Project Summary
Gynecologic malignancies accounted for over 114,810 new cancer cases and approximately 35,640
deaths in 2023 in the United States. Brachytherapy has been used to treat locally advanced cervical and
endometrial cancers since the early 20th century and is now part of the standard of care. Brachytherapy involves
the precise placement of short-range radioactive sources near or in direct contact with the tumor through thin
catheters, enabling high radiation doses in the target volume with rapid fall-off to protect adjacent normal
structures. Today, high-dose-rate (HDR) brachytherapy is commonly employed along with a computer-controlled
remote afterloading system, which allows accurate control of radiation dose for each catheter by adjusting the
“dwell time.” Though computer-controlled afterloading systems are widespread, the quality of brachytherapy is
still limited by suboptimal catheter placement. Clinicians often struggle to properly deploy the catheters in the
target volume because of the deviation of the catheters from the intended path during insertion and lack of
quantitative catheter position feedback or the dosimetric consequences resulting from the current catheter
locations. Intraoperative imaging, either computed tomography (CT) or magnetic resonance (MR), potentially
provides such feedback and allows for “adaptive catheter placement,” where the clinician adjusts catheter
location until optimal dosimetry is achieved. However, adaptive catheter placement is not practical in the current
form because it requires iterative implantation and imaging; each iteration involves positioning of the patient for
imaging and catheter placement and moving of the clinician between the imaging room and the control room. To
enable adaptive catheter placement in a wide range of clinical settings, we will develop a catheter placement
manipulator system that combines (1) a state-of-the-art fiber-optic shape-sensing stylet to obtain real-time
quantitative measurement of the catheter trajectories in the patient, and (2) a teleoperated catheter placement
manipulator to shorten the turnaround time for catheter placement and evaluation, (3) a visualization framework
that provides quantitative measures of a catheter’s deviation from its intended trajectory and real-time evaluation
of the consequences to the achievable radiation dose distribution. We hypothesize that the combination of real-
time catheter trajectory digitization and quick catheter insertion will allow adaptive catheter placement, where
the catheter locations are optimized through frequent iteration of the plan-insert-check cycle with real-time
quantitative dosimetry feedback, leading to optimal radiation dose distribution. We will pursue the following
specific aims: (Aim 1) Develop a fiber-optic shape-sensing stylet for real-time catheter tracking to achieve real-
time tracking and prediction of the catheter trajectory for real-time feedback; (Aim 2) Develop a teleoperated
catheter insertion manipulator for quick catheter placement to achieve a shorter turnaround time for the frequent
plan-insert-check cycle; (Aim 3) Develop, optimize, and validate the system for teleoperated adaptive catheter
placement to test the impact of teleoperated adaptive catheter placement for optimal dose distribution.
