Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

Koutrouvelis, Panos G.; Lailas, Niko; Hendricks, Fred; Gil-Montero, Guillermo; Sehn, James; Katz, Stuart

doi:10.1016/s0167-8140(01)00372-3

Cited by 13 publications

(3 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Different approaches aimed at complete intraoperative seed localization are being investigated, including the use of echogenic seeds, 5,6 multiple fluoroscopic images, 7-10 transurethral ultrasound, 11 ultrasound vibroacoustography, 12,13 magnetic resonance imaging ͑MRI͒, 14 and computed tomography ͑CT͒. 15 Some of the modalities being investigated have demonstrated improved, but still incomplete, seed identification rates. If it is accepted that conventional postimplant CT usually serves to identify 100% of the seeds and enables complete radiation dosimetry; then this imaging modality represents the standard by which others may be com-pared.…”

Section: Introductionmentioning

confidence: 99%

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

Davis

Herman

et al. 2005

Medical Physics

View full text Add to dashboard Cite

The variation of permanent prostate brachytherapy dosimetry as a function of seed detection rates was investigated for I125 implants with seed activities commonly employed in contemporary practice. Post-implant imaging and radiation dosimetry data from nine patients who underwent PPB served as the basis of this simulation study. One-thousand random configurations of detected seeds were generated for each patient dataset using various seed detection levels from 30% to 99%. Dose parameters, including D90, were computed for each configuration and compared with the actual dosimetry data. A total of 108 000 complete sets of post-PPB dose volume statistics were computed. The results demonstrated that although the average D90 differed from the true value by less than 5% when 70% or more seeds were identified, the D90 of an individual case could deviate up to 13%. The 95% confidence interval (CI) of estimated D90 values differ by less than 5% from the actual value when 95% or more seeds are detected, or approximately a 7 Gy difference in the D90 value for a prescription dose of 144 Gy. Estimated target volume dose parameters tended to decrease with reduced seed detection rates. The most variable dose parameter was the prostate V100 in absolute scale while the urethral V100 was most variable in a relative sense. Based on this comprehensive simulation study, it is suggested that 95% or more seeds need to be localized in order to provide an accurate estimation of dose parameters for contemporary iodine 125 permanent prostate brachytherapy.

show abstract

Section: Introductionmentioning

confidence: 99%

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

Davis

Herman

et al. 2005

Medical Physics

View full text Add to dashboard Cite

show abstract

“…Very few studies evaluated the potential clinical benefit from including the SV in the CTV during LDR-BT [9,15,16]. The present study investigated the inclusion of the SV in the CTV during HDR-BT.…”

Section: Introductionmentioning

confidence: 99%

Experiences with a New High-Dose-Rate Brachytherapy (HDR-BT) Boost Technique for T3b Prostate Cancer

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Image-based treatment planning in interstitial high dose rate (HDR) brachytherapy using the modalities of computed tomography (CT) (Kovacs et al 1996, Vicini et al 1998, Kolotas et al 1999, Martinez et al 2000, Polgar et al 2000, Koutrouvelis et al 2001, magnetic resonance (MR) (Di Biase et al 2002) and ultrasound (US) (Kini et al 1999) has been around for several years, and is nowadays well established in a variety of localizations such as prostate, breast and gynaecological tumours. The use of imaging makes it possible to accurately define the target volume and the organs at risk (OAR) in three dimensions, and at the same time to determine the position of the HDR applicators relative to these structures (Milickovic et al 2000(Milickovic et al , 2001.…”

Section: Introductionmentioning

confidence: 99%

Multiobjective anatomy-based dose optimization for HDR-brachytherapy with constraint free deterministic algorithms

et al. 2002

View full text Add to dashboard Cite

In high dose rate (HDR) brachytherapy, conventional dose optimization algorithms consider multiple objectives in the form of an aggregate function that transforms the multiobjective problem into a single-objective problem. As a result, there is a loss of information on the available alternative possible solutions. This method assumes that the treatment planner exactly understands the correlation between competing objectives and knows the physical constraints. This knowledge is provided by the Pareto trade-off set obtained by single-objective optimization algorithms with a repeated optimization with different importance vectors. A mapping technique avoids non-feasible solutions with negative dwell weights and allows the use of constraint free gradient-based deterministic algorithms. We compare various such algorithms and methods which could improve their performance. This finally allows us to generate a large number of solutions in a few minutes. We use objectives expressed in terms of dose variances obtained from a few hundred sampling points in the planning target volume (PTV) and in organs at risk (OAR). We compare two- to four-dimensional Pareto fronts obtained with the deterministic algorithms and with a fast-simulated annealing algorithm. For PTV-based objectives, due to the convex objective functions, the obtained solutions are global optimal. If OARs are included, then the solutions found are also global optimal, although local minima may be present as suggested.

show abstract

Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

Cited by 13 publications

References 13 publications

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

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

Experiences with a New High-Dose-Rate Brachytherapy (HDR-BT) Boost Technique for T3b Prostate Cancer

Multiobjective anatomy-based dose optimization for HDR-brachytherapy with constraint free deterministic algorithms

Contact Info

Product

Resources

About