Treatment Planning CT Radiomics for Predicting Treatment outcomes and
Hematologic Toxicities to Intensity-modulated Radiation Therapy in
Locally Advanced Cervical Cancer
Abstract
Objectives: We evaluated radiotherapy planning CT-based radiomics for
predicting clinical endpoints [tumor complete response (CR), 5-year
overall survival (OS), hypohemoglobin, and leucopenia] after
intensity-modulated radiation therapy (IMRT) in locally advanced
cervical cancer (LACC). Methods: This study retrospectively collected
257 LACC patients treated with IMRT from 2014 to 2017. Patients were
allocated into the training/validation sets (3:1 ratio) using
proportional random sampling, resulting in the same proportion of groups
in the two sets. We extracted 254 radiomic features from each of the
gross target volume (GTV), pelvis, and sacral vertebrae in planning CT
images. The sequentially backward elimination support vector machine
algorithm was used for feature selection and endpoint prediction. Model
performance was evaluated using area under the curve (AUC). Results: A
combination of 10 clinicopathological parameters and 34 radiomic
features achieved the best performance for predicting CR [validation
balanced accuracy: 80.79%]. For OS, 54 radiomic features showed good
prediction accuracy [validation balanced accuracy: 85.75%], and the
threshold value of their scores can stratify patients into the low-risk
and high-risk groups (P<0.001). The clinical and radiomic
models were also predictive of hypohemoglobin and severe leucopenia
[validation balanced accuracies: 70.96% and 69.93%]. Conclusion:
This study demonstrated that combining clinicopathological parameters
with CT-based radiomics had good predictive value for treatment outcomes
and hematologic toxicities to radiotherapy in LACC. The prediction of
clinical endpoints prior to radiotherapy may assist the radiation
therapists to select the optimal therapeutic strategy with the minimal
toxicity and best curative effect.