» Articles » PMID: 18561681

Management of Three-dimensional Intrafraction Motion Through Real-time DMLC Tracking

Overview
Journal Med Phys
Specialty Biophysics
Date 2008 Jun 20
PMID 18561681
Citations 62
Authors
Affiliations
Soon will be listed here.
Abstract

Tumor tracking using a dynamic multileaf collimator (DMLC) represents a promising approach for intrafraction motion management in thoracic and abdominal cancer radiotherapy. In this work, we develop, empirically demonstrate, and characterize a novel 3D tracking algorithm for real-time, conformal, intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT)-based radiation delivery to targets moving in three dimensions. The algorithm obtains real-time information of target location from an independent position monitoring system and dynamically calculates MLC leaf positions to account for changes in target position. Initial studies were performed to evaluate the geometric accuracy of DMLC tracking of 3D target motion. In addition, dosimetric studies were performed on a clinical linac to evaluate the impact of real-time DMLC tracking for conformal, step-and-shoot (S-IMRT), dynamic (D-IMRT), and VMAT deliveries to a moving target. The efficiency of conformal and IMRT delivery in the presence of tracking was determined. Results show that submillimeter geometric accuracy in all three dimensions is achievable with DMLC tracking. Significant dosimetric improvements were observed in the presence of tracking for conformal and IMRT deliveries to moving targets. A gamma index evaluation with a 3%-3 mm criterion showed that deliveries without DMLC tracking exhibit between 1.7 (S-IMRT) and 4.8 (D-IMRT) times more dose points that fail the evaluation compared to corresponding deliveries with tracking. The efficiency of IMRT delivery, as measured in the lab, was observed to be significantly lower in case of tracking target motion perpendicular to MLC leaf travel compared to motion parallel to leaf travel. Nevertheless, these early results indicate that accurate, real-time DMLC tracking of 3D tumor motion is feasible and can potentially result in significant geometric and dosimetric advantages leading to more effective management of intrafraction motion.

Citing Articles

Demonstration of motion-compensated volumetric modulated arc radiotherapy on an MR-linac.

Borman P, Uijtewaal P, Snyder J, Allen B, Atienza C, Woodhead P Phys Imaging Radiat Oncol. 2025; 33:100729.

PMID: 40046572 PMC: 11880728. DOI: 10.1016/j.phro.2025.100729.


Respiration-Induced Organ Motion Compensation: A Review.

Wilcox S, Huang Z, Shah J, Yang X, Chen Y Ann Biomed Eng. 2024; 53(2):271-283.

PMID: 39384667 DOI: 10.1007/s10439-024-03630-w.


A four-dimensional dynamic conformal arc approach for real-time tumor tracking: A retrospective treatment planning study.

Yau T, Kempe J, Gaede S J Appl Clin Med Phys. 2023; 25(3):e14224.

PMID: 38146134 PMC: 10930003. DOI: 10.1002/acm2.14224.


Markerless dynamic tumor tracking (MDTT) radiotherapy using diaphragm as a surrogate for liver targets.

Rostamzadeh M, Thomas S, Camborde M, Karan T, Liu M, Ma R J Appl Clin Med Phys. 2023; 25(2):e14161.

PMID: 37789572 PMC: 10860457. DOI: 10.1002/acm2.14161.


Sequential monoscopic image-guided motion compensation in tomotherapy stereotactic body radiotherapy (SBRT) for prostate cancer.

Lu L, Chao E, Zhu T, Wang A, Lian J Med Phys. 2022; 50(1):518-528.

PMID: 36397645 PMC: 9868108. DOI: 10.1002/mp.16112.


References
1.
Seppenwoolde Y, Shirato H, Kitamura K, Shimizu S, Van Herk M, Lebesque J . Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. Int J Radiat Oncol Biol Phys. 2002; 53(4):822-34. DOI: 10.1016/s0360-3016(02)02803-1. View

2.
Yan H, Yin F, Zhu G, Ajlouni M, Kim J . The correlation evaluation of a tumor tracking system using multiple external markers. Med Phys. 2006; 33(11):4073-84. DOI: 10.1118/1.2358830. View

3.
Keall P, Vedam S, George R, Bartee C, Siebers J, Lerma F . The clinical implementation of respiratory-gated intensity-modulated radiotherapy. Med Dosim. 2006; 31(2):152-62. DOI: 10.1016/j.meddos.2005.12.002. View

4.
Court L, Dong L, Lee A, Cheung R, Bonnen M, ODaniel J . An automatic CT-guided adaptive radiation therapy technique by online modification of multileaf collimator leaf positions for prostate cancer. Int J Radiat Oncol Biol Phys. 2005; 62(1):154-63. DOI: 10.1016/j.ijrobp.2004.09.045. View

5.
Otto K . Volumetric modulated arc therapy: IMRT in a single gantry arc. Med Phys. 2008; 35(1):310-7. DOI: 10.1118/1.2818738. View