Examination of dosimetry accuracy as a function of seed detection rate in permanent prostate brachytherapy

Su, Yi; Davis, Brian J.; Herman, Michael; Manduca, Armando; Robb, Richard A.

doi:10.1118/1.2012789

Cited by 26 publications

(21 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this particular case, the prescribed dose was 145 Gy. are undetected or a large number of false positives are generated, the resulting dosimetry parameters will not be significantly affected [24]. In the initial simulation study, a 0.14% deviation of D90 was observed using the fusion-based technique as compared to the CT-based dosimetry.…”

Section: Discussionmentioning

confidence: 89%

Seed localization and TRUS-fluoroscopy fusion for intraoperative prostate brachytherapy dosimetry

Davis

Furutani

et al. 2007

Computer Aided Surgery

Self Cite

View full text Add to dashboard Cite

Objective: To develop and evaluate an integrated approach to intra-operative dosimetry for permanent prostate brachytherapy (PPB) by combining a fluoroscopy-based seed localization routine with a transrectal ultrasound (TRUS)-to-fluoroscopy fusion technique. Materials and Methods: Three-dimensional seed coordinates are reconstructed based on the two-dimensional seed locations identified from three fluoroscopic images acquired at different angles. A seed-based registration approach was examined in both simulation and phantom studies to register the seed locations identified from the fluoroscopic images to the TRUS images. Dose parameters were then evaluated and compared to CT-based dosimetry from a patient dataset. Results: Less than 0.2% error in the D90 value was observed using the TRUS-fluoroscopy image-fusion-based method relative to the CT-based post-implantation dosimetry. In the phantom study, an average distance of 3 mm was observed between the seeds identified from TRUS and the reconstructed seeds at registration. Isodose contours were displayed superimposed on the TRUS images. Conclusions: Promising results were observed in this preliminary study of a TRUS-fluoroscopy fusion-based brachytherapy dosimetry analysis method, suggesting that the method is highly sensitive and calculates clinically relevant dosimetry, including the prostate D90. Further validation of the method is required for eventual clinical application.

show abstract

Section: Discussionmentioning

confidence: 89%

Seed localization and TRUS-fluoroscopy fusion for intraoperative prostate brachytherapy dosimetry

Davis

Furutani

et al. 2007

Computer Aided Surgery

Self Cite

View full text Add to dashboard Cite

show abstract

“…Su et al 55 showed that in 125 I prostate implants a seed detection rate of above 95% is sufficient to achieve clinically accurate dose calculations. Our seed detection rates are above this threshold for all the patients.…”

Section: Iiic Clinical Resultsmentioning

confidence: 99%

Prostate implant reconstruction from C-arm images with motion-compensated tomosynthesis

et al. 2011

View full text Add to dashboard Cite

Purpose: Accurate localization of prostate implants from several C-arm images is necessary for ultrasound-fluoroscopy fusion and intraoperative dosimetry. The authors propose a computational motion compensation method for tomosynthesis-based reconstruction that enables 3D localization of prostate implants from C-arm images despite C-arm oscillation and sagging. Methods: Five C-arm images are captured by rotating the C-arm around its primary axis, while measuring its rotation angle using a protractor or the C-arm joint encoder. The C-arm images are processed to obtain binary seed-only images from which a volume of interest is reconstructed. The motion compensation algorithm, iteratively, compensates for 2D translational motion of the C-arm by maximizing the number of voxels that project on a seed projection in all of the images. This obviates the need for C-arm full pose tracking traditionally implemented using radio-opaque fiducials or external trackers. The proposed reconstruction method is tested in simulations, in a phantom study and on ten patient data sets. Results: In a phantom implanted with 136 dummy seeds, the seed detection rate was 100% with a localization error of 0.86 6 0.44 mm (Mean 6 STD) compared to CT. For patient data sets, a detection rate of 99.5% was achieved in approximately 1 min per patient. The reconstruction results for patient data sets were compared against an available matching-based reconstruction method and showed relative localization difference of 0.5 6 0.4 mm. Conclusions: The motion compensation method can successfully compensate for large C-arm motion without using radio-opaque fiducial or external trackers. Considering the efficacy of the algorithm, its successful reconstruction rate and low computational burden, the algorithm is feasible for clinical use.

show abstract

“…However, since this optimal coverage problem is NP-hard [14] and it requires impractical amount of time for a large number of seeds, a greedy search to minimize local costs rather than the global cost is adopted to reduce the computational burden.…”

Section: False Positive Seeds Removalmentioning

confidence: 99%

Tomosynthesis-based radioactive seed localization in prostate brachytherapy using modified distance map images

Lee

Liu

Jain

et al. 2008

2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro

View full text Add to dashboard Cite

We have developed a tomosynthesis-based radioactive seed localization method for prostate brachytherapy. In contrast to the projection image-based matching approach, our method does not involve explicit segmentation of seeds and can recover hidden seeds. Modified distance map images are computed from a limited number of x-ray projection images, and are backprojected to reconstuct a 3-D volume of interest. Candidate seed locations are extracted from the reconstructed volume and false positive seeds are eliminated by solving an optimal geometry coverage problem. The simulation results indicate that the implanted seed locations can be estimated from three or four images depending on the number of seeds if the pose of a C-arm is known. The algorithm was validated using phantom and clinical patient data.

show abstract

Examination of dosimetry accuracy as a function of seed detection rate in permanent prostate brachytherapy

Cited by 26 publications

References 38 publications

Seed localization and TRUS-fluoroscopy fusion for intraoperative prostate brachytherapy dosimetry

Seed localization and TRUS-fluoroscopy fusion for intraoperative prostate brachytherapy dosimetry

Prostate implant reconstruction from C-arm images with motion-compensated tomosynthesis

Tomosynthesis-based radioactive seed localization in prostate brachytherapy using modified distance map images

Contact Info

Product

Resources

About