Feasibility of fully automated detection of fiducial markers implanted into the prostate using electronic portal imaging: a comparison of methods.
نویسندگان
چکیده
PURPOSE To investigate the feasibility of fully automated detection of fiducial markers implanted into the prostate using portal images acquired with an electronic portal imaging device. METHODS AND MATERIALS We have made a direct comparison of 4 different methods (2 template matching-based methods, a method incorporating attenuation and constellation analyses and a cross correlation method) that have been published in the literature for the automatic detection of fiducial markers. The cross-correlation technique requires a-priory information from the portal images, therefore the technique is not fully automated for the first treatment fraction. Images of 7 patients implanted with gold fiducial markers (8 mm in length and 1 mm in diameter) were acquired before treatment (set-up images) and during treatment (movie images) using 1MU and 15MU per image respectively. Images included: 75 anterior (AP) and 69 lateral (LAT) set-up images and 51 AP and 83 LAT movie images. Using the different methods described in the literature, marker positions were automatically identified. RESULTS The method based upon cross correlation techniques gave the highest percentage detection success rate of 99% (AP) and 83% (LAT) set-up (1MU) images. The methods gave detection success rates of less than 91% (AP) and 42% (LAT) set-up images. The amount of a-priory information used and how it affects the way the techniques are implemented, is discussed. CONCLUSIONS Fully automated marker detection in set-up images for the first treatment fraction is unachievable using these methods and that using cross-correlation is the best technique for automatic detection on subsequent radiotherapy treatment fractions.
منابع مشابه
Accuracy of the dose delivery in prostate cancer patients-using an electronic portal imaging device (EPID)
Background: To correct patient positioning errors (setup errors) during prostate cancer treatment using EPID and fiducial gold markers, to improve the accuracy of the dose delivery in these patients. Materials and Methods: Fifteen patients with localized prostate carcinoma after implantation of fiducial gold markers in their prostate gland underwent the five-field IMRT planning technique. The p...
متن کاملImage-guided prostate radiotherapy: analysis of inter- fractional setup errors
Introduction: The accuracy of the patient setup and tumor location are major factors that determine the efficacy of radiotherapy treatment planning. In the prostate radiotherapy, reproducibility of the prostate location for each treatment fraction is problematic owing to varying filling of the rectum and bladder. According to this, the aim of this study was to measure the inte...
متن کاملThe effect of Rectal Retractor, a rectal protector on rectal dose in radical prostate radiotherapy
Introduction: The close proximity of the rectum tissue to the prostate gland results in rectal toxicity during prostate radiotherapy. Rectal Retractor (RR) is a rectal displacement technique that inserts into the rectum, as a result, the lateral and dorsal part of the rectal wall push away from high dose areas. The aim of this study was to investigate the dosimetric consequence...
متن کاملPlanning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers
BACKGROUND Fiducial markers and daily electronic portal imaging (EPI) can reduce the risk of geographic miss in prostate cancer radiotherapy. The purpose of this study was to estimate CTV to PTV margin requirements, without and with the use of this image guidance strategy. METHODS 46 patients underwent placement of 3 radio-opaque fiducial markers prior to prostate RT. Daily pre-treatment EPIs...
متن کاملComparison of low‐dose, half‐rotation, cone‐beam CT with electronic portal imaging device for registration of fiducial markers during prostate radiotherapy
This study evaluated the agreement of fiducial marker localization between two modalities--an electronic portal imaging device (EPID) and cone-beam computed tomography (CBCT)--using a low-dose, half-rotation scanning protocol. Twenty-five prostate cancer patients with implanted fiducial markers were enrolled. Before each daily treatment, EPID and half-rotation CBCT images were acquired. Transla...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- International journal of radiation oncology, biology, physics
دوره 66 4 شماره
صفحات -
تاریخ انتشار 2006