In the world of digital avatars, three-dimensional (3D) human models are utilized to replicate real-world appearance and movements with a higher degree of realism compared to traditional 2D representations. Currently, extensive person-specific data capturing and 3D artists are required to create photorealistic avatars of existing people. Determining the 3D pose and articulation of an avatar from 2D images requires complex algorithms, a capability commonly found in the Visual Effects (VFX) industry but not readily available elsewhere. Hence, this study proposes an approach to generate 3D avatar from a 2D image of a person with uncanny resemblance and an accurate depiction of the subject’s likeness. The proposed approach, PIFu+CycleGAN, combines Pixel-aligned Implicit Function (PIFu) and cycleGAN for textured avatar construction. PIFu is specifically used to capture intricate details and arbitrary topology. Additionally, the hourglass architecture-based module is utilized for T-pose estimation for predicting the initial geometry and shape. Evaluating the proposed approach on the benchmark RenderPeople dataset, it outperforms the state-of-the-art models with values of 1.53 and 1.50 for the Chamfer and P2S distance, respectively. This indicates the creation of high-quality 3D meshes with promising textures, which are of exceptional quality and suitable for animation.

Radiotherapy commonly utilizes CBCT for patient positioning and treatment monitoring. CBCT is deemed to be secure for patients, making it suitable for the delivery of fractional doses. However, limitations such as a narrow field of view, beam hardening, scattered radiation artifacts, and variability in pixel intensity hinder the direct use of raw CBCT for dose recalculation during treatment. To address this issue, reliable correction techniques are necessary to remove artifacts and remap pixel intensity into HU values. This study proposes a deep-learning framework for calibrating CBCT images acquired with narrow FOV systems and demonstrates its potential use in proton treatment planning updates. Cycle-consistent GAN processes raw CBCT to reduce scatter and remap HU. Monte Carlo simulation is used to generate CBCT scans, enabling the possibility to focus solely on the algorithm’s ability to reduce artifacts and cupping effects without considering intra-patient longitudinal variability and producing a fair comparison between planning CT and calibrated CBCT dosimetry. To showcase the viability of the approach using real-world data, experiments were also conducted using real CBCT. Tests were performed on a publicly available dataset of 40 patients who received ablative radiation therapy for pancreatic cancer. The simulated CBCT calibration led to a difference in proton dosimetry of less than 2%, compared to the planning CT. The potential toxicity effect on the organs at risk decreased from about 50% (uncalibrated) up the 2% (calibrated). The gamma pass rate at 3%/2mm produced an improvement of about 37% in replicating the prescribed dose before and after calibration (53.78% vs 90.26%). Real data also confirmed this with slightly inferior performances for the same criteria (65.36% vs 87.20%). These results may confirm that generative artificial intelligence brings the use of narrow FOV CBCT scans incrementally closer to clinical translation in proton therapy planning updates.