantly elevated in patients with grade ≥2 RILT in this study population. Among the metrics compared, mid-Tx DFH seemed to have better predictive accuracy, but this difference did not reach statistical difference.