» Articles » PMID: 33458289

An Ultrasound Based Platform for Image-guided Radiotherapy in Canine Bladder Cancer Patients

Overview
Specialty Oncology
Date 2021 Jan 18
PMID 33458289
Authors
Affiliations
Soon will be listed here.
Abstract

Background And Purpose: Ultrasound (US) is a non-invasive, non-radiographic imaging technique with high spatial and temporal resolution that can be used for localizing soft-tissue structures and tumors in real-time during radiotherapy (RT) (inter- and intra-fraction). A comprehensive approach incorporating an in-house 3D-US system within RT is presented. This system is easier to adopt into existing treatment protocols than current US based systems, with the aim of providing millimeter intra-fraction alignment errors and sensitivity to track intra-fraction bladder movement.

Materials And Methods: An in-house integrated US manipulator and platform was designed to relate the computed tomographic (CT) scanner, 3D-US and linear accelerator coordinate systems. An agar-based phantom with measured speed of sound and densities consistent with tissues surrounding the bladder was rotated (0-45°) and translated (up to 55 mm) relative to the US and CT coordinate systems to validate this device. After acquiring and integrating CT and US images into the treatment planning system, US-to-US and US-to-CT images were co-registered to re-align the phantom relative to the linear accelerator.

Results: Statistical errors from US-to-US registrations for various patient orientations ranged from 0.1 to 1.7 mm for x, y, and z translation components, and 0.0-1.1° for rotational components. Statistical errors from US-to-CT registrations were 0.3-1.2 mm for the x, y and z translational components and 0.1-2.5° for the rotational components.

Conclusions: An ultrasound-based platform was designed, constructed and tested on a CT/US tissue-equivalent phantom to track bladder displacement with a statistical uncertainty to correct and track inter- and intra-fractional displacements of the bladder during radiation treatments.

References
1.
Chadha M, Young A, Geraghty C, Masino R, Harrison L . Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation. Radiat Oncol. 2011; 6:45. PMC: 3113959. DOI: 10.1186/1748-717X-6-45. View

2.
Paul Muren L, Redpath A, Lord H, McLaren D . Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins. Radiother Oncol. 2007; 84(3):307-13. DOI: 10.1016/j.radonc.2007.06.014. View

3.
Feigenberg S, Paskalev K, McNeeley S, Horwitz E, Konski A, Wang L . Comparing computed tomography localization with daily ultrasound during image-guided radiation therapy for the treatment of prostate cancer: a prospective evaluation. J Appl Clin Med Phys. 2007; 8(3):99-110. PMC: 5722608. DOI: 10.1120/jacmp.v8i3.2268. View

4.
Nasoni R, Bowen T, Connor W, Sholes R . In vivo temperature dependence of ultrasound speed in tissue and its application to noninvasive temperature monitoring. Ultrason Imaging. 1979; 1(1):34-43. DOI: 10.1177/016173467900100103. View

5.
Fraser D, Chen Y, Poon E, Cury F, Falco T, Verhaegen F . Dosimetric consequences of misalignment and realignment in prostate 3DCRT using intramodality ultrasound image guidance. Med Phys. 2010; 37(6):2787-95. DOI: 10.1118/1.3429127. View