The first clinical implementation of a real-time six degree of freedom target tracking system during radiation therapy based on Kilovoltage Intrafraction Monitoring (KIM)

Abstract

Purpose: We present the first clinical implementation of a real-time six-degree of freedom (6DoF) Kilovoltage Intrafraction Monitoring (KIM) system which tracks the cancer target translational and rotational motions during treatment. The method was applied to measure and correct for target motion during stereotactic body radiotherapy (SBRT) for prostate cancer. The 6 DoF KIM system has sub-millimetre accuracy and precision in all three translational axes, and less than 1° accuracy and 4° precision in all three rotational axes.

The accuracy and precision of Kilovoltage Intrafraction Monitoring (KIM) six degree-of-freedom prostate motion measurements during patient treatments

“…With the clinical introduction of a real-time six degrees-of-freedom (6DoF) tumor motion monitoring system [15], an obvious question is how accurate and precise are the translation and rotational measurements. To answer this question, we performed a quantitative analysis of the clinical accuracy and precision of the KIM six degree-of-freedom prostate motion measurements based on the in-treatment kV and MV imaging data collected from 377 fractions of 14 patients.…”

“…One technology that has been clinically implemented using a linear-accelerator gantry-mounted imaging system is kilovoltage intrafraction monitoring (KIM) [13,14],, which measures the 3D 5 tumor positions in real-time from 2D projections of the implanted fiducial markers acquired by a single kV imager based on a probability distribution function. wWith the most recent step being the clinical implementation of real-time six-degree of freedom (6DoF) target motion monitoring, in which both the target translation and rotation are being measured in real-time [15].…”

First online real‐time evaluation of motion‐induced 4D dose errors during radiotherapy delivery

“…While not utilized here, extension to nonisocentric and noncoplanar treatments, including 4 π treatments, would be straightforward by inclusion of additional time‐resolved variables, that is, couch translation and rotation and collimator rotations. Furthermore, the current motion‐including dose reconstruction can easily, and without further computational cost, be extended from translational shifts to rotations and deformations when such information is available during treatment, for example, by MR imaging or 6 degree‐of‐freedom motion monitoring by KIM or COSMIK . It is important to stress that DoseTracker works equally well for tracking and conventional nontracking treatments.…”

“…This study helps in bringing independent plan QA into the real-time era by exploiting the growing possibilities of real-time motion monitoring [3][4][5][6][7][8][9]28,[31][32][33] to follow the dose as it gradually builds up during the treatment delivery. The real-time dose reconstruction by DoseTracker provides a seamless form of QA similar to the time-consuming QA presently being used for tumor tracking in the clinic 20 and could help pave the way for broader clinical use of tumor tracking.…”

The 3D Pelvic Inclination Correction System (PICS): A universally applicable coordinate system for isovolumetric imaging measurements, tested in women with pelvic organ prolapse (POP)

“…The acceptance and utilization of a standardized method for the measurement and presentation of pelvic organ measurements is vital to improving understanding of POP and other disorders of the pelvic organs; we assume that a normogram of organ height on MR images could also help to improve the specificity of oncologic radiotherapy, including brachytherapy, or diagnosing pelvic tumor extent though this has to be proven by clinical studies (Mazeron et al, 2016; Nguyen et al, 2017). For this kind of investigation all series of images have to be in the same coordinate system.…”