deepPERFECT: Novel Deep Learning CT Synthesis Method for Expeditious Pancreatic Cancer Radiotherapy

Pancreatic cancer with more than 60,000 new cases each year has less than 10 percent 5-year overall survival. Radiation therapy (RT) is an effective treatment for Locally advanced pancreatic cancer (LAPC). The current clinical RT workflow is lengthy and involves separate image acquisition for diagnostic CT (dCT) and planning CT (pCT). Studies have shown a reduction in mortality rate from expeditious radiotherapy treatment. dCT and pCT are acquired separately because of the differences in the image acquisition setup and patient body. We are presenting deepPERFECT: deep learning-based model to adapt the shape of the patient body on dCT to the treatment delivery setup. Our method expedites the treatment course by allowing the design of the initial RT planning before the pCT acquisition. Thus, the physicians can evaluate the potential RT prognosis ahead of time, verify the plan on the treatment day-one CT and apply any online adaptation if needed. We used the data from 25 pancreatic cancer patients. The model was trained on 15 cases and tested on the remaining ten cases. We evaluated the performance of four different deep-learning architectures for this task. The synthesized CT (sCT) and regions of interest (ROIs) were compared with ground truth (pCT) using Dice similarity coefficient (DSC) and Hausdorff distance (HD). We found that the three-dimensional Generative Adversarial Network (GAN) model trained on large patches has the best performance. The average DSC and HD for body contours were 0.93, and 4.6 mm. We found no statistically significant difference between the synthesized CT plans and the ground truth. We showed that employing deepPERFECT shortens the current lengthy clinical workflow by at least one week and improves the effectiveness of treatment and the quality of life of pancreatic cancer patients.