Chang Ming Charlie Ma, PhD

To physically model the presence of CT/MR-compatible vaginal applicators in HDR dose calculations and accurately quantify the heterogeneity effects on main DVH parameters (D90, D100, V100, and V150).

Adaptive radiotherapy (ART) is designed to improve target coverage and normal tissue sparing compared with non-ART treatment. While in prostate SBRT differences between adaptive and non-adaptive plans are often modest, certain fractions exhibit clinically sig...

To understand underlying differences in beam modeling leading to occasionally falling gamma analysis criteria

Single-isocenter SBRT enables efficient treatment of multiple liver metastases but limits mitigation of rotational error. This study evaluates rotational uncertainty effects on target coverage in single-isocenter liver SBRT for patients with 5+ metastases.

Conventional sphere-packing techniques for Gamma Knife treatment plan optimization often produce less conformal dose distributions for non-spherical targets and are inefficient for dose delivery. This work investigates a dose-painting technique to improve dos...

Ethos Version 2 has several new capabilities, including high-fidelity (HF) adaptive planning, AI-based auto-segmentation, and dose calculation using HyperSight CBCT. This study evaluates these new features for online adaptive radiotherapy (ART) for prostate S...

Surface-guided radiation therapy (SGRT) uses external surface motion as a surrogate for internal target position. While strict SGRT tolerances (typically ±1mm) are common, they may still be permissive for patients with small surface excursions. In these cases...

End-expiration breath hold (EEBH) is commonly employed in GI radiotherapy to enable dose escalation while minimizing dose spillage to adjacent organs at risk. Surface-tracking systems are frequently used to support patient breath-hold stability. This study co...

Adaptive radiotherapy (ART) enables daily plan adjustment to account for anatomical changes. Given the high doses and tight margins in prostate SBRT, this study quantifies intrafractional prostate motion and its implications in the PTV margins.

Organ at risk dose limits as a function of varying fractionation scheme are conveniently given in the well-known “Timmerman tables”. Application of these limits in the re-treatment environment using the LQ approach (EQD2) can lead to overestimation of availab...

5-aminolevulinic acid (5-ALA)-mediated radiodynamic therapy (RDT), which integrates principles of radiotherapy and photodynamic therapy, exploits the effective tumoricidal capabilities of x-ray irradiation and the activation of protoporphyrin IX (PpIX) metabo...