Photoacoustic imaging of prostate brachytherapy seeds with transurethral light delivery

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

2014-03-01

We present a novel approach to photoacoustic imaging of prostate brachytherapy seeds utilizing an existing urinary catheter for transurethral light delivery. Two canine prostates were surgically implanted with brachyther- apy seeds under transrectal ultrasound guidance. One prostate was excised shortly after euthanasia and fixed in gelatin. The second prostate was imaged in the native tissue environment shortly after euthanasia. A urinary catheter was inserted in the urethra of each prostate. A 1-mm core diameter optical fiber coupled to a 1064 nm Nd:YAG laser was inserted into the urinary catheter. Light from the fiber was either directed mostly parallel to the fiber axis (i.e. end-fire fire) or mostly 90° to the fiber axis (i.e. side-fire fiber). An Ultrasonix SonixTouch scanner, transrectal ultrasound probe with curvilinear (BPC8-4) and linear (BPL9-5) arrays, and DAQ unit were utilized for synchronized laser light emission and photoacoustic signal acquisition. The implanted brachytherapy seeds were visualized at radial distances of 6-16 mm from the catheter. Multiple brachytherapy seeds were si- multaneously visualized with each array of the transrectal probe using both delay-and-sum (DAS) and short-lag spatial coherence (SLSC) beamforming. This work is the first to demonstrate the feasibility of photoacoustic imaging of prostate brachytherapy seeds using a transurethral light delivery method.

SU-F-J-167: Use of MR for Permanent Prostate Implant Preplanning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narayana, V; McLaughlin, P; University of Michigan, Ann Arbor, MI

Purpose: To study the feasibility using MR imaging to improve target definition on ultrasound during permanent prostate implants and aid in source strength determination for treatment planning in the OR. Methods: Patients who receive permanent prostate implants undergo MR and CT imaging prior to the implant procedure to determine the volume of the prostate, bony restriction to the procedure, bladder extension, external sphincter length and neurovascular bundle. The volume of the prostate is generally used to order seeds for the procedure. In 10 patients, the MR was used as the preplanning study with the PTV defined as a 2 mmmore » expansion of the MR prostate in all directions except the posterior. Various dose volume parameters for the MR prostate and the PTV were compared to the actual preplan developed and executed in the OR. In addition, there parameters were compared to the post implant dosimetry performed 3 weeks after the implant procedure. Results: The results show that the number of seeds used using MR and US (ultrasound) planning was generally with 2 seeds and the maximum difference was 7 seeds. There is no significant difference between any of the dose index parameters of V100, V150, V200, D99 and D90 parameters between MR planning, US planning and postimplant evaluation There was a significant difference between planned D99 (avg of 105%) and achieved D99 (avg 91%). Conclusion: MR imaging is an invaluable tool to improve target definition for permanent prostate implants. Use of MR images for preplanning improves the confidence with which source can be ordered for the procedure that is OR planned. Ordering a maximum of 10 seeds more than planned would be sufficient to deliver a plan in the OR using US. Moving ahead to non-rigid registration between MR ad US images could further increase the confidence level of MR planning.« less

SU-E-J-166: Sensitivity of Clinically Relevant Dosimetric Parameters to Contouring Uncertainty During Post Implant Dosimetry of Prostate Permanent Seed Implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mashouf, S; University of Toronto, Dept. of Radiation Oncology, Toronto, ON; Ravi, A

Purpose: There is a strong evidence relating post-implant dosimetry for permanent seed prostate brachytherpy to local control rates. The delineation of the prostate on CT images, however, represents a challenge as it is difficult to confidently identify the prostate borders from soft tissue surrounding it. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to prostate contouring uncertainty. Methods: The post-implant CT images and plans for a cohort of 43 patients, who have received I–125 permanent prostate seed implant in our centre, were exported to MIM Symphony LDR brachytherapy treatment planning system (MIM Software Inc., Cleveland, OH).more » The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00mm, ±2.00mm, ±3.00mm, ±4.00mm and ±5.00mm (±0.01mm). The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: The mean value of V100 and D90 was obtained as 92.3±8.4% and 108.4±12.3% respectively (Rx=145Gy). V100 was reduced by −3.2±1.5%, −7.2±3.0%, −12.8±4.0%, −19.0±4.8%, − 25.5±5.4% for expanded contours of prostate with margins of +1mm, +2mm, +3mm, +4mm, and +5mm, respectively, while it was increased by 1.6±1.2%, 2.4±2.4%, 2.7±3.2%, 2.9±4.2%, 2.9±5.1% for the contracted contours. D90 was reduced by −6.9±3.5%, −14.5±6.1%, −23.8±7.1%, − 33.6±8.5%, −40.6±8.7% and increased by 4.1±2.6%, 6.1±5.0%, 7.2±5.7%, 8.1±7.3% and 8.1±7.3% for the same set of contours. Conclusion: Systematic expansion errors of more than 1mm may likely render a plan sub-optimal. Conversely contraction errors may Result in labeling a plan likely as optimal. The use of MRI images to contour the prostate should results in better delineation of prostate organ which increases the predictive value of post-op plans. Since observers tend to overestimate the prostate volume on CT, compared with MRI, the impact of

Moving Toward Focal Therapy in Prostate Cancer: Dual-Isotope Permanent Seed Implants as a Possible Solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Todor, Dorin A., E-mail: dtodor@mcvh-vcu.edu; Barani, Igor J.; Lin, Peck-Sun

2011-09-01

Purpose: To compare the ability of single- and dual-isotope prostate seed implants to escalate biologically effective dose (BED) to foci of disease while reducing prescription dose to the prostate. Methods and Materials: Nine plans, using {sup 125}I, {sup 103}Pd, and {sup 131}Cs alone and in combination were created retrospectively for 2 patients. Ultrasound and MRI/MRS datasets were used for treatment planning. Voxel-by-voxel BED was calculated for single- and dual-isotope plans. Equivalent uniform BED (EUBED) was used to compare plans. The MRS-positive planning target volumes (PTV{sub i}) were delineated along with PTV (prostate + 5 mm), rectum, and urethra. Single-isotope implants,more » prescribed to conventional doses, were generated to achieve good PTV coverage. The PTV{sub i} were prospectively used to generate implants using mixtures of isotopes. For mixed-radioisotope implants, we also explored the impact on EUBED of lowering prescription doses by 15%. Results: The EUBED of PTV{sub i} in the setting of primary {sup 125}I implant increased 20-66% when {sup 103}Pd and {sup 131}Cs were used compared with {sup 125}I boost. Decreasing prescription dose by 15% in mixed-isotope implants results in a potential 10% reduction in urethral EUBED with preservation of PTV coverage while still boosting PTV{sub i} (up to 80%). When radiobiologic parameters corresponding to more-aggressive disease are assigned to foci, faster-decaying isotopes used in mixed implants have the potential to preserve the equivalent biological effect of mono-isotope implants considering less-aggressive disease distributed in the entire prostate. Conclusions: This is a hypothesis-generating study proposing a treatment paradigm that could be the middle ground between whole-gland irradiation and focal-only treatment. The use of two isotopes concurrent with decreasing the minimal peripheral dose is shown to increase EUBED of selected subvolumes while preserving the therapeutic effect at the level

SU-E-T-301: Dosimetric Comparison Between Adaptive and Rectilinear Template-Based Prostate Seed Implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugar, E Neubauer; Buzurovic, I; O’Farrell, D

2015-06-15

Purpose: To compare the dosimetry of a standard rectilinear and an adaptive technique used in I125 prostate seed implants. Methods: To achieve favorable dosimetry in prostate implants we used adaptive needle updates to match actual positions in real-time. The seed locations were optimized based on actual needle locations. The seeds were delivered automatically with a robotic device seedSelectron™ (Elekta Brachytherapy). In this study, we evaluated the former approach against the standard rectilinear technique in which the needles have a parallel distribution. The treatment plans for 10 patients were analyzed. For comparison, the actual treatment plans were revised so each needlemore » was repositioned to its original parallel location through the template. The analysis was performed by comparing the target coverage and dose to the organs at risk. The comparison was done using the following planning goals: the target D90> 90%, V100% > 90%, V50% <70% and V200% <30%; the urethra V125% < 1cm3 and V150%= 0cm3; and the Rectum V100%<1cm3 and V69% < 8cm3. The prescription dose to the target was 145Gy. Results: The average target volume and number of seeds were 44.39cm3(SD=11.14) and 74(SD=12), respectively. The D90 for adaptive and rectilinear plans was 159.9Gy(SD=2.99) and 155.53Gy(SD=4.04) resulting in a 2.74% difference for the average target coverage. A similar difference (1.75%) was noticed in the target V100[%]. No significant difference was noticed in the dose to the urethra and rectum. All planning goals were met with both the adaptive and rectilinear approach for each plan. Conclusion: The study reveals enhanced coverage of the target when using the adaptive needle adjustments as compared to the rectilinear approach for the analyzed cases. However, the differences in dosimetry did not translate to meaningful clinical outcomes.« less

Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

PubMed

Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

2012-03-01

The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (prostate contour, cold spots (<95% prescription dose) of the order of 20 mm(3) were observed. D(90) proved insensitive to the presence of FM for the cases selected. There is a major local impact of FM present in LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions

Automated seed localization from CT datasets of the prostate.

PubMed

Brinkmann, D H; Kline, R W

1998-09-01

With the increasing utilization of permanent brachytherapy implants for treating carcinoma of the prostate, the importance of accurate post-treatment dose calculation also increases for assessing patient outcome and planning future treatments. An automatic method for seed localization of permanent brachytherapy implants, using CT datasets of the prostate, has been developed and tested on a phantom using an actual patient planned seed distribution. This method was also compared to results with the three-film technique for three patient datasets. The automatic method is as accurate or more accurate than the three film technique for 1 mm, 3 mm, and 5 mm contiguous CT slices, and eliminates the inter- and intra-observer variability of the manual methods. The automated method improves the localization of brachytherapy seeds while reducing the time required for the user to input information, and is demonstrated to be less operator dependent, less time consuming, and potentially more accurate than the three-film technique.

Comparison of intraoperative dosimetric implant representation with postimplant dosimetry in patients receiving prostate brachytherapy.

PubMed

Stone, Nelson N; Hong, Suzanne; Lo, Yeh-Chi; Howard, Victor; Stock, Richard G

2003-01-01

To compare the results of intraoperative dosimetry with those of CT-based postimplant dosimetry in patients undergoing prostate seed implantation. Seventy-seven patients with T1-T3 prostate cancer received an ultrasound-guided permanent seed implant (36 received (125)I, 7 (103)Pd, and 34 a partial (103)Pd implant plus external beam radiation therapy). The implantation was augmented with an intraoperative dosimetric planning system. After the peripheral needles were placed, 5-mm axial images were acquired into the treatment planning system. Soft tissue structures (prostate, urethra, and rectum) were contoured, and exact needle positions were registered. Seeds were placed with an applicator, and their positions were entered into the planning system. The dose distributions for the implant were calculated after interior needle and seed placement. Postimplant dosimetry was performed 1 month later on the basis of CT imaging. Prostate and urethral doses were compared, by using paired t tests, for the real-time dosimetry in the operating room (OR) and the postimplant dosimetry. The mean preimplant prostate volume was 39.8 cm(3), the postneedle planning volume was 41.5 cm(3) (p<0.001), and the 1-month CT volume was 43.6 cm(3) (p<0.001). The mean difference between the OR dose received by 90% of the prostate (D(90)) and the CT D(90) was 3.4% (95% confidence interval, 2.5-6.6%; p=0.034). The mean dose to 30% of the urethra was 120% of prescription in the OR and 138% on CT. The mean difference was 18% (95% confidence interval, 13-24%; p<0.001). Although small differences exist between the OR and CT dosimetry results, these data suggest that this intraoperative implant dosimetric representation system provides a close match to the actual delivered doses. These data support the use of this system to modify the implant during surgery to achieve more consistent dosimetry results.

Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy.

PubMed

Benzaquen, David; Delouya, Guila; Ménard, Cynthia; Barkati, Maroie; Taussky, Daniel

In prostate seed brachytherapy, a D 90 of <130 Gy is an accepted predictive factor for biochemical failure (BF). We studied whether there is a subpopulation that does not need additional treatment after a suboptimal permanent seed brachytherapy implantation. A total of 486 patients who had either BF or a minimum followup of 48 months without BF were identified. BF was defined according to the Phoenix definition (nadir prostate-specific antigen + 2). Univariate and multivariate analyses were performed, adjusting for known prognostic factors such as D 90 and prostate-specific antigen density (PSAD) of ≥0.15 ng/mL/cm 3 , to evaluate their ability to predict BF. Median followup for patients without BF was 72 months (interquartile range 56-96). BF-free recurrence rate at 5 years was 95% and at 8 years 88%. In univariate analysis, PSAD and cancer of the prostate risk assessment score were predictive of BF. On multivariate analysis, none of the factors remained significant. The best prognosis had patients with a low PSAD (<0.15 ng/mL/cm 3 ) and an optimal implant at 30 days after implantation (as defined by D 90  ≥ 130 Gy) compared to patients with both factors unfavorable (p = 0.006). A favorable PSAD was associate with a good prognosis, independently of the D 90 (<130 Gy vs. ≥130 Gy, p = 0.7). Patients with a PSAD of <0.15 ng/mL/cm 3 have little risk of BF, even in the case of a suboptimal implant. These results need to be validated in other patients' cohorts. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Real-time photoacoustic imaging of prostate brachytherapy seeds using a clinical ultrasound system.

PubMed

Kuo, Nathanael; Kang, Hyun Jae; Song, Danny Y; Kang, Jin U; Boctor, Emad M

2012-06-01

Prostate brachytherapy is a popular prostate cancer treatment option that involves the permanent implantation of radioactive seeds into the prostate. However, contemporary brachytherapy procedure is limited by the lack of an imaging system that can provide real-time seed-position feedback. While many other imaging systems have been proposed, photoacoustic imaging has emerged as a potential ideal modality to address this need, since it could easily be incorporated into the current ultrasound system used in the operating room. We present such a photoacoustic imaging system built around a clinical ultrasound system to achieve the task of visualizing and localizing seeds. We performed several experiments to analyze the effects of various parameters on the appearance of brachytherapy seeds in photoacoustic images. We also imaged multiple seeds in an ex vivo dog prostate phantom to demonstrate the possibility of using this system in a clinical setting. Although still in its infancy, these initial results of a photoacoustic imaging system for the application of prostate brachytherapy seed localization are highly promising.

Prostate brachytherapy

MedlinePlus

Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... CT scan to plan and then place the seeds that deliver radiation into your prostate. The seeds ...

Prostate Brachytherapy Seed Reconstruction with Gaussian Blurring and Optimal Coverage Cost

PubMed Central

Lee, Junghoon; Liu, Xiaofeng; Jain, Ameet K.; Song, Danny Y.; Burdette, E. Clif; Prince, Jerry L.; Fichtinger, Gabor

2009-01-01

Intraoperative dosimetry in prostate brachytherapy requires localization of the implanted radioactive seeds. A tomosynthesis-based seed reconstruction method is proposed. A three-dimensional volume is reconstructed from Gaussian-blurred projection images and candidate seed locations are computed from the reconstructed volume. A false positive seed removal process, formulated as an optimal coverage problem, iteratively removes “ghost” seeds that are created by tomosynthesis reconstruction. In an effort to minimize pose errors that are common in conventional C-arms, initial pose parameter estimates are iteratively corrected by using the detected candidate seeds as fiducials, which automatically “focuses” the collected images and improves successive reconstructed volumes. Simulation results imply that the implanted seed locations can be estimated with a detection rate of ≥ 97.9% and ≥ 99.3% from three and four images, respectively, when the C-arm is calibrated and the pose of the C-arm is known. The algorithm was also validated on phantom data sets successfully localizing the implanted seeds from four or five images. In a Phase-1 clinical trial, we were able to localize the implanted seeds from five intraoperative fluoroscopy images with 98.8% (STD=1.6) overall detection rate. PMID:19605321

Feasibility of vibro-acoustography with a quasi-2D ultrasound array transducer for detection and localizing of permanent prostate brachytherapy seeds: A pilot ex vivo study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehrmohammadi, Mohammad; Kinnick, Randall R.; Fatemi, Mostafa, E-mail: fatemi.mostafa@mayo.edu

2014-09-15

Purpose: Effective permanent prostate brachytherapy (PPB) requires precise placement of radioactive seeds in and around the prostate. The impetus for this research is to examine a new ultrasound-based imaging modality, vibro-acoustography (VA), which may serve to provide a high rate of PPB seed detection while also effecting enhanced prostate imaging. The authors investigate the ability of VA, implemented on a clinical ultrasound (US) scanner and equipped with a quasi-2D (Q2D) array US transducer, to detect and localize PPB seeds in excised prostate specimens. Methods: Nonradioactive brachytherapy seeds were implanted into four excised cadaver prostates. A clinical US scanner equipped withmore » a Q2D array US transducer was customized to acquire both US and C-scan VA images at various depths. The VA images were then used to detect and localize the implanted seeds in prostate tissue. To validate the VA results, computed tomography (CT) images of the same tissue samples were obtained to serve as the reference by which to evaluate the performance of VA in PPB seed detection. Results: The results indicate that VA is capable of accurately identifying the presence and distribution of PPB seeds with a high imaging contrast. Moreover, a large ratio of the PPB seeds implanted into prostate tissue samples could be detected through acquired VA images. Using CT-based seed identification as the standard, VA was capable of detecting 74%–92% of the implanted seeds. Additionally, the angular independency of VA in detecting PPB seeds was demonstrated through a well-controlled phantom experiment. Conclusions: Q2DVA detected a substantial portion of the seeds by using a 2D array US transducer in excised prostate tissue specimens. While VA has inherent advantages associated with conventional US imaging, it has the additional advantage of permitting detection of PPB seeds independent of their orientation. These results suggest the potential of VA as a method for PPB imaging that

Feasibility of vibro-acoustography with a quasi-2D ultrasound array transducer for detection and localizing of permanent prostate brachytherapy seeds: A pilot ex vivo study

PubMed Central

Mehrmohammadi, Mohammad; Alizad, Azra; Kinnick, Randall R.; Davis, Brian J.; Fatemi, Mostafa

2014-01-01

Purpose: Effective permanent prostate brachytherapy (PPB) requires precise placement of radioactive seeds in and around the prostate. The impetus for this research is to examine a new ultrasound-based imaging modality, vibro-acoustography (VA), which may serve to provide a high rate of PPB seed detection while also effecting enhanced prostate imaging. The authors investigate the ability of VA, implemented on a clinical ultrasound (US) scanner and equipped with a quasi-2D (Q2D) array US transducer, to detect and localize PPB seeds in excised prostate specimens. Methods: Nonradioactive brachytherapy seeds were implanted into four excised cadaver prostates. A clinical US scanner equipped with a Q2D array US transducer was customized to acquire both US and C-scan VA images at various depths. The VA images were then used to detect and localize the implanted seeds in prostate tissue. To validate the VA results, computed tomography (CT) images of the same tissue samples were obtained to serve as the reference by which to evaluate the performance of VA in PPB seed detection. Results: The results indicate that VA is capable of accurately identifying the presence and distribution of PPB seeds with a high imaging contrast. Moreover, a large ratio of the PPB seeds implanted into prostate tissue samples could be detected through acquired VA images. Using CT-based seed identification as the standard, VA was capable of detecting 74%–92% of the implanted seeds. Additionally, the angular independency of VA in detecting PPB seeds was demonstrated through a well-controlled phantom experiment. Conclusions: Q2DVA detected a substantial portion of the seeds by using a 2D array US transducer in excised prostate tissue specimens. While VA has inherent advantages associated with conventional US imaging, it has the additional advantage of permitting detection of PPB seeds independent of their orientation. These results suggest the potential of VA as a method for PPB imaging that

Optimal matching for prostate brachytherapy seed localization with dimension reduction.

PubMed

Lee, Junghoon; Labat, Christian; Jain, Ameet K; Song, Danny Y; Burdette, Everette C; Fichtinger, Gabor; Prince, Jerry L

2009-01-01

In prostate brachytherapy, x-ray fluoroscopy has been used for intra-operative dosimetry to provide qualitative assessment of implant quality. More recent developments have made possible 3D localization of the implanted radioactive seeds. This is usually modeled as an assignment problem and solved by resolving the correspondence of seeds. It is, however, NP-hard, and the problem is even harder in practice due to the significant number of hidden seeds. In this paper, we propose an algorithm that can find an optimal solution from multiple projection images with hidden seeds. It solves an equivalent problem with reduced dimensional complexity, thus allowing us to find an optimal solution in polynomial time. Simulation results show the robustness of the algorithm. It was validated on 5 phantom and 18 patient datasets, successfully localizing the seeds with detection rate of > or = 97.6% and reconstruction error of < or = 1.2 mm. This is considered to be clinically excellent performance.

BrachyView: Combining LDR seed positions with transrectal ultrasound imaging in a prostate gel phantom.

PubMed

Alnaghy, S; Cutajar, D L; Bucci, J A; Enari, K; Safavi-Naeini, M; Favoino, M; Tartaglia, M; Carriero, F; Jakubek, J; Pospisil, S; Lerch, M; Rosenfeld, A B; Petasecca, M

2017-02-01

BrachyView is a novel in-body imaging system which aims to provide LDR brachytherapy seeds position reconstruction within the prostate in real-time. The first prototype is presented in this study: the probe consists of a gamma camera featuring three single cone pinhole collimators embedded in a tungsten tube, above three, high resolution pixelated detectors (Timepix). The prostate was imaged with a TRUS system using a sagittal crystal with a 2.5mm slice thickness. Eleven needles containing a total of thirty 0.508U 125 I seeds were implanted under ultrasound guidance. A CT scan was used to localise the seed positions, as well as provide a reference when performing the image co-registration between the BrachyView coordinate system and the TRUS coordinate system. An in-house visualisation software interface was developed to provide a quantitative 3D reconstructed prostate based on the TRUS images and co-registered with the LDR seeds in situ. A rigid body image registration was performed between the BrachyView and TRUS systems, with the BrachyView and CT-derived source locations compared. The reconstructed seed positions determined by the BrachyView probe showed a maximum discrepancy of 1.78mm, with 75% of the seeds reconstructed within 1mm of their nominal location. An accurate co-registration between the BrachyView and TRUS coordinate system was established. The BrachyView system has shown its ability to reconstruct all implanted LDR seeds within a tissue equivalent prostate gel phantom, providing both anatomical and seed position information in a single interface. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Edema and Seed Displacements Affect Intraoperative Permanent Prostate Brachytherapy Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westendorp, Hendrik, E-mail: r.westendorp@radiotherapiegroep.nl; Nuver, Tonnis T.; Department of Radiation Oncology, Radiotherapiegroep Behandellocatie Deventer, Deventer

Purpose: We sought to identify the intraoperative displacement patterns of seeds and to evaluate the correlation of intraoperative dosimetry with day 30 for permanent prostate brachytherapy. Methods and Materials: We analyzed the data from 699 patients. Intraoperative dosimetry was acquired using transrectal ultrasonography (TRUS) and C-arm cone beam computed tomography (CBCT). Intraoperative dosimetry (minimal dose to 40%-95% of the volume [D{sub 40}-D{sub 95}]) was compared with the day 30 dosimetry for both modalities. An additional edema-compensating comparison was performed for D{sub 90}. Stranded seeds were linked between TRUS and CBCT using an automatic and fast linking procedure. Displacement patterns weremore » analyzed for each seed implantation location. Results: On average, an intraoperative (TRUS to CBCT) D{sub 90} decline of 10.6% ± 7.4% was observed. Intraoperative CBCT D{sub 90} showed a greater correlation (R{sup 2} = 0.33) with respect to Day 30 than did TRUS (R{sup 2} = 0.17). Compensating for edema, the correlation increased to 0.41 for CBCT and 0.38 for TRUS. The mean absolute intraoperative seed displacement was 3.9 ± 2.0 mm. The largest seed displacements were observed near the rectal wall. The central and posterior seeds showed less caudal displacement than lateral and anterior seeds. Seeds that were implanted closer to the base showed more divergence than seeds close to the apex. Conclusions: Intraoperative CBCT D{sub 90} showed a greater correlation with the day 30 dosimetry than intraoperative TRUS. Edema seemed to cause most of the systematic difference between the intraoperative and day 30 dosimetry. Seeds near the rectal wall showed the most displacement, comparing TRUS and CBCT, probably because of TRUS probe–induced prostate deformation.« less

WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, S; Song, D; Lee, J

Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed bymore » geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of

Defining the rectal dose constraint for permanent radioactive seed implantation of the prostate.

PubMed

Albert, Michele; Song, Jun S; Schultz, Delray; Cormack, Robert A; Tempany, Clare M; Haker, Steve; Devlin, Phillip M; Beard, Clair; Hurwitz, Mark D; Suh, Wonsuk W; Jolesz, Ferenc; D'Amico, Anthony V

2008-01-01

This study was performed to define the rectal dose constraint that would predict late rectal bleeding requiring argon plasma coagulation (APC) following prostate brachy mono-therapy. Between February 1999 and April 2002, 91 patients with low risk prostate cancer underwent permanent I(125) radioactive seed implantation without the use of supplemental external beam radiation or androgen suppression therapy. Patients received both CT and MRI scans 6 weeks postimplant for evaluation of dosimetry. The CT and MRI scans were fused. Rectal volumes were contoured on the T2 weighted MR images. For those patients requiring APC, the date on which a patient reported rectal bleeding was recorded. A Cox regression analysis was performed to assess whether there was a significant association between the rectal volume (continuous) exceeding 100 Gy time rectal bleeding. Comparisons of estimates of rectal bleeding requiring APC were made using a 2-sided log rank test. There was a significant association (hazard ratio = 5.6 [95% confidence interval: 1.3, 23.8]; P = 0.002) between the rectal volume exceeding 100 Gy and rectal bleeding requiring APC. After a median follow-up of 4.25 (1-6) years, no patient with less than a median value of 8 cc of rectum exceeding 100 Gy required APC, whereas 20% (P = 0.004) were estimated to require APC within 3 years following treatment. Keeping the rectal volume receiving more than 100 Gy below 8 cc will minimize the risk of rectal bleeding requiring APC following I(125) permanent prostate brachy mono-therapy.

Real-time intraoperative evaluation of implant quality and dose correction during prostate brachytherapy consistently improves target coverage using a novel image fusion and optimization program.

PubMed

Zelefsky, Michael J; Cohen, Gilad N; Taggar, Amandeep S; Kollmeier, Marisa; McBride, Sean; Mageras, Gig; Zaider, Marco

Our purpose was to describe the process and outcome of performing postimplantation dosimetric assessment and intraoperative dose correction during prostate brachytherapy using a novel image fusion-based treatment-planning program. Twenty-six consecutive patients underwent intraoperative real-time corrections of their dose distributions at the end of their permanent seed interstitial procedures. After intraoperatively planned seeds were implanted and while the patient remained in the lithotomy position, a cone beam computed tomography scan was obtained to assess adequacy of the prescription dose coverage. The implanted seed positions were automatically segmented from the cone-beam images, fused onto a new set of acquired ultrasound images, reimported into the planning system, and recontoured. Dose distributions were recalculated based upon actual implanted seed coordinates and recontoured ultrasound images and were reviewed. If any dose deficiencies within the prostate target were identified, additional needles and seeds were added. Once an implant was deemed acceptable, the procedure was completed, and anesthesia was reversed. When the intraoperative ultrasound-based quality assurance assessment was performed after seed placement, the median volume receiving 100% of the dose (V100) was 93% (range, 74% to 98%). Before seed correction, 23% (6/26) of cases were noted to have V100 <90%. Based on this intraoperative assessment and replanning, additional seeds were placed into dose-deficient regions within the target to improve target dose distributions. Postcorrection, the median V100 was 97% (range, 93% to 99%). Following intraoperative dose corrections, all implants achieved V100 >90%. In these patients, postimplantation evaluation during the actual prostate seed implant procedure was successfully applied to determine the need for additional seeds to correct dose deficiencies before anesthesia reversal. When applied, this approach should significantly reduce

SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elzibak, A; Fatemi-Ardekani, A; Soliman, A

Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/more » TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best

SU-F-T-40: Can CBCT Images Be Used for Volume Studies of Prostate Seed Implants for Boost Treatment?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, H; Lee, S; Diwanji, T

Purpose: In our clinic, the planning CT is used for definitive and boost low-dose-rate (LDR) brachytherapy treatments to determine the ultrasound volume in the operating room (OR) at the time of the implant. While the CT overestimation of OR volume is known, a larger estimation discrepancy has been observed for boost treatments. A possible reason is the prostate size reduction during EBRT for boost patients. Since cone-beam CT (CBCT) is often used as routine imaging guidance of EBRT, this prostate volume change may be captured. This study investigates if CBCT taken during EBRT includes the volume change information and thereforemore » beats CT in estimating the prostate OR volumes. Methods: 9 prostate patients treated with EBRT (45Gy in 1.8Gy per fractions to the whole pelvis) and I-125 seed implants (108Gy) were involved in this study. During EBRT, CBCT image guidance was performed on a weekly basis. For each patient, the prostate volumes on the first and the last available CBCT images were manually contoured by a physician. These volumes were then compared to each other and with the contoured volumes from the planning CT and from the ultrasound images in the OR. Results: The first and the last CBCT images did not show significant prostate volume change. Their average +/− standard deviation of prostate volumes were 24.4cc+/−14.6cc and 29.9cc+/−16.1cc, respectively (T-test p=0.68). The ratio of the OR volume to the last CBCT (0.71+/−0.21) was not significantly different from the ratio of OR volumes to the planning CT (0.61+/−0.13) (p=0.25). Conclusion: In this study, CBCT does not show significant prostate volume changes during EBRT. CBCT and CT volumes are quite consistent and no improvement of volume estimation using CBCT is observed. The advantage of CBCT as a replacement of CT for volume study of boost LDR brachytherapy is limited.« less

Monte Carlo investigation of I-125 interseed attenuation for standard and thinner seeds in prostate brachytherapy with phantom validation using a MOSFET.

PubMed

Mason, J; Al-Qaisieh, B; Bownes, P; Henry, A; Thwaites, D

2013-03-01

In permanent seed implant prostate brachytherapy the actual dose delivered to the patient may be less than that calculated by TG-43U1 due to interseed attenuation (ISA) and differences between prostate tissue composition and water. In this study the magnitude of the ISA effect is assessed in a phantom and in clinical prostate postimplant cases. Results are compared for seed models 6711 and 9011 with 0.8 and 0.5 mm diameters, respectively. A polymethyl methacrylate (PMMA) phantom was designed to perform ISA measurements in a simple eight-seed arrangement and at the center of an implant of 36 seeds. Monte Carlo (MC) simulation and experimental measurements using a MOSFET dosimeter were used to measure dose rate and the ISA effect. MC simulations of 15 CT-based postimplant prostate treatment plans were performed to compare the clinical impact of ISA on dose to prostate, urethra, rectum, and the volume enclosed by the 100% isodose, for 6711 and 9011 seed models. In the phantom, ISA reduced the dose rate at the MOSFET position by 8.6%-18.3% (6711) and 7.8%-16.7% (9011) depending on the measurement configuration. MOSFET measured dose rates agreed with MC simulation predictions within the MOSFET measurement uncertainty, which ranged from 5.5% to 7.2% depending on the measurement configuration (k = 1, for the mean of four measurements). For 15 clinical implants, the mean ISA effect for 6711 was to reduce prostate D90 by 4.2 Gy (3%), prostate V100 by 0.5 cc (1.4%), urethra D10 by 11.3 Gy (4.4%), rectal D2cc by 5.5 Gy (4.6%), and the 100% isodose volume by 2.3 cc. For the 9011 seed the mean ISA effect reduced prostate D90 by 2.2 Gy (1.6%), prostate V100 by 0.3 cc (0.7%), urethra D10 by 8.0 Gy (3.2%), rectal D2cc by 3.1 Gy (2.7%), and the 100% isodose volume by 1.2 cc. Differences between the MC simulation and TG-43U1 consensus data for the 6711 seed model had a similar impact, reducing mean prostate D90 by 6 Gy (4.2%) and V100 by 0.6 cc (1.8%). ISA causes the delivered dose

In vivo photoacoustic imaging of prostate brachytherapy seeds

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin; Boctor, Emad M.

2014-03-01

We conducted an approved canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. Brachytherapy seeds coated with black ink were inserted into the canine prostate using methods similar to a human procedure. A transperineal, interstitial, fiber optic light delivery method, coupled to a 1064 nm laser, was utilized to irradiate the prostate and the resulting acoustic waves were detected with a transrectal ultrasound probe. The fiber was inserted into a high dose rate (HDR) brachytherapy needle that acted as a light-diffusing sheath, enabling radial light delivery from the tip of the fiber inside the sheath. The axis of the fiber was located at a distance of 4-9 mm from the long axis of the cylindrical seeds. Ultrasound images acquired with the transrectal probe and post-operative CT images of the implanted seeds were analyzed to confirm seed locations. In vivo limitations with insufficient light delivery within the ANSI laser safety limit (100 mJ/cm2) were overcome by utilizing a short-lag spatial coherence (SLSC) beamformer, which provided average seed contrasts of 20-30 dB for energy densities ranging 8-84 mJ/cm2. The average contrast was improved by up to 20 dB with SLSC beamforming compared to conventional delay-and-sum beamforming. There was excellent agreement between photoacoustic, ultrasound, and CT images. Challenges included visualization of photoacoustic artifacts that corresponded with locations of the optical fiber and hyperechoic tissue structures.

On the use of Kodak CR film for quality assurance of needle loading in I-125 seed prostate brachytherapy.

PubMed

Fog, L S; Nicholls, R; van Doom, T

2007-09-01

Low dose rate brachytherapy using implanted I-125 seeds as a monotherapy for prostate cancer is now in use in many hospitals. In contrast to fractionated brachytherapy treatments, where the effect of incorrect positioning of the source in one treatment fraction can be diminished by correcting the position in subsequent fractions, the I-125 seed implant is permanent, making correct positioning of the seeds in the prostate essential. The seeds are inserted into the prostate using needles. Correct configuration of seeds in the needles is essential in order to deliver the planned treatment. A comparison of an autoradiograph obtained by exposing film to the seed-loaded needles with the patient treatment plan is a valuable quality assurance tool. However, the time required to sufficiently expose Kodak XOMAT V film, currently used in this department is significant. This technical note presents the use of Kodak CR film for acquisition of the radiograph. The digital radiograph can be acquired significantly faster, has superior signal-to-noise ratio and contrast and has the usual benefits of digital film, e.g. a processing time which is shorter than that required for non-digital film, the possibility of image manipulation, possibility of paper printing and electronic storage.

Nationwide Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS): first analysis on survival.

PubMed

Ito, Kazuto; Saito, Shiro; Yorozu, Atsunori; Kojima, Shinsuke; Kikuchi, Takashi; Higashide, Satoshi; Aoki, Manabu; Koga, Hirofumi; Satoh, Takefumi; Ohashi, Toshio; Nakamura, Katsumasa; Katayama, Norihisa; Tanaka, Nobumichi; Nakano, Masahiro; Shigematsu, Naoyuki; Dokiya, Takushi; Fukushima, Masanori

2018-06-22

Investigating oncological outcomes in patients registered in the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS) in terms of biochemical relapse-free survival (bRFS) by the Phoenix and the newly developed J-POPS definitions, exploration of predictive factors for bRFS, and preliminary verification of pitfalls of prostate-specific antigen (PSA) failure definitions. Between July 2005 and June 2007, 2316 clinically localized patients underwent permanent seed implantation. The primary endpoint was bRFS. One of the secondary endpoints was overall survival (OS). The median age was 69 and performance status was 0 in 99.1% of participants. The median biologically effective dose (BED) was about 180 Gy 2 . During a median follow-up of 60.0 months, 8.4 and 5.9% had PSA failure by the Phoenix and the J-POPS definitions, respectively. The 5-year bRFSs based on the Phoenix and the J-POPS definitions were 89.1 and 91.6%, respectively. The 5-year OS was 97.3%. According to multivariate analyses, only age affected bRFS based on the Phoenix definition, whereas the risk group and BED independently affected bRFS based on the J-POPS definition. A spontaneous PSA decrease was seen in 91.1% of participants after PSA failure based on the Phoenix definition alone, but in only 22.2% after PSA failure based on the J-POPS definition alone. The world's largest registration study, J-POPS, consisted of patients with longevity, and a highly quality-controlled BED resulted in excellent bRFS and OS. The high likelihood of PSA bounce by the Phoenix definition should be taken into account, especially in younger patients. NCT00534196.

Deformable registration of x-ray to MRI for post-implant dosimetry in prostate brachytherapy

NASA Astrophysics Data System (ADS)

Park, Seyoun; Song, Danny Y.; Lee, Junghoon

2016-03-01

Post-implant dosimetric assessment in prostate brachytherapy is typically performed using CT as the standard imaging modality. However, poor soft tissue contrast in CT causes significant variability in target contouring, resulting in incorrect dose calculations for organs of interest. CT-MR fusion-based approach has been advocated taking advantage of the complementary capabilities of CT (seed identification) and MRI (soft tissue visibility), and has proved to provide more accurate dosimetry calculations. However, seed segmentation in CT requires manual review, and the accuracy is limited by the reconstructed voxel resolution. In addition, CT deposits considerable amount of radiation to the patient. In this paper, we propose an X-ray and MRI based post-implant dosimetry approach. Implanted seeds are localized using three X-ray images by solving a combinatorial optimization problem, and the identified seeds are registered to MR images by an intensity-based points-to-volume registration. We pre-process the MR images using geometric and Gaussian filtering. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine transformation and local deformable registration. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. We tested our algorithm on six patient data sets, achieving registration error of (1.2+/-0.8) mm in < 30 sec. Our proposed approach has the potential to be a fast and cost-effective solution for post-implant dosimetry with equivalent accuracy as the CT-MR fusion-based approach.

CT, MR, and ultrasound image artifacts from prostate brachytherapy seed implants: The impact of seed size

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, Andrew K. H.; Basran, Parminder S.; Thomas, Steven D.

Purpose: To investigate the effects of brachytherapy seed size on the quality of x-ray computed tomography (CT), ultrasound (US), and magnetic resonance (MR) images and seed localization through comparison of the 6711 and 9011 {sup 125}I sources. Methods: For CT images, an acrylic phantom mimicking a clinical implantation plan and embedded with low contrast regions of interest (ROIs) was designed for both the 0.774 mm diameter 6711 (standard) and the 0.508 mm diameter 9011 (thin) seed models (Oncura, Inc., and GE Healthcare, Arlington Heights, IL). Image quality metrics were assessed using the standard deviation of ROIs between the seeds andmore » the contrast to noise ratio (CNR) within the low contrast ROIs. For US images, water phantoms with both single and multiseed arrangements were constructed for both seed sizes. For MR images, both seeds were implanted into a porcine gel and imaged with pelvic imaging protocols. The standard deviation of ROIs and CNR values were used as metrics of artifact quantification. Seed localization within the CT images was assessed using the automated seed finder in a commercial brachytherapy treatment planning system. The number of erroneous seed placements and the average and maximum error in seed placements were recorded as metrics of the localization accuracy. Results: With the thin seeds, CT image noise was reduced from 48.5 {+-} 0.2 to 32.0 {+-} 0.2 HU and CNR improved by a median value of 74% when compared with the standard seeds. Ultrasound image noise was measured at 50.3 {+-} 17.1 dB for the thin seed images and 50.0 {+-} 19.8 dB for the standard seed images, and artifacts directly behind the seeds were smaller and less prominent with the thin seed model. For MR images, CNR of the standard seeds reduced on average 17% when using the thin seeds for all different imaging sequences and seed orientations, but these differences are not appreciable. Automated seed localization required an average ({+-}SD) of 7.0 {+-} 3

Vibro-acoustography with 1.75D ultrasound array transducer for detection and localization of permanent prostate brachytherapy seeds: ex vivo study

NASA Astrophysics Data System (ADS)

Mehrmohammadi, Mohammad; Alizad, Azra; Kinnick, Randall R.; Davis, Brian J.; Fatemi, Mostafa

2013-03-01

Effective brachytherapy procedures require precise placement of radioactive seeds in the prostate. Currently, transrectal ultrasound (TRUS) imaging is one of the main intraoperative imaging modalities to assist physicians in placement of brachytherapy seeds. However, the seed detection rate with TRUS is poor mainly because ultrasound imaging is highly sensitive to variations in seed orientation. The purpose of this study is to investigate the abilities of a new acoustic radiation force imaging modality, vibro-acoustography (VA), equipped with a 1.75D array transducer and implemented on a customized clinical ultrasound scanner, to image and localize brachytherapy seeds in prostatic tissue. To perform experiments, excised cadaver prostate specimens were implanted with dummy brachytherapy seeds, and embedded in tissue mimicking gel to simulate the properties of the surrounding soft tissues. The samples were scanned using the VA system and the resulting VA signals were used to reconstruct VA images at several depths inside the tissue. To further evaluate the performance of VA in detecting seeds, X-ray computed tomography (CT) images of the same tissue sample, were obtained and used as a gold-standard to compare the number of seeds detected by the two methods. Our results indicate that VA is capable of imaging of brachytherapy seeds with accuracy and high contrast, and can detect a large percentage of the seeds implanted within the tissue samples.

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

PubMed Central

Dehghan, Ehsan; Moradi, Mehdi; Wen, Xu; French, Danny; Lobo, Julio; Morris, W. James; Salcudean, Septimiu E.; Fichtinger, Gabor

2011-01-01

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 ± 0.44 mm (Mean ± 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 ± 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. PMID:21992346

Detection and correction of patient movement in prostate brachytherapy seed reconstruction

NASA Astrophysics Data System (ADS)

Lam, Steve T.; Cho, Paul S.; Marks, Robert J., II; Narayanan, Sreeram

2005-05-01

Intraoperative dosimetry of prostate brachytherapy can help optimize the dose distribution and potentially improve clinical outcome. Evaluation of dose distribution during the seed implant procedure requires the knowledge of 3D seed coordinates. Fluoroscopy-based seed localization is a viable option. From three x-ray projections obtained at different gantry angles, 3D seed positions can be determined. However, when local anaesthesia is used for prostate brachytherapy, the patient movement during fluoroscopy image capture becomes a practical problem. If uncorrected, the errors introduced by patient motion between image captures would cause seed mismatches. Subsequently, the seed reconstruction algorithm would either fail to reconstruct or yield erroneous results. We have developed an algorithm that permits detection and correction of patient movement that may occur between fluoroscopy image captures. The patient movement is decomposed into translational shifts along the tabletop and rotation about an axis perpendicular to the tabletop. The property of spatial invariance of the co-planar imaging geometry is used for lateral movement correction. Cranio-caudal movement is corrected by analysing the perspective invariance along the x-ray axis. Rotation is estimated by an iterative method. The method can detect and correct for the range of patient movement commonly seen in the clinical environment. The algorithm has been implemented for routine clinical use as the preprocessing step for seed reconstruction.

Radioactive implant migration in patients treated for localized prostate cancer with interstitial brachytherapy.

PubMed

Older, R A; Synder, B; Krupski, T L; Glembocki, D J; Gillenwater, J Y

2001-05-01

In several of the initial patients undergoing brachytherapy at our institution radioactive implants were visible in the thorax on chest radiography. The clinical ramifications of this unanticipated finding were unclear. Thus, we investigated the incidence of brachytherapy seed migration to the chest and whether these seeds were associated with any clinical significance. We retrospectively reviewed the records of all patients who underwent ultrasound or computerized tomography guided brachytherapy of 103palladium seeds from March 1997 to March 1999. This list of patients on brachytherapy was then matched against the radiology computer system to determine those who had undergone chest X-ray after brachytherapy. When the radiology report was unclear regarding brachytherapy seeds, chest x-rays were reviewed by one of us (R. O.) to determine the presence and position of the seeds. Post-brachytherapy chest x-rays were available in 110 of the 183 patients. In 78 cases no brachytherapy seeds were identified. Radioactive implants were identified on chest radiography in 32 patients (29%), including 1 to 5 seeds in 20, 8, 1, 2 and 1, respectively. No patients complained of any change in pulmonary symptoms after brachytherapy. Radioactive implants migrated after brachytherapy for localized prostate cancer in 29% of the patients who underwent post-procedure radiography. There did not appear to be a pattern to the seed distribution. However, while the incidence was not negligible, no patient appeared to have any acute pulmonary symptoms. Therefore, while the migration of radioactive implants to the chest is a real phenomenon, it appears to have no adverse clinical consequences in the early post-procedure period.

Sci-Sat AM(2): Brachy-07: Tomosynthesis-based seed reconstruction in LDR prostate brachytherapy: A clinical study.

PubMed

Brunet-Benkhoucha, M; Verhaegen, F; Lassalle, S; Béliveau-Nadeau, D; Reniers, B; Donath, D; Taussky, D; Carrier, J-F

2008-07-01

To develop a tomosynthesis-based dose assessment procedure that can be performed after an I-125 prostate seed implantation, while the patient is still under anaesthesia on the treatment table. Our seed detection procedure involves the reconstruction of a volume of interest based on the backprojection of 7 seed-only binary images acquired over an angle of 60° with an isocentric imaging system. A binary seed-only volume is generated by a simple thresholding of the volume of interest. Seeds positions are extracted from this volume with a 3D connected component analysis and a statistical classifier that determines the number of seeds in each cluster of connected voxels. A graphical user interface (GUI) allows to visualize the result and to introduce corrections, if needed. A phantom and a clinical study (24 patients) were carried out to validate the technique. A phantom study demonstrated a very good localization accuracy of (0.4+/-0.4) mm when compared to CT-based reconstruction. This leads to dosimetric error on D90 and V100 of respectively 0.5% and 0.1%. In a patient study with an average of 56 seeds per implant, the automatic tomosynthesis-based reconstruction yields a detection rate of 96% of the seeds and less than 1.5% of false-positives. With the help of the GUI, the user can achieve a 100% detection rate in an average of 3 minutes. This technique would allow to identify possible underdosage and to correct it by potentially reimplanting additional seeds. A more uniform dose coverage could then be achieved in LDR prostate brachytherapy. © 2008 American Association of Physicists in Medicine.

Transperineal implantation of gold fiducial markers (gold seeds) for prostate image-guided radiation therapy: a feasible technique associated with a low risk of complications.

PubMed

Saad, Akram; Goldstein, Jeffrey; Lawrence, Yaacov Richard; Weiss, Ilana; Saad, Rasha; Spieler, Benjamin; Symon, Zvi

2015-12-01

The purpose is to describe the method, safety and efficacy of transperineal gold seed placement for image-guided radiation therapy. An ethics committee approved database was used to review records of consecutive patients from October 2008 through December 2013, who underwent transperineal implantation of three gold markers into the prostate using staged local anaesthesia and transrectal ultrasound. Seeds were counted on radiographs from CT simulation, first treatment and last treatment. Retention and use of at least three markers for kV/kV matching was considered a successful implant. A visual analogue scale (VAS) pain assessment was performed. SAS was used for data analysis. Fiducial marker placement was successful for kV/kV matching in 556/581 patients (95.7%). The procedure was aborted due to pain in two patients. Additional sedation during the procedure was required in two patients. Complications include urinary infections (2 patients, <0.5%) and transient haematuria (2 patients, <0.5%). There were no recorded calls requesting additional pain medication or delays in radiation due to complications. The number of seeds identified at simulation: 4 (2 patients), 3 (554 patients), 2 (21 patients), 1 (1 patient), 0 (1 patient). One patient with three seeds and two patients with <2 seeds had cone beam CT instead of kV/kV imaging for image guidance. No seeds were lost after simulation. The mean visual analogue pain score associated with transperineal gold seed insertion met patients' expectations (respectively 4.1 vs. 4.4 P = 0.19). Outpatient transperineal insertion of fiducials avoids the rectum, is effective, convenient, well tolerated and has few side effects.

Brachytherapy in early prostate cancer--early experience.

PubMed

Jose, B O; Bailen, J L; Albrink, F H; Steinbock, G S; Cornett, M S; Benson, D C; Schmied, W K; Medley, R N; Spanos, W J; Paris, K J; Koerner, P D; Gatenby, R A; Wilson, D L; Meyer, R

1999-01-01

Use of brachytherapy with radioactive seeds in the management of early prostate cancer is commonly used in the United States. The early experience has been reported from the prostate treatment centers in Seattle for the last 10 years. In this manuscript we are reporting our early experience of 150 radioactive seed implantations in early stage prostate cancer using either Iodine 125 or Palladium 103 seeds. The average age of the patient is 66 years and the median Gleason score is 5.4 with a median PSA of 6. A brief description of the evolution of the treatment of prostate cancer as well as the preparation for the seed implantation using the volume study with ultrasound of the prostate, pubic arch study using CT scan of the pelvis and the complete planning using the treatment planning computers are discussed. We also have described the current technique which is used in our experience based on the Seattle guidelines. We plan a follow-up report with the results of the studies with longer follow-up.

Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer.

PubMed

Yang, Ruijie; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

2016-01-01

To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D90 of 34Gy in 8.5Gy per fraction, and 145Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2Gy per fraction, EQD2) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The Dmean (EQD2) of rectum decreased 22.36Gy in HDR and 17.01Gy in LDR from 30.24Gy in VMAT, respectively. The Dmean (EQD2) of bladder decreased 6.91Gy in HDR and 2.53Gy in LDR from 13.46Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD2) was 80.26, 70.23, and 104.91Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Ruijie, E-mail: ruijyang@yahoo.com; Zhao, Nan; Liao, Anyan

To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5 mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78 Gy in 39 fractions were prescribed for PTV. For HDR andmore » LDR plans, the dose prescription was D{sub 90} of 34 Gy in 8.5 Gy per fraction, and 145 Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2 Gy per fraction, EQD{sub 2}) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The D{sub mean} (EQD{sub 2}) of rectum decreased 22.36 Gy in HDR and 17.01 Gy in LDR from 30.24 Gy in VMAT, respectively. The D{sub mean} (EQD{sub 2}) of bladder decreased 6.91 Gy in HDR and 2.53 Gy in LDR from 13.46 Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD{sub 2}) was 80.26, 70.23, and 104.91 Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.« less

Real-time computed tomography dosimetry during ultrasound-guided brachytherapy for prostate cancer.

PubMed

Kaplan, Irving D; Meskell, Paul; Oldenburg, Nicklas E; Saltzman, Brian; Kearney, Gary P; Holupka, Edward J

2006-01-01

Ultrasound-guided implantation of permanent radioactive seeds is a treatment option for localized prostate cancer. Several techniques have been described for the optimal placement of the seeds in the prostate during this procedure. Postimplantation dosimetric calculations are performed after the implant. Areas of underdosing can only be corrected with either an external beam boost or by performing a second implant. We demonstrate the feasibility of performing computed tomography (CT)-based postplanning during the ultrasound-guided implant and subsequently correcting for underdosed areas. Ultrasound-guided brachytherapy is performed on a modified CT table with general anesthesia. The postplanning CT scan is performed after the implant, while the patient is still under anesthesia. Additional seeds are implanted into "cold spots," and the resultant dosimetry confirmed with CT. Intraoperative postplanning was successfully performed. Dose-volume histograms demonstrated adequate dose coverage during the initial implant, but on detailed analysis, for some patients, areas of underdosing were observed either at the apex or the peripheral zone. Additional seeds were implanted to bring these areas to prescription dose. Intraoperative postplanning is feasible during ultrasound-guided brachytherapy for prostate cancer. Although the postimplant dose-volume histograms for all patients, before the implantation of additional seeds, were adequate according to the American Brachytherapy Society criteria, specific critical areas can be underdosed. Additional seeds can then be implanted to optimize the dosimetry and reduce the risk of underdosing areas of cancer.

Prospective study of direct radiation exposure measurements for family members living with patients with prostate (125)I seed implantation: Evidence of radiation safety.

PubMed

Hanada, Takashi; Yorozu, Atsunori; Shinya, Yukiko; Kuroiwa, Nobuko; Ohashi, Toshio; Saito, Shiro; Shigematsu, Naoyuki

2016-01-01

To broaden the current understanding of radiation exposure and risk and to provide concrete evidence of radiation safety related to (125)I seed implantation. Direct radiation exposure measurements were obtained from dosimeters provided to 25 patients who underwent (125)I seed implantation, along with their family members. The estimated lifetime exposure dose and the precaution time for holding children near the patient's chest were calculated in two study periods. During the first and second study period, the mean estimated lifetime exposure doses were, respectively, 7.61 (range: 0.45, 20.21) mSv and 6.84 (range: 0.41, 19.20) mSv for patients, and 0.19 (range: 0.02, 0.54) mSv and 0.25 (range: 0.04, 1.00) mSv for family members. The mean ratios of first and second period measurements were 1.05 (range: 0.44, 3.18) for patients and 1.82 (range: 0.21, 7.04) for family members. The corresponding absolute differences between first and second period measurements were -0.77 (range: -11.40, 7.63) mSv and 0.06 (range: -0.26, 0.79) mSv, respectively. Assuming a dose limit of 1 mSv, the precaution times for holding a child every day of the first and second periods were 250.9 (range: 71.3, 849.4) min and 275.2 (range: 75.0, 883.4) min, respectively. Assuming a dose limit of 0.5 mSv, the corresponding precaution times were 179.0 (range: 35.6, 811.5) min and 178.9 (range: 37.5, 1131.8) min, respectively. Our study demonstrated low radiation exposures to family members of patients undergoing (125)I prostate implantation. It was clear that (125)I seed implantation did not pose a threat to the safety of family members. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Seed Placement in Permanent Breast Seed Implant Brachytherapy: Are Concerns Over Accuracy Valid?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morton, Daniel, E-mail: dmorton@bccancer.bc.ca; Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia; Hilts, Michelle

Purpose: To evaluate seed placement accuracy in permanent breast seed implant brachytherapy (PBSI), to identify any systematic errors and evaluate their effect on dosimetry. Methods and Materials: Treatment plans and postimplant computed tomography scans for 20 PBSI patients were spatially registered and used to evaluate differences between planned and implanted seed positions, termed seed displacements. For each patient, the mean total and directional seed displacements were determined in both standard room coordinates and in needle coordinates relative to needle insertion angle. Seeds were labeled according to their proximity to the anatomy within the breast, to evaluate the influence of anatomicmore » regions on seed placement. Dosimetry within an evaluative target volume (seroma + 5 mm), skin, breast, and ribs was evaluated to determine the impact of seed placement on the treatment. Results: The overall mean (±SD) difference between implanted and planned positions was 9 ± 5 mm for the aggregate seed population. No significant systematic directional displacements were observed for this whole population. However, for individual patients, systematic displacements were observed, implying that intrapatient offsets occur during the procedure. Mean displacements for seeds in the different anatomic areas were not found to be significantly different from the mean for the entire seed population. However, small directional trends were observed within the anatomy, potentially indicating some bias in the delivery. Despite observed differences between the planned and implanted seed positions, the median (range) V{sub 90} for the 20 patients was 97% (66%-100%), and acceptable dosimetry was achieved for critical structures. Conclusions: No significant trends or systematic errors were observed in the placement of seeds in PBSI, including seeds implanted directly into the seroma. Recorded seed displacements may be related to intrapatient setup adjustments. Despite

SU-G-JeP1-10: Feasibility of CyberKnife Tracking Using the Previously-Implanted Permanent Brachytherapy Seed Cloud

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheung, J; Cunha, J; Sudhyadhom, A

Purpose: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. Methods: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking. CyberKnife treatment plans were generated from themore » MAR CT and regular CT (no-MAR) using spine tracking. The spine-tracking grid was centered on the bolus of seeds and resized to encompass the full seed cloud. A third plan was created from the regular CT scan, using fiducial tracking based on the 4 superficial gold seeds with identical align-center coordinates. The phantom was initially aligned using the fiducial-tracking plan. Then the MAR and no-MAR spine-tracking plans were loaded without moving the phantom. Differences in couch correction parameters were recorded in the case of perfect alignment and after the application of known rotations and translations (roll/pitch of 2 degrees; translations XYZ of 2 cm). Results: The spine tracking software was able to lock on to the bolus of seeds and provide couch corrections both in the MAR and no-MAR plans. In all cases, differences in the couch correction parameters from fiducial alignment were <0.5 mm in translations and <1 degree in rotations. Conclusion: We were able to successfully track the bolus of seeds with the spine-tracking grid in phantom experiments. For clinical applications, further investigation and developments to adapt the spine-tracking algorithm to optimize for PPI seed cloud tracking is needed to provide reliable tracking in patients. One of the authors (MD) has received

Poster - Thur Eve - 06: Comparison of an open source genetic algorithm to the commercially used IPSA for generation of seed distributions in LDR prostate brachytherapy.

PubMed

McGeachy, P; Khan, R

2012-07-01

In early stage prostate cancer, low dose rate (LDR) prostate brachytherapy is a favorable treatment modality, where small radioactive seeds are permanently implanted throughout the prostate. Treatment centres currently rely on a commercial optimization algorithm, IPSA, to generate seed distributions for treatment plans. However, commercial software does not allow the user access to the source code, thus reducing the flexibility for treatment planning and impeding any implementation of new and, perhaps, improved clinical techniques. An open source genetic algorithm (GA) has been encoded in MATLAB to generate seed distributions for a simplified prostate and urethra model. To assess the quality of the seed distributions created by the GA, both the GA and IPSA were used to generate seed distributions for two clinically relevant scenarios and the quality of the GA distributions relative to IPSA distributions and clinically accepted standards for seed distributions was investigated. The first clinically relevant scenario involved generating seed distributions for three different prostate volumes (19.2 cc, 32.4 cc, and 54.7 cc). The second scenario involved generating distributions for three separate seed activities (0.397 mCi, 0.455 mCi, and 0.5 mCi). Both GA and IPSA met the clinically accepted criteria for the two scenarios, where distributions produced by the GA were comparable to IPSA in terms of full coverage of the prostate by the prescribed dose, and minimized dose to the urethra, which passed straight through the prostate. Further, the GA offered improved reduction of high dose regions (i.e hot spots) within the planned target volume. © 2012 American Association of Physicists in Medicine.

A Prospective Quasi-Randomized Comparison of Intraoperatively Built Custom-Linked Seeds Versus Loose Seeds for Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishiyama, Hiromichi, E-mail: hishiyam@kitasato-u.ac.jp; Satoh, Takefumi; Kawakami, Shogo

Purpose: To compare dosimetric parameters, seed migration rates, operation times, and acute toxicities of intraoperatively built custom-linked (IBCL) seeds with those of loose seeds for prostate brachytherapy. Methods and Materials: Participants were 140 patients with low or intermediate prostate cancer prospectively allocated to an IBCL seed group (n=74) or a loose seed group (n=66), using quasirandomization (allocated by week of the month). All patients underwent prostate brachytherapy using an interactive plan technique. Computed tomography and plain radiography were performed the next day and 1 month after brachytherapy. The primary endpoint was detection of a 5% difference in dose to 90% ofmore » prostate volume on postimplant computed tomography 1 month after treatment. Seed migration was defined as a seed position >1 cm from the cluster of other seeds on radiography. A seed dropped into the seminal vesicle was also defined as a migrated seed. Results: Dosimetric parameters including the primary endpoint did not differ significantly between groups, but seed migration rate was significantly lower in the IBCL seed group (0%) than in the loose seed group (55%; P<.001). Mean operation time was slightly but significantly longer in the IBCL seed group (57 min) than in the loose seed group (50 min; P<.001). No significant differences in acute toxicities were seen between groups (median follow-up, 9 months). Conclusions: This prospective quasirandomized control trial showed no dosimetric differences between IBCL seed and loose seed groups. However, a strong trend toward decreased postimplant seed migration was shown in the IBCL seed group.« less

Online gamma-camera imaging of 103Pd seeds (OGIPS) for permanent breast seed implantation

NASA Astrophysics Data System (ADS)

Ravi, Ananth; Caldwell, Curtis B.; Keller, Brian M.; Reznik, Alla; Pignol, Jean-Philippe

2007-09-01

Permanent brachytherapy seed implantation is being investigated as a mode of accelerated partial breast irradiation for early stage breast cancer patients. Currently, the seeds are poorly visualized during the procedure making it difficult to perform a real-time correction of the implantation if required. The objective was to determine if a customized gamma-camera can accurately localize the seeds during implantation. Monte Carlo simulations of a CZT based gamma-camera were used to assess whether images of suitable quality could be derived by detecting the 21 keV photons emitted from 74 MBq 103Pd brachytherapy seeds. A hexagonal parallel hole collimator with a hole length of 38 mm, hole diameter of 1.2 mm and 0.2 mm septa, was modeled. The design of the gamma-camera was evaluated on a realistic model of the breast and three layers of the seed distribution (55 seeds) based on a pre-implantation CT treatment plan. The Monte Carlo simulations showed that the gamma-camera was able to localize the seeds with a maximum error of 2.0 mm, using only two views and 20 s of imaging. A gamma-camera can potentially be used as an intra-procedural image guidance system for quality assurance for permanent breast seed implantation.

Patient positioning based on a radioactive tracer implanted in patients with localized prostate cancer: a performance and safety evaluation.

PubMed

de Kruijf, Willy J M; Verstraete, Jan; Neustadter, David; Corn, Benjamin W; Hol, Sandra; Venselaar, Jack L M; Davits, Rob J; Wijsman, Bart P; Van den Bergh, Laura; Budiharto, Tom; Oyen, Raymond; Haustermans, Karin; Poortmans, Philip M P

2013-02-01

To evaluate the performance and safety of a radiation therapy positioning system (RealEye) based on tracking a radioactive marker (Tracer) implanted in patients with localized prostate cancer. We performed a single-arm multi-institutional trial in 20 patients. The iridium-192 ((192)Ir)-containing Tracer was implanted in the patient together with 4 standard gold seed fiducials. Patient prostate-related symptoms were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Computed tomography (CT) was performed for treatment planning, during treatment, and after treatment to evaluate the migration stability of the Tracer. At 5 treatment sessions, cone beam CT was performed to test the positioning accuracy of the RealEye. The Tracer was successfully implanted in all patients. No device or procedure-related adverse events occurred. Changes in IPSS scores were limited. The difference between the mean change in Tracer-fiducial distance and the mean change in fiducial-fiducial distance was -0.39 mm (95% confidence interval [CI] upper boundary, -0.22 mm). The adjusted mean difference between Tracer position according to RealEye and the Tracer position on the CBCT for all patients was 1.34 mm (95% CI upper boundary, 1.41 mm). Implantation of the Tracer is feasible and safe. Migration stability of the Tracer is good. Prostate patients can be positioned and monitored accurately by using RealEye. Copyright © 2013 Elsevier Inc. All rights reserved.

Methods for prostate stabilization during transperineal LDR brachytherapy.

PubMed

Podder, Tarun; Sherman, Jason; Rubens, Deborah; Messing, Edward; Strang, John; Ng, Wan-Sing; Yu, Yan

2008-03-21

In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

Renal Capsule Xenografting and Subcutaneous Pellet Implantation for the Evaluation of Prostate Carcinogenesis and Benign Prostatic Hyperplasia

PubMed Central

Nicholson, Tristan M.; Uchtmann, Kristen S.; Valdez, Conrad D.; Theberge, Ashleigh B.; Miralem, Tihomir; Ricke, William A.

2013-01-01

New therapies for two common prostate diseases, prostate cancer (PrCa) and benign prostatic hyperplasia (BPH), depend critically on experiments evaluating their hormonal regulation. Sex steroid hormones (notably androgens and estrogens) are important in PrCa and BPH; we probe their respective roles in inducing prostate growth and carcinogenesis in mice with experiments using compressed hormone pellets. Hormone and/or drug pellets are easily manufactured with a pellet press, and surgically implanted into the subcutaneous tissue of the male mouse host. We also describe a protocol for the evaluation of hormonal carcinogenesis by combining subcutaneous hormone pellet implantation with xenografting of prostate cell recombinants under the renal capsule of immunocompromised mice. Moreover, subcutaneous hormone pellet implantation, in combination with renal capsule xenografting of BPH tissue, is useful to better understand hormonal regulation of benign prostate growth, and to test new therapies targeting sex steroid hormone pathways. PMID:24022657

Patient Positioning Based on a Radioactive Tracer Implanted in Patients With Localized Prostate Cancer: A Performance and Safety Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruijf, Willy J.M. de, E-mail: kruijf.de.w@bvi.nl; Verstraete, Jan; Neustadter, David

2013-02-01

Purpose: To evaluate the performance and safety of a radiation therapy positioning system (RealEye) based on tracking a radioactive marker (Tracer) implanted in patients with localized prostate cancer. Methods and Materials: We performed a single-arm multi-institutional trial in 20 patients. The iridium-192 ({sup 192}Ir)-containing Tracer was implanted in the patient together with 4 standard gold seed fiducials. Patient prostate-related symptoms were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Computed tomography (CT) was performed for treatment planning, during treatment, and after treatment to evaluate the migration stability of the Tracer. At 5 treatment sessions, cone beam CT was performedmore » to test the positioning accuracy of the RealEye. Results: The Tracer was successfully implanted in all patients. No device or procedure-related adverse events occurred. Changes in IPSS scores were limited. The difference between the mean change in Tracer-fiducial distance and the mean change in fiducial-fiducial distance was -0.39 mm (95% confidence interval [CI] upper boundary, -0.22 mm). The adjusted mean difference between Tracer position according to RealEye and the Tracer position on the CBCT for all patients was 1.34 mm (95% CI upper boundary, 1.41 mm). Conclusions: Implantation of the Tracer is feasible and safe. Migration stability of the Tracer is good. Prostate patients can be positioned and monitored accurately by using RealEye.« less

Comparison of Intraoperatively Built Custom Linked Seeds Versus Loose Seed Gun Applicator Technique Using Real-Time Intraoperative Planning for Permanent Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zauls, A. Jason; Ashenafi, Michael S.; Onicescu, Georgiana

2011-11-15

Purpose: To report our dosimetric results using a novel push-button seed delivery system that constructs custom links of seeds intraoperatively. Methods and Materials: From 2005 to 2007, 43 patients underwent implantation using a gun applicator (GA), and from 2007 to 2008, 48 patientsunderwent implantation with a novel technique allowing creation of intraoperatively built custom links of seeds (IBCL). Specific endpoint analyses were prostate D90% (pD90%), rV100% > 1.3 cc, and overall time under anesthesia. Results: Final analyses included 91 patients, 43 GA and 48 IBCL. Absolute change in pD90% ({Delta}pD90%) between intraoperative and postoperative plans was evaluated. Using GA method,more » the {Delta}pD90% was -8.1Gy and -12.8Gy for I-125 and Pd-103 implants, respectively. Similarly, the IBCL technique resulted in a {Delta}pD90% of -8.7Gy and -9.8Gy for I-125 and Pd-103 implants, respectively. No statistically significant difference in {Delta}pD90% was found comparing methods. The GA method had two intraoperative and 10 postoperative rV100% >1.3 cc. For IBCL, five intraoperative and eight postoperative plans had rV100% >1.3 cc. For GA, the mean time under anesthesia was 75 min and 87 min for Pd-103 and I-125 implants, respectively. For IBCL, the mean time was 86 and 98 min for Pd-103 and I-125. There was a statistical difference between the methods when comparing mean time under anesthesia. Conclusions: Dosimetrically relevant endpoints were equivalent between the two methods. Currently, time under anesthesia is longer using the IBCL technique but has decreased over time. IBCL is a straightforward brachytherapy technique that can be implemented into clinical practice as an alternative to gun applicators.« less

Laparoscopic implantation of an artificial urinary sphincter around the prostatic urethra

PubMed Central

Chłosta, Piotr; Aboumarzouk, Omar; Bondad, Jasper; Szopiński, Tomasz; Korzelik, Ignacy; Borówka, Andrzej

2015-01-01

Objective To report the first laparoscopic periprostatic implantation of an artificial urinary sphincter (AUS) after a transurethral resection of the prostate. Background The implantation of an AUS is a standard procedure for severe urinary incontinence. In men it is usually implanted through a perineal approach, with the cuff placed around the bulbous urethra, bladder neck, or even around the prostate. Method We report a laparoscopic periprostatic implantation of an AUS after a transurethral resection of a prostate in a 72-year-old-man with incontinence. Results The operative duration was 180 min and the blood loss was 150 mL. There were no complications. After activating the AUS the patient was totally continent. Conclusion The laparoscopic periprostatic implantation of an AUS is a safe, effective and considerably less invasive procedure. PMID:26413345

MRI/TRUS data fusion for prostate brachytherapy. Preliminary results.

PubMed

Reynier, Christophe; Troccaz, Jocelyne; Fourneret, Philippe; Dusserre, André; Gay-Jeune, Cécile; Descotes, Jean-Luc; Bolla, Michel; Giraud, Jean-Yves

2004-06-01

Prostate brachytherapy involves implanting radioactive seeds (I125 for instance) permanently in the gland for the treatment of localized prostate cancers, e.g., cT1c-T2a N0 M0 with good prognostic factors. Treatment planning and seed implanting are most often based on the intensive use of transrectal ultrasound (TRUS) imaging. This is not easy because prostate visualization is difficult in this imaging modality particularly as regards the apex of the gland and from an intra- and interobserver variability standpoint. Radioactive seeds are implanted inside open interventional MR machines in some centers. Since MRI was shown to be sensitive and specific for prostate imaging whilst open MR is prohibitive for most centers and makes surgical procedures very complex, this work suggests bringing the MR virtually in the operating room with MRI/TRUS data fusion. This involves providing the physician with bi-modality images (TRUS plus MRI) intended to improve treatment planning from the data registration stage. The paper describes the method developed and implemented in the PROCUR system. Results are reported for a phantom and first series of patients. Phantom experiments helped characterize the accuracy of the process. Patient experiments have shown that using MRI data linked with TRUS data improves TRUS image segmentation especially regarding the apex and base of the prostate. This may significantly modify prostate volume definition and have an impact on treatment planning.

New transurethral system for interstitial radiation of prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumgartner, G.; Callahan, D.; McKiel, C.F. Jr.

Direct endoscopic implantation of radioactive materials for carcinoma of the prostate without an open operation was accomplished by the use of modified existing transurethral instrumentation and techniques. The closed approach seems applicable particularly to the geriatric population, which is afflicted more commonly but is frequently not treated because of concurrent diseases or because the patient had transurethral resection of the prostate as a diagnostic procedure. Eleven patients were implanted using the transurethral route. Implantations were accomplished successfully with extremely low morbidity. Along with more conventional dosimetry studies, computer tomography was used to assess the placement of seeds. The direct visualizationmore » of the method suggests a potential for greater precision of seed placement as illustrated by computer tomography. In addition, this new instrumentation and method offers a low-risk procedure for carcinoma of the prostate that can be performed on an outpatient basis for selected patients.« less

SU-E-J-181: Effect of Prostate Motion On Combined Brachytherapy and External Beam Dose Based On Daily Motion of the Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narayana, V; McLaughlin, P; University of Michigan, Ann Arbor, MI

2015-06-15

Purpose: In this study, the adequacy of target expansions on the combined external beam and implant dose was examined based on the measured daily motion of the prostate. Methods: Thirty patients received an I–125 prostate implant prescribed to dose of 90Gy. This was followed by external beam to deliver a dose of 90Gyeq (external beam equivalent) to the prostate over 25 to 30 fractions. An ideal IMRT plan was developed by optimizing the external beam dose based on the delivered implant dose. The implant dose was converted to an equivalent external beam dose using the linear quadratic model. Patients weremore » set up on the treatment table by daily orthogonal imaging and aligning the marker seeds in the prostate. Orthogonal images were obtained at the end of treatment to assess prostate intrafraction motion. Based on the observed motion of the markers between the initial and final images, 5 individual plans showing the actual dose delivered to the patient were calculated. A final true dose distribution was established based on summing the implant dose and the 5 external beam plans. Dose to the prostate, seminal vesicles, lymphnodes and normal tissues, rectal wall, urethra and lower sphincter were calculated and compared to ideal. On 18 patients who were sexually active, dose to the corpus cavernosum and internal pudendal artery was also calculated. Results: The average prostate motion in 3 orthogonal directions was less than 1 mm with a standard deviation of less than +2 mm. Dose and volume parameters showed that there was no decrease in dose to the targets and a marginal decrease in dose to in normal tissues. Conclusion: Dose delivered by seed implant moves with the prostate, decreasing the impact of intrafractions dose movement on actual dose delivered. Combined brachytherapy and external beam dose delivered to the prostate was not sensitive to prostate motion.« less

Salvage low-dose-rate 125I partial prostate brachytherapy after dose-escalated external beam radiotherapy

PubMed Central

Chang, Lynn

2014-01-01

Purpose To report outcomes on 5 patients treated with salvage partial low-dose-rate (LDR) 125-iodine (125I) permanent prostate seed brachytherapy (BT) for biopsy-proven locally persistent prostate cancer, following failure of dose-escalated external beam radiotherapy (EBRT). Material and methods A retrospective review of the Fox Chase Cancer Center prostate cancer database identified five patients treated with salvage partial LDR 125I seed implant for locally persistent disease following dose-escalated EBRT to 76-84 Gy in 2 Gy per fraction equivalent. All patients had post-EBRT biopsies confirming unilateral locally persistent prostate cancer. Pre-treatment, EBRT and BT details, as well as post-treatment characteristics were documented and assessed. Results The median follow-up post-implant was 41 months. All five patients exhibited low acute genitourinary and gastrointestinal toxicities. Increased erectile dysfunction was noted in three patients. There were no biochemical failures following salvage LDR 125I seed BT to date, with a median post-salvage PSA of 0.4 ng/mL. Conclusions In carefully selected patients with local persistence of disease, partial LDR 125I permanent prostate seed implant appears to be a feasible option for salvage local therapy with an acceptable toxicity profile. Further study is needed to determine long-term results of this approach. PMID:25337135

Intra-operative Localization of Brachytherapy Implants Using Intensity-based Registration

PubMed Central

KarimAghaloo, Z.; Abolmaesumi, P.; Ahmidi, N.; Chen, T.K.; Gobbi, D. G.; Fichtinger, G.

2010-01-01

In prostate brachytherapy, a transrectal ultrasound (TRUS) will show the prostate boundary but not all the implanted seeds, while fluoroscopy will show all the seeds clearly but not the boundary. We propose an intensity-based registration between TRUS images and the implant reconstructed from uoroscopy as a means of achieving accurate intra-operative dosimetry. The TRUS images are first filtered and compounded, and then registered to the uoroscopy model via mutual information. A training phantom was implanted with 48 seeds and imaged. Various ultrasound filtering techniques were analyzed, and the best results were achieved with the Bayesian combination of adaptive thresholding, phase congruency, and compensation for the non-uniform ultrasound beam profile in the elevation and lateral directions. The average registration error between corresponding seeds relative to the ground truth was 0.78 mm. The effect of false positives and false negatives in ultrasound were investigated by masking true seeds in the uoroscopy volume or adding false seeds. The registration error remained below 1.01 mm when the false positive rate was 31%, and 0.96 mm when the false negative rate was 31%. This fully automated method delivers excellent registration accuracy and robustness in phantom studies, and promises to demonstrate clinically adequate performance on human data as well. Keywords: Prostate brachytherapy, Ultrasound, Fluoroscopy, Registration. PMID:21152376

Effect of Gold Marker Seeds on Magnetic Resonance Spectroscopy of the Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, Murshed, E-mail: Murshed.Hossain@fccc.edu; Schirmer, Timo; Richardson, Theresa

2012-05-01

Purpose: Magnetic resonance stereoscopic imaging (MRSI) of the prostate is an emerging technique that may enhance targeting and assessment in radiotherapy. Current practices in radiotherapy invariably involve image guidance. Gold seed fiducial markers are often used to perform daily prostate localization. If MRSI is to be used in targeting prostate cancer and therapy assessment, the impact of gold seeds on MRSI must be investigated. The purpose of this study was to quantify the effects of gold seeds on the quality of MRSI data acquired in phantom experiments. Methods and Materials: A cylindrical plastic phantom with a spherical cavity 10 centimetersmore » in diameter wss filled with water solution containing choline, creatine, and citrate. A gold seed fiducial marker was put near the center of the phantom mounted on a plastic stem. Spectra were acquired at 1.5 Tesla by use of a clinical MRSI sequence. The ratios of choline + creatine to citrate (CC/Ci) were compared in the presence and absence of gold seeds. Spectra in the vicinity of the gold seed were analyzed. Results: The maximum coefficient of variation of CC/Ci induced by the gold seed was found to be 10% in phantom experiments at 1.5 T. Conclusion: MRSI can be used in prostate radiotherapy in the presence of gold seed markers. Gold seeds cause small effects (in the order of the standard deviation) on the ratio of the metabolite's CC/Ci in the phantom study done on a 1.5-T scanner. It is expected that gold seed markers will have similar negligible effect on spectra from prostate patients. The maximum of 10% of variation in CC/Ci found in the phantom study also sets a limit on the threshold accuracy of CC/Ci values for deciding whether the tissue characterized by a local spectrum is considered malignant and whether it is a candidate for local boost in radiotherapy dose.« less

Prostate volume changes during permanent seed brachytherapy: an analysis of intra-operative variations, predictive factors and clinical implication.

PubMed

Chira, Ciprian; Delouya, Guila; Larrivée, Sandra; Carrier, Jean-Francois; Taussky, Daniel

2013-07-09

To determine prostate volume (Pvol) changes at 3 different time points during the course of I¹²⁵ permanent seed brachytherapy (PB). To assess the impact of these changes on acute urinary retention (AUR) and dosimetric outcome. We analyzed 149 hormone-naïve patients. Measurements of the prostate volume were done using three-dimensional transrectal ultrasound (3D-TRUS) in the operating room before insertion of any needle (V1), after the insertion of 2 fixation needles with a harpoon (V2) and upon completion of the implant (V3). The quality of the implant was analyzed with the D90 (minimum dose in Grays received by 90% of the prostate volume) at day 30. Mean baseline prostate volume (V1) was 37.4 ± 9.6 cc. A volume increase of >5% was seen in 51% between V1-V2 (mean = 2.5 cc, p < 0.01), in 42% between V2-V3 (mean = 1.9 cc, p < 0.01) and in 71% between V1-V3 (mean = 4.5 cc, p < 0.01). Pvol changes caused by insertion of the fixation needles were not statistically different than those caused by the implant itself (p = 0.23).In multivariate linear regression analysis, baseline Pvol is predictive of Pvol changes between V2 and V1 and V3 and V1 but not between V3 and V2. The extent of prostate swelling had an influence on D90. An increase of 10% in prostate volume between V1 and V2 results in an increase of D90 at Day 30 by 11.7%. Baseline Pvol (V1) was the only predictor of the duration of urinary retention in both univariate and multivariate (p = 0.04) regression analysis. A large part of intraoperative swelling occurs already after the insertion of the fixation needles. This early prostate swelling predicts for D90 but not for AUR.

In vivo dosimetry using a linear Mosfet-array dosimeter to determine the urethra dose in 125I permanent prostate implants.

PubMed

Bloemen-van Gurp, Esther J; Murrer, Lars H P; Haanstra, Björk K C; van Gils, Francis C J M; Dekker, Andre L A J; Mijnheer, Ben J; Lambin, Philippe

2009-01-01

In vivo dosimetry during brachytherapy of the prostate with (125)I seeds is challenging because of the high dose gradients and low photon energies involved. We present the results of a study using metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to evaluate the dose in the urethra after a permanent prostate implantation procedure. Phantom measurements were made to validate the measurement technique, determine the measurement accuracy, and define action levels for clinical measurements. Patient measurements were performed with a MOSFET array in the urinary catheter immediately after the implantation procedure. A CT scan was performed, and dose values, calculated by the treatment planning system, were compared to in vivo dose values measured with MOSFET dosimeters. Corrections for temperature dependence of the MOSFET array response and photon attenuation in the catheter on the in vivo dose values are necessary. The overall uncertainty in the measurement procedure, determined in a simulation experiment, is 8.0% (1 SD). In vivo dose values were obtained for 17 patients. In the high-dose region (> 100 Gy), calculated and measured dose values agreed within 1.7% +/- 10.7% (1 SD). In the low-dose region outside the prostate (< 100 Gy), larger deviations occurred. MOSFET detectors are suitable for in vivo dosimetry during (125)I brachytherapy of prostate cancer. An action level of +/- 16% (2 SD) for detection of errors in the implantation procedure is achievable after validation of the detector system and measurement conditions.

Establishing High-Quality Prostate Brachytherapy Using a Phantom Simulator Training Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thaker, Nikhil G.; Kudchadker, Rajat J.; Swanson, David A.

2014-11-01

Purpose: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. Methods and Materials: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ({sup 125}I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parametersmore » were compared and correlated using regression analysis. Results: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. Conclusions: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB.« less

Favorable toxicity and biochemical control using real-time inverse optimization technique for prostate brachytherapy.

PubMed

Raben, Adam; Rusthoven, Kyle E; Sarkar, Abrihup; Glick, Andrew; Benge, Bruce; Jacobs, Dayee; Raben, David

2009-01-01

Favorable dosimetric results have been reported using intraoperative inverse optimization (IO) for permanent prostate brachytherapy. The clinical implications of these improvements in dosimetry are unclear. We review toxicity and early biochemical outcomes for patients implanted using IO technique. Between 2001 and 2007, 165 patients received permanent prostate implants using real-time IO and had >/=3 months of followup. Dose constraints for inverse planning were: the prostate volume receiving 100% of the prescription dose [prostate V(100)] was >95%; the dose received by 90% of the gland [prostate D(90)] was within the 140-180 by dose range; the volume of urethra receiving 150% of the prescription dose [urethra V(150)] was <30%; and the volume of rectal wall receiving 110% of the prescription dose [rectal V(110)] was <1.0 cc. Toxicity was prospectively scored using the Radiation Therapy Oncology Group toxicity scale and the International Prostate Symptom Score questionnaire. Biochemical control was determined using the nadir + 2 ng/mL definition. Mean followup was 30 months (range, 6-63 months). Risk classification was low risk in 89% and intermediate risk in 11%. Iodine-125 sources were used for 161 implants and palladium-103 sources for four implants. The median number of seeds and total activity implanted were 61 and 999 MBq, respectively, for a median prostate volume of 33.6 cc. Late GU and GI morbidity was uncommon. Among patients with at least 24 months followup, 16% had persistent Grade 2-3 urinary morbidity. Grade 2 rectal bleeding occurred in 1 patient (0.6%). Biochemical failure has occurred in only 4 patients at last followup. IO technique for prostate brachytherapy is associated with low rates of late morbidity and excellent early biochemical control. Additionally, the number of seeds and total implanted activity required to achieve a high-quality implant are lower compared with historical controls.

TU-AB-201-04: Optimizing the Number of Catheter Implants and Their Tracks for Prostate HDR Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riofrio, D; Luan, S; Zhou, J

Purpose: In prostate HDR brachytherapy, interstitial implants are placed manually on the fly. The aim for this research is to develop a computer algorithm to find optimal and reliable implant trajectories using minimal number of implants. Methods: Our new algorithm mainly uses these key ideas: (1) positive charged static particles are uniformly placed on the surface of prostate and critical structures such as urethra, bladder, and rectum. (2) Positive charged kinetic particles are placed at a cross-section of the prostate with an initial velocity parallel to the principal implant direction. (3) The kinetic particles move through the prostate, interacting withmore » each other, spreading out, while staying away from the prostate surface and critical structures. The initial velocity ensures that the trajectories observe the curvature constraints of typical implant procedures. (4) The finial trajectories of kinetic particles are smoothed using a third-degree polynomial regression, which become the implant trajectories. (5) The dwelling times and final dose distribution are calculated using least-distance programming. Results: (1) We experimented with previously treated cases. Our plan achieves all prescription goals while reducing the number of implants by 41%! Our plan also has less uniform target dose, which implies a higher dose is delivered to the prostate. (2) We expect future implant procedures will be performed under the guidance of such pre-calculated trajectories. To assess the applicability, we randomly perturb the tracks to mimic the manual implant errors. Our studies showed the impact of these perturbations are negligible, which is compensated by the least distance programming. Conclusions: We developed a new inverse planning system for prostate HDR therapy that can find optimal implant trajectories while minimizing the number of implants. For future work, we plan to integrate our new inverse planning system with an existing needle tracking system.« less

Long-Term Results of a Phase II Trial of Ultrasound-Guided Radioactive Implantation of the Prostate for Definitive Management of Localized Adenocarcinoma of the Prostate (RTOG 98-05)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawton, Colleen A., E-mail: clawton@mcw.edu; Hunt, Daniel; Lee, W. Robert

2011-09-01

Purpose: To evaluate the long-term effectiveness of transrectal ultrasound-guided permanent radioactive I{sup 125} implantation of the prostate for organ confined adenocarcinoma of the prostate compared with historical data of prostatectomy and external beam radiotherapy within a cooperative group setting. Methods and Materials: Patients accrued to this study had histologically confirmed, locally confined adenocarcinoma of the prostate clinical stage T1b, T1c, or T2a; no nodal or metastatic disease; prostate-specific antigen level of {<=}10 ng/ml; and a Gleason score of {<=}6. All patients underwent transrectal ultrasound-guided radioactive I{sup 125} seed implantation into the prostate. The prescribed dose was 145 Gy to themore » prostate planning target volume. Results: A total of 101 patients from 27 institutions were accrued to this protocol; by design, no single institution accrued more than 8 patients. There were 94 eligible patients. The median follow up was 8.1 years (range, 0.1-9.2 years). After 8 years, 8 patients had protocol-defined biochemical (prostate-specific antigen) failure (cumulative incidence, 8.0%); 5 patients had local failure (cumulative incidence, 5.5%); and 1 patient had distant failure (cumulative incidence, 1.1%; this patient also had biochemical failure and died of causes not related to prostate cancer). The 8-year overall survival rate was 88%. At last follow-up, no patient had died of prostate cancer or related toxicities. Three patients had maximum late toxicities of Grade 3, all of which were genitourinary. No Grade 4 or 5 toxicities were observed. Conclusions: The long-term results of this clinical trial have demonstrated that this kind of trial can be successfully completed through the RTOG and that results in terms of biochemical failure and toxicity compare very favorably with other brachytherapy published series as well as surgical and external beam radiotherapy series. In addition, the prospective, multicenter design

The use of nomograms in LDR-HDR prostate brachytherapy.

PubMed

Pujades, Ma Carmen; Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

2011-09-01

The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification.

Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

NASA Astrophysics Data System (ADS)

Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

2013-03-01

A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

Examining the relationship between pre- and postimplant geometry in prostate low-dose-rate brachytherapy and its correlation with dosimetric quality using the similarity concept.

PubMed

Todor, Dorin A; Anscher, Mitchell S; Karlin, Jeremy D; Hagan, Michael P

2014-01-01

This is a retrospective study in which we define multiple metrics for similarity and then inquire on the relationship between similarity and currently used dosimetric quantities describing preimplant and postimplant plans. We analyzed a unique cohort of 94 consecutively performed prostate seed implant patients, associated with excellent dosimetric and clinical outcomes. For each patient, an ultrasound (US) preimplant and two CT postimplant (Day 0 and Day 30) studies were available. Measures for similarity were created and computed using feature vectors based on two classes of moments: first, invariant to rotation and translation, and the second polar-radius moments invariant to rotation, translation, and scaling. Both similarity measures were calibrated using controlled perturbations (random and systematic) of seed positions and contours in different size implants, thus producing meaningful numerical threshold values used in the clinical analysis. An important finding is that similarity, for both seed distributions and contours, improves significantly when scaling invariance is added to translation and rotation. No correlation between seed and contours similarity was found. In the setting of preplanned prostate seed implants using preloaded needles, based on our data, similarity between preimplant and postimplant plans does not correlate with either minimum dose to 90% of the volume of the prostate or analogous similarity metrics for prostate contours. We have developed novel tools and metrics, which will allow practitioners to better understand the relationship between preimplant and postimplant plans. Geometrical similarity between a preplan and an actual implant, although useful, does not seem to be necessary to achieve minimum dose to 90% of the volume of the prostate-good dosimetric implants. Copyright © 2014 American Brachytherapy Society. All rights reserved.

I-125 seed calibration using the SeedSelectron® afterloader: a practical solution to fulfill AAPM-ESTRO recommendations

PubMed Central

Perez-Calatayud, Jose; Richart, Jose; Guirado, Damián; Pérez-García, Jordi; Rodríguez, Silvia; Santos, Manuel

2012-01-01

Purpose SeedSelectron® v1.26b (Nucletron BV, The Netherlands) is an afterloader system used in prostate interstitial permanent brachytherapy with I-125 selectSeed seeds. It contains a diode array to assay all implanted seeds. Only one or two seeds can be extracted during the surgical procedure and assayed using a well chamber to check the manufacturer air-kerma strength (SK) and to calibrate the diode array. Therefore, it is not feasible to assay 5–10% seeds as required by the AAPM-ESTRO. In this study, we present a practical solution of the SeedSelectron® users to fulfill the AAPM- ESTRO recommendations. Material and methods The method is based on: a) the SourceCheck® well ionization chamber (PTW, Germany) provided with a PTW insert; b) n = 10 selectSeed from the same batch and class as the seeds for the implant; c) the Nucletron insert to accommodate the n = 10 seeds on the SourceCheck® and to measure their averaged SK. Results for 56 implants have been studied comparing the SK value from the manufacturer with the one obtained with the n = 10 seeds using the Nucletron insert prior to the implant and with the SK of just one seed measured with the PTW insert during the implant. Results We are faced with SK deviation for individual seeds up to 7.8%. However, in the majority of cases SK is in agreement with the manufacturer value. With the method proposed using the Nucletron insert, the large deviations of SK are reduced and for 56 implants studied no deviation outside the range of the class were found. Conclusions The new Nucletron insert and the proposed procedure allow to evaluate the SK of the n = 10 seeds prior to the implant, fulfilling the AAPM-ESTRO recommendations. It has been adopted by Nucletron to be extended to seedSelectron® users under request. PMID:23346136

Dosimetric comparison between model 9011 and 6711 sources in prostate implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hualin, E-mail: zhang248@iupui.edu; Arizona Oncology Services, Phoenix, AZ; Beyer, David

2013-07-01

The purpose of this work is to evaluate the model 9011 iodine-125 ({sup 125}I) in prostate implants by comparing dosimetric coverage provided by the 6711 vs 9011 source implants. Postimplant dosimetry was performed in 18 consecutively implanted patients with prostate cancer. Two were implanted with the 9011 source and 16 with the 6711 source. For purposes of comparison, each implant was then recalculated assuming use of the other source. The same commercially available planning system was used and the specific source data for both 6711 and 9011 products were entered. The results of these calculations are compared side by sidemore » in the terms of the isodose values covering 100% (D100) and 90% (D90) of prostate volume, and the percentages of volumes of prostate, bladder, rectum, and urethra covered by 200% (V200), 150% (V150), 100% (V100), 50% (V50), and 20% (V20) of the prescribed dose as well. The 6711 source data overestimate coverage by 6.4% (ranging from 4.9% to 6.9%; median 6.6%) at D100 and by 6.6% (ranging from 6.2% to 6.8%; median 6.6%) at D90 compared with actual 9011 data. Greater discrepancies of up to 67% are seen at higher dose levels: average reduction for V100 is 2.7% (ranging from 0.6% to 7.7%; median 2.3%), for V150 is 14.6% (ranging from 6.1% to 20.5%; median 15.3%), for V200 is 14.9% (ranging from 4.8% to 19.1%; median 16%); similarly seen in bladder, rectal, and urethral coverage. This work demonstrates a clear difference in dosimetric behavior between the 9011 and 6711 sources. Using the 6711 source data for 9011 source implants would create a pronounced error in dose calculation. This study provides evidence that the 9011 source can provide the same dosimetric quality as the 6711 source, if properly used; however, the 6711 source data should not be considered as a surrogate for the 9011 source implants.« less

Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, C. D.; Kron, T.; Leahy, M.

Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set wasmore » assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.« less

SU-F-T-41: 3D MTP-TRUS for Prostate Implant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, P

Purpose: Prostate brachytherapy is an effective treatment for early prostate cancer. The current prostate implant is limited to using 2D transrectal ultrassound (TRUS) or machenical motor driven 2D array either in the end or on the side. Real-time 3D images can improve the accuracy of the guidance of prostate implant. The concept of our system is to allow realtime full visualization of the entire prostate with the multiple transverse scan. Methods: The prototype of 3D Multiple-Transverse-Plane Transrectal Ultrasound probe (MTP-TRUS) has been designed by us and manufactured by Blatek inc. It has 7 convex linear arrays and each array hasmore » 96 elements. It is connected to cQuest Fire bird research system (Cephasonics inc.) which is a flexible and configurable ultrasound-development platform. The size of cQuest Firebird system is compact and supports the real-time wireless image transferring. A relay based mux board is designed for the cQuest Firebird system to be able to connect 672 elements. Results: The center frequency of probe is 6MHz±10%. The diameter of probe is 3cm and the length is 20cm. The element pitch is 0.205 mm. Array focus is 30mm and spacing 1.6cm. The beam data for each array was measured and met our expectation. The interface board of MTP-TURS is made and able to connect to cQuest Firebird system. The image display interface is still under the development. Our real-time needle tracking algorithm will be implemented too. Conclusion: Our MTP-TRUS system for prostate implant will be able to acquire real-time 3D images of prostate and do the real-time needle segmentation and tracking. The system is compact and have wireless function.« less

Surface coating for prevention of metallic seed migration in tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hyunseok; Park, Jong In; Lee, Won Seok

Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress betweenmore » the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy.« less

Comparison of 3 different postimplant dosimetry methods following permanent {sup 125}I prostate seed brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marcu, Loredana G., E-mail: loredana@marcunet.com; Faculty of Science, University of Oradea; School of Chemistry and Physics, University of Adelaide, South Australia

2013-10-01

Postimplant dosimetry (PID) after Iodine-125 ({sup 125}I) implant of the prostate should offer a reliable qualitative assessment. So far, there is no consensus regarding the optimum PID method, though the latest literature is in favor of magnetic resonance imaging (MRI). This study aims to simultaneously compare 3 PID techniques: (1) MRI-computed tomography (CT) fusion; (2) ultrasound (US)-CT fusion; and (3) manual target delineation on CT. The study comprised 10 patients with prostate cancer. CT/MR scans with urinary catheters in place for PID were done either on day 0 or day 1 postimplantation. The main parameter evaluated and compared among methodsmore » was target D90. The results show that CT-based D90s are lower than US-CT D90s (median difference,−6.85%), whereas MR-CT PID gives higher D90 than US-CT PID (median difference, 4.25%). Manual contouring on CT images tends to overestimate the prostate volume compared with transrectal ultrasound (TRUS) (median difference, 23.33%), whereas on US images the target is overestimated compared with MR-based contouring (median difference, 13.25%). Although there are certain differences among the results given by various PID techniques, the differences are statistically insignificant for this small group of patients. Any dosimetric comparison between 2 PID techniques should also account for the limitations of each technique, to allow for an accurate quantification of data. Given that PID after permanent radioactive seed implant is mandatory for quality assurance, any imaging method–based PID (MR-CT, US-CT, and CT) available in a radiotherapy department can be indicative of the quality of the procedure.« less

The use of nomograms in LDR-HDR prostate brachytherapy

PubMed Central

Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

2011-01-01

Purpose The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. Material and methods Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. Results For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. Conclusions Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification. PMID:23346120

SU-E-J-214: MR Protocol Development to Visualize Sirius MRI Markers in Prostate Brachytherapy Patients for MR-Based Post-Implant Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, T; Wang, J; Frank, S

Purpose: The current CT-based post-implant dosimetry allows precise seed localization but limited anatomical delineation. Switching to MR-based post-implant dosimetry is confounded by imprecise seed localization. One approach is to place positive-contrast markers (Sirius) adjacent to the negative-contrast seeds. This patient study aims to assess the utility of a 3D fast spoiled gradient-recalled echo (FSPGR) sequence to visualize Sirius markers for post-implant dosimetry. Methods: MRI images were acquired in prostate implant patients (n=10) on Day 0 (day-of-implant) and Day 30. The post-implant MR protocol consisted of 3D T2-weighted fast-spin-echo (FSE), T2-weighted 2D-FSE (axial) and T1-weighted 2D-FSE (axial/sagittal/coronal). We incorporated a 3D-FSPGRmore » sequence into the post-implant MR protocol to visualize the Sirius markers. Patients were scanned with different number-of-excitations (6, 8, 10), field-of-view (10cm, 14cm, 18cm), slice thickness (1mm, 0.8mm), flip angle (14 degrees, 20 degrees), bandwidth (122.070 Hz/pixel, 325.508 Hz/pixel, 390.625 Hz/pixel), phase encoding steps (160, 192, 224, 256), frequency-encoding direction (right/left, anterior/posterior), echo-time type (minimum-full, out-of-phase), field strength (1.5T, 3T), contrast (with, without), scanner vendor (Siemens, GE), coil (endorectal-coil only, endorectal-and-torso-coil, torsocoil only), endorectal-coil filling (30cc, 50cc) and endorectal-coil filling type (air, perfluorocarbon [PFC]). For post-implant dosimetric evaluation with greater anatomical detail, 3D-FSE images were fused with 3D-FSPGR images. For comparison with CT-based post-implant dosimetry, CT images were fused with 3D-FSPGR images. Results: The 3D-FSPGR sequence facilitated visualization of markers in patients. Marker visualization helped distinguish signal voids as seeds versus needle tracks for more definitive MR-based post-implant dosimetry. On the CT-MR fused images, the distance between the seed on CT to MR

Monte Carlo study of LDR seed dosimetry with an application in a clinical brachytherapy breast implant.

PubMed

Furstoss, C; Reniers, B; Bertrand, M J; Poon, E; Carrier, J-F; Keller, B M; Pignol, J P; Beaulieu, L; Verhaegen, F

2009-05-01

A Monte Carlo (MC) study was carried out to evaluate the effects of the interseed attenuation and the tissue composition for two models of 125I low dose rate (LDR) brachytherapy seeds (Medi-Physics 6711, IBt InterSource) in a permanent breast implant. The effect of the tissue composition was investigated because the breast localization presents heterogeneities such as glandular and adipose tissue surrounded by air, lungs, and ribs. The absolute MC dose calculations were benchmarked by comparison to the absolute dose obtained from experimental results. Before modeling a clinical case of an implant in heterogeneous breast, the effects of the tissue composition and the interseed attenuation were studied in homogeneous phantoms. To investigate the tissue composition effect, the dose along the transverse axis of the two seed models were calculated and compared in different materials. For each seed model, three seeds sharing the same transverse axis were simulated to evaluate the interseed effect in water as a function of the distance from the seed. A clinical study of a permanent breast 125I implant for a single patient was carried out using four dose calculation techniques: (1) A TG-43 based calculation, (2) a full MC simulation with realistic tissues and seed models, (3) a MC simulation in water and modeled seeds, and (4) a MC simulation without modeling the seed geometry but with realistic tissues. In the latter, a phase space file corresponding to the particles emitted from the external surface of the seed is used at each seed location. The results were compared by calculating the relevant clinical metrics V85, V100, and V200 for this kind of treatment in the target. D90 and D50 were also determined to evaluate the differences in dose and compare the results to the studies published for permanent prostate seed implants in literature. The experimental results are in agreement with the MC absolute doses (within 5% for EBT Gafchromic film and within 7% for TLD-100

Effects of pumpkin seed oil and saw palmetto oil in Korean men with symptomatic benign prostatic hyperplasia.

PubMed

Hong, Heeok; Kim, Chun-Soo; Maeng, Sungho

2009-01-01

This study was to investigate the role of complementary and alternative medicine in the prevention and treatment of benign prostatic hyperplasia. For this purpose, a randomized, double-blind, placebo-controlled trial was performed over 12 months on 47 benign prostatic hyperplasia patients with average age of 53.3 years and international prostate symptom score over 8. Subjects received either sweet potato starch (group A, placebo, 320 mg/day), pumpkin seed oil (group B, 320 mg/day), saw palmetto oil (group C, 320 mg/day) or pumpkin seed oil plus saw palmetto oil (group D, each 320 mg/day). International prostate symptom score, quality of life, serum prostate specific antigen, prostate volume and maximal urinary flow rate were measured. In groups B, C and D, the international prostate symptom score were reduced by 3 months. Quality of life score was improved after 6 months in group D, while those of groups B and C were improved after 3 months, compared to the baseline value. Serum prostate specific antigen was reduced only in group D after 3 months, but no difference was observed in prostate volume in all treatment groups. Maximal urinary flow rate were gradually improved in groups B and C, with statistical significance after 6 months in group B and after 12 months in group C. None of the parameters were significantly improved by combined treatment with pumpkin seed oil and saw palmetto oil. From these results, it is suggested that administrations of pumpkin seed oil and saw palmetto oil are clinically safe and may be effective as complementary and alternative medicine treatments for benign prostatic hyperplasia.

Effects of pumpkin seed oil and saw palmetto oil in Korean men with symptomatic benign prostatic hyperplasia

PubMed Central

Hong, Heeok; Kim, Chun-Soo

2009-01-01

This study was to investigate the role of complementary and alternative medicine in the prevention and treatment of benign prostatic hyperplasia. For this purpose, a randomized, double-blind, placebo-controlled trial was performed over 12 months on 47 benign prostatic hyperplasia patients with average age of 53.3 years and international prostate symptom score over 8. Subjects received either sweet potato starch (group A, placebo, 320 mg/day), pumpkin seed oil (group B, 320 mg/day), saw palmetto oil (group C, 320 mg/day) or pumpkin seed oil plus saw palmetto oil (group D, each 320 mg/day). International prostate symptom score, quality of life, serum prostate specific antigen, prostate volume and maximal urinary flow rate were measured. In groups B, C and D, the international prostate symptom score were reduced by 3 months. Quality of life score was improved after 6 months in group D, while those of groups B and C were improved after 3 months, compared to the baseline value. Serum prostate specific antigen was reduced only in group D after 3 months, but no difference was observed in prostate volume in all treatment groups. Maximal urinary flow rate were gradually improved in groups B and C, with statistical significance after 6 months in group B and after 12 months in group C. None of the parameters were significantly improved by combined treatment with pumpkin seed oil and saw palmetto oil. From these results, it is suggested that administrations of pumpkin seed oil and saw palmetto oil are clinically safe and may be effective as complementary and alternative medicine treatments for benign prostatic hyperplasia. PMID:20098586

Brachytherapy optimization using radiobiological-based planning for high dose rate and permanent implants for prostate cancer treatment

NASA Astrophysics Data System (ADS)

Seeley, Kaelyn; Cunha, J. Adam; Hong, Tae Min

2017-01-01

We discuss an improvement in brachytherapy--a prostate cancer treatment method that directly places radioactive seeds inside target cancerous regions--by optimizing the current standard for delivering dose. Currently, the seeds' spatiotemporal placement is determined by optimizing the dose based on a set of physical, user-defined constraints. One particular approach is the ``inverse planning'' algorithms that allow for tightly fit isodose lines around the target volumes in order to reduce dose to the patient's organs at risk. However, these dose distributions are typically computed assuming the same biological response to radiation for different types of tissues. In our work, we consider radiobiological parameters to account for the differences in the individual sensitivities and responses to radiation for tissues surrounding the target. Among the benefits are a more accurate toxicity rate and more coverage to target regions for planning high-dose-rate treatments as well as permanent implants.

Brachytherapy for Prostate Cancer: A Systematic Review

PubMed Central

Koukourakis, Georgios; Kelekis, Nikolaos; Armonis, Vassilios; Kouloulias, Vassilios

2009-01-01

Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. To a great extend due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. High-dose-rate (HDR) afterloading brachytherapy in the management of localised prostate cancer has practical, physical, and biological advantages over low-dose-rate seed brachytherapy. There are no free live sources used, no risk of source loss, and since the implant is a temporary procedure following discharge no issues with regard to radioprotection use of existing facilities exist. Patients with localized prostate cancer may benefit from high-dose-rate brachytherapy, which may be used alone in certain circumstances or in combination with external-beam radiotherapy in other settings. The purpose of this paper is to present the essentials of brachytherapies techniques along with the most important studies that support their effectiveness in the treatment of prostate cancer. PMID:19730753

Evaluation of the effect of prostate volume change on tumor control probability in LDR brachytherapy.

PubMed

Knaup, Courtney; Mavroidis, Panayiotis; Stathakis, Sotirios; Smith, Mark; Swanson, Gregory; Papanikolaou, Niko

2011-09-01

This study evaluates low dose-rate brachytherapy (LDR) prostate plans to determine the biological effect of dose degradation due to prostate volume changes. In this study, 39 patients were evaluated. Pre-implant prostate volume was determined using ultrasound. These images were used with the treatment planning system (Nucletron Spot Pro 3.1(®)) to create treatment plans using (103)Pd seeds. Following the implant, patients were imaged using CT for post-implant dosimetry. From the pre and post-implant DVHs, the biologically equivalent dose and the tumor control probability (TCP) were determined using the biologically effective uniform dose. The model used RBE = 1.75 and α/β = 2 Gy. The prostate volume changed between pre and post implant image sets ranged from -8% to 110%. TCP and the mean dose were reduced up to 21% and 56%, respectively. TCP is observed to decrease as the mean dose decreases to the prostate. The post-implant tumor dose was generally observed to decrease, compared to the planned dose. A critical uniform dose of 130 Gy was established. Below this dose, TCP begins to fall-off. It was also determined that patients with a small prostates were more likely to suffer TCP decrease. The biological effect of post operative prostate growth due to operative trauma in LDR was evaluated using the concept. The post-implant dose was lower than the planned dose due to an increase of prostate volume post-implant. A critical uniform dose of 130 Gy was determined, below which TCP begun to decline.

Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bloch, B. Nicolas; Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna; Lenkinski, Robert E.

2007-09-01

Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of datamore » read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.« less

BrachyView: multiple seed position reconstruction and comparison with CT post-implant dosimetry

NASA Astrophysics Data System (ADS)

Alnaghy, S.; Loo, K. J.; Cutajar, D. L.; Jalayer, M.; Tenconi, C.; Favoino, M.; Rietti, R.; Tartaglia, M.; Carriero, F.; Safavi-Naeini, M.; Bucci, J.; Jakubek, J.; Pospisil, S.; Zaider, M.; Lerch, M. L. F.; Rosenfeld, A. B.; Petasecca, M.

2016-05-01

BrachyView is a novel in-body imaging system utilising high-resolution pixelated silicon detectors (Timepix) and a pinhole collimator for brachytherapy source localisation. Recent studies have investigated various options for real-time intraoperative dynamic dose treatment planning to increase the quality of implants. In a previous proof-of-concept study, the justification of the pinhole concept was shown, allowing for the next step whereby multiple active seeds are implanted into a PMMA phantom to simulate a more realistic clinical scenario. In this study, 20 seeds were implanted and imaged using a lead pinhole of 400 μ m diameter. BrachyView was able to resolve the seed positions within 1-2 mm of expected positions, which was verified by co-registering with a full clinical post-implant CT scan.

Biodegradable seeds of holmium don't change neurological function after implant in brain of rats.

PubMed

Diniz, Mirla Fiuza; Ferreira, Diogo Milioli; de Lima, Wanderson Geraldo; Pedrosa, Maria Lucia; Silva, Marcelo Eustáquio; de Almeida Araujo, Stanley; Sampaio, Kinulpe Honorato; de Campos, Tarcisio Passos Ribeiro; Siqueira, Savio Lana

2017-01-01

To evaluate the surgical procedure and parenchymal abnormalities related to implantation of ceramic seeds with holmium-165 in rats' brain. An effective method of cancer treatment is brachytherapy in which radioactive seeds are implanted in the tumor, generating a high local dose of ionizing radiation that can eliminate tumor cells while protecting the surrounding healthy tissue. Biodegradable Ho 166 -ceramic-seeds have been addressed recently. The experiments in this study were approved by the Ethics Committee on Animal Use at the Federal University of Ouro Preto, protocol number 2012/034. Twenty-one adult Fischer rats were divided into Naive Group, Sham Group and Group for seed implants (ISH). Surgical procedures for implantation of biodegradable seeds were done and 30 days after the implant radiographic examination and biopsy of the brain were performed. Neurological assays were also accomplished to exclude any injury resulting from either surgery or implantation of the seeds. Radiographic examination confirmed the location of the seeds in the brain. Neurological assays showed animals with regular spontaneous activity. The histological analysis showed an increase of inflammatory cells in the brain of the ISH group. Electron microscopy evidenced cytoplasmic organelles to be unchanged. Biochemical analyzes indicate there was neither oxidative stress nor oxidative damage in the ISH brain. CAT activity showed no difference between the groups as well as lipid peroxidation measured by TBARS. The analysis of the data pointed out that the performed procedure is safe as no animal showed alterations of the neurological parameters and the seeds did not promote histological architectural changes in the brain tissue.

Maintenance of human hyperplastic prostate implants at different sites in athymic mice.

PubMed

Soós, G; Debiec-Rychter, M; Jones, R F; Zukowski, K; Haas, G P; Wang, C Y

1995-01-01

The present study determined the influence of implantation sites, androgens, and the graft's fibrovascular elements on the maintenance of epithelial elements of human benign hyperplastic prostate tissue (BPH) in the nude mouse. BPH fragments prepared from fresh surgical specimens were implanted subcutaneously (s.c.), intraperitoneally (i.p.), or under the renal capsules (r.c.) into male Beige nude mice, which had been implanted s.c. with a Silastic tube filled with 4-dihydrotestosterone (DHT) or cholesterol. Two weeks later the BPH tissues were removed from the mouse and examined microscopically. The implants from all three sites maintained a comparable morphology, with epithelial and/or angio-leiomyomatous stromal hyperplastic appearance, without striking signs of atrophy, irrespective of supplementation with DHT. Expression of proliferating cell nuclear antigen in the implants was comparable, indicating that there was no significant influence of implantation site on the proliferative ability of either epithelia or the stromal fibroblasts. The PCNA-positive cells in the implants, including the vascular and myofibrous elements, hybridized in situ to a human-specific repeated-sequence DNA probe, indicating that these proliferating cells were of human origin. Our data suggest that during the early phases of the adaptation and maintenance of BPH implants, survival of epithelial cells is actively supported by fibro-vascular mesenchymal elements of the prostate grafts in a manner apparently unaffected by DHT supplements.

Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

PubMed

de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

2016-01-01

To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

SU-F-T-653: Radiation Exposure from Cs-131 Permanent Seed Implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giaddui, T; Hardin, M; To, D

Purpose: Permanent seed implants have traditionally been used to treat prostate, lung and head or neck cancers using I-125 and Pd-103. Cs-131, which has higher dose rate is being used to treat brain, head and/or neck cancers in our clinic, therefore, we chose to monitor the dose received by surgeons during the extensive procedure. The aims of this work are to assess the level of radiation exposure to surgeons and the instantaneous exposure at bedside and 1 m from patients. Methods: Ten patients received Cs-131 implants for recurrent brain,head and/or neck cancer; the median implanted activity, number of implanted seedsmore » and prescription dose at 0.5 cm from the perpendicular plane of the implant were: 54.3 mCi (14.52 – 77); 19 (4 – 24) and 60 Gy (range 42 – 60) respectively. Radiation exposure was recorded at bedside and 1 m from the patient using Victoreen ion chamber (Fluke Biomedical, Cleveland, OH). Exposure to surgeons was measured using TLD (Mirion Technologies (GDS), Inc., USA). Results: The median equivalent dose rate at 1 m and bedside immediately following implantation were 1.49×10-2 mSv/h (8.77×10-3–2.63×10-2) and 7.76×10-2 mSv/h (3.1×10-2– 1.53×10-1) respectively. Median equivalent dose to surgeons’ hands was 0.60 mSv (0.33 – 1.48) and no doses were detected for whole-body. Surgical reconstruction for one patient was performed 71 days post-implant and resulted in zero exposure to surgeons. Conclusion: The recorded exposure rates were low when compared with the literature. Post procedure surveys at bed site and 1 m indicated that all patients were within safe limits for discharge (< 0.05 mSv/h at 1 m). However, as a precautionary measure, patients were advised to avoid direct contact with children and pregnant women within four weeks of the implant and stay at least at 3 ft from other people. Surgeons doses were well within occupational dose limits.« less

Transperineal ultrasound-guided implantation of electromagnetic transponders in the prostatic fossa for localization and tracking during external beam radiation therapy.

PubMed

Garsa, Adam A; Verma, Vivek; Michalski, Jeff M; Gay, Hiram A

2014-01-01

To describe a transperineal ultrasound-guided technique for implantation of electromagnetic transponders into the prostatic fossa. Patients were placed in the dorsal lithotomy position, and local anesthetic was administered. On ultrasound, the bladder, urethra, vesicourethral anastomosis, rectum, and the prostatic fossa were carefully identified. Three transponders were implanted into the prostatic fossa under ultrasound guidance in a triangular configuration and implantation was verified by fluoroscopy. Patients underwent computed tomography (CT) simulation approximately 1 week later. All patients in this study were subsequently treated with intensity modulated radiation therapy (IMRT) to the prostatic fossa. From 2008 to 2012, 180 patients received transperineal implantation of electromagnetic transponders into the prostatic fossa and subsequently received IMRT. There were no cases of severe hematuria or rectal bleeding requiring intervention. There were no grade 3 or 4 toxicities. Three patients (1.7%) had a transponder missing on the subsequent CT simulation. Thirteen patients (7.3%) had transponder migration with a geometric residual that exceeded 2 mm for 3 consecutive days (5.6%) or rotation that exceeded 10 degrees for 5 consecutive days (1.7%). These patients underwent a resimulation CT scan to identify the new transponder coordinates. A transperineal technique for implantation of electromagnetic transponders into the prostatic fossa is safe and well tolerated, with no severe toxicity after implantation. There is a low rate of transponder loss or migration.

TU-AB-201-11: A Novel Theoretical Framework for MRI-Only Image Guided LDR Prostate and Breast Brachytherapy Implant Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soliman, A; Elzibak, A; Fatemi, A

Purpose: To propose a novel framework for accurate model-based dose calculations using only MR images for LDR prostate and breast seed implant brachytherapy. Methods: Model-based dose calculation methodologies recommended by TG-186 require further knowledge about specific tissue composition, which is challenging with MRI. However, relying on MRI-only for implant dosimetry would reduce the soft tissue delineation uncertainty, costs, and uncertainties associated with multi-modality registration and fusion processes. We propose a novel framework to address this problem using quantitative MRI acquisitions and reconstruction techniques. The framework includes three steps: (1) Identify the locations of seeds(2) Identify the presence (or absence) ofmore » calcification(s)(3) Quantify the water and fat content in the underlying tissueSteps (1) and (2) consider the sources that limit patient dosimetry, particularly the inter-seed attenuation and the calcified regions; while step (3) targets the quantification of the tissue composition to consider the heterogeneities in the medium. Our preliminary work has shown that the seeds and the calcifications can be identified with MRI using both the magnitude and the phase images. By employing susceptibility-weighted imaging with specific post-processing techniques, the phase images can be further explored to distinguish the seeds from the calcifications. Absolute quantification of tissue, water, and fat content is feasible and was previously demonstrated in phantoms and in-vivo applications, particularly for brain diseases. The approach relies on the proportionality of the MR signal to the number of protons in an image volume. By employing appropriate correction algorithms for T1 - and T2*-related biases, B1 transmit and receive field inhomogeneities, absolute water/fat content can be determined. Results: By considering calcification and interseed attenuation, and through the knowledge of water and fat mass density, accurate

Radioactive iodine-125 implantation for cancer of the prostate.

PubMed

Nag, S

1985-01-01

Localized cancer of the prostate can be treated by radical prostatectomy, external beam irradiation, or radioactive implantation with similar survival results. Radical prostatectomy, however, almost universally results in impotency, although a new, nerve-sparing procedure may preserve potency in B1 patients. External beam irradiation radiates a large volume of tissue with significant rectal and bladder morbidity, 23-47% risk of impotency, and requires prolonged treatment (6-8 weeks). Radioactive implantation may be done suprapubically or transperineally using iodine-125, gold-198, or radon-222 permanent implantation techniques and iridium-192 or radium-226 removable implantation techniques. Interstitial iodine-125 implantation is frequently employed since it is a short procedure and limits the morbidity to a 7% incidence of impotency, 20% urinary complications, and 5% rectal complications. The overall 5-year survival of patients with iodine-125 is 79%, the survival rate decreasing with increasing T or N stage or increasing grade of tumor.

Phase I Trial of Adenovirus-Mediated IL-12 Gene Transduction in Patients with Recurrent Locally Advanced Prostate Cancer Following Therapy

DTIC Science & Technology

2005-10-01

salvage seed implant, cryotherapy ) or who have a rising PSA while on hormone therapy for locally advanced prostate cancer are as follows: a. A...Gene Transduction in Patients with Recurrent Locally Advanced Prostate Cancer Following Therapy PRINCIPAL INVESTIGATOR: Simon J. Hall, MD...CONTRACT NUMBER Phase I Trial of Adenovirus-Mediated IL-12 Gene Transduction in Patients with Recurrent Locally Advanced Prostate Cancer Following

Transurethral light delivery for prostate photoacoustic imaging

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

2015-03-01

Photoacoustic imaging has broad clinical potential to enhance prostate cancer detection and treatment, yet it is challenged by the lack of minimally invasive, deeply penetrating light delivery methods that provide sufficient visualization of targets (e.g., tumors, contrast agents, brachytherapy seeds). We constructed a side-firing fiber prototype for transurethral photoacoustic imaging of prostates with a dual-array (linear and curvilinear) transrectal ultrasound probe. A method to calculate the surface area and, thereby, estimate the laser fluence at this fiber tip was derived, validated, applied to various design parameters, and used as an input to three-dimensional Monte Carlo simulations. Brachytherapy seeds implanted in phantom, ex vivo, and in vivo canine prostates at radial distances of 5 to 30 mm from the urethra were imaged with the fiber prototype transmitting 1064 nm wavelength light with 2 to 8 mJ pulse energy. Prebeamformed images were displayed in real time at a rate of 3 to 5 frames per second to guide fiber placement and beamformed offline. A conventional delay-and-sum beamformer provided decreasing seed contrast (23 to 9 dB) with increasing urethra-to-target distance, while the short-lag spatial coherence beamformer provided improved and relatively constant seed contrast (28 to 32 dB) regardless of distance, thus improving multitarget visualization in single and combined curvilinear images acquired with the fiber rotating and the probe fixed. The proposed light delivery and beamforming methods promise to improve key prostate cancer detection and treatment strategies.

The effects of metallic implants on electroporation therapies: feasibility of irreversible electroporation for brachytherapy salvage.

PubMed

Neal, Robert E; Smith, Ryan L; Kavnoudias, Helen; Rosenfeldt, Franklin; Ou, Ruchong; Mclean, Catriona A; Davalos, Rafael V; Thomson, Kenneth R

2013-12-01

Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

Sci-Sat AM(2): Brachy-05: Dosimetry effects of the TG-43 approximations for two iodine seeds in LDR brachytherapy.

PubMed

Furstoss, C; Bertrand, M J; Poon, E; Reniers, B; Pignol, J P; Carrier, J F; Beaulieu, L; Verhaegen, F

2008-07-01

This work consists of studying the interseed and tissue composition effects for two model iodine seeds: the IBt Interseed-125 and the 6711 model seed. Three seeds were modeled with the MCNP MC code in a water sphere to evaluate the interseed effect. The dose calculated at different distances from the centre was compared to the dose summed when the seeds were simulated separately. The tissue composition effect was studied calculating the radial dose function for different tissues. Before carrying out post-implant studies, the absolute dose calculated by MC was compared to experiment results: with LiF TLDs in an acrylic breast phantom and with an EBT Gafchromic film placed in a water tank. Afterwards, the TG-43 approximation effects were studied for a prostate and breast post-implant. The interseed effect study shows that this effect is more important for model 6711 (15%) than for IBt (10%) due to the silver rod in 6711. For both seed models the variations of the radial dose function as a function of the tissue composition are quasi similar. The absolute dose comparisons between MC calculations and experiments give good agreement (inferior to 3% in general). For the prostate and breast post-implant studies, a 10% difference between MC calculations and the TG-43 is found for both models of seeds. This study shows that the differences in dose distributions between TG43 and MC are quite similar for the two models of seeds and are about 10% for the studied post-implant treatments. © 2008 American Association of Physicists in Medicine.

A novel imaging approach for prostate cancer is tested in new clinical trial | Center for Cancer Research

Cancer.gov

Prostate cancer patients who have failed standard radiation therapy have the options of surgery, radioactive seed implantation or cryoablation. Deborah Citrin, M.D., of the Radiation Oncology Branch is leading a study of stereotactic body radiation therapy (SBRT) to treat prostate cancer that has recurred locally after standard radiation therapy. The goal of this study is to

Dose Escalation to the Dominant Intraprostatic Lesion Defined by Sextant Biopsy in a Permanent Prostate I-125 Implant: A Prospective Comparative Toxicity Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaudet, Marc; Vigneault, Eric; Aubin, Sylviane

2010-05-01

Purpose: Using real-time intraoperative inverse-planned permanent seed prostate implant (RTIOP/PSI), multiple core biopsy maps, and three-dimensional ultrasound guidance, we planned a boost volume (BV) within the prostate to which hyperdosage was delivered selectively. The aim of this study was to investigate the potential negative effects of such a procedure. Methods and Materials: Patients treated with RTIOP/PSI for localized prostate cancer with topographic biopsy results received an intraprostatic boost (boost group [BG]). They were compared with patients treated with a standard plan (reference group [RG]). Plans were generated using a simulated annealing inverse planning algorithm. Prospectively recorded urinary, rectal, and sexualmore » toxicities and dosimetric parameters were compared between groups. Results: The study included 120 patients treated with boost technique who were compared with 70 patients treated with a standard plan. Boost technique did not significantly change the number of seeds (55.1/RG vs. 53.6/BG). The intraoperative prostate V150 was slightly higher in BG (75.2/RG vs. 77.2/BG, p = 0.039). Urethra V100, urethra D90, and rectal D50 were significantly lower in the BG. No significant differences were seen in acute or late urinary, rectal, or sexual toxicities. Conclusions: Because there were no differences between the groups in acute and late toxicities, we believe that BV can be planned and delivered to the dominant intraprostatic lesion without increasing toxicity. It is too soon to say whether a boost technique will ultimately increase local control.« less

Computational and Experimental Evaluations of a Novel Thermo-Brachytherapy Seed for Treatment of Solid Tumors

NASA Astrophysics Data System (ADS)

Warrell, Gregory R.

Hyperthermia has long been known as a radiation therapy sensitizer of high potential; however successful delivery of this modality and integrating it with radiation have often proved technically difficult. We present the dual-modality thermobrachytherapy (TB) seed, based on the ubiquitous low dose-rate (LDR) brachytherapy permanent implant, as a simple and effective combination of hyperthermia and radiation therapy. Heat is generated from a ferromagnetic or ferrimagnetic core within the seed, which produces Joule heating by eddy currents. A strategically-selected Curie temperature provides thermal self-regulation. In order to obtain a uniform and sufficiently high temperature distribution, additional hyperthermia-only (HT-only) seeds are proposed to be used in vacant spots within the needles used to implant the TB seeds; this permits a high seed density without the use of additional needles. Experimental and computational studies were done both to optimize the design of the TB and HT-only seeds and to quantitatively assess their ability to heat and irradiate defined, patient-specific targets. Experiments were performed with seed-sized ferromagnetic samples in tissue-mimicking phantoms heated by an industrial induction heater. The magnetic and thermal properties of the seeds were studied computationally in the finite element analysis (FEA) solver COMSOL Multiphysics, modelling realistic patient-specific seed distributions. These distributions were derived from LDR permanent prostate implants previously conducted at our institution; various modifications of the seeds' design were studied. The calculated temperature distributions were analyzed by generating temperature-volume histograms, which were used to quantify coverage and temperature homogeneity for a range of blood perfusion rates, as well as for a range of seed Curie temperatures and thermal power production rates. The impact of the interseed attenuation and scatter (ISA) effect on radiation dose distributions

In vitro comparative study of vibro-acoustography versus pulse-echo ultrasound in imaging permanent prostate brachytherapy seeds

PubMed Central

Mitri, F.G.; Davis, B.J.; Greenleaf, J.F.; Fatemi, M.

2010-01-01

Background Permanent prostate brachytherapy (PPB) is a common treatment for early stage prostate cancer. While the modern approach using trans-rectal ultrasound guidance has demonstrated excellent outcome, the efficacy of PPB depends on achieving complete radiation dose coverage of the prostate by obtaining a proper radiation source (seed) distribution. Currently, brachytherapy seed placement is guided by trans-rectal ultrasound imaging and fluoroscopy. A significant percentage of seeds are not detected by trans-rectal ultrasound because certain seed orientations are invisible making accurate intra-operative feedback of radiation dosimetry very difficult, if not impossible. Therefore, intra-operative correction of suboptimal seed distributions cannot easily be done with current methods. Vibro-acoustography (VA) is an imaging modality that is capable of imaging solids at any orientation, and the resulting images are speckle free. Objective and methods The purpose of this study is to compare the capabilities of VA and pulse-echo ultrasound in imaging PPB seeds at various angles and show the sensitivity of detection to seed orientation. In the VA experiment, two intersecting ultrasound beams driven at f1 = 3.00 MHz and f2 = 3.020 MHz respectively were focused on the seeds attached to a latex membrane while the amplitude of the acoustic emission produced at the difference frequency 20 kHz was detected by a low frequency hydrophone. Results Finite element simulations and results of experiments conducted under well-controlled conditions in a water tank on a series of seeds indicate that the seeds can be detected at any orientation with VA, whereas pulse-echo ultrasound is very sensitive to the seed orientation. Conclusion It is concluded that vibro-acoustography is superior to pulse-echo ultrasound for detection of PPB seeds. PMID:18538365

High Intensity Focused Ultrasound (HIFU) as a Salvage Treatment for Recurrent Prostate Cancer after Brachytherapy — a Feasibility Study

NASA Astrophysics Data System (ADS)

Chapman, Alexander T.; Rivens, Ian H.; Thompson, Alan C.; ter Haar, Gail R.

2007-05-01

HIFU may be an effective salvage treatment for patients who develop local recurrence after permanent low-dose brachytherapy. It has been suggested that the presence of seeds in the prostate may obstruct the HIFU beam or alter the heating characteristics of the prostate tissue. Acoustic field measurements were made using a membrane hydrophone and lesioning experiments were carried out in ex vivo bovine liver. These revealed a significant effect of the seeds on the HIFU focal region as well as a reduction in lesion length when seeds were placed in a pre-focal position. Further work is needed to evaluate the full effects of implanted brachytherapy seeds on the clinical delivery of HIFU.

The Effects of Metallic Implants on Electroporation Therapies: Feasibility of Irreversible Electroporation for Brachytherapy Salvage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neal, Robert E., E-mail: robert.neal@alfred.org.au; Smith, Ryan L., E-mail: ryan.smith@wbrc.org.au; Kavnoudias, Helen, E-mail: H.Kavnoudias@alfred.org.au

2013-12-15

Purpose: Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. Materials and Methods: This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expiredmore » radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. Results: There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. Conclusion: This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.« less

SU-F-T-46: The Effect of Inter-Seed Attenuation and Tissue Composition in Prostate 125I Brachytherapy Dose Calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamura, K; Araki, F; Ohno, T

Purpose: To investigate the difference of dose distributions with/without the effect of inter-seed attenuation and tissue compositions in prostate {sup 125}I brachytherapy dose calculations, using Monte Carlo simulations of Particle and Heavy Ion Transport code System (PHITS). Methods: The dose distributions in {sup 125}I prostate brachytherapy were calculated using PHITS for non-simultaneous and simultaneous alignments of STM1251 sources in water or prostate phantom for six patients. The PHITS input file was created from DICOM-RT file which includes source coordinates and structures for clinical target volume (CTV) and organs at risk (OARs) of urethra and rectum, using in-house Matlab software. Photonmore » and electron cutoff energies were set to 1 keV and 100 MeV, respectively. The dose distributions were calculated with the kerma approximation and the voxel size of 1 × 1 × 1 mm{sup 3}. The number of incident photon was set to be the statistical uncertainty (1σ) of less than 1%. The effect of inter-seed attenuation and prostate tissue compositions was evaluated from dose volume histograms (DVHs) for each structure, by comparing to results of the AAPM TG-43 dose calculation (without the effect of inter-seed attenuation and prostate tissue compositions). Results: The dose reduction due to the inter-seed attenuation by source capsules was approximately 2% for CTV and OARs compared to those of TG-43. In additions, by considering prostate tissue composition, the D{sub 90} and V{sub 100} of CTV reduced by 6% and 1%, respectively. Conclusion: It needs to consider the dose reduction due to the inter-seed attenuation and tissue composition in prostate {sup 125}I brachytherapy dose calculations.« less

Prophylactic urethral stenting with Memokath® 028SW in prostate cancer patients undergoing prostate 125I seed implants: phase I/II study

PubMed Central

Chao, Samuel T.; Angermeier, Kenneth; Klein, Eric A.; Reddy, Chandana A.; Ulchaker, James C.; Stephenson, Andrew; Campbell, Steven

2011-01-01

Purpose To study the feasibility/toxicity of urethral stenting with the Memokath® 028SW stent in patients undergoing prostate implant (PI) for prostate adenocarcinoma. Material and methods An Investigational Device Exemption from the Food and Drug Administration (FDA) and institutional review board (IRB) approval were obtained. Twenty patients enrolled. Baseline American Urological Association (AUA) score was obtained prior to PI. Follow-up information was obtained with weekly phone calls for the first 12 weeks and biweekly calls for the next 12 weeks to assess toxicity and AUA score. Removal of the stent was planned at six months after PI, or earlier due to excessive toxicity/patient request. Results Median age was 66.5 years. The median prostate volume was 39 cc (range: 10-90). The median baseline AUA score was 7.5 (range: 1-21). Three patients required intermittent self-catheterization (ISC) within 3 days after PI. No patients required ISC beyond day 3 after PI. The median duration of ISC was 1 day (range: 1-2). AUA scores returned to baseline values 6 weeks after PI. The week 6 AUA score was 10 (range: 4-16). Seven patients (35%) underwent early removal because of patient preference. The reasons were: incontinence (n = 3), discomfort (n = 2), hematuria (n = 1), and obstructive symptoms (n = 1). The median time of stent removal in these patients was 13.9 weeks (range: 0.9-21.4). Thirteen patients (65%) had ISC and/or urinary catheterization post stent removal. Median time for ISC use was 10 days (range: 1-90). Conclusions Urethral stenting with Memokath® in patients undergoing PI was feasible, but resulted in relatively high rate of urinary incontinence and discomfort. Given the adverse effects experienced by patients of this study, further studies should focus only on patients with highest risk of urinary obstruction from PI or those with obstruction needing ISC. PMID:27877196

SU-F-T-44: A Comparison of the Pre-Plan, Intra-Operative Plan, and Post-Implant Dosimetry for a Prostate Implant Case Using Prefabricated Linear Polymer-Encapsulated Pd-103

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheu, R; Powers, A; McGee, H

Purpose: To investigate the reproducibility and limitations of Pd-103 prostate brachytherapy using fixed length linear sources (CivaString). Methods: An LDR prostate brachytherapy case which was preplanned on MR images with prefabricated linear polymer-encapsulated Pd-103 sources (CivaString) was studied and compared with ultrasound based intra-operative planning and CT based post-implant dosimetry. We evaluated the following parameters among the three studies: prostate geometry (volume and cross sectional area), needle position and alignment deviations, and dosimetry parameters (D90). Results: The prostate volumes and axial cross sectional areas at center of prostate were measured as 41.8, 39.3 and 36.8 cc, and 14.9, 14.3, andmore » 11.3 respectively on pre-plan MR, inter-op US, and post-implant CT studies. The deviation of prostate volumes and axial cross sectional areas measured on pre-planning MR and intra-operative US were within 5%. 17 out of 19 pre-planned needles were positioned within 5mm (the template grid size). One needle location was adjusted intra-operatively and another needle was removed due to proximity to urethra. The needle pathways were not always parallel to the trans-rectal probe due to the flexibility of CivaString. The angle of deviation was up to 10 degrees. Two pairs of needles were exchanged to better fit the length of prostate at the time of implant. This resulted in a prostate D90 of 153.8 Gy (124%) and 131.4 Gy (106.7%) for intra-op and PID respectively. Conclusion: Preplanning is a necessary part of implants performed with prefabricated linear polymer sources. However, as is often the case, there were real-time deviations from the pre-plan. Intra-op planning provides the ability conform to anatomy at the time of implant. Therefore, we propose to develop a systematic way to order extra strings of different length to provide the flexibility to perform intra-operative planning with fixed length strands.« less

Beyond Seed and Soil: Understanding and Targeting Metastatic Prostate Cancer; Report From the 2016 Coffey-Holden Prostate Cancer Academy Meeting.

PubMed

Miyahira, Andrea K; Roychowdhury, Sameek; Goswami, Sangeeta; Ippolito, Joseph E; Priceman, Saul J; Pritchard, Colin C; Sfanos, Karen S; Subudhi, Sumit K; Simons, Jonathan W; Pienta, Kenneth J; Soule, Howard R

2017-02-01

The 2016 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Beyond Seed and Soil: Understanding and Targeting Metastatic Prostate Cancer," was held from June 23 to June 26, 2016, in Coronado, California. For the 4th year in a row, the Prostate Cancer Foundation (PCF) hosted the CHPCA Meeting, a think tank-structured scientific conference, which focuses on a specific topic of critical unmet need on the biology and treatment of advanced prostate cancer. The 2016 CHPCA Meeting was attended by 71 investigators from prostate cancer and other fields, who discussed the biology, study methodologies, treatment strategies, and critical unmet needs concerning metastatic prostate cancer, with the ultimate goal of advancing strategies to treat and eliminate this disease. The major topics of discussion included: the molecular landscape and molecular heterogeneity of metastatic prostate cancer, the role of the metastatic microenvironment, optimizing immunotherapy in metastatic prostate cancer, learning from exceptional responders and non-responders, targeting DNA repair deficiency in advanced prostate cancer, developing and applying novel biomarkers and imaging techniques, and potential roles for the microbiome in prostate cancer. This article reviews the topics presented and discussions held at the CHPCA Meeting, with a focus on the unknowns and next steps needed to advance our understanding of the biology and most effective treatment strategies for metastatic prostate cancer. Prostate 77:123-144, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Parameters predicting for prostate specific antigen response rates at one year post low-dose-rate intraoperative prostate brachytherapy

PubMed Central

Meyer, Tyler; Sia, Michael; Angyalfi, Steve; Husain, Siraj

2017-01-01

Purpose To develop a model for prostate specific antigen (PSA) values at one year among patients treated with intraoperatively planned 125I prostate brachytherapy (IOPB). Material and methods Four hundred and deven patients treated with IOPB for prostate adenocarcinoma were divided into four groups: those with PSA values ≥ 3 ng/ml; < 3 and ≥ 2; < 2 and ≥ 1 or PSA < 1 between 10.5 and 14.5 months post implantation (1yPSA). Ordinal regression analysis was then performed between patient, tumor, and treatment characteristics. 1yPSA values were also compared with toxicity outcomes. Results Median 1yPSA was 0.77 (0.04-17.36). Thirty-two patients (8%) had a PSA ≥ 3; 35 (9%) had PSA < 3, ≥ 2; 87 (21%) had PSA < 2, ≥ 1, and most patients 254 (62%) had PSA < 1. PSA response was independent of gland volume, Gleason score, clinical stage, seed activity, V90, V200, D90, or number of needles and seeds used. Older patients had significantly lower 1yPSA; median ages 65.1 (46.5-81.0), 62.1 (50.4-79.5), 60.5 (47.1-80.3), and 58.1 (45.1-74.2) years for each of the 1yPSA groups respectively (p < 0.001). Also, both implant V150 (p < 0.001) and initial PSA values (p = 0.04) were predictive of 1yPSA values. There was no correlation between 1yPSA values and toxicity encountered. Conclusions PSA response at 1 year post IOPB appears to be dependent on patient age, initial PSA, and implant V150. Our results provide reassurance that parameters other than biochemical failure influence 1yPSA values. PMID:28533796

Photon counting readout pixel array in 0.18-μm CMOS technology for on-line gamma-ray imaging of 103palladium seeds for permanent breast seed implant (PBSI) brachytherapy

NASA Astrophysics Data System (ADS)

Goldan, A. H.; Karim, K. S.; Reznik, A.; Caldwell, C. B.; Rowlands, J. A.

2008-03-01

Permanent breast seed implant (PBSI) brachytherapy technique was recently introduced as an alternative to high dose rate (HDR) brachytherapy and involves the permanent implantation of radioactive 103Palladium seeds into the surgical cavity of the breast for cancer treatment. To enable accurate seed implantation, this research introduces a gamma camera based on a hybrid amorphous selenium detector and CMOS readout pixel architecture for real-time imaging of 103Palladium seeds during the PBSI procedure. A prototype chip was designed and fabricated in 0.18-μm n-well CMOS process. We present the experimental results obtained from this integrated photon counting readout pixel.

SU-E-T-546: Use of Implant Volume for Quality Assurance of Low Dose Rate Brachytherapy Treatment Plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkinson, D; Kolar, M

Purpose: To analyze the application of volume implant (V100) data as a method for a global check of low dose rate (LDR) brachytherapy plans. Methods: Treatment plans for 335 consecutive patients undergoing permanent seed implants for prostate cancer and for 113 patients treated with plaque therapy for ocular melanoma were analyzed. Plaques used were 54 COMS (10 to 20 mm, notched and regular) and 59 Eye Physics EP917s with variable loading. Plots of treatment time x implanted activity per unit dose versus v100 ^.667 were made. V100 values were obtained using dose volume histograms calculated by the treatment planning systemsmore » (Variseed 8.02 and Plaque Simulator 5.4). Four different physicists were involved in planning the prostate seed cases; two physicists for the eye plaques. Results: Since the time and dose for the prostate cases did not vary, a plot of implanted activity vs V100 ^.667 was made. A linear fit with no intercept had an r{sup 2} = 0.978; more than 94% of the actual activities fell within 5% of the activities calculated from the linear fit. The greatest deviations were in cases where the implant volumes were large (> 100 cc). Both COMS and EP917 plaque linear fits were good (r{sup 2} = .967 and .957); the largest deviations were seen for large volumes. Conclusions: The method outlined here is effective for checking planning consistency and quality assurance of two types of LDR brachytherapy treatment plans (temporary and permanent). A spreadsheet for the calculations enables a quick check of the plan in situations were time is short (e.g. OR-based prostate planning)« less

A novel imaging approach for prostate cancer is tested in new clinical trial | Center for Cancer Research

Cancer.gov

Prostate cancer patients who have failed standard radiation therapy have the options of surgery, radioactive seed implantation or cryoablation. Deborah Citrin, M.D., of the Radiation Oncology Branch is leading a study of stereotactic body radiation therapy (SBRT) to treat prostate cancer that has recurred locally after standard radiation therapy. The goal of this study is to use a novel imaging approach to guide treatment and to define the best dose of SBRT for patients whose prostate cancer has recurred after standard radiotherapy. Read more...

SU-E-J-232: Feasibility of MRI-Based Preplan On Low Dose Rate Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Y; Tward, J; Rassiah-Szegedi, P

Purpose: To investigate the feasibility of using MRI-based preplan for low dose rate prostate brachytherapy. Methods: 12 patients who received transrectal ultrasound (TRUS) guided prostate brachytherapy with Pd-103 were retrospectively studied. Our care-standard of the TRUS-based preplan served as the control. One or more prostate T2-weighted wide and/or narrow-field of view MRIs obtained within the 3 months prior to the implant were imported into the MIM Symphony software v6.3 (MIM Software Inc., Cleveland, OH) for each patient. In total, 37 MRI preplans (10 different image sequences with average thickness of 4.8mm) were generated. The contoured prostate volume and the seedmore » counts required to achieve adequate dosimetric coverage from TRUS and MRI preplans were compared for each patient. The effects of different MRI sequences and image thicknesses were also investigated statistically using Student’s t-test. Lastly, the nomogram from the MRI preplan and TRUS preplan from our historical treatment data were compared. Results: The average prostate volume contoured on the TRUS and MRI were 26.6cc (range: 12.6∼41.3cc), and 27.4 cc (range: 14.3∼50.0cc), respectively. Axial MRI thicknesses (range: 3.5∼8.1mm) did not significantly affect the contoured volume or the number of seeds required on the preplan (R2 = 0.0002 and 0.0012, respectively). Four of the MRI sequences (AX-T2, AX-T2-Whole-Pelvis, AX-T2-FSE, and AXIALT2- Hi-Res) showed statistically significant better prostate volume agreement with TRUS than the other seven sequences (P <0.01). Nomogram overlay between the MRI and TRUS preplans showed good agreement; indicating volumes contoured on MRI preplan scan reliably predict how many seeds are needed for implant. Conclusion: Although MRI does not allow for determination of the actual implant geometry, it can give reliable volumes for seed ordering purposes. Our future work will investigate if MRI is sufficient to reliably replace TRUS preplanning in

Preventive effects of 125I seeds on benign restenosis following esophageal stent implantation in a dog model

PubMed Central

GAN, ZHEN; JING, JIAN; ZHU, GUANGYU; QIN, YONGLIN; TENG, GAOJUN; GUO, JINHE

2015-01-01

The present study aimed to evaluate the effects of iodine-125 (125I) seeds on the proliferation of primary esophageal fibroblasts in dogs, and to assess the safety and preventive efficacy of 125I seed-pre-loaded esophageal stents in benign restenosis following implantation. Primary fibroblasts were cultured with various 125I seed activities, which were then evaluated using cell proliferation and apoptosis assays as well as cell cycle analysis using Annexin V/propidium iodide (PI) double staining and PI staining. Prior to sacrification, animals were submitted to esophageal radiography under digital subtraction angiography. Esophageal tissues were collected and examined for macroscopic, microscopic and pathological alterations. The results demonstrated a significant and dose-dependent inhibition of fibroblast proliferation and increased apoptosis following exposure to 125I seeds. G0/G1 fibroblast populations increased in a dose-dependent manner following treatment with 125I seeds, in contrast to cells in S phase. Four weeks following implantation, α-smooth muscle actin and proliferating cell nuclear antigen expression levels in the experimental group were significantly lower compared with those in the control group; in addition, eight weeks following implantation, esophageal inner diameters were increased in the experimental group. 125I seeds inhibited proliferation of dog esophageal fibroblasts via cell cycle arrest and apoptosis. In conclusion, 125I seed-pre-loaded esophageal stents inhibited benign hyperplasia in the upper edge of the stent to a certain extent, which relieved benign restenosis following implantation with a good safety profile. PMID:25543838

SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watt, E; Spencer, DP; Meyer, T

Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P{sub TP}, may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ {sup 103}Pd and Nucletron selectSeed {sup 125}I) for which empiricalmore » altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P{sub TP}, were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P{sub TP} can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ {sup

Treatment-related symptoms during the first year following transperineal [sup 125]I prostate implantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleinberg, L.; Wallner, K.; Roy, J.

The purpose was to summarize the urinary, rectal, and sexual symptoms occurring during the first 12 months following [sup 125]I prostatic implantation. Thirty-one patients with Stage T[sub 1] or T[sub 2] prostatic carcinoma were evaluate for morbidity following computed tomography-guided transperineal [sup 125]I implants from 1988 to 1991. The median total activity used was 47 mCi (range 35-37 mCi). Toxicity was evaluated using a modification of the Radiation Therapy Oncology Group grading system. Nocturia was the most common treatment-related symptom, reported by 80% of patients within 2 months after implantation, and persisted at 12 months in 45% of the patients.more » Mild dysuria developed in 48% of patients within 2 months of implantation; two patients needed analgesics for their dysuria. Terazosin hydrochloride (2-10 mg qd) provided subjective improvement of urinary symptoms in seven of eight patients in whom it was tried. Rectal urgency, soft stools, and increased frequency of bowel movements was reported by 25% of the patients within 1-2 months after implantation. The incidence of assymptomatic rectal bleeding or ulceration occurring at any time after implantation was 47%, but resolved in all patients with expectant treatment. Self-limiting ulceration of the rectal mucosal occurred in 16%, but only one patient developed a prostato-rectal fistula, managed with an ileal conduit. Five of the 18 potent patients experienced discomfort on erection or ejaculation, beginning within several weeks of their implant. The discomfort resolved within 6 months in three of the patients, but persisted for 18 and 24 months in the other two. [sup 125]I implantation, as performed in this series, is generally associated with only mild-moderate genitourinary and rectal symptoms that may persist 6 months or more after implantation. 16 refs., 6 figs., 2 tabs.« less

SU-E-T-378: Evaluation of An Analytical Model for the Inter-Seed Attenuation Effect in 103-Pd Multi-Seed Implant Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safigholi, H; Soliman, A; Song, W

Purpose: Brachytherapy treatment planning systems based on TG-43 protocol calculate the dose in water and neglects the heterogeneity effect of seeds in multi-seed implant brachytherapy. In this research, the accuracy of a novel analytical model that we propose for the inter-seed attenuation effect (ISA) for 103-Pd seed model is evaluated. Methods: In the analytical model, dose perturbation due to the ISA effect for each seed in an LDR multi-seed implant for 103-Pd is calculated by assuming that the seed of interest is active and the other surrounding seeds are inactive. The cumulative dosimetric effect of all seeds is then summedmore » using the superposition principle. The model is based on pre Monte Carlo (MC) simulated 3D kernels of the dose perturbations caused by the ISA effect. The cumulative ISA effect due to multiple surrounding seeds is obtained by a simple multiplication of the individual ISA effect by each seed, the effect of which is determined by the distance from the seed of interest. This novel algorithm is then compared with full MC water-based simulations (FMCW). Results: The results show that the dose perturbation model we propose is in excellent agreement with the FMCW values for a case with three seeds separated by 1 cm. The average difference of the model and the FMCW simulations was less than 8%±2%. Conclusion: Using the proposed novel analytical ISA effect model, one could expedite the corrections due to the ISA dose perturbation effects during permanent seed 103-Pd brachytherapy planning with minimal increase in time since the model is based on multiplications and superposition. This model can be applied, in principle, to any other brachytherapy seeds. Further work is necessary to validate this model on a more complicated geometry as well.« less

WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warrell, G; Shvydka, D; Parsai, E I

Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapymore » seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less

Well-ionization chamber response relative to NIST air-kerma strength standard for prostate brachytherapy seeds.

PubMed

Mitch, M G; Zimmerman, B E; Lamperti, P J; Seltzer, S M; Coursey, B M

2000-10-01

The response of well-ionization chambers to the emissions of 103Pd and 125I radioactive seed sources used in prostate cancer brachytherapy has been measured. Calibration factors relating chamber response (current or dial setting) to measured air-kerma strength have been determined for seeds from nine manufacturers, each with different designs. Variations in well-ionization chamber response relative to measured air-kerma strength have been observed because of differences in the emitted energy spectrum due to both the radionuclide support material (125I seeds) and the mass ratio of 103Pd to 102Pd (103Pd seeds). Obtaining accurate results from quality assurance measurements using well-ionization chambers at a therapy clinic requires knowledge of such differences in chamber response as a function of seed design.

Intra-operative Iodine-125 prostatic implant following bilateral pelvic lymphadenectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwong, E.W.H.; Huh, S.H.; Nobler, M.P.

Sixty-five patients with prostatic adenocarcinoma Stages B and C were treated with intraoperative Iodine-125 prostatic implantation following bilateral pelvic lymphadenectomy. Pelvic nodal metastases were found in 31% of the patients. All the patients have been followed for a period of 1 1/2 to 6 years. Serial digital rectal examination revealed complete regression of the palpable disease in 15% of the patients at 6 months, 47% at 1 year, and 87% at 2 years. Post-operative complications were also evaluated: 13% of the patients became sexually impotent, 11% had impaired potency after the procedure, and 26% of patients complained of dry ejaculation;more » and 17% developed scrotal and/or penile swelling, which persisted up to 14 months, but usually subsided within 5 months. Two patients developed local recurrence.« less

SU-F-T-42: MRI and TRUS Image Fusion as a Mode of Generating More Accurate Prostate Contours

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petronek, M; Purysko, A; Balik, S

Purpose: Transrectal Ultrasound (TRUS) imaging is utilized intra-operatively for LDR permanent prostate seed implant treatment planning. Prostate contouring with TRUS can be challenging at the apex and base. This study attempts to improve accuracy of prostate contouring with MRI-TRUS fusion to prevent over- or under-estimation of the prostate volume. Methods: 14 patients with previous MRI guided prostate biopsy and undergone an LDR permanent prostate seed implant have been selected. The prostate was contoured on the MRI images (1 mm slice thickness) by a radiologist. The prostate was also contoured on TRUS images (5 mm slice thickness) during LDR procedure bymore » a urologist. MRI and TRUS images were rigidly fused manually and the prostate contours from MRI and TRUS were compared using Dice similarity coefficient, percentage volume difference and length, height and width differences. Results: The prostate volume was overestimated by 8 ± 18% (range: 34% to −25%) in TRUS images compared to MRI. The mean Dice was 0.77 ± 0.09 (range: 0.53 to 0.88). The mean difference (TRUS-MRI) in the prostate width was 0 ± 4 mm (range: −11 to 5 mm), height was −3 ± 6 mm (range: −13 to 6 mm) and length was 6 ± 6 (range: −10 to 16 mm). Prostate was overestimated with TRUS imaging at the base for 6 cases (mean: 8 ± 4 mm and range: 5 to 14 mm), at the apex for 6 cases (mean: 11 ± 3 mm and range: 5 to 15 mm) and 1 case was underestimated at both base and apex by 4 mm. Conclusion: Use of intra-operative TRUS and MRI image fusion can help to improve the accuracy of prostate contouring by accurately accounting for prostate over- or under-estimations, especially at the base and apex. The mean amount of discrepancy is within a range that is significant for LDR sources.« less

SU-G-IeP1-01: A Novel MRI Post-Processing Algorithm for Visualization of the Prostate LDR Brachytherapy Seeds and Calcifications Based On B0 Field Inhomogeneity Correction and Hough Transform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nosrati, R; Sunnybrook Health Sciences Centre, Toronto, Ontario; Soliman, A

Purpose: This study aims at developing an MRI-only workflow for post-implant dosimetry of the prostate LDR brachytherapy seeds. The specific goal here is to develop a post-processing algorithm to produce positive contrast for the seeds and prostatic calcifications and differentiate between them on MR images. Methods: An agar-based phantom incorporating four dummy seeds (I-125) and five calcifications of different sizes (from sheep cortical bone) was constructed. Seeds were placed arbitrarily in the coronal plane. The phantom was scanned with 3T Philips Achieva MR scanner using an 8-channel head coil array. Multi-echo turbo spin echo (ME-TSE) and multi-echo gradient recalled echomore » (ME-GRE) sequences were acquired. Due to minimal susceptibility artifacts around seeds, ME-GRE sequence (flip angle=15; TR/TE=20/2.3/2.3; resolution=0.7×0.7×2mm3) was further processed.The induced field inhomogeneity due to the presence of titaniumencapsulated seeds was corrected using a B0 field map. B0 map was calculated using the ME-GRE sequence by calculating the phase difference at two different echo times. Initially, the product of the first echo and B0 map was calculated. The features corresponding to the seeds were then extracted in three steps: 1) the edge pixels were isolated using “Prewitt” operator; 2) the Hough transform was employed to detect ellipses approximately matching the dimensions of the seeds and 3) at the position and orientation of the detected ellipses an ellipse was drawn on the B0-corrected image. Results: The proposed B0-correction process produced positive contrast for the seeds and calcifications. The Hough transform based on Prewitt edge operator successfully identified all the seeds according to their ellipsoidal shape and dimensions in the edge image. Conclusion: The proposed post-processing algorithm successfully visualized the seeds and calcifications with positive contrast and differentiates between them according to their shapes. Further

SU-C-17A-02: Sirius MRI Markers for Prostate Post-Implant Assessment: MR Protocol Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, T; Wang, J; Kudchadker, R

Purpose: Currently, CT is used to visualize prostate brachytherapy sources, at the expense of accurate structure contouring. MRI is superior to CT for anatomical delineation, but the sources appear as voids on MRI images. Previously we have developed Sirius MRI markers (C4 Imaging) to replace spacers to assist source localization on MRI images. Here we develop an MRI pulse sequence protocol that enhances the signal of these markers to enable MRI-only post-implant prostate dosimetric analysis. Methods: To simulate a clinical scenario, a CIRS multi-modality prostate phantom was implanted with 66 markers and 86 sources. The implanted phantom was imaged onmore » both 1.5T and 3.0T GE scanners under various conditions, different pulse sequences (2D fast spin echo [FSE], 3D balanced steadystate free precession [bSSFP] and 3D fast spoiled gradient echo [FSPGR]), as well as varying amount of padding to simulate various patient sizes and associated signal fall-off from the surface coil elements. Standard FSE sequences from the current clinical protocols were also evaluated. Marker visibility, marker size, intra-marker distance, total scan time and artifacts were evaluated for various combinations of echo time, repetition time, flip angle, number of excitations, bandwidth, slice thickness and spacing, fieldof- view, frequency/phase encoding steps and frequency direction. Results: We have developed a 3D FSPGR pulse sequence that enhances marker signal and ensures the integrity of the marker shape while maintaining reasonable scan time. For patients contraindicated for 3.0T, we have also developed a similar sequence for 1.5T scanners. Signal fall-off with distance from prostate to coil can be compensated mainly by decreasing bandwidth. The markers are not visible using standard FSE sequences. FSPGR sequences are more robust for consistent marker visualization as compared to bSSFP sequences. Conclusion: The developed MRI pulse sequence protocol for Sirius MRI markers assists

Role of step size and max dwell time in anatomy based inverse optimization for prostate implants

PubMed Central

Manikandan, Arjunan; Sarkar, Biplab; Rajendran, Vivek Thirupathur; King, Paul R.; Sresty, N.V. Madhusudhana; Holla, Ragavendra; Kotur, Sachin; Nadendla, Sujatha

2013-01-01

In high dose rate (HDR) brachytherapy, the source dwell times and dwell positions are vital parameters in achieving a desirable implant dose distribution. Inverse treatment planning requires an optimal choice of these parameters to achieve the desired target coverage with the lowest achievable dose to the organs at risk (OAR). This study was designed to evaluate the optimum source step size and maximum source dwell time for prostate brachytherapy implants using an Ir-192 source. In total, one hundred inverse treatment plans were generated for the four patients included in this study. Twenty-five treatment plans were created for each patient by varying the step size and maximum source dwell time during anatomy-based, inverse-planned optimization. Other relevant treatment planning parameters were kept constant, including the dose constraints and source dwell positions. Each plan was evaluated for target coverage, urethral and rectal dose sparing, treatment time, relative target dose homogeneity, and nonuniformity ratio. The plans with 0.5 cm step size were seen to have clinically acceptable tumor coverage, minimal normal structure doses, and minimum treatment time as compared with the other step sizes. The target coverage for this step size is 87% of the prescription dose, while the urethral and maximum rectal doses were 107.3 and 68.7%, respectively. No appreciable difference in plan quality was observed with variation in maximum source dwell time. The step size plays a significant role in plan optimization for prostate implants. Our study supports use of a 0.5 cm step size for prostate implants. PMID:24049323

Comparison of Dosimetric and Biologic Effective Dose Parameters for Prostate and Urethra Using {sup 131}Cs and {sup 125}I for Prostate Permanent Implant Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sahgal, Arjun; Department of Radiation Oncology, Odette Cancer Centre at Sunnybrook Hospital, University of Toronto, Toronto, ON; Jabbari, Siavash

2008-09-01

Purpose: To compare the urethral and prostate absolute and biologic effective doses (BEDs) for {sup 131}Cs and {sup 125}I prostate permanent implant brachytherapy (PPI). Methods and Materials: Eight previously implanted manually planned {sup 125}I PPI patients were replanned manually with {sup 131}Cs, and re-planned using Inverse Planning Simulated Annealing. {sup 131}Cs activity and the prescribed dose (115 Gy) were determined from that recommended by IsoRay. The BED was calculated for the prostate and urethra using an {alpha}/{beta} ratio of 2 and was also calculated for the prostate using an {alpha}/{beta} ratio of 6 and a urethral {alpha}/{beta} ratio of 2.more » The primary endpoints of this study were the prostate D{sub 90} BED (pD{sub 90}BED) and urethral D{sub 30} BED normalized to the maximal potential prostate D{sub 90} BED (nuD{sub 30}BED). Results: The manual plan comparison ({alpha}/{beta} = 2) yielded no significant difference in the prostate D{sub 90} BED (median, 192 Gy{sub 2} for both isotopes). No significant difference was observed for the nuD{sub 30}BED (median, 199 Gy{sub 2} and 202 Gy{sub 2} for {sup 125}I and {sup 131}Cs, respectively). For the inverse planning simulated annealing plan comparisons ({alpha}/{beta} 2), the prostate D{sub 90} BED was significantly lower with {sup 131}Cs than with {sup 125}I (median, 177 Gy{sub 2} vs. 187 Gy{sub 2}, respectively; p = 0.01). However, the nuD{sub 30}BED was significantly greater with {sup 131}Cs than with {sup 125}I (median, 192 Gy{sub 2} vs. 189 Gy{sub 2}, respectively; p = 0.01). Both the manual and the inverse planning simulated annealing plans resulted in a significantly lower prostate D{sub 90} BED (p = 0.01) and significantly greater nuD{sub 30}BED for {sup 131}Cs (p = 0.01), compared with {sup 125}I, when the prostate {alpha}/{beta} ratio was 6 and the urethral {alpha}/{beta} ratio was 2. Conclusion: This report highlights the controversy in comparing the dose to both the prostate and the

A digital model individual template and CT-guided 125I seed implants for malignant tumors of the head and neck.

PubMed

Huang, Ming-Wei; Liu, Shu-Ming; Zheng, Lei; Shi, Yan; Zhang, Jie; Li, Yan-Sheng; Yu, Guang-Yan; Zhang, Jian-Guo

2012-11-01

To enhance the accuracy of radioactive seed implants in the head and neck, a digital model individual template, containing information simultaneously on needle pathway and facial features, was designed to guide implantation with CT imaging. Thirty-one patients with recurrent and local advanced malignant tumors of head and neck after prior surgery and radiotherapy were involved in this study. Before (125)I implants, patients received CT scans based on 0.75mm thickness. And the brachytherapy treatment planning system (BTPS) software was used to make the implantation plan based on the CT images. Mimics software and Geomagic software were used to read the data containing CT images and implantation plan, and to design the individual template. Then the individual template containing the information of needle pathway and face features simultaneously was made through rapid prototyping (RP) technique. All patients received (125)I seeds interstitial implantation under the guide of the individual template and CT. The individual templates were positioned easily and accurately, and were stable. After implants, treatment quality evaluation was made by CT and TPS. The seeds and dosages distribution (D(90),V(100),V(150)) were well meet the treatment requirement. Clinical practice confirms that this approach can facilitate easier and more accurate implantation.

The side effects and complications of percutaneous iodine-125 seeds implantation under CT-guide for patients with advanced pancreatic cancer.

PubMed

Lv, Wei-Fu; Lu, Dong; Xiao, Jing-Kun; Mukhiya, Gauri; Tan, Zhong-Xiao; Cheng, De-Lei; Zhou, Chun-Ze; Zhang, Xing-Min; Zhang, Zheng-Feng; Hou, Chang-Long

2017-12-01

The present study investigates the side effects and complications of computed tomography (CT)-guided percutaneous iodine-125 (I-125) seeds implantation for advanced pancreatic cancer. The clinical data were retrospectively analyzed for patients treated with implantation of I-125 seeds under CT-guide in our hospital from May 2010 to April 2015. The side effects and complications were collected and their possible reasons were analyzed. A total of 78 patients were enrolled. The side effects were categorized as fever in 29 cases (37.18%), abdominal pain in 26 cases (33.33%), nausea and vomiting in 9 cases (11.54%), diarrhea in 5 cases (6.41%), and constipation in 4 cases (5.13%). Complications were composed of pancreatitis in 9 cases (11.54%), infection in 5 cases (6.41%), seed migration in 2 cases (2.56%), intestinal perforation in 1 case (1.28%), and intestinal obstruction in 1 case. The incidence of complication was 23.08% (18/78). The difference in incidence of complication was statistically significant between patients implanted with ≤27 seeds and those with >27 seeds (P = .032). The side effects and complications frequently occur in implantation of I-125 seeds for patients with advanced pancreatic cancer. More concern should be given to the patients treated by this technique. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

SU-E-J-39: Dosimetric Benefit of Implanted Marker-Based CBCT Setup for Definitive Prostatic Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhen, H; Wu, Z; Bluemenfeld, P

Purpose Daily setup for definitive prostatic radiotherapy is challenged by suboptimal visibility of the prostate boundary and daily variation of rectum shape and position. For patients with improved bowel preparation, we conducted a dosimetric comparison between prostate implanted marker (IM)-based daily setup and anterior rectal wall (ARW)-based setup, with the hypothesis that the former leads to adequate target coverage with better rectal sparing. Methods Five IMRT/VMAT prostate cases with implanted markers were selected for analysis. Daily CBCT showed improvement of the rectal volume compared to planning CT. For each patient, the prostate and rectum were contoured on three CBCT imagesmore » (fraction 5/15/25) with subsequent physician review. The CBCTs were then registered to a planning CT using IM-based registration. The deviation of ARW positions from planning CT to CBCT were analyzed at various sup-inf levels (−1.8 cm to 1.8 cm from level of prostate center). To estimate the potential dosimetric impact from ARW-based setup, the treatment plans were recalculated using A-P shifts ranging from −1mm to +6mm. Clinically important rectum DVH values including Dmax, D3cc and Dmean were computed. Results For the studied patients, we observed on average 32% rectum volume reduction from planning CT to CBCT. As a Results, the ARW on average shifts posteriorly by −1mm to +5mm, depending on the sup-inf level of observation, with larger shifts observed at more superior levels. Recalculation shows that when ARW shifts 1mm posteriorly, ARW-based CBCT setup leads to a 1.0%, 4.2%, and 3.2% increase in rectum Dmax, D3cc, and Dmean, respectively, compared to IM-based setup. The dosimetric deviations increase to 4.7%, 25.8% and 24.7% when ARW shifts 6mm posteriorly. No significant prostate-only dose difference was observed. Conclusion For patients with improved bowel preparation, IM-based CBCT setup leads to accurate prostate coverage along with significantly lower rectal

Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

NASA Astrophysics Data System (ADS)

Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

2012-09-01

To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

Cell Seeding Densities in Autologous Chondrocyte Implantation Techniques for Cartilage Repair.

PubMed

Foldager, Casper Bindzus; Gomoll, Andreas H; Lind, Martin; Spector, Myron

2012-04-01

Cartilage repair techniques have been among the most intensively investigated treatments in orthopedics for the past decade, and several different treatment modalities are currently available. Despite the extensive research effort within this field, the generation of hyaline cartilage remains a considerable challenge. There are many parameters attendant to each of the cartilage repair techniques that can affect the amount and types of reparative tissue generated in the cartilage defect, and some of the most fundamental of these parameters have yet to be fully investigated. For procedures in which in vitro-cultured autologous chondrocytes are implanted under a periosteal or synthetic membrane cover, or seeded onto a porous membrane or scaffold, little is known about how the number of cells affects the clinical outcome. Few published clinical studies address the cell seeding density that was employed. The principal objective of this review is to provide an overview of the cell seeding densities used in cell-based treatments currently available in the clinic for cartilage repair. Select preclinical studies that have informed the use of specific cell seeding densities in the clinic are also discussed.

[CT guidance 125I seed implantation for pelvic recurrent rectal cancer assisted by 3D printing individual non-coplanar template].

PubMed

Wang, H; Wang, J J; Jiang, Y L; Tian, S Q; Ji, Z; Guo, F X; Sun, H T; Fan, J H; Xu, Y P

2016-12-20

Objective: To analyze the difference of dosimetric parameters between pre-plan and post-plan of 125 I radioactive seed implantation assisted by 3D printing individual non-coplanar template (3D printing template) for locally recurrent rectal cancer (LRRC). Methods: From February 2016 to April 2016, a total of 10 patients with locally recurrent rectal cancer received 125 I seeds implantation under CT guidance assisted by 3D printing template in Department of Radiation Oncology, Peking University Third Hospital.Each patient underwent CT simulation, three-dimentional treatment planning pre-implantation, 3D printing template design, radioactive seed implantation assisted by 3D printing template and dosimetric verification post implantation. The median activity of seed was 0.63 mCi (0.58 to 0.7 mCi) (2.15- 2.59×10 7 Bq), and the median number of seeds was 80 (19 to 192). D 90 , D 100 , V 100 , V 150 , CI, EI, HI, D 5cc , D 2cc of bladder and bowel of pre-plan and post-plan were calculated, respectively.Paired t test was used to evaluate the difference of dosimetric parameters between pre-plan and post-plan. Results: The median D 90 of pre-plan and post-plan were 13 761.0 and 12 798.8 cGy, respectively.The median D 100 of pre-plan and post-plan were 5 293.6 and 5 397.9 cGy, respectively.The median V 100 of pre-plan and post-plan were 90.0% and 90.0%, respectively.The median V 150 of pre-plan and post-plan were 63.8% and 62.4%, respectively.The median CI of pre-plan and post-plan were 0.73 and 0.67.The median EI of pre-plan and post-plan were 0.22 and 0.30, respectively. The median HI of pre-plan and post-plan were 0.29 and 0.31.The median bladder D 2cc of pre-plan and post-plan were 3 088.8 and 4 240.4 cGy, respectively.The median bowel D 2cc of pre-plan and post-plan were 7 051.6 and 7 903.9 cGy, respectively. Conclusions: 3D printing template might be helpful for locally recurrent rectal cancer patients who received 125 I radioactive seed implantation assisted by 3D

Three-dimensional verification of ¹²⁵I seed stability after permanent implantation in the parotid gland and periparotid region.

PubMed

Fan, Yi; Huang, Ming-Wei; Zheng, Lei; Zhao, Yi-Jiao; Zhang, Jian-Guo

2015-11-24

To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data. Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive (125)I interstitial brachytherapy were retrospectively reviewed in this study. Serial CT data were obtained during follow-up. Mimics and Geomagic Studio software were used for seed reconstruction and stability analysis, respectively. Seed loss and/or migration outside of the treated area were absent in all patients during follow-up (23-71 months). Total seed cluster volume was maximized on day 1 post-implantation due to edema and decreased significantly by an average of 13.5 % (SD = 9.80 %; 95 % CI, 6.82-17.68 %) during the first two months and an average of 4.5 % (SD = 3.60 %; 95 % CI, 2.29-6.29 %) during the next four months. Volume stabilized over the subsequent six months. (125)I seed number and location were stable with a general volumetric shrinkage tendency in the parotid gland and periparotid region. Three-dimensional seed reconstruction of CT images is feasible for visualization and verification of implanted seeds in parotid brachytherapy.

Trans-bronchoscopy with implantation of 125I radioactive seeds in patients with pulmonary atelectasis induced by lung cancer.

PubMed

Lu, Mingjian; Pu, Deli; Zhang, Weidong; Liao, Jiangrong; Zhang, Tao; Yang, Guang; Liu, Zhenyin; Singh, Sristi; Gao, Fei; Zhang, Fujun

2015-07-01

To evaluate the role of low-dose-rate interstitial brachytherapy using trans-bronchoscope 125 I radioactive seeds implantation in patients with pulmonary atelectasis induced by lung cancer, in terms of feasibility, safety, quality of life (QOL), and survival time. Between April 2008 and June 2011, 15 patients from two medical institutions that had obstructive pulmonary atelectasis caused by inoperable lung cancer were assigned to receive 125 I implantation endoluminal brachytherapy by bronchoscopy. Subsequent to the implantation of 125 I seeds, the outcomes were measured in terms of procedure success rate, reopening of atelectasis, complications associated with the procedure, Karnofsky performance status (KPS) scores and survival time. The surgical procedure was successfully performed in all 15 patients. No procedure-associated mortality occurred and the complications were mild and considered acceptable. Irritable cough and temporary increase of hemoptysis occurred in 11 (73.3%) and 10 (66.7%) patients respectively, and were the most common complications. The pulmonary atelectasis reopening rate subsequent to the procedure was 86.7, 76.9, 80.0, 75.0 and 50.0% at 2, 6, 12, 18 and 24 months, respectively. The KPS score significantly improved following the implantation of 125 I seeds and the duration of improvement ranged between 3 and 27 months. The median and mean survival times were 15.6 and 16 months, respectively. Actuarial survival rates at 6, 12 and 24 months after the procedure were 86.7, 66.7 and 13.3%, respectively. In patients with advanced lung cancer and those presenting with obstructive pulmonary atelectasis, treatment with intraluminal implantation of 125 I seeds is a safe and effective therapy option with easy accessibility.

Trans-bronchoscopy with implantation of 125I radioactive seeds in patients with pulmonary atelectasis induced by lung cancer

PubMed Central

LU, MINGJIAN; PU, DELI; ZHANG, WEIDONG; LIAO, JIANGRONG; ZHANG, TAO; YANG, GUANG; LIU, ZHENYIN; SINGH, SRISTI; GAO, FEI; ZHANG, FUJUN

2015-01-01

To evaluate the role of low-dose-rate interstitial brachytherapy using trans-bronchoscope 125I radioactive seeds implantation in patients with pulmonary atelectasis induced by lung cancer, in terms of feasibility, safety, quality of life (QOL), and survival time. Between April 2008 and June 2011, 15 patients from two medical institutions that had obstructive pulmonary atelectasis caused by inoperable lung cancer were assigned to receive 125I implantation endoluminal brachytherapy by bronchoscopy. Subsequent to the implantation of 125I seeds, the outcomes were measured in terms of procedure success rate, reopening of atelectasis, complications associated with the procedure, Karnofsky performance status (KPS) scores and survival time. The surgical procedure was successfully performed in all 15 patients. No procedure-associated mortality occurred and the complications were mild and considered acceptable. Irritable cough and temporary increase of hemoptysis occurred in 11 (73.3%) and 10 (66.7%) patients respectively, and were the most common complications. The pulmonary atelectasis reopening rate subsequent to the procedure was 86.7, 76.9, 80.0, 75.0 and 50.0% at 2, 6, 12, 18 and 24 months, respectively. The KPS score significantly improved following the implantation of 125I seeds and the duration of improvement ranged between 3 and 27 months. The median and mean survival times were 15.6 and 16 months, respectively. Actuarial survival rates at 6, 12 and 24 months after the procedure were 86.7, 66.7 and 13.3%, respectively. In patients with advanced lung cancer and those presenting with obstructive pulmonary atelectasis, treatment with intraluminal implantation of 125I seeds is a safe and effective therapy option with easy accessibility. PMID:26171002

Potential ameliorative effects of grape seed-derived polyphenols against cadmium induced prostatic deficits.

PubMed

Lei, Yongfang; Chen, Qian; Chen, Jinglou; Liu, Dong

2017-07-01

Grape (Vitis vinifera) is consumed as fruit and wine for people. In this study, rat model of prostatic deficits was induced by orally receiving 60mg/L cadmium chlorine (CdCl 2 ) through drinking water for 20 weeks. Grape seed-derived polyphenols extract (GSP) was orally given for 20 weeks. Finally, the prostatic levels of E-cadherin, fibronectin, and α-smooth muscle actin were measured by immunohistochemical and qPCR analysis. The oxidative stress was measured by detecting the levels of malondialdehyde, nitric oxide, reduced glutathione/oxidized glutathione and enzymatic antioxidant status. Additionally, the prostatic expressions of transforming growth factor-β1 (TGF-β1), type I TGF-β receptor (TGF-βRI), Smad3, phosphorylation-Smad3 (p-Smad3), Smad7, nuclear related factor-2 (Nrf-2), heme oxygenase-1 (HO-1) and γ-glutamate cysteine ligase catalytic subunit (γ-GCLC) were measured by western blot. The levels of microRNA (miR)-133a/b were measured by qPCR. It was observed that GSP ameliorated the prostatic oxidative stress and fibrosis induced by CdCl 2 . GSP also inhibited the over-generation of TGF-β1 and p-Smad3, as well as enhanced the levels of Smad7, Nrf-2, HO-1, γ-GCLC and miR-133a/b. These results showed that GSP could attenuate Cd-induced prostatic deficits. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A Biodistribution and Toxicity Study of Cobalt Dichloride-N-Acetyl Cysteine in an Implantable MRI Marker for Prostate Cancer Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, Steven J., E-mail: sjfrank@mdanderson.org; Johansen, Mary J.; Martirosyan, Karen S.

2013-03-15

Purpose: C4, a cobalt dichloride-N-acetyl cysteine complex, is being developed as a positive-signal magnetic resonance imaging (MRI) marker to localize implanted radioactive seeds in prostate brachytherapy. We evaluated the toxicity and biodistribution of C4 in rats with the goal of simulating the systemic effects of potential leakage from C4 MRI markers within the prostate. Methods and Materials: 9-μL doses (equivalent to leakage from 120 markers in a human) of control solution (0.9% sodium chloride), 1% (proposed for clinical use), and 10% C4 solution were injected into the prostates of male Sprague-Dawley rats via laparotomy. Organ toxicity and cobalt disposition inmore » plasma, tissues, feces, and urine were evaluated. Results: No C4-related morbidity or mortality was observed in the biodistribution arm (60 rats). Biodistribution was measurable after 10% C4 injection: cobalt was cleared rapidly from periprostatic tissue; mean concentrations in prostate were 163 μg/g and 268 μg/g at 5 and 30 minutes but were undetectable by 60 minutes. Expected dual renal-hepatic elimination was observed, with percentages of injected dose recovered in tissues of 39.0 ± 5.6% (liver), >11.8 ± 6.5% (prostate), and >5.3 ± 0.9% (kidney), with low plasma concentrations detected up to 1 hour (1.40 μg/mL at 5-60 minutes). Excretion in urine was 13.1 ± 4.6%, with 3.1 ± 0.54% recovered in feces by 24 hours. In the toxicity arm, 3 animals died in the control group and 1 each in the 1% and 10% groups from surgical or anesthesia-related complications; all others survived to scheduled termination at 14 days. No C4-related adverse clinical signs or organ toxicity were observed. Conclusion: C4-related toxicity was not observed at exposures at least 10-fold the exposure proposed for use in humans. These data demonstrating lack of systemic toxicity with dual routes of elimination in the event of in situ rupture suggest that C4 warrants further investigation as an MRI marker for

Dose escalation in permanent brachytherapy for prostate cancer: dosimetric and biological considerations

NASA Astrophysics Data System (ADS)

Li, X. Allen; Wang, Jian Z.; Stewart, Robert D.; Di Biase, Steven J.

2003-09-01

No prospective dose escalation study for prostate brachytherapy (PB) with permanent implants has been reported. In this work, we have performed a dosimetric and biological analysis to explore the implications of dose escalation in PB using 125I and 103Pd implants. The concept of equivalent uniform dose (EUD), proposed originally for external-beam radiotherapy (EBRT), is applied to low dose rate brachytherapy. For a given 125I or 103Pd PB, the EUD for tumour that corresponds to a dose distribution delivered by EBRT is calculated based on the linear quadratic model. The EUD calculation is based on the dose volume histogram (DVH) obtained retrospectively from representative actual patient data. Tumour control probabilities (TCPs) are also determined in order to compare the relative effectiveness of different dose levels. The EUD for normal tissue is computed using the Lyman model. A commercial inverse treatment planning algorithm is used to investigate the feasibility of escalating the dose to prostate with acceptable dose increases in the rectum and urethra. The dosimetric calculation is performed for five representative patients with different prostate sizes. A series of PB dose levels are considered for each patient using 125I and 103Pd seeds. It is found that the PB prescribed doses (minimum peripheral dose) that give an equivalent EBRT dose of 64.8, 70.2, 75.6 and 81 Gy with a fraction size of 1.8 Gy are 129, 139, 150 and 161 Gy for 125I and 103, 112, 122 and 132 Gy for 103Pd implants, respectively. Estimates of the EUD and TCP for a series of possible prescribed dose levels (e.g., 145, 160, 170 and 180 Gy for 125I and 125, 135, 145 and 155 for 103Pd implants) are tabulated. The EUD calculation was found to depend strongly on DVHs and radiobiological parameters. The dosimetric calculations suggest that the dose to prostate can be escalated without a substantial increase in both rectal and urethral dose. For example, increasing the PB prescribed dose from 145 to

SU-E-T-55: Biological Equivalent Dose (BED) Comparison Between Permanent Interstitial Brachytherapy and Conventional External Beam Radiotherapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X; Rahimian, J; Cosmatos, H

2014-06-01

Purpose: The goal of this research is to calculate and compare the Biological Equivalent Dose (BED) between permanent prostate Iodine-125 implant brachytherapy as monotherapy with the BED of conventional external beam radiation therapy (EBRT). Methods: A retrospective study of 605 patients treated with Iodine-125 seed implant was performed in which physician A treated 274 patients and physician B treated 331 patients. All the Brachytherapy treatment plans were created using VariSeed 8 planning system. The Iodine-125 seed source activities and loading patterns varied slightly between the two physicians. The prescription dose is 145 Gy to PTV for each patient. The BEDmore » and Tumor Control Probability (TCP) were calculated based on the TG 137 formulas. The BED for conventional EBRT of the prostate given in our institution in 2Gy per fraction for 38 fractions was calculated and compared. Results: Physician A treated 274 patients with an average BED of 123.92±0.87 Gy and an average TCP of 99.20%; Physician B treated 331 patients with an average BED of 124.87±1.12 Gy and an average TCP of 99.30%. There are no statistically significant differences (T-Test) between the BED and TCP values calculated for these two group patients.The BED of the patients undergoing conventional EBRT is calculated to be 126.92Gy. The BED of the patients treated with permanent implant brachytherapy and EBRT are comparable. Our BED and TCP values are higher than the reported values by TG 137 due to higher Iodine-125 seed activity used in our institution. Conclusion: We calculated the BED,a surrogate of the biological response to a permanent prostate brachytherapy using TG 137 formulas and recommendation. The TCP of better than 99% is calculated for these patients. A clinical outcome study of these patients correlating the BED and TCP values with PSA and Gleason Levels as well as patient survival is warranted.« less

Praseodymium-142 glass seeds for the brachytherapy of prostate cancer

NASA Astrophysics Data System (ADS)

Jung, Jae Won

A beta-emitting glass seed was proposed for the brachytherapy treatment of prostate cancer. Criteria for seed design were derived and several beta-emitting nuclides were examined for suitability. 142Pr was selected as the isotope of choice. Seeds 0.08 cm in diameter and 0.9 cm long were manufactured for testing. The seeds were activated in the Texas A&M University research reactor. The activity produced was as expected when considering the meta-stable state and epi-thermal neutron flux. The MCNP5 Monte Carlo code was used to calculate the quantitative dosimetric parameters suggested in the American Association of Physicists in Medicine (AAPM) TG-43/60. The Monte Carlo calculation results were compared with those from a dose point kernel code. The dose profiles agree well with each other. The gamma dose of 142Pr was evaluated. The gamma dose is 0.3 Gy at 1.0 cm with initial activity of 5.95 mCi and is insignificant to other organs. Measurements were performed to assess the 2-dimensional axial dose distributions using Gafchromic radiochromic film. The radiochromic film was calibrated using an X-ray machine calibrated against a National Institute of Standards and Technology (NIST) traceable ion chamber. A calibration curve was derived using a least squares fit of a second order polynomial. The measured dose distribution agrees well with results from the Monte Carlo simulation. The dose was 130.8 Gy at 6 mm from the seed center with initial activity of 5.95 mCi. AAPM TG-43/60 parameters were determined. The reference dose rate for 2 mm and 6 mm were 0.67 and 0.02 cGy/s/mCi, respectively. The geometry function, radial dose function and anisotropy function were generated.

[Application of (125)I seeds combined with biliary stent implantation in the treatment of malignant obstructive jaundice].

PubMed

Wang, T; Liu, S; Zheng, Y B; Song, X P; Jiang, W J; Sun, B L; Wang, L G

2016-03-23

To study the feasibility and therapeutic effect of the application of (125)I seeds combined with biliary stent implantation on the treatment of malignant obstructive jaundice. Fifty patients with malignant obstructive jaundice treated from September 2010 to February 2013 in Yantai Yuhuangding Hospital were included in this study. Among them, 24 patients received biliary stent implantation combined with (125)I seeds intraluminal brachytherapy as experimental group, and 26 were treated by biliary stent implantation as control group.The total bilirubin, direct bilirubin and tumor markers (CA-199, CA-242, CEA) before and after surgery, the biliary stent patency status was assessed, and the survival time was evaluated. The 24 patients in experimental group were implanted with 30 (125)I seeds successfully in a total of 450 seeds. Jaundice was improved greatly in both groups. The CA-199 and CA-242 after treatment in the experimental group were significantly decreased than that before treatment (P=0.003 and P=0.004). CEA was also decreased, but showed no statistical significance (P>0.05). There were no significant improvement comparing the CA-199, CA-242 and CEA before and 2 months after surgery in the control group (P>0.05). The rate of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (P=0.048). The mean biliary stent patency time in the experimental group was 9.84 months (range 1-15.5 months). The mean biliary stent patency time in the control group was 5.57 months (range 0.8-9 months). There was a significant difference between the two groups (P=0.018). The median survival time was 10.2 months in the experimental group and 5.4 months in the control group (P<0.05). (125)I seeds combined with biliary stent implantation can inhibit the proliferation of vascular endothelial cells and the growth of tumor effectively, and can prolong the biliary stent patency time and the survival time obviously for patients with

Intra-operative 3D guidance and edema detection in prostate brachytherapy using a non-isocentric C-arm

PubMed Central

Jain, A.; Deguet, A.; Iordachita, I.; Chintalapani, G.; Vikal, S.; Blevins, J.; Le, Y.; Armour, E.; Burdette, C.; Song, D.; Fichtinger, G.

2015-01-01

Purpose Brachytherapy (radioactive seed insertion) has emerged as one of the most effective treatment options for patients with prostate cancer, with the added benefit of a convenient outpatient procedure. The main limitation in contemporary brachytherapy is faulty seed placement, predominantly due to the presence of intra-operative edema (tissue expansion). Though currently not available, the capability to intra-operatively monitor the seed distribution, can make a significant improvement in cancer control. We present such a system here. Methods Intra-operative measurement of edema in prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate. Seeds were reconstructed using a typical non-isocentric C-arm, and exported to a commercial brachytherapy treatment planning system. Technical obstacles for 3D reconstruction on a non-isocentric C-arm include pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction; and C-arm to TRUS registration. Results In precision-machined hard phantoms with 40–100 seeds and soft tissue phantoms with 45–87 seeds, we correctly reconstructed the seed implant shape with an average 3D precision of 0.35 mm and 0.24 mm, respectively. In a DoD Phase-1 clinical trial on six patients with 48–82 planned seeds, we achieved intra-operative monitoring of seed distribution and dosimetry, correcting for dose inhomogeneities by inserting an average of over four additional seeds in the six enrolled patients (minimum 1; maximum 9). Additionally, in each patient, the system automatically detected intra-operative seed migration induced due to edema (mean 3.84 mm, STD 2.13 mm, Max 16.19 mm). Conclusions The proposed system is the first of a kind that makes intra-operative detection of edema (and subsequent re-optimization) possible on any typical non-isocentric C-arm, at negligible additional cost to the existing clinical installation. It achieves a

Positive visualization of implanted devices with susceptibility gradient mapping using the original resolution.

PubMed

Varma, Gopal; Clough, Rachel E; Acher, Peter; Sénégas, Julien; Dahnke, Hannes; Keevil, Stephen F; Schaeffter, Tobias

2011-05-01

In magnetic resonance imaging, implantable devices are usually visualized with a negative contrast. Recently, positive contrast techniques have been proposed, such as susceptibility gradient mapping (SGM). However, SGM reduces the spatial resolution making positive visualization of small structures difficult. Here, a development of SGM using the original resolution (SUMO) is presented. For this, a filter is applied in k-space and the signal amplitude is analyzed in the image domain to determine quantitatively the susceptibility gradient for each pixel. It is shown in simulations and experiments that SUMO results in a better visualization of small structures in comparison to SGM. SUMO is applied to patient datasets for visualization of stent and prostate brachytherapy seeds. In addition, SUMO also provides quantitative information about the number of prostate brachytherapy seeds. The method might be extended to application for visualization of other interventional devices, and, like SGM, it might also be used to visualize magnetically labelled cells. Copyright © 2010 Wiley-Liss, Inc.

CT-Guided Radioactive {sup 125}I Seed Implantation Therapy of Symptomatic Retroperitoneal Lymph Node Metastases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhongmin, E-mail: wzm0722@hotmail.com; Lu, Jian; Gong, Ju

2013-04-12

PurposeThis study explored the clinical efficacy of CT-guided radioactive {sup 125}I seed implantation in treating patients with symptomatic retroperitoneal lymph node metastases.MethodsTwenty-five patients with pathologically confirmed malignant tumors received CT-guided radioactive {sup 125}I seed implantation to treat metastatic lymph nodes. The diameter of the metastatic lymph nodes ranged from 1.5 to 4.5 cm. Treatment planning system (TPS) was used to reconstruct the three-dimensional image of the tumor and then calculate the corresponding quantity and distribution of {sup 125}I seeds.ResultsFollow-up period for this group of patients was 2–30 months, and median time was 16 months. Symptoms of refractory pain were significantly resolved postimplantationmore » (P < 0.05), and Karnofsky score rose dramatically (P < 0.05). Most patients reported pain relief 2–5 days after treatment. Follow-up imaging studies were performed 2 months later, which revealed CR in 7 patients, PR in 13 patients, SD in 3 patients, and PD in 2 patients. The overall effective rate (CR + PR) was 80 %. Median survival time was 25.5 months. Seven patients died of recurrent tumor; 16 patients died of multiorgan failure or other metastases. Two patients survived after 30 months follow-up. Two patients reported localized skin erythema 1 week postimplantation, which disappeared after topical treatment.ConclusionsCT-guided radioactive {sup 125}I seed implantation, which showed good palliative pain relief with acceptable short-term effects, has proved in our study to be a new, safe, effective, and relatively uncomplicated treatment option for symptomatic retroperitoneal metastatic lymph nodes.« less

Ejaculatory function after permanent 125I prostate brachytherapy for localized prostate cancer.

PubMed

Huyghe, Eric; Delannes, Martine; Wagner, Fabien; Delaunay, Boris; Nohra, Joe; Thoulouzan, Matthieu; Shut-Yee, J Yeung; Plante, Pierre; Soulie, Michel; Thonneau, Patrick; Bachaud, Jean Marc

2009-05-01

Ejaculatory function is an underreported aspect of male sexuality in men treated for prostate cancer. We conducted the first detailed analysis of ejaculatory function in patients treated with permanent (125)I prostate brachytherapy for localized prostate cancer. Of 270 sexually active men with localized prostate cancer treated with permanent (125)I prostate brachytherapy, 241 (89%), with a mean age of 65 years (range, 43-80), responded to a mailed questionnaire derived from the Male Sexual Health Questionnaire regarding ejaculatory function. Five aspects of ejaculatory function were examined: frequency, volume, dry ejaculation, pleasure, and pain. Of the 241 sexually active men, 81.3% had conserved ejaculatory function after prostate brachytherapy; however, the number of patients with rare/absent ejaculatory function was double the pretreatment number (p < .0001). The latter finding was correlated with age (p < .001) and the preimplant International Index of Erectile Function score (p < .001). However, 84.9% of patients with maintained ejaculatory function after implantation reported a reduced volume of ejaculate compared with 26.9% before (p < .001), with dry ejaculation accounting for 18.7% of these cases. After treatment, 30.3% of the patients experienced painful ejaculation compared with 12.9% before (p = .0001), and this was associated with a greater number of implanted needles (p = .021) and the existence of painful ejaculation before implantation (p < .0001). After implantation, 10% of patients who continued to be sexually active experienced no orgasm compared with only 1% before treatment. in addition, more patients experienced late/difficult or weak orgasms (p = .001). Most men treated with brachytherapy have conserved ejaculatory function after prostate brachytherapy. However, most of these men experience a reduction in volume and a deterioration in orgasm.

Fast GPU-based Monte Carlo simulations for LDR prostate brachytherapy.

PubMed

Bonenfant, Éric; Magnoux, Vincent; Hissoiny, Sami; Ozell, Benoît; Beaulieu, Luc; Després, Philippe

2015-07-07

The aim of this study was to evaluate the potential of bGPUMCD, a Monte Carlo algorithm executed on Graphics Processing Units (GPUs), for fast dose calculations in permanent prostate implant dosimetry. It also aimed to validate a low dose rate brachytherapy source in terms of TG-43 metrics and to use this source to compute dose distributions for permanent prostate implant in very short times. The physics of bGPUMCD was reviewed and extended to include Rayleigh scattering and fluorescence from photoelectric interactions for all materials involved. The radial and anisotropy functions were obtained for the Nucletron SelectSeed in TG-43 conditions. These functions were compared to those found in the MD Anderson Imaging and Radiation Oncology Core brachytherapy source registry which are considered the TG-43 reference values. After appropriate calibration of the source, permanent prostate implant dose distributions were calculated for four patients and compared to an already validated Geant4 algorithm. The radial function calculated from bGPUMCD showed excellent agreement (differences within 1.3%) with TG-43 accepted values. The anisotropy functions at r = 1 cm and r = 4 cm were within 2% of TG-43 values for angles over 17.5°. For permanent prostate implants, Monte Carlo-based dose distributions with a statistical uncertainty of 1% or less for the target volume were obtained in 30 s or less for 1 × 1 × 1 mm(3) calculation grids. Dosimetric indices were very similar (within 2.7%) to those obtained with a validated, independent Monte Carlo code (Geant4) performing the calculations for the same cases in a much longer time (tens of minutes to more than a hour). bGPUMCD is a promising code that lets envision the use of Monte Carlo techniques in a clinical environment, with sub-minute execution times on a standard workstation. Future work will explore the use of this code with an inverse planning method to provide a complete Monte Carlo-based planning solution.

Fast GPU-based Monte Carlo simulations for LDR prostate brachytherapy

NASA Astrophysics Data System (ADS)

Bonenfant, Éric; Magnoux, Vincent; Hissoiny, Sami; Ozell, Benoît; Beaulieu, Luc; Després, Philippe

2015-07-01

The aim of this study was to evaluate the potential of bGPUMCD, a Monte Carlo algorithm executed on Graphics Processing Units (GPUs), for fast dose calculations in permanent prostate implant dosimetry. It also aimed to validate a low dose rate brachytherapy source in terms of TG-43 metrics and to use this source to compute dose distributions for permanent prostate implant in very short times. The physics of bGPUMCD was reviewed and extended to include Rayleigh scattering and fluorescence from photoelectric interactions for all materials involved. The radial and anisotropy functions were obtained for the Nucletron SelectSeed in TG-43 conditions. These functions were compared to those found in the MD Anderson Imaging and Radiation Oncology Core brachytherapy source registry which are considered the TG-43 reference values. After appropriate calibration of the source, permanent prostate implant dose distributions were calculated for four patients and compared to an already validated Geant4 algorithm. The radial function calculated from bGPUMCD showed excellent agreement (differences within 1.3%) with TG-43 accepted values. The anisotropy functions at r = 1 cm and r = 4 cm were within 2% of TG-43 values for angles over 17.5°. For permanent prostate implants, Monte Carlo-based dose distributions with a statistical uncertainty of 1% or less for the target volume were obtained in 30 s or less for 1 × 1 × 1 mm3 calculation grids. Dosimetric indices were very similar (within 2.7%) to those obtained with a validated, independent Monte Carlo code (Geant4) performing the calculations for the same cases in a much longer time (tens of minutes to more than a hour). bGPUMCD is a promising code that lets envision the use of Monte Carlo techniques in a clinical environment, with sub-minute execution times on a standard workstation. Future work will explore the use of this code with an inverse planning method to provide a complete Monte Carlo-based planning solution.

Goserelin Implant

MedlinePlus

Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer ... and other symptoms) and to help with the treatment of abnormal bleeding of the uterus. Goserelin implant ...

A radiobiology-based inverse treatment planning method for optimisation of permanent l-125 prostate implants in focal brachytherapy.

PubMed

Haworth, Annette; Mears, Christopher; Betts, John M; Reynolds, Hayley M; Tack, Guido; Leo, Kevin; Williams, Scott; Ebert, Martin A

2016-01-07

Treatment plans for ten patients, initially treated with a conventional approach to low dose-rate brachytherapy (LDR, 145 Gy to entire prostate), were compared with plans for the same patients created with an inverse-optimisation planning process utilising a biologically-based objective. The 'biological optimisation' considered a non-uniform distribution of tumour cell density through the prostate based on known and expected locations of the tumour. Using dose planning-objectives derived from our previous biological-model validation study, the volume of the urethra receiving 125% of the conventional prescription (145 Gy) was reduced from a median value of 64% to less than 8% whilst maintaining high values of TCP. On average, the number of planned seeds was reduced from 85 to less than 75. The robustness of plans to random seed displacements needs to be carefully considered when using contemporary seed placement techniques. We conclude that an inverse planning approach to LDR treatments, based on a biological objective, has the potential to maintain high rates of tumour control whilst minimising dose to healthy tissue. In future, the radiobiological model will be informed using multi-parametric MRI to provide a personalised medicine approach.

A radiobiology-based inverse treatment planning method for optimisation of permanent l-125 prostate implants in focal brachytherapy

NASA Astrophysics Data System (ADS)

Haworth, Annette; Mears, Christopher; Betts, John M.; Reynolds, Hayley M.; Tack, Guido; Leo, Kevin; Williams, Scott; Ebert, Martin A.

2016-01-01

Treatment plans for ten patients, initially treated with a conventional approach to low dose-rate brachytherapy (LDR, 145 Gy to entire prostate), were compared with plans for the same patients created with an inverse-optimisation planning process utilising a biologically-based objective. The ‘biological optimisation’ considered a non-uniform distribution of tumour cell density through the prostate based on known and expected locations of the tumour. Using dose planning-objectives derived from our previous biological-model validation study, the volume of the urethra receiving 125% of the conventional prescription (145 Gy) was reduced from a median value of 64% to less than 8% whilst maintaining high values of TCP. On average, the number of planned seeds was reduced from 85 to less than 75. The robustness of plans to random seed displacements needs to be carefully considered when using contemporary seed placement techniques. We conclude that an inverse planning approach to LDR treatments, based on a biological objective, has the potential to maintain high rates of tumour control whilst minimising dose to healthy tissue. In future, the radiobiological model will be informed using multi-parametric MRI to provide a personalised medicine approach.

Effect of pulse sequence parameter selection on signal strength in positive-contrast MRI markers for MRI-based prostate postimplant assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Tze Yee

Purpose: For postimplant dosimetric assessment, computed tomography (CT) is commonly used to identify prostate brachytherapy seeds, at the expense of accurate anatomical contouring. Magnetic resonance imaging (MRI) is superior to CT for anatomical delineation, but identification of the negative-contrast seeds is challenging. Positive-contrast MRI markers were proposed to replace spacers to assist seed localization on MRI images. Visualization of these markers under varying scan parameters was investigated. Methods: To simulate a clinical scenario, a prostate phantom was implanted with 66 markers and 86 seeds, and imaged on a 3.0T MRI scanner using a 3D fast radiofrequency-spoiled gradient recalled echo acquisitionmore » with various combinations of scan parameters. Scan parameters, including flip angle, number of excitations, bandwidth, field-of-view, slice thickness, and encoding steps were systematically varied to study their effects on signal, noise, scan time, image resolution, and artifacts. Results: The effects of pulse sequence parameter selection on the marker signal strength and image noise were characterized. The authors also examined the tradeoff between signal-to-noise ratio, scan time, and image artifacts, such as the wraparound artifact, susceptibility artifact, chemical shift artifact, and partial volume averaging artifact. Given reasonable scan time and managable artifacts, the authors recommended scan parameter combinations that can provide robust visualization of the MRI markers. Conclusions: The recommended MRI pulse sequence protocol allows for consistent visualization of the markers to assist seed localization, potentially enabling MRI-only prostate postimplant dosimetry.« less

Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment.

PubMed

Miksys, N; Xu, C; Beaulieu, L; Thomson, R M

2015-08-07

This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

SU-E-J-79: Evaluation of Prostate Volume Changes During Radiotherapy Using Implanted Markers and On-Board Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ispir, B; Akdeniz, Y; Ugurluer, G

2015-06-15

Purpose: To evaluate prostate volume changes during radiation therapy using implanted gold markers and on-board imaging. Methods: Twenty-five patients were included who underwent an implantation of three gold markers. Cartesian coordinates of markers were assessed in kV-images. The coordinates of centers of two markers were measured on kV-images from the center of the marker at the apex which was reference. The distances between the markers were extrapolated from the coordinates using the Euclid formula. The radius of the sphere through markers was calculated using sinus theorem. The prostate volume for the first and last fraction was substituted with a spheremore » model and was calculated for each patient. The t-test was used for analysis. Results: The mean prostate volume for first and last fraction was 24.65 and 20.87 cc, respectively (p≤0.05). The prostate volume was smaller for 23 patients, whereas there was an expansion for 2 patients. Fifteen patients had androgen deprivation during radiotherapy (H group) and ten did not (NH group). The mean prostate volume for the first and last fraction for the NH group was 30.73 cc and 24.89 cc and for the H group 20.84 cc and 18.19 cc, respectively. There was a 15.8% volume change during treatment for the NH group and 12.2% for the H group, but the difference was not statistically significant. The radius difference of the theoretical sphere for the first and last fraction was 0.98 mm (range, 0.09–2.95 mm) and remained below 2 mm in 88% of measurements. Conclusion: There was a significant volume change during prostate radiotherapy. The difference between H group and NH group was not significant. The radius changes did not exceed 3 mm and it was below adaptive treatment requirements. Our results indicate that prostate volume changes during treatment should be taken into account during contouring and treatment planning.« less

SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

PubMed Central

Matena, Julia; Petersen, Svea; Gieseke, Matthias; Kampmann, Andreas; Teske, Michael; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

2015-01-01

To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release. PMID:25849656

SLM produced porous titanium implant improvements for enhanced vascularization and osteoblast seeding.

PubMed

Matena, Julia; Petersen, Svea; Gieseke, Matthias; Kampmann, Andreas; Teske, Michael; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

2015-04-02

To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release.

Alternative to radical surgery for cancer of the prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathes, G.L.; Page, R.C.

1978-08-01

We have used the technique of retropubic implantation of /sup 125/I seeds, as introduced by Whitmore and associates in 1972, in 12 selected patients with prostatic cancer. Morbidity has been minimal, and the tumor has been effectively controlled. This technique delivers more radiation and has fewer side effects than external cobalt irradiation, and it should be offered to the patient as an effective alternative to radical prostatectomy. It is best suited for patients with stage A, stage B, or small stage C lesions who have negative bone scans. Edema of the penis follows the lymphadenectomy but gradually subsides.

SU-F-BRA-03: Integrating Novel Electromagnetic Tracking Hollow Needle Assistance in Permanent Implant Brachytherapy Procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Racine, E; Hautvast, G; Binnekamp, D

Purpose: To report on the results of a complete permanent implant brachytherapy procedure assisted by an electromagnetic (EM) hollow needle possessing both 3D tracking and seed drop detection abilities. Methods: End-to-end in-phantom EM-assisted LDR procedures were conducted. The novel system consisted of an EM tracking apparatus (NDI Aurora V2, Planar Field Generator), a 3D US scanner (Philips CX50), a hollow needle prototype allowing 3D tracking and seed drop detection and a specially designed treatment planning software (Philips Healthcare). A tungsten-doped 30 cc spherical agarose prostate immersed in gelatin was used for the treatment. A cylindrical shape of 0.8 cc wasmore » carved along its diameter to mimic the urethra. An initial plan of 26 needles and 47 seeds was established with the system. The plan was delivered with the EM-tracked hollow needle, and individual seed drop locations were recorded on the fly. The phantom was subsequently imaged with a CT scanner from which seed positions and contour definitions were obtained. The DVHs were then independently recomputed and compared with those produced by the planning system, both before and after the treatment. Results: Of the 47 seeds, 45 (96%) were detected by the EM technology embedded in the hollow needle design. The executed plan (from CT analysis) differed from the initial plan by 2%, 14% and 8% respectively in terms of V100, D90 and V150 for the prostate, and by 8%, 7% and 10% respectively in terms of D5, V100 and V120 for the urethra. Conclusion: The average DVH deviations between initial and executed plans were within a 5% tolerance imposed for this proof-of-concept assessment. This relatively good concordance demonstrates the feasibility and potential benefits of combining EM tracking and seed drop detection for real-time dosimetry validation and assistance in permanent implant brachytherapy procedures. This project has been entirely funded by Philips Healthcare.« less

Planning Target Margin Calculations for Prostate Radiotherapy Based on Intrafraction and Interfraction Motion Using Four Localization Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beltran, Chris; Herman, Michael G.; Davis, Brian J.

2008-01-01

Purpose: To determine planning target volume (PTV) margins for prostate radiotherapy based on the internal margin (IM) (intrafractional motion) and the setup margin (SM) (interfractional motion) for four daily localization methods: skin marks (tattoo), pelvic bony anatomy (bone), intraprostatic gold seeds using a 5-mm action threshold, and using no threshold. Methods and Materials: Forty prostate cancer patients were treated with external radiotherapy according to an online localization protocol using four intraprostatic gold seeds and electronic portal images (EPIs). Daily localization and treatment EPIs were obtained. These data allowed inter- and intrafractional analysis of prostate motion. The SM for the fourmore » daily localization methods and the IM were determined. Results: A total of 1532 fractions were analyzed. Tattoo localization requires a SM of 6.8 mm left-right (LR), 7.2 mm inferior-superior (IS), and 9.8 mm anterior-posterior (AP). Bone localization requires 3.1, 8.9, and 10.7 mm, respectively. The 5-mm threshold localization requires 4.0, 3.9, and 3.7 mm. No threshold localization requires 3.4, 3.2, and 3.2 mm. The intrafractional prostate motion requires an IM of 2.4 mm LR, 3.4 mm IS and AP. The PTV margin using the 5-mm threshold, including interobserver uncertainty, IM, and SM, is 4.8 mm LR, 5.4 mm IS, and 5.2 mm AP. Conclusions: Localization based on EPI with implanted gold seeds allows a large PTV margin reduction when compared with tattoo localization. Except for the LR direction, bony anatomy localization does not decrease the margins compared with tattoo localization. Intrafractional prostate motion is a limiting factor on margin reduction.« less

Ejaculatory Function After Permanent {sup 125}I Prostate Brachytherapy for Localized Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huyghe, Eric; Department of Urology and Andrology, Paul Sabatier University, CHU Paule de Viguier, Toulouse; Delannes, Martine

Purpose: Ejaculatory function is an underreported aspect of male sexuality in men treated for prostate cancer. We conducted the first detailed analysis of ejaculatory function in patients treated with permanent {sup 125}I prostate brachytherapy for localized prostate cancer. Patients and Methods: Of 270 sexually active men with localized prostate cancer treated with permanent {sup 125}I prostate brachytherapy, 241 (89%), with a mean age of 65 years (range, 43-80), responded to a mailed questionnaire derived from the Male Sexual Health Questionnaire regarding ejaculatory function. Five aspects of ejaculatory function were examined: frequency, volume, dry ejaculation, pleasure, and pain. Results: Of themore » 241 sexually active men, 81.3% had conserved ejaculatory function after prostate brachytherapy; however, the number of patients with rare/absent ejaculatory function was double the pretreatment number (p < .0001). The latter finding was correlated with age (p < .001) and the preimplant International Index of Erectile Function score (p < .001). However, 84.9% of patients with maintained ejaculatory function after implantation reported a reduced volume of ejaculate compared with 26.9% before (p < .001), with dry ejaculation accounting for 18.7% of these cases. After treatment, 30.3% of the patients experienced painful ejaculation compared with 12.9% before (p = .0001), and this was associated with a greater number of implanted needles (p = .021) and the existence of painful ejaculation before implantation (p < .0001). After implantation, 10% of patients who continued to be sexually active experienced no orgasm compared with only 1% before treatment. in addition, more patients experienced late/difficult or weak orgasms (p = .001). Conclusion: Most men treated with brachytherapy have conserved ejaculatory function after prostate brachytherapy. However, most of these men experience a reduction in volume and a deterioration in orgasm.« less

[Grape seed extract induces morphological changes of prostate cancer PC-3 cells].

PubMed

Shang, Xue-Jun; Yin, Hong-Lin; Ge, Jing-Ping; Sun, Yi; Teng, Wen-Hui; Huang, Yu-Feng

2008-12-01

To observe the morphological changes of prostate cancer PC-3 cells induced by grape seed extract (GSE). PC-3 cells were incubated with different concentrations of GSE (100, 200 and 300 microg/ml) for 24, 48 and 72 hours, and then observed for morphological changes by invert microscopy, HE staining and transmission electron microscopy. The incubated PC-3 cells appeared round, small, wrinkled and broken under the invert microscope and exhibited the classical morphological characteristics of cell death under the electron microscope, including cell atrophy, increased vacuoles, crumpled nuclear membrane, and chromosome aggregation. GSE can cause morphological changes and induce necrosis and apoptosis of PC-3 cells.

SU-F-J-27: Segmentation of Prostate CBCT Images with Implanted Calypso Transponders Using Double Haar Wavelet Transform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Y; Saleh, Z; Tang, X

Purpose: Segmentation of prostate CBCT images is an essential step towards real-time adaptive radiotherapy. It is challenging For Calypso patients, as more artifacts are generated by the beacon transponders. We herein propose a novel wavelet-based segmentation algorithm for rectum, bladder, and prostate of CBCT images with implanted Calypso transponders. Methods: Five hypofractionated prostate patients with daily CBCT were studied. Each patient had 3 Calypso transponder beacons implanted, and the patients were setup and treated with Calypso tracking system. Two sets of CBCT images from each patient were studied. The structures (i.e. rectum, bladder, and prostate) were contoured by a trainedmore » expert, and these served as ground truth. For a given CBCT, the moving window-based Double Haar transformation is applied first to obtain the wavelet coefficients. Based on a user defined point in the object of interest, a cluster algorithm based adaptive thresholding is applied to the low frequency components of the wavelet coefficients, and a Lee filter theory based adaptive thresholding is applied to the high frequency components. For the next step, the wavelet reconstruction is applied to the thresholded wavelet coefficients. A binary/segmented image of the object of interest is therefore obtained. DICE, sensitivity, inclusiveness and ΔV were used to evaluate the segmentation result. Results: Considering all patients, the bladder has the DICE, sensitivity, inclusiveness, and ΔV ranges of [0.81–0.95], [0.76–0.99], [0.83–0.94], [0.02–0.21]. For prostate, the ranges are [0.77–0.93], [0.84–0.97], [0.68–0.92], [0.1–0.46]. For rectum, the ranges are [0.72–0.93], [0.57–0.99], [0.73–0.98], [0.03–0.42]. Conclusion: The proposed algorithm appeared effective segmenting prostate CBCT images with the present of the Calypso artifacts. However, it is not robust in two scenarios: 1) rectum with significant amount of gas; 2) prostate with very low contrast

MRI-alone radiation therapy planning for prostate cancer: Automatic fiducial marker detection.

PubMed

Ghose, Soumya; Mitra, Jhimli; Rivest-Hénault, David; Fazlollahi, Amir; Stanwell, Peter; Pichler, Peter; Sun, Jidi; Fripp, Jurgen; Greer, Peter B; Dowling, Jason A

2016-05-01

The feasibility of radiation therapy treatment planning using substitute computed tomography (sCT) generated from magnetic resonance images (MRIs) has been demonstrated by a number of research groups. One challenge with an MRI-alone workflow is the accurate identification of intraprostatic gold fiducial markers, which are frequently used for prostate localization prior to each dose delivery fraction. This paper investigates a template-matching approach for the detection of these seeds in MRI. Two different gradient echo T1 and T2* weighted MRI sequences were acquired from fifteen prostate cancer patients and evaluated for seed detection. For training, seed templates from manual contours were selected in a spectral clustering manifold learning framework. This aids in clustering "similar" gold fiducial markers together. The marker with the minimum distance to a cluster centroid was selected as the representative template of that cluster during training. During testing, Gaussian mixture modeling followed by a Markovian model was used in automatic detection of the probable candidates. The probable candidates were rigidly registered to the templates identified from spectral clustering, and a similarity metric is computed for ranking and detection. A fiducial detection accuracy of 95% was obtained compared to manual observations. Expert radiation therapist observers were able to correctly identify all three implanted seeds on 11 of the 15 scans (the proposed method correctly identified all seeds on 10 of the 15). An novel automatic framework for gold fiducial marker detection in MRI is proposed and evaluated with detection accuracies comparable to manual detection. When radiation therapists are unable to determine the seed location in MRI, they refer back to the planning CT (only available in the existing clinical framework); similarly, an automatic quality control is built into the automatic software to ensure that all gold seeds are either correctly detected or a

Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology.

PubMed

Nag, Subir; Demanes, D Jeffrey; Hagan, Michael; Rivard, Mark J; Thomadsen, Bruce R; Welsh, James S; Williamson, Jeffrey F

2011-10-01

The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.

Effects of pumpkin seed in men with lower urinary tract symptoms due to benign prostatic hyperplasia in the one-year, randomized, placebo-controlled GRANU study.

PubMed

Vahlensieck, Winfried; Theurer, Christoph; Pfitzer, Edith; Patz, Brigitte; Banik, Norbert; Engelmann, Udo

2015-01-01

The German Research Activities on Natural Urologicals (GRANU) study was a randomized, partially blinded, placebo-controlled, parallel-group trial that investigated the efficacy of pumpkin seed in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH/LUTS). A total of 1,431 men (50-80 years) with BPH/LUTS were randomly assigned to either pumpkin seed (5 g b.i.d.), capsules with pumpkin seed extract (500 mg b.i.d.) or matching placebo. The primary response criterion was a decrease in International Prostate Symptom Score (IPSS) of ≥5 points from baseline after 12 months. Secondary outcome measures included IPSS-related quality of life, IPSS single items and diary-recorded nocturia. After 12 months, the response rate (intention-to-treat/last-observation-carried-forward approach) did not differ between pumpkin seed extract and placebo. In the case of pumpkin seed (responders: 58.5%), the difference compared with placebo (responders: 47.3%) was descriptively significant. The study products were well tolerated. Overall, in men with BPH, 12 months of treatment with pumpkin seed led to a clinically relevant reduction in IPSS compared with placebo. In order to fully justify a recommendation for the use of pumpkin seed to treat moderate LUTS, these findings need to be substantiated in a confirmatory study or systematic review. 2014 S. Karger AG, Basel

Sci-Thur PM – Brachytherapy 02: Positional accuracy in Pd-103 permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederick, Amy; Watt, Elizabeth; Peacock, Michael

Purpose: This retrospective study aims to quantify the positional accuracy of seed delivery in permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC). Methods: Treatment planning and post-implant CT scans for 5 patients were rigidly registered using the MIM Symphony™ software (MIM Software, Cleveland, OH) and used to evaluate differences between planned and implanted seed positions. Total and directional seed displacements were calculated for each patient in a clinically relevant ‘needle coordinate system’, defined relative to the angle of fiducial needle insertion. Results: The overall average total seed displacement was 10±8 mm. Systematic seed displacements weremore » observed in individual patients and the magnitude and direction of these offsets varied among patients. One patient showed a significant directional seed displacement in the shallow-deep direction compared with the other four patients. With the exception of this one patient outlier, no significant systematic directional displacements in the needle coordinate system were observed for this cohort; the average directional displacements were −1±5 mm, 2±3 mm, and −2±4 mm in the shallow-deep, up-down, and right-left directions respectively. Conclusion: With the exception of one patient outlier, the magnitude of seed displacements were relatively consistent among patients. The results indicate that the shallow-deep direction possesses the largest uncertainty for the seed delivery method used at the TBCC. The relatively large uncertainty in seed placement in this direction is expected, as this is the direction of needle insertion. Further work will involve evaluating deflections of delivered needle tracks from their planned positions.« less

An online x-ray based position validation system for prostate hypofractionated radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arumugam, Sankar, E-mail: Sankar.Arumugam@sswahs.nsw.gov.au; Xing, Aitang; Sidhom, Mark

Purpose: Accurate positioning of the target volume during treatment is paramount for stereotactic body radiation therapy (SBRT). In this work, the authors present the development of an in-house software tool to verify target position with an Elekta-Synergy linear accelerator using kV planar images acquired during treatment delivery. Methods: In-house software, SeedTracker, was developed in MATLAB to perform the following three functions: 1. predict intended seed positions in a planar view perpendicular to any gantry angle, simulating a portal imaging device, from the 3D seed co-ordinates derived from the treatment planning system; 2. autosegment seed positions in kV planar images; andmore » 3. report the position shift based on the seed positions in the projection images. The performance of SeedTracker was verified using a CIRS humanoid phantom (CIRS, VA, USA) implanted with three Civco gold seed markers (Civco, IA, USA) in the prostate. The true positive rate of autosegmentation (TPR{sub seg}) and the accuracy of the software in alerting the user when the isocenter position was outside the tolerance (TPR{sub trig}) were studied. Two-dimensional and 3D static position offsets introduced to the humanoid phantom and 3D dynamic offsets introduced to a gel phantom containing gold seeds were used for evaluation of the system. Results: SeedTracker showed a TPR{sub seg} of 100% in the humanoid phantom for projection images acquired at all angles except in the ranges of 80°–100° and 260°–280° where seeds are obscured by anatomy. This resulted in a TPR{sub trig} of 88% over the entire treatment range for considered 3D static offsets introduced to the phantom. For 2D static offsets where the position offsets were only introduced in the anterior–posterior and lateral directions, the TPR{sub trig} of SeedTracker was limited by both seed detectability and positional offset. SeedTracker showed a false positive trigger in the projection angle range between 130°–170

The value of spectral imaging to reduce artefacts in the body after 125 I seed implantation.

PubMed

Liu, Jingang; Wang, Wenjuan; Zhao, Xingsheng; Shen, Zhen; Shao, Weiguang; Wang, Xizhen; Li, Lixin; Wang, Bin

2016-10-01

To explore the value of gemstone spectral imaging (GSI) and metal artefact reduction sequence (MARs) to reduce the artefacts of metal seeds. Thirty-five patients with 125 I seed implantation in their abdomens underwent GSI CT. Six types of monochromatic images and the corresponding MARs images at 60-110 keV (interval of 10 keV) were reconstructed. The differences in the quality of the images of three imaging methods were subjectively assessed by three radiologists. Length of artefacts, the CT value and noise value of tissue adjacent to 125 I seeds, contrast-to-noise ratio (CNR), and artefact index (AI) were recorded. The differences in subjective scoring were statistically significant (t = 10.87, P < 0.001). Images at 70 keV showed the best CNR (0.84 ± 0.17) of tissues adjacent to 125 I seeds, and received the highest subjective score (2.82 ± 0.18). Images at 80 keV had the lowest AI (70.67 ± 19.17). Images at 110 keV had the shortest artefact lengths. High-density metal artefacts in the MARs spectral images were reduced. The length of metal artefacts in images at 110 keV was shorter than that of the polychromatic images and MARs spectral images (t = 3.35, 3.89, P < 0.05). The difference in CNR between MARs spectral images and polychromatic images, and images at 70 keV was statistically significant (t = 3.57, 4.16, P < 0.01). Gemstone spectral imaging technique can reduce metal artefacts of 125 I seeds effectively in CT images, and improve the quality of images, and improve the display of tissues adjacent to 125 I seeds after implantation. MARs technique cannot reduce the artefacts caused by radioactive seeds effectively. © 2016 The Royal Australian and New Zealand College of Radiologists.

MO-B-BRC-04: MRI-Based Prostate HDR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mourtada, F.

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR ismore » U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.« less

MO-B-BRC-02: Ultrasound Based Prostate HDR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Z.

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR ismore » U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.« less

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo

PubMed Central

Wang, Piwen; Solorzano, Walter; Diaz, Tanya; Magyar, Clara E.; Henning, Susanne M.; Vadgama, Jaydutt V.

2017-01-01

The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa, has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (< 2μM) significantly inhibited the proliferation of LNCaP and LAPC-4 cells by 30-50% at 48h compared to control, and inhibited WPE1-NA22 cells by 75%, while did not affect normal prostate epithelial cells. Male severe combined immunodeficiency (SCID) mice were implanted subcutaneously with LAPC-4 cells for in vivo studies. In one experiment, the intervention started one week after tumor implantation. Mice received arctigenin at 50mg/kg (LD) or 100mg/kg (HD) b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD) and 70% (HD) compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo, which provides a high promise in its translation to human application

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo.

PubMed

Wang, Piwen; Solorzano, Walter; Diaz, Tanya; Magyar, Clara E; Henning, Susanne M; Vadgama, Jaydutt V

2017-06-01

The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa , has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (< 2μM) significantly inhibited the proliferation of LNCaP and LAPC-4 cells by 30-50% at 48h compared to control, and inhibited WPE1-NA22 cells by 75%, while did not affect normal prostate epithelial cells. Male severe combined immunodeficiency (SCID) mice were implanted subcutaneously with LAPC-4 cells for in vivo studies. In one experiment, the intervention started one week after tumor implantation. Mice received arctigenin at 50mg/kg (LD) or 100mg/kg (HD) b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD) and 70% (HD) compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo , which provides a high promise in its translation to human application.

Towards clinical application of RayStretch for heterogeneity corrections in LDR permanent 125I prostate brachytherapy.

PubMed

Hueso-González, Fernando; Ballester, Facundo; Perez-Calatayud, Jose; Siebert, Frank-André; Vijande, Javier

RayStretch is a simple algorithm proposed for heterogeneity corrections in low-dose-rate brachytherapy. It is built on top of TG-43 consensus data, and it has been validated with Monte Carlo (MC) simulations. In this study, we take a real clinical prostate implant with 71 125 I seeds as reference and we apply RayStretch to analyze its performance in worst-case scenarios. To do so, we design two cases where large calcifications are located in the prostate lobules. RayStretch resilience under various calcification density values is also explored. Comparisons against MC calculations are performed. Dose-volume histogram-related parameters like prostate D 90 , rectum D 2cc , or urethra D 10 obtained with RayStretch agree within a few percent with the detailed MC results for all cases considered. The robustness and compatibility of RayStretch with commercial treatment planning systems indicate its applicability in clinical practice for dosimetric corrections in prostate calcifications. Its use during intraoperative ultrasound planning is foreseen. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

An experimental palladium-103 seed (OptiSeed{sup exp}) in a biocompatible polymer without a gold marker: Characterization of dosimetric parameters including the interseed effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abboud, F.; Scalliet, P.; Vynckier, S.

Permanent implantation of {sup 125}I (iodine) or {sup 103}Pd (palladium) sources is a popular treatment option in the management of early stage prostate cancer. New sources are being developed, some of which are being marketed for different clinical applications. A new technique of adjuvant stereotactic permanent seed breast implant, similar to that used in the treatment of prostate cancer, has been proposed by [N. Jansen et al., Int. J. Radiat. Oncol. Biol. Phys. 67, 1052-1058 (2007)] with encouraging results. The presence of artifacts from the metallic seeds, however, can disturb follow-up imaging. The development of plastic seeds has reduced thesemore » artifacts. This paper presents a feasibility study of the advantages of palladium-103 seeds, encapsulated with a biocompatible polymer, for future clinical applications, and on the effect of the gold marker on the dosimetric characteristics of such seeds. Experimental palladium seeds, OptiSeed{sup exp}, were manufactured by International Brachytherapy (IBt), Seneffe, Belgium, from a biocompatible polymer, including the marker. Apart from the absence of a gold marker, the studied seed has an identical design to the OptiSeed{sup 103}[Phys. Med. Biol. 50, 1493-1504 (2005)]; [Appl. Radiat. Isot. 63, 311-321 (2005)]. Polymer encapsulation was preferred by IBt in order to reduce the quantity of radioactive material needed for a given dose rate and to reduce the anisotropy of the radiation field around the seed. In addition, this design is intended to decrease the interseed effects that can occur as a result of the marker and the encapsulation. Dosimetric measurements were performed using LiF thermoluminescent dosimeters (1 mm{sup 3}) in solid water phantoms (WT1). Measured data were compared to Monte Carlo simulated data in solid water using the MCNP code, version 4C. Updated cross sections [Med. Phys. 30, 701-711 (2003)] were used. As the measured and calculated data were in agreement, Monte Carlo calculations were

[Dosimetry verification of radioactive seed implantation with 3D printing template and CT guidance for paravertebral/retroperitoneal malignant tumor].

PubMed

Ji, Z; Jiang, Y L; Guo, F X; Peng, R; Sun, H T; Fan, J H; Wang, J J

2017-04-04

Objective: To compare the dose distributions of postoperative plans with preoperative plans for seeds implantations of paravertebral/retroperitoneal tumors assisted by 3D printing guide template and CT guidance, explore the effects of the technology for seeds implantations in dosimetry level and provide data support for the optimization and standardization in seeds implantation. Methods: Between December 2015 and July 2016, a total of 10 patients with paravertebral/retroperitoneal tumors (12 lesions) received 3D printing template assist radioactive seeds implantations in department of radiation oncology of Peking University Third Hospital, and included in the study. The diseases included cervical cancer, kidney cancer, abdominal stromal tumor, leiomyosarcoma of kidney, esophageal cancer and carcinoma of ureter. The prescribed doses was 110-150 Gy. All patients received preoperative planning design, individual template design and production, and the dose distribution of postoperative plan was compared with preoperative plan. Dose parameters including D(90), MPD, V(100), V(150,)conformal index(CI), EI of target volume and D(2cc) of organs at risk (spinal cord, aorta, kidney). Statistical software was SPSS 19.0 and statistical method was non-parameters Wilcoxon symbols test. Results: A total of 10 3D printing templates were designed and produced which were including 12 treatment areas.The mean D(90) of postoperative target area (GTV) was 131.1 (97.8-167.4 Gy) Gy. The actual seeds number of post operation increased by 3 to 12 in 5 cases (42.0%). The needle was well distributed. For postoperative plans, the mean D(90,)MPD, V(100,)V(150) was 131.1 Gy, 69.3 Gy, 90.2% and 65.2%, respectively, and which was 140.2 Gy, 65.6 Gy, 91.7% and 26.8%, respectively, in preoperative plans. This meant that the actual dose of target volume was slightly lower than preplanned dose, and the high dose area of target volume was larger than preplanned range, but there was no statistical

Influence of source batch S{sub K} dispersion on dosimetry for prostate cancer treatment with permanent implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuñez-Cumplido, E., E-mail: ejnc-mccg@hotmail.com; Hernandez-Armas, J.; Perez-Calatayud, J.

2015-08-15

Purpose: In clinical practice, specific air kerma strength (S{sub K}) value is used in treatment planning system (TPS) permanent brachytherapy implant calculations with {sup 125}I and {sup 103}Pd sources; in fact, commercial TPS provide only one S{sub K} input value for all implanted sources and the certified shipment average is typically used. However, the value for S{sub K} is dispersed: this dispersion is not only due to the manufacturing process and variation between different source batches but also due to the classification of sources into different classes according to their S{sub K} values. The purpose of this work is tomore » examine the impact of S{sub K} dispersion on typical implant parameters that are used to evaluate the dose volume histogram (DVH) for both planning target volume (PTV) and organs at risk (OARs). Methods: The authors have developed a new algorithm to compute dose distributions with different S{sub K} values for each source. Three different prostate volumes (20, 30, and 40 cm{sup 3}) were considered and two typical commercial sources of different radionuclides were used. Using a conventional TPS, clinically accepted calculations were made for {sup 125}I sources; for the palladium, typical implants were simulated. To assess the many different possible S{sub K} values for each source belonging to a class, the authors assigned an S{sub K} value to each source in a randomized process 1000 times for each source and volume. All the dose distributions generated for each set of simulations were assessed through the DVH distributions comparing with dose distributions obtained using a uniform S{sub K} value for all the implanted sources. The authors analyzed several dose coverage (V{sub 100} and D{sub 90}) and overdosage parameters for prostate and PTV and also the limiting and overdosage parameters for OARs, urethra and rectum. Results: The parameters analyzed followed a Gaussian distribution for the entire set of computed dosimetries. PTV and

Prostate cancer involving bilateral seminal vesicles along with bone and testicular metastases: a case report.

PubMed

Gao, Qingqiang; Chen, Jianhuai; Dai, Yutian

2018-03-09

In the past 20 years, the incidence of prostate cancer has risen rapidly. It has been ranked as the third most common malignant tumor of the male genitourinary system. Testicular metastasis is uncommon in prostate cancer. Most cases are incidentally found in the treatment of prostate cancer with orchiectomy. Therefore, we believed it was necessary to report the case of our patient with this disease. We present a case of a 69-year-old Han Chinese man with a high total prostate-specific antigen level. A transrectal ultrasound-guided prostate biopsy was performed. A pathology report showed prostate cancer tissue with a Gleason score of 4 + 4 = 8/10. Imaging findings suggested that the prostate cancer tissue involved bilateral seminal vesicles and multiple bones. Next, radioactive seed implantation was carried out, and endocrine therapy was continued after the operation. Then enlargement of the left scrotum was found along with a total prostate-specific antigen level of 19.21 ng/ml. Computed tomography of the middle abdomen and pelvic cavity revealed 2.0 × 1.3-cm lesions of the left testis. The patient underwent a left testicular high resection and right orchiectomy. The postoperative pathology report showed metastatic prostate cancer cells in the left testis. Testicular metastasis of prostate cancer is rare. Therefore, a testicular physical examination is necessary for patients without relapse to avoid a missed diagnosis. Testicular metastasis should be treated according to the principle of treatment for advanced prostate adenocarcinoma if testicular metastasis of prostate adenocarcinoma is detected.

Management of experimental benign prostatic hyperplasia in rats using a food-based therapy containing Telfairia occidentalis seeds.

PubMed

Ejike, Chukwunonso E C C; Ezeanyika, Lawrence U S

2011-01-01

The usefulness of diet containing Telfairia occidentalis seeds, in managing benign prostatic hyperplasia (BPH) in rats was studied. Twenty male Wistar rats were divided into four equal groups. BPH was induced by sub-cutaneous injection of dihydrotestosterone (DHT) and estradiol valerate (ratio, 10:1) every other day for 28 days. Rats in the test group were placed on the test diet for 7 days following disease induction. One control group (DC) was fed on a normal diet for 7 days following disease induction. Two other control groups, HC and HDC, were given sub-cutaneous olive oil (vehicle) for the same duration, and placed on the test diet and normal diet, respectively. Markers of BPH, and hormone profile were determined using standard methods. The results show that relative prostate weight and protein content of the prostates were lower [albeit not significantly (p>0.05)] in the test group, relative to the DC group. Serum prostatic acid phosphatase concentrations (U/L) decreased significantly (p<0.05) from 2.9 ± 0.2 in the DC group to 2.1 ± 0.7 in the test group. Histological findings corroborate these data. The testosterone: estradiol ratio (× 10(3)) was increased from 4.0 ± 0.2 in the DC group to 4.6 ± 0.2 in the test group. The test diet reduced the mass and secretory activity of the enlarged prostate and may act by increasing the testosterone: estradiol ratio.

Medical malpractice of prostate brachytherapy.

PubMed

Elliott, Kathryn; Wallner, Kent; Merrick, Gregory; Herstein, Paul

2004-01-01

To summarize the basis for brachytherapy-associated legal complaints. The cases summarized here were those worked on by one author (KW) from 1992 through 2002. Summary information about cases is kept solely for the purpose of informing opposing counsel regarding past experience as a defendant or expert witness. No information summarized here is kept for medical research purposes. KW was the defendant in three cases, and an expert witness in the remaining 10 cases. Eleven cases were initiated due to a prostatic-rectal fistula--an abnormal communication between the prostatic urethra and rectum formed because of breakdown of irradiated tissue. Of the cases not involving a fistula, one was initiated due to chronic urinary burning, and the other arose from a patient identification mix-up, such that the plaintiff was treated with the implant planned for another patient. The principal physician defendant(s), after pre-trial winnowing, was the radiation oncologist alone in eight cases and the radiation oncologist and the urologist in five cases. In no case was a urologist named as a defendant without the radiation oncologist. None of the eleven rectal fistula cases involved an egregious seed placement error. Instead, plaintiff attorneys typically claimed breach of standard for care for what most physicians would likely consider to be variations within the standard of care. Prostate brachytherapists should brace themselves for the likelihood of more lawsuits. In addition to fistulas, plaintiff attorneys are likely to devise more bases for lawsuits in the future.

Experimental and Monte Carlo measurements of dose perturbation around a non-radioactive brachytherapy seed in external beam radiotherapy

NASA Astrophysics Data System (ADS)

Steinman, James P.

I-125 seeds used in permanent prostate brachytherapy are composed of high-Z metals and may number from 40 to over 100 in a typical implant. If any supplemental external beam treatment is administered afterward (as for salvaging failed brachytherapy treatment), it is possible that the seeds may cause substantial dose perturbation which will depend on numerous factors (photon energy, depth, field size, number of seeds, etc.) and this effect needs to be thoroughly investigated. Film measurements were primarily done using Kodak XV2 layered above and below a non-radioactive I-125 seed placed in a groove on a Lucite plate with 5 cm buildup and 10 cm backscatter added at 95 cm SSD. The phantom was irradiated with and without seed with 6 MV photons for a 1 x 1 cm2 field size. Monte Carlo simulations were carried out using DOSXYZnrc using the same parameters and compared with Gafchromic EBT2 film. Other comparisons looked at changing energy, depth, and field size in both with and without seeds configuration. This study was further extended to include metals of various Z of the seed's dimensions and also looked into effect of 3 seeds spaced 0.5 cm vertically. Another measurement was done using two opposing fields using single as well as 3 seed configuration to see whether the dose enhancement and attenuation cancel out in multi-field treatments which is the norm clinically in a prostate treatment. For a single I-125 seed, on XV film a localized dose enhancement of 6.3% upstream and -10.9% downstream was noticed. With three seeds, this effect did not change. With two opposing fields, a cold spot around the seed of ~3% was noticed from film measurements. Increasing energy and field size decreased the effect while increase in Z of material greatly increased the effect. Increasing depth appeared to have no effect. DOSXYZnrc and EBT2 film verified maximum dose enhancement of +15% upstream and -20% downstream of the I-125 seed surface. In general, the range of the effect was

WE-DE-201-04: Cross Validation of Knowledge-Based Treatment Planning for Prostate LDR Brachytherapy Using Principle Component Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roper, J; Ghavidel, B; Godette, K

Purpose: To validate a knowledge-based algorithm for prostate LDR brachytherapy treatment planning. Methods: A dataset of 100 cases was compiled from an active prostate seed implant service. Cases were randomized into 10 subsets. For each subset, the 90 remaining library cases were registered to a common reference frame and then characterized on a point by point basis using principle component analysis (PCA). Each test case was converted to PCA vectors using the same process and compared with each library case using a Mahalanobis distance to evaluate similarity. Rank order PCA scores were used to select the best-matched library case. Themore » seed arrangement was extracted from the best-matched case and used as a starting point for planning the test case. Any subsequent modifications were recorded that required input from a treatment planner to achieve V100>95%, V150<60%, V200<20%. To simulate operating-room planning constraints, seed activity was held constant, and the seed count could not increase. Results: The computational time required to register test-case contours and evaluate PCA similarity across the library was 10s. Preliminary analysis of 2 subsets shows that 9 of 20 test cases did not require any seed modifications to obtain an acceptable plan. Five test cases required fewer than 10 seed modifications or a grid shift. Another 5 test cases required approximately 20 seed modifications. An acceptable plan was not achieved for 1 outlier, which was substantially larger than its best match. Modifications took between 5s and 6min. Conclusion: A knowledge-based treatment planning algorithm for prostate LDR brachytherapy is being cross validated using 100 prior cases. Preliminary results suggest that for this size library, acceptable plans can be achieved without planner input in about half of the cases while varying amounts of planner input are needed in remaining cases. Computational time and planning time are compatible with clinical practice.« less

Clinical application of computed tomography-guided (125)I seed interstitial implantation for head and neck cancer patients with unmanageable cervical lymph node metastases.

PubMed

Huang, Hai; Xu, Shaonian; Li, Fusheng; Du, Zhenguang; Wang, Liang

2016-04-27

To assess clinical application of computed tomography (CT)-guided (125)I seed implantation for patients who cannot endure or unwillingly receive repeated surgery, chemotherapy, or radiotherapy for unmanageable cervical lymph node metastases in head and neck cancer (HNC). Thirty-one consecutive patients received CT-guided (125)I seed implantation between February 2010 and December 2013. To evaluate the clinical efficiency, karnofsky performance score (KPS), numeric rating scale (NRS), and tumor volume at 3-, and 6-month post-implantation were compared with pre-implantation, along with local control rate (LCR), overall survival rate (OSR), and complications at 3, 6 months, 1, and 2 years. The tumor volume was obviously decreased at 3-, and 6-month post-implantation (21.23 ± 8.83 versus 9.19 ± 7.52 cm(2); 21.23 ± 8.83 versus 6.42 ± 9.79 cm(2); P < 0.05) compared with pre-implantation. The NRS was statistically reduced (3.06 ± 1.06 versus 7.77 ± 0.92; 2.39 ± 1.15 versus 7.77 ± 0.92; P < 0.05), while KPS was significantly improved (83.18 ± 5.97 versus 73.60 ± 7.90; 82.86 ± 5.43 versus 73.60 ± 7.90; P < 0.05) postoperatively at 3 and 6 months, respectively. The LCR at 3, 6 months, 1, and 2 years was 96.30, 83.87, 64.51, and 45.16%, respectively. The OSR was 100, 100, 67.74, and 45.16%, respectively. Three cases experienced grade I and two had grade II acute radiation toxicity. CT-guided seed implantation may be feasible and safe for HNC patients whose neck nodes are not manageable by routine strategies with fewer complications, higher LCR, and significant pain relief.

Fiducial marker guided prostate radiotherapy: a review

PubMed Central

Jain, Suneil; Hounsell, Alan R; O'Sullivan, Joe M

2016-01-01

Image-guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogeneous whole-pelvic radiotherapy dose, but these surrogates are not reliable when using reduced margins, dose escalation or hypofractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990s. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aimed to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied, which resulted in 50 articles being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft-tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardization of all techniques and procedures in relation to the use of prostate FMs is required. Finally, a clinical trial investigating a non-surgical alternative to prostate FMs is introduced. PMID:27585736

MRI-alone radiation therapy planning for prostate cancer: Automatic fiducial marker detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghose, Soumya, E-mail: soumya.ghose@case.edu; Mitra, Jhimli; Rivest-Hénault, David

Purpose: The feasibility of radiation therapy treatment planning using substitute computed tomography (sCT) generated from magnetic resonance images (MRIs) has been demonstrated by a number of research groups. One challenge with an MRI-alone workflow is the accurate identification of intraprostatic gold fiducial markers, which are frequently used for prostate localization prior to each dose delivery fraction. This paper investigates a template-matching approach for the detection of these seeds in MRI. Methods: Two different gradient echo T1 and T2* weighted MRI sequences were acquired from fifteen prostate cancer patients and evaluated for seed detection. For training, seed templates from manual contoursmore » were selected in a spectral clustering manifold learning framework. This aids in clustering “similar” gold fiducial markers together. The marker with the minimum distance to a cluster centroid was selected as the representative template of that cluster during training. During testing, Gaussian mixture modeling followed by a Markovian model was used in automatic detection of the probable candidates. The probable candidates were rigidly registered to the templates identified from spectral clustering, and a similarity metric is computed for ranking and detection. Results: A fiducial detection accuracy of 95% was obtained compared to manual observations. Expert radiation therapist observers were able to correctly identify all three implanted seeds on 11 of the 15 scans (the proposed method correctly identified all seeds on 10 of the 15). Conclusions: An novel automatic framework for gold fiducial marker detection in MRI is proposed and evaluated with detection accuracies comparable to manual detection. When radiation therapists are unable to determine the seed location in MRI, they refer back to the planning CT (only available in the existing clinical framework); similarly, an automatic quality control is built into the automatic software to ensure that all

Corrosion analysis of NiCu and PdCo thermal seed alloys used as interstitial hyperthermia implants.

PubMed

Paulus, J A; Parida, G R; Tucker, R D; Park, J B

1997-12-01

Ferromagnetic materials with low Curie temperatures are being investigated for use as interstitial implants for fractionated hyperthermia treatment of prostatic disease. Previous investigations of the system have utilized alloys, such as NiCu, with inadequate corrosion resistance, requiring the use of catheters for removal of the implants following treatment or inert surface coatings which may interfere with thermal characteristics of the implants. We are evaluating a palladium-cobalt (PdCo) binary alloy which is very similar to high palladium alloys used in dentistry. Electrochemical corrosion tests and immersion tests at 37 degrees C for both NiCu and PdCo alloy samples in mammalian Ringer's solution were performed. Long-term corrosion rates are 5.8 x 10(-5) microm per year (NiCu) and 7.7 x 10(-8) microm per year (PdCo) from average immersion test results, indicating higher corrosion resistance of PdCo (P < 0.02); immersion corrosion rates were much lower than initial corrosion rates found electrochemically. Both alloys had significantly lower corrosion rates than standard surgical implant rates of 0.04 microm per year (P < 0.001 for both alloys). Scanning electron microscopy illustrates changes in the NiCu alloy surface due to pitting corrosion; no difference is observed for PdCo. The data indicate that the PdCo alloy may be suitable as a long-term implant for use in fractionated hyperthermia.

Single-nucleotide polymorphisms studied for associations with urinary toxicity from (125)I prostate brachytherapy implants.

PubMed

Usmani, Nawaid; Leong, Nelson; Martell, Kevin; Lan, Lanna; Ghosh, Sunita; Pervez, Nadeem; Pedersen, John; Yee, Don; Murtha, Albert; Amanie, John; Sloboda, Ron; Murray, David; Parliament, Matthew

2014-01-01

To identify clinical, dosimetric, and genetic factors that are associated with late urinary toxicity after a (125)I prostate brachytherapy implant. Genomic DNA from 296 men treated with (125)I prostate brachytherapy monotherapy was extracted from saliva samples for this study. A retrospective database was compiled including clinical, dosimetric, and toxicity data for this cohort of patients. Fourteen candidate single-nucleotide polymorphism (SNPs) from 13 genes (TP53, ERCC2, GSTP1, NOS, TGFβ1, MSH6, RAD51, ATM, LIG4, XRCC1, XRCC3, GSTA1, and SOD2) were tested in this cohort for correlations with toxicity. This study identified 217 men with at least 2 years of followup. Of these, 39 patients developed Grade ≥2 late urinary complications with a transurethral resection of prostate, urethral stricture, gross hematuria, or a sustained increase in their International Prostate Symptom Score. The only clinical or dosimetric factor that was associated with late urinary toxicity was age (p = 0.02). None of the 14 SNPs tested in this study were associated with late urinary toxicity in the univariate analysis. This study identified age as the only variable being associated with late urinary toxicity. However, the small sample size and the candidate gene approach used in this study mean that further investigations are essential. Genome-wide association studies are emerging as the preferred approach for future radiogenomic studies to overcome the limitations from a candidate gene approach. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Portal Vein Stenting Combined with Iodine-125 Seeds Endovascular Implantation Followed by Transcatheter Arterial Chemoembolization for Treatment of Hepatocellular Carcinoma Patients with Portal Vein Tumor Thrombus

PubMed Central

Zhou, Tanyang; Zhu, Tongyin; Zhang, Yuelin; Nie, Chunhui; Ai, Jing; Zhou, Guanhui; Zhang, Aibin; Dong, Meng-Jie; Wang, Wei-Lin

2016-01-01

Aim was to assess the therapeutic value of portal vein stenting (PVS) combined with iodine-125 seed (125I seed) strand endovascular implantation followed by transcatheter arterial chemoembolization (TACE) for treating patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). This was a retrospective study of 34 patients aged 29–81 years, diagnosed HCC with PVTT, and treated with PVS combined with 125I seed strand endovascular implantation followed by TACE between January 2012 and August 2014. Survival, stent patency, technical success rate, complications related to the procedure, and adverse events were recorded. The technical success rate was 100%. No serious procedure-related adverse event was recorded. The median survival was 147 days. The cumulative survival rates and stent patency rates at 90, 180, and 360 days were 94.1%, 61.8%, and 32.4% and 97.1% (33/34), 76.9% (24/34), and 29.4% (10/34), respectively. PVS combined with 125I seed strand endovascular implantation followed by TACE is feasible for patients with HCC and PVTT. It resulted in appropriate survival and stent patency, with no procedure-related adverse effects. PMID:27999793

A technical evaluation of the Nucletron FIRST system: conformance of a remote afterloading brachytherapy seed implantation system to manufacturer specifications and AAPM Task Group report recommendations.

PubMed

Rivard, Mark J; Evans, Dee-Ann Radford; Kay, Ian

2005-01-01

The Fully Integrated Real-time Seed Treatment (FIRST) system by Nucletron has been available in Europe since November 2001 and is being used more and more in Canada and the United States. Like the conventional transrectal ultrasound implant procedure, the FIRST system utilizes an ultrasound probe, needles, and brachytherapy seeds. However, this system is unique in that it (1) utilizes a low-dose-rate brachytherapy seed remote afterloader (the seedSelectron), (2) utilizes 3D image reconstruction acquired from electromechanically controlled, nonstepping rotation of the ultrasound probe, (3) integrates the control of a remote afterloader with electromechanical control of the ultrasound probe for integrating the clinical procedure into a single system, and (4) automates the transfer of planning information and seed delivery to improve quality assurance and radiation safety. This automated delivery system is specifically intended to address reproducibility and accuracy of seed positioning during implantation. The FIRST computer system includes two software environments: SPOT PRO and seedSelectron; both are used to facilitate treatment planning and brachytherapy seed implantation from beginning to completion of the entire procedure. In addition to these features, the system is reported to meet certain product specifications for seed delivery positioning accuracy and reproducibility, seed calibration accuracy and reliability, and brachytherapy dosimetry calculations. Consequently, a technical evaluation of the FIRST system was performed to determine adherence to manufacturer specifications and to the American Association of Physicists in Medicine (AAPM) Task Group Reports 43, 53, 56, 59, and 64 and recommendations of the American Brachytherapy Society (ABS). The United States Nuclear Regulatory Commission (NRC) has recently added Licensing Guidance for the seedSelectron system under 10 CFR 35.1000. Adherence to licensing guidance is made by referencing applicable AAPM

Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Qaisieh, Bashar; Mason, Josh, E-mail: joshua.mason@nhs.net; Bownes, Peter

2015-07-15

Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focalmore » (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a

Magnetic resonance spectroscopy-guided transperineal prostate biopsy and brachytherapy for recurrent prostate cancer.

PubMed

Barnes, Agnieszka Szot; Haker, Steven J; Mulkern, Robert V; So, Minna; D'Amico, Anthony V; Tempany, Clare M

2005-12-01

Brachytherapy targeted to the peripheral zone with magnetic resonance imaging (MRI) guidance is a prostate cancer treatment option with potentially fewer complications than other treatments. Follow-up MRI when failure is suspected is, however, difficult because of radiation-induced changes. Furthermore, MR spectroscopy (MRS) is compromised by susceptibility artifacts from radioactive seeds in the peripheral zone. We report a case in which combined MRI/MRS was useful for the detection of prostate cancer in the transitional zone in patients previously treated with MR-guided brachytherapy. We propose that MRI/MRS can help detect recurrent prostate cancer, guide prostate biopsy, and help manage salvage treatment decisions.

Transrectal implantation and stability of gold markers in prostate bed for salvage radiotherapy of macroscopic recurrences.

PubMed

Shakir, Shakir I; Udrescu, Corina; Enachescu, Ciprian; Rouviere, Olivier; Arion, Simona; Caraivan, Ionela; Chapet, Olivier

2016-11-01

The objective of the study was to verify the stability of gold markers in the prostatic bed (PB) during salvage radiotherapy. Seven patients, diagnosed with a macroscopic nodule visible on MRI, underwent targeted MRI-guided biopsies. Three gold markers were implanted into the PB close to the relapsing nodule for CT/MRI fusion. A dose of 60Gy was delivered using IMRT to the PB followed by a dose escalation up to 72Gy to the macroscopic nodule. Daily anterior and left-lateral kV-images were acquired for repositioning. The coordinates of the center of each marker were measured on the two kV-images. The distance variations (Dvar) of the markers in the first session and the subsequent ones were compared. No marker was lost during treatment. The average distance between markers was 7.8mm. The average Dvar was 0.8mm, in absolute value. A total of 380/528 (72%) Dvar were ⩽1mm. A Dvar greater than 2mm was observed in 5.7% of measurements, with a maximum value of 4.8mm. Despite the absence of the prostate, the implantation of gold markers in the PB remains feasible, with Dvar often less than 2mm, and could be used to develop new approaches of salvage focal radiotherapy on the macroscopic relapse after prostatectomy. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Clinical Study on Using 125I Seeds Articles Combined with Biliary Stent Implantation in the Treatment of Malignant Obstructive Jaundice.

PubMed

Wang, Tao; Liu, Sheng; Zheng, Yan-Bo; Song, Xue-Peng; Sun, Bo-Lin; Jiang, Wen-Jin; Wang, Li-Gang

2017-08-01

Aim: To study the feasibility and curative effect of 125 I seeds articles combined with biliary stent implantation in the treatment of malignant obstructive jaundice. Patients and Methods: Fifty patients with malignant obstructive jaundice were included. Twenty-four were treated by biliary stent implantation combined with intraluminal brachytherapy by 125 I seeds articles as the experimental group, while the remaining 26 were treated by biliary stent implantation only as the control group. The goal of this study was to evaluate total bilirubin, direct bilirubin and tumor markers (cancer antigen (CA)-199, CA-242 and carcinoembryonic antigen (CEA)), as well as biliary stent patency status and survival time before and after surgery. Results: Jaundice improved greatly in both groups. The decreases of CA-199 and CA-242 had statistical significance (p=0.003 and p=0.004) in the experimental group. The ratio of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (p=0.048). The biliary stent patency time in the experimental group was 1~15.5 (mean=9.84) months. The biliary stent patency time in the control group was 0.8~9 (mean=5.57) months, which was statistically significant (p=0.018). The median survival time was 10.2 months in the experimental group, while 5.4 months in control group (p<0.05). Conclusion: 125 I seeds articles combined with biliary stent implantation significantly prolongs biliary stent patency time and survival time for patients with malignant obstructive jaundice possibly by inhibiting the proliferation of vascular endothelial cells and the growth of tumor. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The evolution of brachytherapy for prostate cancer.

PubMed

Zaorsky, Nicholas G; Davis, Brian J; Nguyen, Paul L; Showalter, Timothy N; Hoskin, Peter J; Yoshioka, Yasuo; Morton, Gerard C; Horwitz, Eric M

2017-06-30

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

Dosimetric variations in permanent breast seed implant due to patient arm position.

PubMed

Watt, Elizabeth; Husain, Siraj; Sia, Michael; Brown, Derek; Long, Karen; Meyer, Tyler

2015-01-01

Planning and delivery for permanent breast seed implant (PBSI) are performed with the ipsilateral arm raised; however, changes in implant geometry can be expected because of healing and anatomical motion as the patient resumes her daily activities. The purpose of this study is to quantify the effect of ipsilateral arm position on postplan dosimetry. Twelve patients treated at the Tom Baker Cancer Centre were included in this study. Patients underwent two postimplant CT scans on the day of implant (Day 0) and two scans approximately 8 weeks later (Day 60). One scan at each time was taken with the ipsilateral arm raised, recreating the planning scan position, and the other with both arms down in a relaxed position beside the body, recreating a more realistic postimplant arm position. Postplans were completed on all four scans using deformable image registration (MIM Maestro). On the Day 0 scan, the V200 for the evaluation planning target volume was significantly increased in the arm-down position compared with the arm-up position. Lung, rib, and chest wall dose were significantly reduced at both time points. Left anterior descending coronary artery, heart, and skin dose showed no significant differences at either time point. Although some dosimetric indices show significant differences between the arm-up and arm-down positions, the magnitude of these differences is small and the values remain indicative of implant quality. Despite the delivery of the majority of dose with the arm down, it is reasonable to use CT scans taken in the arm-up position for postplanning. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Influence of the number of elongated fiducial markers on the localization accuracy of the prostate

NASA Astrophysics Data System (ADS)

de Boer, Johan; de Bois, Josien; van Herk, Marcel; Sonke, Jan-Jakob

2012-10-01

Implanting fiducial markers for localization purposes has become an accepted practice in radiotherapy for prostate cancer. While many correction strategies correct for translations only, advanced correction protocols also require knowledge of the rotation of the prostate. For this purpose, typically, three or more markers are implanted. Elongated fiducial markers provide more information about their orientation than traditional round or cylindrical markers. Potentially, fewer markers are required. In this study, we evaluate the effect of the number of elongated markers on the localization accuracy of the prostate. To quantify the localization error, we developed a model that estimates, at arbitrary locations in the prostate, the registration error caused by translational and rotational uncertainties of the marker registration. Every combination of one, two and three markers was analysed for a group of 24 patients. The average registration errors at the prostate surface were 0.3-0.8 mm and 0.4-1 mm for registrations on, respectively, three markers and two markers located on different sides of the prostate. Substantial registration errors (2.0-2.2 mm) occurred at the prostate surface contralateral to the markers when two markers were implanted on the same side of the prostate or only one marker was used. In conclusion, there is no benefit in using three elongated markers: two markers accurately localize the prostate if they are implanted at some distance from each other.

MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2016-06-15

Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR ismore » U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.« less

SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, F Maria; Podder, T; Yu, Y

Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostatemore » HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system�

Magnetic resonance-guided prostate interventions.

PubMed

Haker, Steven J; Mulkern, Robert V; Roebuck, Joseph R; Barnes, Agnieska Szot; Dimaio, Simon; Hata, Nobuhiko; Tempany, Clare M C

2005-10-01

We review our experience using an open 0.5-T magnetic resonance (MR) interventional unit to guide procedures in the prostate. This system allows access to the patient and real-time MR imaging simultaneously and has made it possible to perform prostate biopsy and brachytherapy under MR guidance. We review MR imaging of the prostate and its use in targeted therapy, and describe our use of image processing methods such as image registration to further facilitate precise targeting. We describe current developments with a robot assist system being developed to aid radioactive seed placement.

Intra-operative 3D guidance in prostate brachytherapy using a non-isocentric C-arm.

PubMed

Jain, A; Deguet, A; Iordachita, I; Chintalapani, G; Blevins, J; Le, Y; Armour, E; Burdette, C; Song, D; Fichtinger, G

2007-01-01

Intra-operative guidance in Transrectal Ultrasound (TRUS) guided prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate. Seeds were reconstructed using a typical C-arm, and exported to a commercial brachytherapy system for dosimetry analysis. Technical obstacles for 3D reconstruction on a non-isocentric C-arm included pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction; and C-arm to TRUS registration. In precision-machined hard phantoms with 40-100 seeds, we correctly reconstructed 99.8% seeds with a mean 3D accuracy of 0.68 mm. In soft tissue phantoms with 45-87 seeds and clinically realistic 15 degrees C-arm motion, we correctly reconstructed 100% seeds with an accuracy of 1.3 mm. The reconstructed 3D seed positions were then registered to the prostate segmented from TRUS. In a Phase-1 clinical trial, so far on 4 patients with 66-84 seeds, we achieved intra-operative monitoring of seed distribution and dosimetry. We optimized the 100% prescribed iso-dose contour by inserting an average of 3.75 additional seeds, making intra-operative dosimetry possible on a typical C-arm, at negligible additional cost to the existing clinical installation.

A multi-organ biomechanical model to analyze prostate deformation due to large deformation of the rectum

NASA Astrophysics Data System (ADS)

Brock, Kristy K.; Ménard, Cynthia; Hensel, Jennifer; Jaffray, David A.

2006-03-01

Magnetic resonance imaging (MRI) with an endorectal receiver coil (ERC) provides superior visualization of the prostate gland and its surrounding anatomy at the expense of large anatomical deformation. The ability to correct for this deformation is critical to integrate the MR images into the CT-based treatment planning for radiotherapy. The ability to quantify and understand the physiological motion due to large changes in rectal filling can also improve the precision of image-guided procedures. The purpose of this study was to understand the biomechanical relationship between the prostate, rectum, and bladder using a finite element-based multi-organ deformable image registration method, 'Morfeus' developed at our institution. Patients diagnosed with prostate cancer were enrolled in the study. Gold seed markers were implanted in the prostate and MR scans performed with the ERC in place and its surrounding balloon inflated to varying volumes (0-100cc). The prostate, bladder, and rectum were then delineated, converted into finite element models, and assigned appropriate material properties. Morfeus was used to assign surface interfaces between the adjacent organs and deform the bladder and rectum from one position to another, obtaining the position of the prostate through finite element analysis. This approach achieves sub-voxel accuracy of image co-registration in the context of a large ERC deformation, while providing a biomechanical understanding of the multi-organ physiological relationship between the prostate, bladder, and rectum. The development of a deformable registration strategy is essential to integrate the superior information offered in MR images into the treatment planning process.

Molecular classification of benign prostatic hyperplasia: A gene expression profiling study in a rat model.

PubMed

Hata, Junya; Satoh, Yuichi; Akaihata, Hidenori; Hiraki, Hiroyuki; Ogawa, Soichiro; Haga, Nobuhiro; Ishibashi, Kei; Aikawa, Ken; Kojima, Yoshiyuki

2016-07-01

To characterize the molecular features of benign prostatic hyperplasia by carrying out a gene expression profiling analysis in a rat model. Fetal urogenital sinus isolated from 20-day-old male rat embryo was implanted into a pubertal male rat ventral prostate. The implanted urogenital sinus grew time-dependently, and the pathological findings at 3 weeks after implantation showed epithelial hyperplasia as well as stromal hyperplasia. Whole-genome oligonucleotide microarray analysis utilizing approximately 30 000 oligonucleotide probes was carried out using prostate specimens during the prostate growth process (3 weeks after implantation). Microarray analyses showed 926 upregulated (>2-fold change, P < 0.01) and 3217 downregulated genes (<0.5-fold change, P < 0.01) in benign prostatic hyperplasia specimens compared with normal prostate. Gene ontology analyses of upregulated genes showed predominant genetic themes of involvement in development (162 genes, P = 2.01 × 10(-4) ), response to stimulus (163 genes, P = 7.37 × 10(-13) ) and growth (32 genes, P = 1.93 × 10(-5) ). When we used both normal prostate and non-transplanted urogenital sinuses as controls to identify benign prostatic hyperplasia-specific genes, 507 and 406 genes were upregulated and downregulated, respectively. Functional network and pathway analyses showed that genes associated with apoptosis modulation by heat shock protein 70, interleukin-1, interleukin-2 and interleukin-5 signaling pathways, KIT signaling pathway, and secretin-like G-protein-coupled receptors, class B, were relatively activated during the growth process in the benign prostatic hyperplasia specimens. In contrast, genes associated with cholesterol biosynthesis were relatively inactivated. Our microarray analyses of the benign prostatic hyperplasia model rat might aid in clarifying the molecular mechanism of benign prostatic hyperplasia progression, and identifying molecular targets for benign prostatic hyperplasia treatment. �

Gene expression profiles in promoted-growth rice seedlings that germinated from the seeds implanted by low-energy N+ beam

PubMed Central

Ya, Huiyuan; Chen, Qiufang; Wang, Weidong; Chen, Wanguang; Qin, Guangyong; Jiao, Zhen

2012-01-01

The stimulation effect that some beneficial agronomic qualities have exhibited in present-generation plants have also been observed due to ion implantation on plants. However, there is relatively little knowledge regarding the molecular mechanism of the stimulation effects of ion-beam implantation. In order to extend our current knowledge about the functional genes related to this stimulation effect, we have reported a comprehensive microarray analysis of the transcriptome features of the promoted-growth rice seedlings germinating from seeds implanted by a low-energy N+ beam. The results showed that 351 up-regulated transcripts and 470 down-regulated transcripts, including signaling proteins, kinases, plant hormones, transposable elements, transcription factors, non-coding protein RNA (including miRNA), secondary metabolites, resistance proteins, peroxidase and chromatin modification, are all involved in the stimulating effects of ion-beam implantation. The divergences of the functional catalog between the vacuum and ion implantation suggest that ion implantation is the principle cause of the ion-beam implantation biological effects, and revealed the complex molecular networks required to adapt to ion-beam implantation stress in plants, including enhanced transposition of transposable elements, promoted ABA biosynthesis and changes in chromatin modification. Our data will extend the current understanding of the molecular mechanisms and gene regulation of stimulation effects. Further research on the candidates reported in this study should provide new insights into the molecular mechanisms of biological effects induced by ion-beam implantation. PMID:22843621

Influence of polyphenol extract from evening primrose (Oenothera paradoxa) seeds on human prostate and breast cancer cell lines.

PubMed

Lewandowska, Urszula; Owczarek, Katarzyna; Szewczyk, Karolina; Podsędek, Anna; Koziołkiewicz, Maria; Hrabec, Elżbieta

2014-02-03

There is growing interest in plant polyphenols which exhibit pleiotropic biological activities, including anti-inflammatory, antioxidant, and anticancer effects. The objective of our study was to evaluate the influence of an evening primrose extract (EPE) from defatted seeds on viability and invasiveness of three human cell lines: PNT1A (normal prostate cells), DU145 (prostate cancer cells) and MDA-MB-231 (breast cancer cells). The results revealed that after 72 h of incubation the tested extract reduced the viability of DU 145 and MDA-MB-231 with IC50 equal to 14.5 μg/mL for both cell lines. In contrast, EPE did not inhibit the viability of normal prostate cells. Furthermore, EPE reduced PNT1A and MDA-MB-231 cell invasiveness; at the concentration of 21.75 μg/mL the suppression of invasion reached 92% and 47%, respectively (versus control). Additionally, zymographic analysis revealed that after 48 h of incubation EPE inhibited metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) activities in a dose-dependent manner. For PNT1A the activities of MMP-2 and MMP-9 decreased 4- and 2-fold, respectively, at EPE concentration of 29 μg/mL. In the case of MDA-MB-231 and DU 145 the decrease in MMP-9 activity at EPE concentration of 29 μg/mL was 5.5-fold and almost 1.9-fold, respectively. In conclusion, this study suggests that EPE may exhibit antimigratory, anti-invasive and antimetastatic potential towards prostate and breast cancer cell lines.

[Drug therapy of benign prostatic hyperplasia].

PubMed

Vahlensieck, W; Fabricius, P G; Hell, U

1996-11-10

BPH patients with Vahlensieck stage II or III disease are suitable for drug treatment. The points of attack are reduction of testosterone, conversion of testosterone to dihydrotestosterone, conversion of testosterone to estrogen using GnRH analogues, antiandrogens and alpha reductase inhibitors or aromatose inhibitors. Furthermore a reduction in obstruction is achieved through the use of phytopharmaceuticals containing 5-lipoxygenase and cyclooxygenase inhibitors. At present, Curcurbitae pepo seeds, Urtica dioica root, Pollinis siccae extract and Sabal serrulata seed extract are approved for the treatment of prostatic diseases in Germany. The use of alpha-1-sympathicolytic treatment may reduce muscular tone in the prostate. Combination of the various modes of action may also offer an effective form of treatment.

SU-E-T-279: Realization of Three-Dimensional Conformal Dose Planning in Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Z; Jiang, S; Yang, Z

2014-06-01

Purpose: Successful clinical treatment in prostate brachytherapy is largely dependent on the effectiveness of pre-surgery dose planning. Conventional dose planning method could hardly arrive at a satisfy result. In this abstract, a three-dimensional conformal localized dose planning method is put forward to ensure the accuracy and effectiveness of pre-implantation dose planning. Methods: Using Monte Carlo method, the pre-calculated 3-D dose map for single source is obtained. As for multiple seeds dose distribution, the maps are combined linearly to acquire the 3-D distribution. The 3-D dose distribution is exhibited in the form of isodose surface together with reconstructed 3-D organs groupmore » real-timely. Then it is possible to observe the dose exposure to target volume and normal tissues intuitively, thus achieving maximum dose irradiation to treatment target and minimum healthy tissues damage. In addition, the exfoliation display of different isodose surfaces can be realized applying multi-values contour extraction algorithm based on voxels. The needles could be displayed in the system by tracking the position of the implanted seeds in real time to conduct block research in optimizing insertion trajectory. Results: This study extends dose planning from two-dimensional to three-dimensional, realizing the three-dimensional conformal irradiation, which could eliminate the limitations of 2-D images and two-dimensional dose planning. A software platform is developed using VC++ and Visualization Toolkit (VTK) to perform dose planning. The 3-D model reconstruction time is within three seconds (on a Intel Core i5 PC). Block research could be conducted to avoid inaccurate insertion into sensitive organs or internal obstructions. Experiments on eight prostate cancer cases prove that this study could make the dose planning results more reasonable. Conclusion: The three-dimensional conformal dose planning method could improve the rationality of dose planning by safely

Feasibility of MR Imaging/MR Spectroscopy-Planned Focal Partial Salvage Permanent Prostate Implant (PPI) for Localized Recurrence After Initial PPI for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, Charles C., E-mail: hsucc@radonc.ucsf.edu; Hsu, Howard; Pickett, Barby

Purpose: To assess the feasibility of magnetic resonance imaging (MRI)-planned partial salvage permanent prostate implant (psPPI) among patients with biopsy-proven local recurrence after initial PPI without evidence of distant disease. Methods and Materials: From 2003-2009, 15 patients underwent MRI/magnetic resonance spectroscopy (MRS) planning for salvage brachytherapy (psPPI, I-125 [n=14; 144 Gy]; Pd-103 [n=1; 125 Gy]) without hormone therapy. Full dose was prescribed to areas of recurrence and underdosage, without entire prostate implantation. Limiting urethral and rectal toxicity was prioritized. Follow-up was from salvage date to prostate-specific antigen (PSA) concentration failure (Phoenix criteria = nadir + 2.0; ASTRO = 3 consecutivemore » rises), recurrence, distant metastases, or last follow-up PSA level. Progression-free survival (PFS) was defined as no PSA failure or biopsy-proven recurrence without all-cause mortality. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Results: At salvage, median age was 68 years, and PSA concentration was 3.5 ng/mL (range, 0.9-5.6 ng/mL). Abnormal MRI/MRS findings were evident in 40% of patients. Biopsy-proven recurrences consisted of a single focus (80%) or 2 foci (20%). At recurrence, Gleason score was 6 (67%) or {>=}7 (27%). Median interval between initial and salvage implantation was 69 months (range, 28-132 months). psPPI planning characteristics limited doses to the rectum (mean V100 = 0.5% [0.07 cc]) and urethra (V100 = 12% [0.3 cc]). At median follow-up (23.3 months; range, 8-88 months), treatment failure (n=2) resulted only in localized recurrence; both patients underwent second psPPI with follow-up PSA tests at 12 and 26 months, resulting in 0.6 and 0.7 ng/mL, respectively. American Society for Radiation Oncology PFS rates at 1, 2, and 3 years were 86.7%, 78.4%, and 62.7%, respectively, with 5 patients for whom treatment failed (n=3 with negative transrectal ultrasound

Multilayer cell-seeded polymer nanofiber constructs for soft-tissue reconstruction.

PubMed

Barker, Daniel A; Bowers, Daniel T; Hughley, Brian; Chance, Elizabeth W; Klembczyk, Kevin J; Brayman, Kenneth L; Park, Stephen S; Botchwey, Edward A

2013-09-01

Cell seeding throughout the thickness of a nanofiber construct allows for patient-specific implant alternatives with long-lasting effects, earlier integration, and reduced inflammation when compared with traditional implants. Cell seeding may improve implant integration with host tissue; however, the effect of cell seeding on thick nanofiber constructs has not been studied. To use a novel cell-preseeded nanofiber tissue engineering technique to create a 3-dimensional biocompatible implant alternative to decellularized extracellular matrix. Animal study with mammalian cell culture to study tissue engineered scaffolds. Academic research laboratory. Thirty-six Sprague-Dawley rats. The rats each received 4 implant types. The grafts included rat primary (enhanced green fluorescent protein-positive [eGFP+]) fibroblast-seeded polycaprolactone (PCL)/collagen nanofiber scaffold, PCL/collagen cell-free nanofiber scaffold, acellular human cadaveric dermis (AlloDerm), and acellular porcine dermis (ENDURAGen). Rats were monitored postoperatively and received enrofloxacin in the drinking water for 4 days prophylactically and buprenorphine (0.2-0.5 mg/kg administered subcutaneously twice a day postoperatively for pain for 48 hours). The viability of NIH/3T3 fibroblasts cultured on PCL electrospun nanofibers was evaluated using fluorescence microscopy. Soft-tissue remodeling was examined histologically and with novel ex vivo volume determinations of implants using micro-computed tomography of cell-seeded implants relative to nanofibers without cells and commonly used dermal grafts of porcine and human origin (ENDURAGen and AlloDerm, respectively). The fate and distribution of eGFP+ seeded donor fibroblasts were assessed using immunohistochemistry. Fibroblasts migrated across nanofiber layers within 12 hours and remained viable on a single layer for up to 14 days. Scanning electron microscopy confirmed a nanoscale structure with a mean (SD) diameter of 158 (72) nm. Low extrusion

Clinical implementation of stereotaxic brain implant optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenow, U.F.; Wojcicka, J.B.

1991-03-01

This optimization method for stereotaxic brain implants is based on seed/strand configurations of the basic type developed for the National Cancer Institute (NCI) atlas of regular brain implants. Irregular target volume shapes are determined from delineation in a stack of contrast enhanced computed tomography scans. The neurosurgeon may then select up to ten directions, or entry points, of surgical approach of which the program finds the optimal one under the criterion of smallest target volume diameter. Target volume cross sections are then reconstructed in 5-mm-spaced planes perpendicular to the implantation direction defined by the entry point and the target volumemore » center. This information is used to define a closed line in an implant cross section along which peripheral seed strands are positioned and which has now an irregular shape. Optimization points are defined opposite peripheral seeds on the target volume surface to which the treatment dose rate is prescribed. Three different optimization algorithms are available: linear least-squares programming, quadratic programming with constraints, and a simplex method. The optimization routine is implemented into a commercial treatment planning system. It generates coordinate and source strength information of the optimized seed configurations for further dose rate distribution calculation with the treatment planning system, and also the coordinate settings for the stereotaxic Brown-Roberts-Wells (BRW) implantation device.« less

Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.

Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bedmore » displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.« less

Long-Term Outcomes of Alternative Brachytherapy Techniques for Early Prostate Cancer. Addendum

DTIC Science & Technology

2008-10-01

radical prostatectomy. The National Medicare Experience: 1988-1990 (updated June 1993). Urology 1993;42:622-9. 3. Litwin MS, Hays RD, Fink A, Ganz PA...implantation for early-stage prostatic cancer. J Clin Oncol 1999;17:517-22. 33. Brandeis JM, Litwin MS, Burnison CM, Reiter RE. Quality of life outcomes after...combination radiotherapy for patients with prostate cancer. I-125 implant followed by external-beam radiation. Cancer 1995;75:2383-91. 35. Litwin M

Prognostic Importance of Small Prostate Size in Men Receiving Definitive Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taira, Al V.; Merrick, Gregory S., E-mail: gmerrick@urologicresearchinstitute.org; Galbreath, Robert W.

Purpose: To assess whether small prostate size is an adverse prognostic factor in men undergoing brachytherapy in the same manner in which it seems to be for men undergoing radical prostatectomy. Methods and Materials: From April 1995 to June 2008, 2024 patients underwent brachytherapy by a single brachytherapist. Median follow-up was 7.4 years. The role of small prostate size ({<=}20 cm{sup 3}) as a prognostic factor for biochemical progression-free survival, cause-specific survival, and all-cause mortality was investigated. The differences in survival between men with small and larger prostates were compared using Kaplan-Meier curves and log-rank tests. Results: Median prostate sizemore » for the entire cohort was 32.7 cm{sup 3}. For the 167 men with small prostates, median prostate size was 17.4 cm{sup 3}. There was no difference in biochemical progression-free survival (95.2% vs 96.2%, P=.603), cause-specific survival (97.7% vs 98.3%, P=.546), or all-cause mortality (78.0% vs 77.2%, P=.838) at 10 years for men with small prostates compared with men with larger prostates. On univariate and multivariate analysis, small prostate size was not associated with any of the primary outcome measures. Conclusion: Men with small prostates treated with brachytherapy have excellent outcomes and are at no higher risk of treatment failure than men with larger glands. High-quality implants with adequate margins seem sufficient to address the increased adverse risk factors associated with small prostate size.« less

Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

PubMed

Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

2016-04-01

Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Cellular responses to various levels of sustained delivery of testosterone in the ventral prostate.

PubMed

Cavett, W; Tucci, M; Cason, Z; Lemos, L; England, B; Tsao, A; Benghuzzi, H

1997-01-01

The objective of this study was to evaluate the effect of various dosages of testosterone (T) delivered in a sustained manner by means of tricalcium phosphate-lysine (TCPL) delivery system on morphological changes of prostatic tissue using adult male rats as a model. In this experiment, adult male rats (250-300 g BW) were randomly divided into five equal groups (n = 8). Rats in group I, II, and III were castrated and implanted subcutaneously with TCPL loaded with three different dosages (10, 100 and 200 mg T, respectively) of T. Rats in group IV were castrated and implanted with sharm TCPL capsules, and rats in group V served as intact unimplanted controls. Surgical aseptic techniques were performed according to standard laboratory procedures. At the end of 4 and 12 weeks post implantation, four animals from each group were sacrificed and the prostate tissues were collected, weighted, and embedded for histo-pathological evaluations. Data collected from this study have shown that exogenous intake of T delivered in a sustained manner for twelve weeks induced several pathophysiological conditions in ventral prostatic tissue in comparison to the control and sham operated groups. This phenomenon was found to be directly proportional to the dose or the level of sustained delivery. The results demonstrated that the use of 10 mg filled TCPL implants decreased the total mass weight of ventral prostate. Light microscopic evaluation of this group (Group I) revealed a cellular adaptation through an atrophy in the epithelium component. Cytopathological observations such as low cuboidal and thin glands, pleomorphism, and occasional presence of connective tissue stroma were detected. In contrast, ventral prostate collected from animals implanted with TCPL filled with 200 mg T (Group III) showed a significant increase in weights of the wet prostatic tissues in comparison to all groups. Histopathological evaluations demonstrated the following. (i) prostatic hypertrophy alone, or in

Report on the Clinical Outcomes of Permanent Breast Seed Implant for Early-Stage Breast Cancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pignol, Jean-Philippe, E-mail: j.p.pignol@erasmusmc.nl; Radiation Oncology Department, Erasmus Medical Center Cancer Institute, Rotterdam; Caudrelier, Jean-Michel

Purpose: Permanent breast seed implant is an accelerated partial breast irradiation technique realizing the insertion of {sup 103}Pd seeds in the seroma after lumpectomy. We report the 5-year efficacy and tolerance for a cohort, pooling patients from 3 clinical trials. Methods and Materials: The trials accrued postmenopausal patients with infiltrating ductal carcinoma or ductal carcinoma in situ ≤3 cm and clear surgical margins, who were node negative, and had a planning target volume <120 cm{sup 3}. The outcomes included overall and disease-free survival and local and contralateral recurrence at 5 years. The true local recurrence rate was compared using 2-tailed paired t testsmore » for estimates calculated using the Tufts University ipsilateral breast tumor recurrence and Memorial Sloan Kettering ductal carcinoma in situ nomograms. Results: The cohort included 134 patients, and the observed local recurrence rate at a median follow-up period of 63 months was 1.2% ± 1.2%, similar to the estimate for whole breast irradiation (P=.23), significantly better than for surgery alone (relative risk 0.27; P<.001), and significantly lower than contralateral recurrence (relative risk 0.33; P<.001). The 5-year overall survival rate was 97.4% ± 1.9%, and the disease-free survival rate was 96.4% ± 2.1%. At 2 months, 42% of the patients had erythema, 20% induration, and 16% moist desquamation. The rate of mainly grade 1 telangiectasia was 22.4% at 2 years and 24% at 5 years. The rate of asymptomatic induration was 23% at 2 years and 40% at 5 years. Conclusions: The 5-year data suggest that permanent breast seed implantation is a safe accelerated partial breast irradiation option after lumpectomy for early-stage breast cancer with a tolerance profile similar to that of whole breast irradiation.« less

Effect of Benincasa hispida fruits on testosterone-induced prostatic hypertrophy in albino rats

PubMed Central

Nandecha, Chetan; Nahata, Alok; Dixit, Vinod Kumar

2010-01-01

Background: Benincasa hispida Cogn. has been used traditionally in India for the management of urinary disorders. The fruit of B hispida is used as a diuretic and the seeds have been reported to possess antiangiogenic effects in prostate cells. Objective: The aim of the present study was to examine the effect of petroleum ether extract, ethanolic extract, and B hispida seed oil on hyperplasia of the prostate induced by the subcutaneous administration of testosterone in rats. Methods: In vitro studies were performed to determine the 5α-reductase inhibitory potential of the extracts. The results of those studies paved the way for the pharmacologic screening of the extracts to assess their potential against testosterone-induced hyperplasia in rats. Nine groups containing 10 rats per group were created for this study. Hyperplasia was induced by administration of testosterone (3 mg/kg SC) for 14 days in all the groups except the vehicle-treated group. Simultaneous administration of petroleum ether extract (100 or 200 mg/kg PO), ethanolic extract (100 or 200 mg/kg PO), and B hispida seed oil (20 or 40 mg/kg PO) was conducted. A standard 5α-reductase inhibitor (ie, finasteride) was used as a positive control. The weight of the rats was recorded on day 0 (ie, day 1 of the study) and on day 14, and the influence of testosterone and test extracts on the weight of the rats was determined. On day 14, rats were euthanized; prostates were dissected out, and weighed. The rats' prostate/body weight (P/BW) ratio was then determined. Histologic examinations were performed on prostates from each group. Results: The petroleum ether extract as well as B hispida seed oil exhibited inhibition of 5α-reductase activity in in vitro studies. Ethanolic extract did not exhibit significant inhibitory potential in vitro. Further in vivo study found that testosterone treatment significantly increased the rats' P/BW ratio in all the groups except the vehicle-treated rats, and this increase in

Repair of Avascular Meniscus Tears with Electrospun Collagen Scaffolds Seeded with Human Cells

PubMed Central

Baek, Jihye; Sovani, Sujata; Glembotski, Nicholas E.; Du, Jiang; Jin, Sungho; Grogan, Shawn P.

2016-01-01

The self-healing capacity of an injured meniscus is limited to the vascularized regions and is especially challenging in the inner avascular regions. As such, we investigated the use of human meniscus cell-seeded electrospun (ES) collagen type I scaffolds to produce meniscal tissue and explored whether these cell-seeded scaffolds can be implanted to repair defects created in meniscal avascular tissue explants. Human meniscal cells (derived from vascular and avascular meniscal tissue) were seeded on ES scaffolds and cultured. Constructs were evaluated for cell viability, gene expression, and mechanical properties. To determine potential for repair of meniscal defects, human meniscus avascular cells were seeded and cultured on aligned ES collagen scaffolds for 4 weeks before implantation. Surgical defects resembling “longitudinal tears” were created in the avascular zone of bovine meniscus and implanted with cell-seeded collagen scaffolds and cultured for 3 weeks. Tissue regeneration and integration were evaluated by histology, immunohistochemistry, mechanical testing, and magentic resonance imaging. Ex vivo implantation with cell-seeded collagen scaffolds resulted in neotissue that was significantly better integrated with the native tissue than acellular collagen scaffolds or untreated defects. Human meniscal cell-seeded ES collagen scaffolds may therefore be useful in facilitating meniscal repair of avascular meniscus tears. PMID:26842062

Clinical investigations on the spinal osteoblastic metastasis treated by combination of percutaneous vertebroplasty and (125)I seeds implantation versus radiotherapy.

PubMed

Yang, Zuozhang; Tan, Jing; Zhao, Ruilian; Wang, Jiaping; Sun, Hongpu; Wang, Xiaoxue; Xu, Lei; Jiang, Hua; Zhang, Jinlei

2013-02-01

To investigate the clinical efficacy of combining digital subtraction angiography-guided percutaneous vertebroplasty (PVP) and (125)I seeds implantation for the treatment of spinal osteoplastic metastasis. A combination of PVP and (125)I implantation was conducted for 50 patients with spinal osteoplastic metastasis, while the other 50 patients who received regular radiation therapy were used as a comparison. Visual analogue pain scale (VAS) and score of life quality (EORTCQLQ-30) were determined for all the patients. Surgery was successful in 89 spinal segments of vertebral body in 50 patients. Each segment of vertebral body was injected with 1-5 mL (2.8 mL for thoracic and 3.1 mL for lumbar vertebral body on average) of bone cement. Postoperative X-ray and CT examination showed that all the patients in the PVP group achieved spinal stability. During the follow-up examination from 6 months to 5 years, 49 patients (98.0%) had significantly relieved back pain, and only 1 case (2.0%) had no obvious improvement. Postoperative VAS score and Karnofsky performance score (KPS) were significantly different from the preoperative scores (p<0.05); and compared to the regular treatment group, PVP combined (125)I seeds showed much better clinical efficacy (p<0.05). PVP is a minimally invasive treatment with easy operation and less complications. PVP can effectively relieve the pain, stabilize the spine, improve the life quality, and reduce the occurrence of paraplegia in patients with spinal osteoplastic metastasis. Utilization of (125)I seeds with PVP can enhance the clinical efficacy.

Targeting Quiescence in Prostate Cancer

DTIC Science & Technology

actively dividing cancer cells causing primary tumor shrinkage, but leave behind quiescent cancer cells which may seed new, more aggressive and chemo...resistant cancers at a later date . During this first year of funding, we have successfully developed prostate cancer cell lines carrying fluorescent cell

Urethral toxicity after LDR brachytherapy: experience in Japan.

PubMed

Tanaka, Nobumichi; Asakawa, Isao; Hasegawa, Masatoshi; Fujimoto, Kiyohide

2015-01-01

Urinary toxicity is common after low-dose-rate (LDR) brachytherapy, and the resolution of urinary toxicity is a concern. In particular, urinary frequency is the most common adverse event among the urinary toxicities. We have previously reported that approximately 70% of patients experience urinary frequency during the first 6 months after seed implantation. Most urinary adverse events were classified as Grade 1, and Grade 2 or higher adverse events were rare. The incidence of urinary retention was approximately 2-4%. A high International Prostate Symptom Score before seed implantation was an independent predictor of acute urinary toxicity of Grade 2 or higher. Several previous reports from the United States also supported this trend. In Japan, LDR brachytherapy was legally approved in 2003. A nationwide prospective cohort study entitled Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation was initiated in July 2005. It is an important issue to limit urinary toxicities in patients who undergo LDR brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Intraoperative 3D Navigation for Single or Multiple 125I-Seed Localization in Breast-Preserving Cancer Surgery.

PubMed

Pouw, Bas; de Wit-van der Veen, Linda J; van Duijnhoven, Frederieke; Rutgers, Emiel J Th; Stokkel, Marcel P M; Valdés Olmos, Renato A; Vrancken Peeters, Marie-Jeanne T F D

2016-05-01

Mammographic screening has led to the identification of more women with nonpalpable breast cancer, many of them to be treated with breast-preserving surgery. To accomplish radical tumor excision, adequate localization techniques such as radioactive seed localization (RSL) are required. For RSL, a radioactive I-seed is implanted central in the tumor to enable intraoperative localization using a γ-probe. In case of extensive tumor or multifocal carcinoma, multiple I-seeds can be used to delineate the involved area. Preoperative imaging is performed different from surgical positioning; therefore, exact I-seed depth remains unknown during surgery. Twenty patients (mean age, 56.8 years) with 25 implanted I-seeds scheduled for RSL were included. Sixteen patients had 1 I-seed implanted in the primary lesion, 3 patients had 2 I-seeds, and 1 patient had 3 I-seeds. Freehand SPECT localized I-seeds by measuring γ-counts from different directions, all registered by an optical tracking system. A reconstruction and visualization algorithm enabled 3-dimensional (3D) navigation toward the I-seeds. Freehand SPECT visualized all I-seeds in primary tumors and provided preincision depth information. The deviation, mean (SD), between the freehand SPECT depth and the surgical depth estimation was 1.9 (2.1) mm (range, 0-7 mm). Three-dimensional freehand SPECT was especially useful identifying multiple implanted I-seeds because the conventional γ-probe has more difficulty discriminating I-seeds transcutaneous. Freehand SPECT with 3D navigation is a valuable tool in RSL for both single and multiple implanted I-seeds in breast-preserving cancer surgery. Freehand SPECT provides continuous updating 3D imaging with information about depth and location of the I-seeds contributing to adequate excision of nonpalpable breast cancer.

SU-G-TeP1-01: A Simulation Study to Investigate Maximum Allowable Deformations of Implant Geometry Before Plan Objectives Are Violated in Prostate HDR Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babier, A; Joshi, C; Cancer Center of Southeastern Ontario, Kingston General Hospital, Kingston, Ontario

Purpose: In prostate HDR brachytherapy dose distributions are highly sensitive to changes in prostate volume and catheter displacements. We investigate the maximum deformations in implant geometry before planning objectives are violated. Methods: A typical prostate Ir-192 HDR brachytherapy reference plan was calculated on the Oncentra planning system, which used CT images from a tissue equivalent prostate phantom (CIRS Model 053S) embedded inside a pelvis wax phantom. The prostate was deformed and catheters were displaced in simulations using a code written in MATLAB. For each deformation dose distributions were calculated, based on TG43 methods, using the MATLAB code. The calculations weremore » validated through comparison with Oncentra calculations for the reference plan, and agreed within 0.12%SD and 0.3%SD for dose and volume, respectively. Isotropic prostate volume deformations of up to +34% to −27% relative to its original volume, and longitudinal catheter displacements of 7.5 mm in superior and inferior directions were simulated. Planning objectives were based on American Brachytherapy Society guidelines for prostate and urethra volumes. A plan violated the planning objectives when less than 90% of the prostate volume received the prescribed dose or higher (V{sub 100}), or the urethral volume receiving 125% of prescribed dose or higher was more than 1 cc (U{sub 125}). Lastly, the dose homogeneity index (DHI=1-V{sub 150}/V{sub 100}) was evaluated; a plan was considered sub-optimal when the DHI fell below 0.62. Results and Conclusion: Planning objectives were violated when the prostate expanded by 10.7±0.5% or contracted by 11.0±0.2%; objectives were also violated when catheters were displaced by 4.15±0.15 mm and 3.70±0.15 mm in the superior and inferior directions, respectively. The DHI changes did not affect the plan optimality, except in the case of prostate compression. In general, catheter displacements have a significantly larger impact on plan

Long-Term Outcomes of Alternative Brachytherapy Techniques for Early Prostate Cancer

DTIC Science & Technology

2007-01-01

Oncol 2003;21:3979-86. 15. Whitmore WF, Jr., Hilaris B, Grabstald H. Retropubic implantation to iodine 125 in the treatment of prostatic cancer. J...brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma. Int J Radiat Oncol Biol Phys 1996;35:875-9. 29. Stock RG

Comparison of Biochemical Relapse-Free Survival Between Primary Gleason Score 3 and Primary Gleason Score 4 for Biopsy Gleason Score 7 Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burdick, Michael J.; Reddy, Chandana A.; Ulchaker, James

2009-04-01

Purpose: To determine whether the primary grade (PG) of biopsy Gleason score (GS) 7 prostate cancer (CaP) was predictive for biochemical relapse-free survival (bRFS). Most of the present data regarding the PG of GS7 CaP refer to surgical specimens. Our goal was to determine whether the biopsy GS used at the time of medical decision making predicted for the biochemical outcome. Methods and Materials: We reviewed the data from 705 patients with biopsy GS7 CaP, from a prospectively maintained database, who had been treated at our institution between September 1996 and March 2005 with radical prostatectomy (n = 310), externalmore » beam radiotherapy (n = 268), or prostate radioactive seed implantation (n = 127). The bRFS rates were estimated using the Kaplan-Meier method. Cox proportional hazards regression analysis was used for univariate and multivariate analyses examining these factors in relation to bRFS: PG of biopsy GS, initial prostate-specific antigen level, clinical T stage, use of androgen deprivation, risk group (high or intermediate), and treatment modality. Results: The 5-year bRFS rate was 78% and 71% (p = 0.0108) for biopsy GS7 PG3 CaP and biopsy GS7 PG4 CaP, respectively. Comparing PG3 and PG4 within treatment modalities, only prostate implantation patients had a significant difference in the 5-year bRFS rate, 88% vs. 76%, respectively (p = 0.0231). On multivariate analysis, the PG of biopsy GS remained an independent predictor of bRFS, with PG3 having better bRFS than PG4 (relative risk, 0.655; 95% confidence interval, 0.472-0.909; p = 0.0113). Conclusion: Biopsy GS7 PG4 CaP carries a worse bRFS than biopsy GS7 PG3 CaP.« less

Sexual Function and the use of Medical Devices or Drugs to Optimize Potency after Prostate Brachytherapy

PubMed Central

Whaley, J. Taylor; Levy, Lawrence B.; Swanson, David A.; Pugh, Thomas J.; Kudchadker, Rajat J.; Bruno, Teresa L.; Frank, Steven J.

2013-01-01

Purpose Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center. Methods and Materials Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile-volume receiving 100% of the prescribed dose (V100) were calculated. Results At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p=0.04) and age (p=0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients over 70 maintained optimal potency (p=0.02). Diabetes was related to a decline in potency (p=0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p<0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested. Conclusions Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry. PMID:22300559

Sexual function and the use of medical devices or drugs to optimize potency after prostate brachytherapy.

PubMed

Whaley, J Taylor; Levy, Lawrence B; Swanson, David A; Pugh, Thomas J; Kudchadker, Rajat J; Bruno, Teresa L; Frank, Steven J

2012-04-01

Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center. Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated. At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested. Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry. Copyright © 2012 Elsevier Inc. All rights reserved.

Sexual Function and the Use of Medical Devices or Drugs to Optimize Potency After Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whaley, J. Taylor; Levy, Lawrence B.; Swanson, David A.

Purpose: Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center. Methods and Materials: Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated. Results: Atmore » baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested. Conclusions: Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry.« less

An accurate method to quantify breathing-induced prostate motion for patients implanted with electromagnetic transponders.

PubMed

Giandini, Tommaso; Panaino, Costanza M V; Avuzzi, Barbara; Morlino, Sara; Villa, Sergio; Bedini, Nice; Carabelli, Gabriele; Frasca, Sarah C; Romanyukha, Anna; Rosenfeld, Anatoly; Pignoli, Emanuele; Valdagni, Riccardo; Carrara, Mauro

2017-03-24

To validate and apply a method for the quantification of breathing-induced prostate motion (BIPM) for patients treated with radiotherapy and implanted with electromagnetic transponders for prostate localization and tracking. For the analysis of electromagnetic transponder signal, dedicated software was developed and validated with a programmable breathing simulator phantom. The software was then applied to 1,132 radiotherapy fractions of 30 patients treated in supine position, and to a further 61 fractions of 2 patients treated in prone position. Application of the software in phantom demonstrated reliability of the developed method in determining simulated breathing frequencies and amplitudes. For supine patients, the in vivo analysis of BIPM resulted in median (maximum) amplitudes of 0.10 mm (0.35 mm), 0.24 mm (0.66 mm), and 0.17 mm (0.61 mm) in the left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions, respectively. Breathing frequency ranged between 7.73 and 29.43 breaths per minute. For prone patients, the ranges of the BIPM amplitudes were 0.1-0.5 mm, 0.5-1.3 mm, and 0.7-1.7 mm in the LR, CC, and AP directions, respectively. The developed method was able to detect the BIPM with sub-millimeter accuracy. While for patients treated in supine position the BIPM represents a reduced source of treatment uncertainty, for patients treated in prone position, it can be higher than 3 mm.

An experimental palladium-103 seed (OptiSeedexp) in a biocompatible polymer without a gold marker: characterization of dosimetric parameters including the interseed effect.

PubMed

Abboud, F; Scalliet, P; Vynckier, S

2008-12-01

Permanent implantation of 125I (iodine) or 103Pd (palladium) sources is a popular treatment option in the management of early stage prostate cancer. New sources are being developed, some of which are being marketed for different clinical applications. A new technique of adjuvant stereotactic permanent seed breast implant, similar to that used in the treatment of prostate cancer, has been proposed by [N. Jansen et al., Int. J. Radiat. Oncol. Biol. Phys. 67, 1052-1058 (2007)] with encouraging results. The presence of artifacts from the metallic seeds, however, can disturb follow-up imaging. The development of plastic seeds has reduced these artifacts. This paper presents a feasibility study of the advantages of palladium-103 seeds, encapsulated with a biocompatible polymer, for future clinical applications, and on the effect of the gold marker on the dosimetric characteristics of such seeds. Experimental palladium seeds, OptiSeedexp, were manufactured by International Brachytherapy (IBt), Seneffe, Belgium, from a biocompatible polymer, including the marker. Apart from the absence of a gold marker, the studied seed has an identical design to the OptiSeed103 [Phys. Med. Biol. 50, 1493-1504 (2005)]; [Appl. Radiat. Isot. 63, 311-321 (2005)]. Polymer encapsulation was preferred by IBt in order to reduce the quantity of radioactive material needed for a given dose rate and to reduce the anisotropy of the radiation field around the seed. In addition, this design is intended to decrease the interseed effects that can occur as a result of the marker and the encapsulation. Dosimetric measurements were performed using LiF thermoluminescent dosimeters (1 mm3) in solid water phantoms (WT1). Measured data were compared to Monte Carlo simulated data in solid water using the MCNP code, version 4C. Updated cross sections [Med. Phys. 30, 701-711 (2003)] were used. As the measured and calculated data were in agreement, Monte Carlo calculations were then performed in liquid water to

Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.

PubMed

Mai, Ronald; Hagedorn, Manolo Gunnar; Gelinsky, Michael; Werner, Carsten; Turhani, Dritan; Späth, Heike; Gedrange, Tomas; Lauer, Günter

2006-09-01

The aim of this study was to evaluate the ectopic bone formation using tissue engineered cell-seeded constructs with two different scaffolds and primary human maxillary osteoblasts in nude rats over an implantation period of up to 96 days. Collagen I-coated Poly(3)hydroxybutyrate (PHB) embroidery and hydroxyapatite (HAP) collagen tapes were seeded with primary human maxillary osteoblasts (hOB) and implanted into athymic rnu/run rats. A total of 72 implants were placed into the back muscles of 18 rats. 24, 48 and 96 days after implantation, histological and histomorphometric analyses were made. The osteoblastic character of the cells was confirmed by immunocytochemistry and RT-PCR for osteocalcin. Histological analysis demonstrated that all cell-seeded constructs induced ectopic bone formation after 24, 48 and 96 days of implantation. There was more mineralized tissue in PHB constructs than in HAP-collagen tapes (at day 24; p < 0.05). Bone formation decreased with the increasing length of the implantation period. Osteocalcin expression verified the osteoblastic character of the cell-seeded constructs after implantation time. No bone formation and no osteocalcin expression were found in the control groups. Cell-seeded constructs either with PHB embroidery or HAP-collagen tapes can induce ectopic bone formation. However, the amount of bone formed decreased with increasing length of implantation.

Prostate Cancer Detection and Diagnosis: The Role of MR and its Comparison to other Diagnostic Modalities – A Radiologist's Perspective

PubMed Central

Penzkofer, Tobias; Tempany-Afdhal, Clare M.

2013-01-01

It is now universally recognized that many prostate cancers are over-diagnosed and over-treated. The European Randomized Study of Screening for Prostate Cancer (ERSPC) from 2009 evidenced that, to save one man from death of prostate cancer, over 1,400 men had to be screened, and 48 had to undergo treatment. Detection of prostate cancer is traditionally based upon digital rectal examination (DRE) and measuring serum prostate specific antigen (PSA), followed by ultrasound guided biopsy. The primary role of imaging for the detection and diagnosis of prostate cancer has been transrectal ultrasound (TRUS) guidance during biopsy. MRI has traditionally been used primarily for staging disease in men with biopsy proven cancer. It is has a well-established role in detecting T3 disease, planning radiation therapy, especially 3D conformal or intensity modulated external beam radiation therapy (IMRT), and planning and guiding interstitial seed implant or brachytherapy. New advances have now established prostate MRI can accurately characterize focal lesions within the gland, an ability that has led to new opportunities for improved cancer detection and guidance for biopsy. There are two new approaches to prostate biopsy are under investigation both use pre-biopsy MRI to define potential targets for sampling and then the biopsy is performed either with direct real-time MR guidance (in-bore) or MR fusion/registration with TRUS images (out-of-bore). In-bore or out-of-bore MRI-guided prostate biopsies have the advantage of using the MR target definition for accurate localization and sampling of targets or suspicious lesions. The out-of-bore method uses combined MRI/TRUS with fusion software that provided target localization and increases the sampling accuracy for TRUS-guided biopsies by integrating prostate MRI information with TRUS. Newer parameters for each imaging modality such as sonoelastography or shear wave elastography (SWE), contrast enhanced US (CEUS) and MRI

Maturation of the developing human fetal prostate in a rodent xenograft model

PubMed Central

Saffarini, Camelia M.; McDonnell, Elizabeth V.; Amin, Ali; Spade, Daniel J.; Huse, Susan M.; Kostadinov, Stefan; Hall, Susan J.; Boekelheide, Kim

2015-01-01

Background Prostate cancer is the most commonly diagnosed non-skin cancer in men. The etiology of prostate cancer is unknown, although both animal and epidemiologic data suggest that early life exposures to various toxicants, may impact DNA methylation status during development, playing an important role. Methods We have developed a xenograft model to characterize the growth and differentiation of human fetal prostate implants (gestational age 12-24 weeks) that can provide new data on the potential role of early life stressors on prostate cancer. The expression of key immunohistochemical markers responsible for prostate maturation was evaluated, including p63, cytokeratin 18, α-smooth muscle actin, vimentin, caldesmon, Ki-67, prostate specific antigen, estrogen receptor-α, and androgen receptor. Xenografts were separated into epithelial and stromal compartments using laser capture microdissection (LCM), and the DNA methylation status was assessed in >480,000 CpG sites throughout the genome. Results Xenografts demonstrated growth and maturation throughout the 200 days of post-implantation evaluation. DNA methylation profiles of laser capture micro-dissected tissue demonstrated tissue-specific markers clustered by their location in either the epithelium or stroma of human prostate tissue. Differential methylated promoter region CpG-associated gene analysis revealed significantly more stromal than epithelial DNA methylation in the 30 and 90-day xenografts. Functional classification analysis identified CpG-related gene clusters in methylated epithelial and stromal human xenografts. Conclusion This study of human fetal prostate tissue establishes a xenograft model that demonstrates dynamic growth and maturation, allowing for future mechanistic studies of the developmental origins of later life proliferative prostate disease. PMID:24038131

Repeated iodine-125 seed implantations combined with external beam radiotherapy for the treatment of locally recurrent or metastatic stage III/IV non-small cell lung cancer: a retrospective study.

PubMed

Li, Wei; Dan, Gang; Jiang, Jianqing; Zheng, Yifeng; Zheng, Xiushan; Deng, Dan

2016-09-13

Recurrent or metastatic lung cancer is difficult to manage. This retrospective study aimed to assess the efficacy of repeated iodine-125 seed implantations combined with external beam radiotherapy (EBRT) for locally recurrent or metastatic stage-III/IV non-small cell lung cancer (NSCLC). Eighteen previously treated stage-III/IV NSCLC patients with local or metastatic recurrences underwent 1-to-3 iodine-125 implantations. Six of these patients received palliative EBRT and six patients received combined chemotherapy using gemcitabine and cisplatin. Near-term treatment efficacy was evaluated 3 months after seed implantation by comparing changes in tumor size on computed tomography images; the evaluated outcomes were complete response, partial response, stable disease, and local tumor control rate. Long-term efficacy was assessed based on 1- and 2-year survival rates. Patients were followed up for 6 to 50 months. The overall (i.e., complete + partial) response rate was 87.4 %. The local control rates after the first, second, and third years were 94.1, 58.8 and 41.2 %, respectively. The results of this study demonstrated that repeated implantation of radioactive particles combined with EBRT is a safe treatment that effectively controlled local recurrence and metastasis of stage III/IV NSCLC.

Radioactive seed migration following parotid gland interstitial brachytherapy.

PubMed

Fan, Yi; Huang, Ming-Wei; Zhao, Yi-Jiao; Gao, Hong; Zhang, Jian-Guo

To evaluate the incidence and associated factors of pulmonary seed migration after parotid brachytherapy using a novel migrated seed detection technique. Patients diagnosed with parotid cancer who underwent permanent parotid brachytherapy from January 2006 to December 2011 were reviewed retrospectively. Head and neck CT scans and chest X-rays were evaluated during routine follow-up. Mimics software and Geomagic Studio software were used for seed reconstruction and migrated seed detection from the original implanted region, respectively. Postimplant dosimetry analysis was performed after seeds migration if the seeds were still in their emitting count. Adverse clinical sequelae from seed embolization to the lung were documented. The radioactive seed implants were identified on chest X-rays in 6 patients. The incidence rate of seed migration in 321 parotid brachytherapy patients was 1.87% (6/321) and that of individual seed migration was 0.04% (6/15218 seeds). All migrated seeds were originally from the retromandibular region. No adverse dosimetric consequences were found in the target region. Pulmonary symptoms were not reported by any patient in this study. In our patient set, migration of radioactive seeds with an initial radioactivity of 0.6-0.7 mCi to the chest following parotid brachytherapy was rare. Late migration of a single seed from the central target region did not affect the dosimetry significantly, and patients did not have severe short-term complications. This study proposed a novel technique to localize the anatomical origin of the migrated seeds during brachytherapy. Our evidence suggested that placement of seeds adjacent to blood vessels was associated with an increased likelihood of seed migration to the lungs. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

The Royal College of Radiologists' audit of prostate brachytherapy in the year 2012.

PubMed

Stewart, A J; Drinkwater, K J; Laing, R W; Nobes, J P; Locke, I

2015-06-01

This audit provides a comprehensive overview of UK prostate brachytherapy practice in the year 2012, measured against existing standards, immediately before the introduction of new Royal College of Radiologists (RCR) guidelines. This audit allows comparison with European and North American brachytherapy practice and for the impact of the RCR 2012 guidelines to be assessed in the future. A web-based data collection tool was developed by the RCR Clinical Audit Committee and sent to audit leads at all cancer centres in the UK. Standards were developed based on available guidelines in use at the start of 2012 covering case mix and dosimetry. Further questions were included to reflect areas of anticipated change with the implementation of the 2012 guidelines. Audit findings were compared with similar audits of practice in Europe, the USA and Latin America. Forty-nine of 59 cancer centres submitted data. Twenty-nine centres reported carrying out prostate brachytherapy; of these, 25 (86%) provided data regarding the number of implants, staffing, dosimetry, medication and anaesthesia and follow-up. Audit standards achieved excellent compliance in most areas, although were low in post-implant dosimetry and in post-implant scanning at 30 days. This audit provides a comprehensive picture of prostate brachytherapy in the UK in 2012. Patterns of care of prostate brachytherapy are similar to practice in the USA and Europe. The number of prostate brachytherapy implants carried out in the UK has grown significantly since a previous RCR audit in 2005 and it is important that centres maintain minimum numbers of cases to ensure that experience can be maintained and compliance to guidelines achieved. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

SU-F-19A-07: Is a Day30 Scan Necessary to Evaluate Activity-Based Regulatory Compliance in Permanent Interstitial Brachytherapy for Prostate Cancer?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapur, P; Ford, J; Moghanaki, D

Purpose: To evaluate the Medical Event (ME) criteria for I-125 prostate implants based on the assessment of post implant dosimetry on “Day0”/“Day30” imaging. The new ME criteria do not mandate a timeframe for this assessment. The compliance criteria are: more than 80% of the activity from the written directive for treatment site (TS) must be implanted inside TS, and doses to 1cc of either uninvolved rectum (D1-UR) or uninvolved bladder (D1-UB), or 2cc of other non-specified tissue (D2-UT) must be less than 150% of the planned dose. Methods: “Day0”/“Day30” post-implant analyses for 25 patients were evaluated. Treatment plans had amore » peripheral loading pattern with 2 core needles placed at least 10 mm away from urethra, with several seeds planned outside of the prostate for adequate target coverage. TS were a uniform 5 mm expansion of the prostate, except posteriorly (no expansion). Results: “Day0”/“Day30”analyses found no MEs. The relative changes for D1-UR, D1-UB, and D2-UT were (ranges): [−37.0, 38.2]%, [−96.5, 74.7]%, and [−41.2, 37.7]%. Furthermore, changes did not correlate with prostate volume changes of −18.7% [σ:16.0%, range:−60.5%, +6.4%]. These unfavorable changes did not lead to ME at “Day30” because these values were generally well below 150% at “Day0”. However, D2-UT dose values exceeded those for D1-UR and D1-UB at both “Day0”/“Day30”. Conclusion: The total activity was relatively insensitive to changes in target volume from “Day0” to ”Day30”. The dose metrics of interest, albeit susceptible to large, often unfavorable changes, remained less than the 150% threshold. Data from this study suggest that “Day0” can be used for the regulatory compliance evaluation. However, further evaluation at “Day30” is advisable if D2-UT is 110% or above (based on the largest D2-UT increase of 37.7% observed in this patient population). Future rigorous statistical analysis of a larger cohort will

Automatic seed picking for brachytherapy postimplant validation with 3D CT images.

PubMed

Zhang, Guobin; Sun, Qiyuan; Jiang, Shan; Yang, Zhiyong; Ma, Xiaodong; Jiang, Haisong

2017-11-01

Postimplant validation is an indispensable part in the brachytherapy technique. It provides the necessary feedback to ensure the quality of operation. The ability to pick implanted seed relates directly to the accuracy of validation. To address it, an automatic approach is proposed for picking implanted brachytherapy seeds in 3D CT images. In order to pick seed configuration (location and orientation) efficiently, the approach starts with the segmentation of seed from CT images using a thresholding filter which based on gray-level histogram. Through the process of filtering and denoising, the touching seed and single seed are classified. The true novelty of this approach is found in the application of the canny edge detection and improved concave points matching algorithm to separate touching seeds. Through the computation of image moments, the seed configuration can be determined efficiently. Finally, two different experiments are designed to verify the performance of the proposed approach: (1) physical phantom with 60 model seeds, and (2) patient data with 16 cases. Through assessment of validated results by a medical physicist, the proposed method exhibited promising results. Experiment on phantom demonstrates that the error of seed location and orientation is within ([Formula: see text]) mm and ([Formula: see text])[Formula: see text], respectively. In addition, the most seed location and orientation error is controlled within 0.8 mm and 3.5[Formula: see text] in all cases, respectively. The average process time of seed picking is 8.7 s per 100 seeds. In this paper, an automatic, efficient and robust approach, performed on CT images, is proposed to determine the implanted seed location as well as orientation in a 3D workspace. Through the experiments with phantom and patient data, this approach also successfully exhibits good performance.

Dose Constraint for Minimizing Grade 2 Rectal Bleeding Following Brachytherapy Combined With External Beam Radiotherapy for Localized Prostate Cancer: Rectal Dose-Volume Histogram Analysis of 457 Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiraishi, Yutaka; Yorozu, Atsunori; Ohashi, Toshio, E-mail: ohashi@rad.med.keio.ac.jp

2011-11-01

Purpose: To determine the rectal tolerance to Grade 2 rectal bleeding after I-125 seed brachytherapy combined with external beam radiotherapy (EBRT), based on the rectal dose-volume histogram. Methods and Materials: A total of 458 consecutive patients with stages T1 to T3 prostate cancer received combined modality treatment consisting of I-125 seed implantation followed by EBRT to the prostate and seminal vesicles. The prescribed doses of brachytherapy and EBRT were 100 Gy and 45 Gy in 25 fractions, respectively. The rectal dosimetric factors were analyzed for rectal volumes receiving >100 Gy and >150 Gy (R100 and R150) during brachytherapy and formore » rectal volumes receiving >30 Gy to 40 Gy (V30-V40) during EBRT therapy in 373 patients for whom datasets were available. The patients were followed from 21 to 72 months (median, 45 months) after the I-125 seed implantation. Results: Forty-four patients (9.7%) developed Grade 2 rectal bleeding. On multivariate analysis, age (p = 0.014), R100 (p = 0.002), and V30 (p = 0.001) were identified as risk factors for Grade 2 rectal bleeding. The rectal bleeding rate increased as the R100 increased: 5.0% (2/40 patients) for 0 ml; 7.5% (20/267 patients) for >0 to 0.5 ml; 11.0% (11/100 patients) for >0.5 to 1 ml; 17.9% (5/28 patients) for >1 to 1.5 ml; and 27.3% (6/22 patients) for >1.5 ml (p = 0.014). Grade 2 rectal bleeding developed in 6.4% (12/188) of patients with a V30 {<=}35% and in 14.1% (26/185) of patients with a V30 >35% (p = 0.02). When these dose-volume parameters were considered in combination, the Grade 2 rectal bleeding rate was 4.2% (5/120 patients) for a R100 {<=}0.5 ml and a V30 {<=}35%, whereas it was 22.4% (13/58 patients) for R100 of >0.5 ml and V30 of >35%. Conclusion: The risk of rectal bleeding was found to be significantly volume-dependent in patients with prostate cancer who received combined modality treatment. Rectal dose-volume analysis is a practical method for predicting the risk of

Sci-Thur PM – Brachytherapy 03: Identifying the impact of seroma visualization on permanent breast seed implant brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morton, Daniel; Batchelar, Deidre; Hilts, Michelle

Purpose: Uncertainties in target identification can reduce treatment accuracy in permanent breast seed implant (PBSI) brachytherapy. This study evaluates the relationship between seroma visualization and seed placement accuracy. Methods: Spatially co-registered CT and 3D ultrasound (US) images were acquired for 10 patients receiving PBSI. Seromas were retrospectively contoured independently by 3 radiation oncologists on both CT and US and respective consensus volumes were defined, CTV{sub CT} and CTV{sub US}. The seroma clarity and inter-user conformity index (CI), as well as inter-modality CI, volume, and positional differences were evaluated. Correlations with seed placement accuracy were then assessed. CTVs were expanded bymore » 1.25cm to create PTV{sub CT} and PTV{sub US} and evaluate the conformity with PTV{sub Clinical} (CTV{sub Clinical}+1.25cm) used in treatment planning. The change in PTV coincidence by expanding PTV{sub Clinical} by 0.25cm was determined. Results: CTV{sub US} were a mean 68 ± 12% smaller than CTV{sub CT} and generally had improved clarity and inter-user conformity. No correlations between seed displacement and CTV{sub US}-CTV{sub CT} positional difference or CI were observed. Greater seed displacements were associated with larger CTV{sub US}-CTV{sub CT} volume differences (r=−0.65) and inter-user CT CI (r=−0.74). A median (range) 88% (71–99%) of PTV{sub CT} and 83% (69–100%) of PTV{sub US} were contained within PTV{sub Clinical}. Expanding treatment margins to 1.5cm increased coincidence to 98% (86–100%) and 94% (82–100%), respectively. Conclusions: Differences in seroma visualization impacts seed displacement in PBSI. Reducing dependence on CT by incorporating 3DUS into target identification, or expanding CT-based treatment margins to 1.5cm may reduce or mitigate uncertainties related to seroma visualization.« less

Primary Gleason Grade 4 Impact on Biochemical Recurrence After Permanent Interstitial Brachytherapy in Japanese Patients With Low- or Intermediate-Risk Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uesugi, Tatsuya; Saika, Takashi, E-mail: saika@cc.okayama-u.ac.jp; Edamura, Kohei

2012-02-01

Purpose: To reveal a predictive factor for biochemical recurrence (BCR) after permanent prostate brachytherapy (PPB) using iodine-125 seed implantation in patients with localized prostate cancer classified as low or intermediate risk based on National Comprehensive Cancer Network (NCCN) guidelines. Methods and Materials: From January 2004 to December 2009, 414 consecutive Japanese patients with clinically localized prostate cancer classified as low or intermediate risk based on the NCCN guidelines were treated with PPB. The clinical factors including pathological data reviewed by a central pathologist and follow-up data were prospectively collected. Kaplan-Meier and Cox regression analyses were used to assess the factorsmore » associated with BCR. Results: Median follow-up was 36.5 months. The 2-, 3-, 4-, and 5-year BCR-free rates using the Phoenix definition were 98.3%, 96.0%, 91.6%, and 87.0%, respectively. On univariate analysis, the Gleason score, especially primary Gleason grade 4 in biopsy specimens, was a strong predicting factor (p < 0.0001), while age, initial prostate-specific antigen (PSA) level, T stage, and minimal dose delivered to 90% of the prostate volume (D90) were insignificant. Multivariate analysis indicated that a primary Gleason grade 4 was the most powerful prognostic factor associated with BCR (hazard ratio = 6.576, 95% confidence interval, 2.597-16.468, p < 0.0001). Conclusions: A primary Gleason grade 4 carried a worse BCR prognosis than the primary grade 3 in patients treated with PPB. Therefore, the indication for PPB in patients with a Gleason sum of 4 + 3 deserves careful and thoughtful consideration.« less

TPS-guided interstitial Iodine-125 implantation in patients with oral cavity and maxillofacial carcinomas.

PubMed

Meng, J; Zhang, J; Zhuang, Q-W; Wang, X; Li, Z-P; Gu, Q-P

2014-10-01

To investigate the efficacy as well as the complications involved in the use of interstitial Iodine-125 implantation for the treatment of oral cavity and maxillofacial carcinomas. Fifteen patients with oral cavity and maxillofacial carcinomas received treatment planning system (TPS)-guided interstitial Iodine-125 implantation. The apparent activity per particle ranged from 0.6 mCi (2.22MBq) to 0.7 mCi (2.59MBq). The matched peripheral dose delivered by radioactive seeds ranged from 90 to 120 Gy. The efficacy of the treatment and the postoperative complications were evaluated during follow-up. The seeds were implanted successfully in all 15 patients and median number of seeds implanted was 36.53. CT scans were performed in all patients at 1-6 months postoperatively. During follow-up at 6-27 months, seed migration occurred and a good local tumor control was achieved with an overall response of 86.7%. No severe side effects were observed. TPS-guided interstitial Iodine-125 implantation is an effective and safe procedure with minimal invasiveness for the treatment of oral cavity and maxillofacial carcinomas, and it effectively prevents the recurrence of cancer and short-term lymphatic metastasis.

Flavanols from evening primrose (Oenothera paradoxa) defatted seeds inhibit prostate cells invasiveness and cause changes in Bcl-2/Bax mRNA ratio.

PubMed

Lewandowska, Urszula; Szewczyk, Karolina; Owczarek, Katarzyna; Hrabec, Zbigniew; Podsędek, Anna; Koziołkiewicz, Maria; Hrabec, Elżbieta

2013-03-27

In this study, we assessed the influence of an evening primrose flavanol preparation (EPFP) on proliferation and invasiveness of human prostate cancer cells (DU 145) and immortalized prostate epithelial cells (PNT1A). We report for the first time that EPFP reduces DU 145 cell proliferation (IC50 = 97 μM GAE for 72 h incubation) and invasiveness (by 24% versus control at 75 μM GAE). EPFP strongly inhibited PNT1A invasiveness in a concentration-dependent manner (by 67% versus control at 75 μM GAE) and did not cause a reduction in their proliferation. Furthermore, EPFP inhibited the activities of MMP-2 and MMP-9 secreted to culture medium by PNT1A cells by 84% and 34% versus control at 100 μM GAE, respectively. In the case of DU 145, MMP-9 activity at 100 μM GAE was reduced by 37% versus control. Moreover, the evening primrose seed flavanols suppressed the expression of selected genes (MMP-1, MMP-9, MMP-14, c-Fos, c-Jun, and VEGF) and also caused favorable changes in Bcl-2/Bax mRNA ratio which render DU 145 cells more sensitive to apoptosis-triggering agents. An additional confirmation of the proapoptotic activity of EPFP toward DU 145 was visualization of characteristic apoptotic bodies by DAPI staining. In conclusion, this study suggests that EPFP may increase apoptosis and reduce angiogenesis of prostate cancer cells.

Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xiaofeng, E-mail: xyang43@emory.edu; Rossi, Peter; Ogunleye, Tomi

2014-11-01

Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approachmore » that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7

Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

PubMed Central

Yang, Xiaofeng; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Mao, Hui; Curran, Walter J.; Liu, Tian

2014-01-01

Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

Automated matching of corresponding seed images of three simulator radiographs to allow 3D triangulation of implanted seeds.

PubMed

Altschuler, M D; Kassaee, A

1997-02-01

To match corresponding seed images in different radiographs so that the 3D seed locations can be triangulated automatically and without ambiguity requires (at least) three radiographs taken from different perspectives, and an algorithm that finds the proper permutations of the seed-image indices. Matching corresponding images in only two radiographs introduces inherent ambiguities which can be resolved only with the use of non-positional information obtained with intensive human effort. Matching images in three or more radiographs is an 'NP (Non-determinant in Polynomial time)-complete' problem. Although the matching problem is fundamental, current methods for three-radiograph seed-image matching use 'local' (seed-by-seed) methods that may lead to incorrect matchings. We describe a permutation-sampling method which not only gives good 'global' (full permutation) matches for the NP-complete three-radiograph seed-matching problem, but also determines the reliability of the radiographic data themselves, namely, whether the patient moved in the interval between radiographic perspectives.

Automated matching of corresponding seed images of three simulator radiographs to allow 3D triangulation of implanted seeds

NASA Astrophysics Data System (ADS)

Altschuler, Martin D.; Kassaee, Alireza

1997-02-01

To match corresponding seed images in different radiographs so that the 3D seed locations can be triangulated automatically and without ambiguity requires (at least) three radiographs taken from different perspectives, and an algorithm that finds the proper permutations of the seed-image indices. Matching corresponding images in only two radiographs introduces inherent ambiguities which can be resolved only with the use of non-positional information obtained with intensive human effort. Matching images in three or more radiographs is an `NP (Non-determinant in Polynomial time)-complete' problem. Although the matching problem is fundamental, current methods for three-radiograph seed-image matching use `local' (seed-by-seed) methods that may lead to incorrect matchings. We describe a permutation-sampling method which not only gives good `global' (full permutation) matches for the NP-complete three-radiograph seed-matching problem, but also determines the reliability of the radiographic data themselves, namely, whether the patient moved in the interval between radiographic perspectives.

Temporary implantable nitinol device (TIND): a novel, minimally invasive treatment for relief of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH): feasibility, safety and functional results at 1 year of follow-up.

PubMed

Porpiglia, Francesco; Fiori, Cristian; Bertolo, Riccardo; Garrou, Diletta; Cattaneo, Giovanni; Amparore, Daniele

2015-08-01

To report the first clinical experience with a temporary implantable nitinol device (TIND; Medi-Tate(®) ) for the treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). In all, 32 patients with LUTS were enrolled in this prospective study, which was approved by our Institutional Ethics Committee. Inclusion criteria were: age >50 years, International Prostate Symptom Score (IPSS) of ≥10, maximum urinary flow rate (Qmax ) of ≤12 mL/s, and prostate volume of <60 mL. The TIND was implanted within the bladder neck and the prostatic urethra under light sedation, using a rigid cystoscope. The device was removed 5 days later in an outpatient setting. Demographics, perioperative results, complications (according to the Clavien system), functional results and quality of life (QoL) were evaluated. Follow-up assessments were made at 3 and 6 weeks, and 3, 6 and 12 months postoperatively. The Student's t-test, analysis of variance (anova), Kruskall-Wallis test, and simple and multiple linear regression models were used in the statistical analyses. The mean patient age was 69.4 years, the mean (standard deviation, sd) prostate volume was 29.5 (7.4) mL and the Qmax was 7.6 (2.2) mL/s. The median (interquartile range, IQR) IPSS was 19 (14-23) and QoL score was 3 (3-4). All the implantations were successful, with no intraoperative complications recorded. The mean operative time (sd) was 5.8 (2.5) min and the median (IQR) postoperative stay was 1 (1-2) day. All but one of the devices (96%) was removed 5 days at after implantation in an outpatient setting. Four complications (12.5%) were recorded, including urinary retention (one, 3.1%), transient incontinence due to device displacement (one, 3.1%), prostatic abscess (one, 3.1%), and urinary tract infection (one, 3.1%). Multiple regression analysis failed to identify any independent prognostic factor for complications. There were statistically significant differences in the

Prostate-specific antigen bounce after intensity-modulated radiotherapy for prostate cancer.

PubMed

Sheinbein, Courtney; Teh, Bin S; Mai, Wei Y; Grant, Walter; Paulino, Arnold; Butler, E Brian

2010-09-01

To report prostate-specific antigen (PSA) bounce in patients treated with intensity-modulated radiotherapy (IMRT) alone. Previous studies have reported PSA bounce in prostate cancer patients treated with conventional radiotherapy, 3D conformal radiotherapy, and permanent seed brachytherapy. From January 1997 to July 2002, 102 patients with clinically localized prostate cancer were treated with IMRT alone. No patients received androgen ablation. PSA bounce was defined as a PSA increase of at least 0.4 ng/mL, followed by any PSA decrease. Biochemical failure was defined by both the American Society for Therapeutic Radiology and Oncology 1996 and 2006 consensus definitions. The median follow-up was 76 months. The median length of time until the first PSA bounce was 13.6 months. Thirty-three patients (32.4%) had at least 1 PSA bounce, with 25 (24.5%) having 1 bounce; 6 (5.9%), 2 bounces; and 2 (2.0%), 4 bounces. PSA bounce was not significantly associated with biochemical no evidence of disease survival, clinical stage, pretreatment PSA, Gleason combined score, prostate planning target volume, PSA nadir, or mean dose to the prostate. The rate of PSA bounce in patients aged ≤ 70 and > 70 years was 44.4% and 22.8%, respectively (P = .032). Our patient series is the first report on PSA bounce in patients treated with IMRT. Our study confirms that the majority of patients with a bouncing PSA remain biochemically and clinically free of disease with extended follow-up. Copyright © 2010 Elsevier Inc. All rights reserved.

Quantitative volumetric imaging of normal, neoplastic and hyperplastic mouse prostate using ultrasound.

PubMed

Singh, Shalini; Pan, Chunliu; Wood, Ronald; Yeh, Chiuan-Ren; Yeh, Shuyuan; Sha, Kai; Krolewski, John J; Nastiuk, Kent L

2015-09-21

Genetically engineered mouse models are essential to the investigation of the molecular mechanisms underlying human prostate pathology and the effects of therapy on the diseased prostate. Serial in vivo volumetric imaging expands the scope and accuracy of experimental investigations of models of normal prostate physiology, benign prostatic hyperplasia and prostate cancer, which are otherwise limited by the anatomy of the mouse prostate. Moreover, accurate imaging of hyperplastic and tumorigenic prostates is now recognized as essential to rigorous pre-clinical trials of new therapies. Bioluminescent imaging has been widely used to determine prostate tumor size, but is semi-quantitative at best. Magnetic resonance imaging can determine prostate volume very accurately, but is expensive and has low throughput. We therefore sought to develop and implement a high throughput, low cost, and accurate serial imaging protocol for the mouse prostate. We developed a high frequency ultrasound imaging technique employing 3D reconstruction that allows rapid and precise assessment of mouse prostate volume. Wild-type mouse prostates were examined (n = 4) for reproducible baseline imaging, and treatment effects on volume were compared, and blinded data analyzed for intra- and inter-operator assessments of reproducibility by correlation and for Bland-Altman analysis. Examples of benign prostatic hyperplasia mouse model prostate (n = 2) and mouse prostate implantation of orthotopic human prostate cancer tumor and its growth (n =  ) are also demonstrated. Serial measurement volume of the mouse prostate revealed that high frequency ultrasound was very precise. Following endocrine manipulation, regression and regrowth of the prostate could be monitored with very low intra- and interobserver variability. This technique was also valuable to monitor the development of prostate growth in a model of benign prostatic hyperplasia. Additionally, we demonstrate accurate ultrasound image

Early fixation of cobalt-chromium based alloy surgical implants to bone using a tissue-engineering approach.

PubMed

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation.

Early Fixation of Cobalt-Chromium Based Alloy Surgical Implants to Bone Using a Tissue-engineering Approach

PubMed Central

Ogawa, Munehiro; Tohma, Yasuaki; Ohgushi, Hajime; Takakura, Yoshinori; Tanaka, Yasuhito

2012-01-01

To establish the methods of demonstrating early fixation of metal implants to bone, one side of a Cobalt-Chromium (CoCr) based alloy implant surface was seeded with rabbit marrow mesenchymal cells and the other side was left unseeded. The mesenchymal cells were further cultured in the presence of ascorbic acid, β-glycerophosphate and dexamethasone, resulting in the appearance of osteoblasts and bone matrix on the implant surface. Thus, we succeeded in generating tissue-engineered bone on one side of the CoCr implant. The CoCr implants were then implanted in rabbit bone defects. Three weeks after the implantation, evaluations of mechanical test, undecalcified histological section and electron microscope analysis were performed. Histological and electron microscope images of the tissue engineered surface exhibited abundant new bone formation. However, newly formed bone tissue was difficult to detect on the side without cell seeding. In the mechanical test, the mean values of pull-out forces were 77.15 N and 44.94 N for the tissue-engineered and non-cell-seeded surfaces, respectively. These findings indicate early bone fixation of the tissue-engineered CoCr surface just three weeks after implantation. PMID:22754313

Bad seeds produce bad crops: a single stage-process of prostate tumor invasion

PubMed Central

Man, Yan-gao; Gardner, William A.

2008-01-01

It is a commonly held belief that prostate carcinogenesis is a multi-stage process and that tumor invasion is triggered by the overproduction of proteolytic enzymes. This belief is consistent with data from cell cultures and animal models, whereas is hard to interpret several critical facts, including the presence of cancer in “healthy” young men and cancer DNA phenotype in morphologically normal prostate tissues. These facts argue that alternative pathways may exist for prostate tumor invasion in some cases. Since degradation of the basal cell layer is the most distinct sign of invasion, our recent studies have attempted to identify pre-invasive lesions with focal basal cell layer alterations. Our studies revealed that about 30% of prostate cancer patients harbored normal appearing duct or acinar clusters with a high frequency of focal basal cell layer disruptions. These focally disrupted basal cell layers had significantly reduced cell proliferation and tumor suppressor expression, whereas significantly elevated degeneration, apoptosis, and infiltration of immunoreactive cells. In sharp contrast, associated epithelial cell had significantly elevated proliferation, expression of malignancy-signature markers, and physical continuity with invasive lesions. Based on these and other findings, we have proposed that these normal appearing duct or acinar clusters are derived from monoclonal proliferation of genetically damaged stem cells and could progress directly to invasion through two pathways: 1) clonal in situ transformation (CIST) and 2) multi-potential progenitor mediated “budding” (MPMB). These pathways may contribute to early onset of prostate cancer at young ages, and to clinically more aggressive prostate tumors. PMID:18725981

A fully actuated robotic assistant for MRI-guided prostate biopsy and brachytherapy

NASA Astrophysics Data System (ADS)

Li, Gang; Su, Hao; Shang, Weijian; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare M.; Fischer, Gregory S.

2013-03-01

Intra-operative medical imaging enables incorporation of human experience and intelligence in a controlled, closed-loop fashion. Magnetic resonance imaging (MRI) is an ideal modality for surgical guidance of diagnostic and therapeutic procedures, with its ability to perform high resolution, real-time, high soft tissue contrast imaging without ionizing radiation. However, for most current image-guided approaches only static pre-operative images are accessible for guidance, which are unable to provide updated information during a surgical procedure. The high magnetic field, electrical interference, and limited access of closed-bore MRI render great challenges to developing robotic systems that can perform inside a diagnostic high-field MRI while obtaining interactively updated MR images. To overcome these limitations, we are developing a piezoelectrically actuated robotic assistant for actuated percutaneous prostate interventions under real-time MRI guidance. Utilizing a modular design, the system enables coherent and straight forward workflow for various percutaneous interventions, including prostate biopsy sampling and brachytherapy seed placement, using various needle driver configurations. The unified workflow compromises: 1) system hardware and software initialization, 2) fiducial frame registration, 3) target selection and motion planning, 4) moving to the target and performing the intervention (e.g. taking a biopsy sample) under live imaging, and 5) visualization and verification. Phantom experiments of prostate biopsy and brachytherapy were executed under MRI-guidance to evaluate the feasibility of the workflow. The robot successfully performed fully actuated biopsy sampling and delivery of simulated brachytherapy seeds under live MR imaging, as well as precise delivery of a prostate brachytherapy seed distribution with an RMS accuracy of 0.98mm.

[Orgasm after curietherapy with permanent iodine-125 radioimplants for localized prostate cancer].

PubMed

Delaunay, B; Delannes, M; Salloum, A; Delavierre, D; Wagner, F; Jonca, F; Thoulouzan, M; Plante, P; Bachaud, J-M; Soulie, M; Huyghe, E

2011-12-01

Orgasm is a domain of male sexuality that remains underreported in literature. Our aim was to realize the first detailed analysis of orgasm in patients treated by 125 I permanent prostate brachytherapy for localized prostate cancer. In a series of 270 sexually active men treated by prostate brachytherapy (125I permanent implantation), 241 (89%), mean age of 65 (43-80), participated in a mailed survey about sexual function after a mean time of 36 months (9-70). Erectile and ejaculatory functions and orgasm were explored using a mailed questionnaire. Two questions focused on orgasm. The first was about quality of orgasm (fast/intense/late, difficult/weak/absent) and the second about the presence of painful orgasm and its frequency (always/sometimes/often). After prostate brachytherapy, 81.3% of sexually active men conserved ejaculation and 90% orgasm. There was a significant deterioration of the quality of orgasm (P=0.0001). More than 50% of the patients had an altered orgasm (weak, difficult, absent) after brachytherapy, vs 16% before implantation (P=0.001). Men with a diminished ejaculation volume often had a weak/difficult orgasm (P=0.007). Neoadjuvant hormonal therapy did not seem to impact the quality of orgasm or the frequency of painful ejaculation. Patients who had an IIEF-5 score higher than 12 had frequently intense orgasm (26.7% vs 2.7%; P<0.001) after brachytherapy. Sixty patients (30.3%) experienced often/sometimes painful ejaculation 12.9% (n=31) before implantation (P=0.0001). Most of the patients treated by prostate brachytherapy conserved orgasm after treatment. However, most of the patients described a deterioration of the quality of orgasm. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Optimization of permanent breast seed implant dosimetry incorporating tissue heterogeneity

NASA Astrophysics Data System (ADS)

Mashouf, Shahram

Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG43 formalism, which generates the dose in homogeneous water medium. Recently, AAPM task group no. 186 (TG186) emphasized the importance of accounting for heterogeneities. In this work we introduce an analytical dose calculation algorithm in heterogeneous media using CT images. The advantages over other methods are computational efficiency and the ease of integration into clinical use. An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of the source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. The dose distributions obtained through applying ICF to TG43 protocol agreed very well with those of Monte Carlo simulations and experiments in all phantoms. In all cases, the mean relative error was reduced by at least a factor of two when ICF correction factor was applied to the TG43 protocol. In conclusion we have developed a new analytical dose calculation method, which enables personalized dose calculations in heterogeneous media using CT images. The methodology offers several advantages including the use of standard TG43 formalism, fast calculation time and extraction of the ICF parameters directly from Hounsfield Units. The methodology was implemented into our clinical treatment planning system where a cohort of 140 patients were processed to study the clinical benefits of a heterogeneity corrected dose.

SU-G-201-15: Nomogram as an Efficient Dosimetric Verification Tool in HDR Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, J; Todor, D

Purpose: Nomogram as a simple QA tool for HDR prostate brachytherapy treatment planning has been developed and validated clinically. Reproducibility including patient-to-patient and physician-to-physician variability was assessed. Methods: The study was performed on HDR prostate implants from physician A (n=34) and B (n=15) using different implant techniques and planning methodologies. A nomogram was implemented as an independent QA of computer-based treatment planning before plan execution. Normalized implant strength (total air kerma strength Sk*t in cGy cm{sup 2} divided by prescribed dose in cGy) was plotted as a function of PTV volume and total V100. A quadratic equation was used tomore » fit the data with R{sup 2} denoting the model predictive power. Results: All plans showed good target coverage while OARs met the dose constraint guidelines. Vastly different implant and planning styles were reflected on conformity index (entire dose matrix V100/PTV volume, physician A implants: 1.27±0.14, physician B: 1.47±0.17) and PTV V150/PTV volume ratio (physician A: 0.34±0.09, physician B: 0.24±0.07). The quadratic model provided a better fit for the curved relationship between normalized implant strength and total V100 (or PTV volume) than a simple linear function. Unlike the normalized implant strength versus PTV volume nomogram which differed between physicians, a unique quadratic model based nomogram (Sk*t)/D=−0.0008V2+0.0542V+1.1185 (R{sup 2}=0.9977) described the dependence of normalized implant strength on total V100 over all the patients from both physicians despite two different implant and planning philosophies. Normalized implant strength - total V100 model also generated less deviant points distorting the smoothed ones with a significantly higher correlation. Conclusion: A simple and universal, excel-based nomogram was created as an independent calculation tool for HDR prostate brachytherapy. Unlike similar attempts, our nomogram is insensitive to

Orthotopic tumorgrafts in nude mice: A new method to study human prostate cancer.

PubMed

Saar, Matthias; Körbel, Christina; Linxweiler, Johannes; Jung, Volker; Kamradt, Jörn; Hasenfus, Andrea; Stöckle, Michael; Unteregger, Gerhard; Menger, Michael D

2015-10-01

In vivo model systems in prostate cancer research that authentically reproduce tumor growth are still sparse. While orthotopic implantation is technically difficult, particularly in the mouse, most models favor subcutaneous tumor growth. This however provides little information about natural tumor growth behavior and tumor stroma interaction. Furthermore, established prostate cancer cell lines grown as in vivo xenografts are not able to reflect the variety of tumor specific growth patterns and growth behavior in men. Primary cell cultures are difficult to handle and an induction of orthotopic tumors has not been successful yet. Therefore, a tumorgraft model using tumor tissue from prostatectomy specimens was developed. Balb/c nude mice were used to graft fresh prostate tumor tissue by renal subcapsular and orthotopic implantation. Testosterone propionate was supplemented. Animals were tracked by means of 30 MHz ultrasound to monitor tumor engraftment and growth. Autopsy, histology, PSA measurements as well as immunostaining and PCR for human tissue were performed to confirm orthotopic tumor growth. Renal subcapsular engraftment was seen in 2 of 3 mice. Orthotopic engraftment was observed in 7 of 11 animals (63.6%) with an overall engraftment of 5 out of 9 patient specimens (55.6%). Ultrasound confirmed the tumor growth over time. Of interest, the tumorgrafts not only retained essential features of the parental tumors, but also stained positive for tumor specific markers such as AR, PSA, and AMACR. Tumor positive animals showed highly elevated serum PSA levels with confirmation of a human specific PCR sequence and a human endothelial cell lining in the tumor vessels. Standardized implantation of fresh tumor tissue in nude mice prostates generates tumorgrafts with histological properties of organ-confined prostate cancer. These tumorgrafts display a new approach for an optimized in vivo model of prostate cancer and will allow further investigations on specific

The inhibiting effects of components of stinging nettle roots on experimentally induced prostatic hyperplasia in mice.

PubMed

Lichius, J J; Renneberg, H; Blaschek, W; Aumüller, G; Muth, C

1999-10-01

Direct implanting of fetal urogenital sinus (UGS) tissue into the ventral prostate gland of adult mice led to a 4-fold weight increase of the manipulated prostatic lobe. The induced growth could be reduced by the polysaccharide fraction (POLY-M) of the 20% methanolic extract of stinging nettle roots by 33.8%.

A comparison study on various low energy sources in interstitial prostate brachytherapy.

PubMed

Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

2016-02-01

Low energy sources are routinely used in prostate brachytherapy. (125)I is one of the most commonly used sources. Low energy (131)Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of (125)I, (103)Pd, and (131)Cs sources in interstitial brachytherapy of prostate. ProstaSeed (125)I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of (103)Pd and (131)Cs were simulated with the same geometry as the ProstaSeed (125)I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, (131)Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the (103)Pd source. The higher initial absolute dose in cGy/(h.U) of (131)Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the (103)Pd source are advantages of this later brachytherapy source. Based on the total dose the (125)I source has advantage over the others due to its longer half-life.

Influence of the neural microenvironment on prostate cancer.

PubMed

Coarfa, Christian; Florentin, Diego; Putluri, NagiReddy; Ding, Yi; Au, Jason; He, Dandan; Ragheb, Ahmed; Frolov, Anna; Michailidis, George; Lee, MinJae; Kadmon, Dov; Miles, Brian; Smith, Christopher; Ittmann, Michael; Rowley, David; Sreekumar, Arun; Creighton, Chad J; Ayala, Gustavo

2018-02-01

Nerves are key factors in prostate cancer (PCa), but the functional role of innervation in prostate cancer is poorly understood. PCa induced neurogenesis and perineural invasion (PNI), are associated with aggressive disease. We denervated rodent prostates chemically and physically, before orthotopically implanting cancer cells. We also performed a human neoadjuvant clinical trial using botulinum toxin type A (Botox) and saline in the same patient, before prostatectomy. Bilateral denervation resulted in reduced tumor incidence and size in mice. Botox treatment in humans resulted in increased apoptosis of cancer cells in the Botox treated side. A similar denervation gene array profile was identified in tumors arising in denervated rodent prostates, in spinal cord injury patients and in the Botox treated side of patients. Denervation induced exhibited a signature gene profile, indicating translation and bioenergetic shutdown. Nerves also regulate basic cellular functions of non-neoplastic epithelial cells. Nerves play a role in the homeostasis of normal epithelial tissues and are involved in prostate cancer tumor survival. This study confirms that interactions between human cancer and nerves are essential to disease progression. This work may make a major impact in general cancer treatment strategies, as nerve/cancer interactions are likely important in other cancers as well. Targeting the neural microenvironment may represent a therapeutic approach for the treatment of human prostate cancer. © 2017 The Authors. The Prostate Published by Wiley Periodicals, Inc.

Comparison of prostate contours between conventional stepping transverse imaging and Twister-based sagittal imaging in permanent interstitial prostate brachytherapy.

PubMed

Kawakami, Shogo; Ishiyama, Hiromichi; Satoh, Takefumi; Tsumura, Hideyasu; Sekiguchi, Akane; Takenaka, Kouji; Tabata, Ken-Ichi; Iwamura, Masatsugu; Hayakawa, Kazushige

2017-08-01

To compare prostate contours on conventional stepping transverse image acquisitions with those on twister-based sagittal image acquisitions. Twenty prostate cancer patients who were planned to have permanent interstitial prostate brachytherapy were prospectively accrued. A transrectal ultrasonography probe was inserted, with the patient in lithotomy position. Transverse images were obtained with stepping movement of the transverse transducer. In the same patient, sagittal images were also obtained through rotation of the sagittal transducer using the "Twister" mode. The differences of prostate size among the two types of image acquisitions were compared. The relationships among the difference of the two types of image acquisitions, dose-volume histogram (DVH) parameters on the post-implant computed tomography (CT) analysis, as well as other factors were analyzed. The sagittal image acquisitions showed a larger prostate size compared to the transverse image acquisitions especially in the anterior-posterior (AP) direction ( p < 0.05). Interestingly, relative size of prostate apex in AP direction in sagittal image acquisitions compared to that in transverse image acquisitions was correlated to DVH parameters such as D 90 ( R = 0.518, p = 0.019), and V 100 ( R = 0.598, p = 0.005). There were small but significant differences in the prostate contours between the transverse and the sagittal planning image acquisitions. Furthermore, our study suggested that the differences between the two types of image acquisitions might correlated to dosimetric results on CT analysis.

Prostate specific antigen bounce is related to overall survival in prostate brachytherapy.

PubMed

Hinnen, Karel A; Monninkhof, Evelyn M; Battermann, Jan J; van Roermund, Joep G H; Frank, Steven J; van Vulpen, Marco

2012-02-01

To investigate the association between prostate specific antigen (PSA) bounce and disease outcome after prostate brachytherapy. We analyzed 975 patients treated with (125)I implantation monotherapy between 1992 and 2006. All patients had tumor Stage ≤ 2c, Gleason score ≤ 7 prostate cancer, a minimum follow-up of 2 years with at least four PSA measurements, and no biochemical failure in the first 2 years. Median follow-up was 6 years. Bounce was defined as a PSA elevation of +0.2 ng/mL with subsequent decrease to previous nadir. We used the Phoenix +2 ng/mL definition for biochemical failure. Additional endpoints were disease-specific and overall survival. Multivariate Cox regression analysis was performed to adjust for potential confounding factors. Bounce occurred in 32% of patients, with a median time to bounce of 1.6 years. More than 90% of bounces took place in the first 3 years after treatment and had disappeared within 2 years of onset. Ten-year freedom from biochemical failure, disease-specific survival, and overall survival rates were, respectively, 90%, 99%, and 88% for the bounce group and 70%, 93%, and 82% for the no-bounce group. Only 1 patient (0.3%) died of prostate cancer in the bounce group, compared with 40 patients (6.1%) in the no-bounce group. Adjusted for confounding, a 70% biochemical failure risk reduction was observed for patients experiencing a bounce (hazard ratio 0.31; 95% confidence interval 0.20-0.48). A PSA bounce after prostate brachytherapy is strongly related to better outcome in terms of biochemical failure, disease-specific survival, and overall survival. Copyright © 2012 Elsevier Inc. All rights reserved.

A standard definition of disease freedom is needed for prostate cancer: undetectable prostate specific antigen compared with the American Society of Therapeutic Radiology and Oncology consensus definition.

PubMed

Critz, Frank A

2002-03-01

Freedom from prostate cancer is defined by undetectable prostate specific antigen (PSA) after surgery and the American Society of Therapeutic Radiology and Oncology (ASTRO) criteria are recommended for irradiation. Whether these definitions of disease freedom are comparable was evaluated in this study. From August 1992 to August 1996 simultaneous irradiation with prostate 125iodine implantation followed by external beam irradiation was performed in 591 consecutive men with stage T1T2NX prostate cancer. All patients had a transperineal implant and none received neoadjuvant hormones. Disease freedom was defined by a PSA cutoff of 0.2 ng./ml. and the ASTRO consensus definition. Median followup was 6 years (range 5 to 8). Of the 591 men in this study 65 had recurrence by ASTRO criteria and 93 had recurrence by a PSA cutoff of 0.2 ng./ml., which was a significant difference (p = 0.001). On multivariate analysis of the factors related to disease-free status the definition of disease freedom, pretreatment PSA and Gleason score were highly significant. Of the 528 men with a minimum 5-year PSA followup the 8-year disease-free survival rate by ASTRO criteria was 99% in those who achieved a PSA nadir of 0.2 ng./ml. and 16% in those with a nadir of 0.3 to 1 ng./ml. Of the 469 disease-free patients by ASTRO criteria with a minimum 5-year followup 455 (97%) achieved a PSA nadir of 0.2 ng./ml. or less. The definition of freedom from prostate cancer significantly affects treatment results. A standard definition is needed and a PSA cutoff of 0.2 ng./ml. is suggested as the standard for all curative treatments for localized prostate cancer.

Alpha 1-Adrenoceptor Blocker May Improve Not Only Voiding But Also Storage Lower Urinary Tract Symptoms Caused by 125I Brachytherapy for Prostate Cancer

PubMed Central

Aoki, Yoshitaka; Ito, Hideaki; Miwa, Yoshiji; Akino, Hironobu; Shioura, Hiroki; Kimura, Hirohiko; Yokoyama, Osamu

2014-01-01

Purpose. To assess changes in lower urinary tract symptoms (LUTS) within 1 year after brachytherapy in patients receiving alpha 1-adrenoceptor antagonists. Methods. We retrospectively evaluated 116 patients who underwent 125I prostate brachytherapy in our institute. Seventy-one patients were treated with a combination of external beam radiation therapy and brachytherapy. Alpha 1-adrenoceptor antagonists were prescribed to all patients after brachytherapy. International Prostate Symptom Score (IPSS) forms and postvoid residual urine volume were recorded at all follow-up visits. Results. Forty-nine patients were given tamsulosin hydrochloride, 32 were given silodosin hydrochloride, and 35 were given naftopidil for up to 6 months after seed implantation. Patients given tamsulosin or naftopidil tended to show a higher peak IPSS and slower recovery to baseline values than those given silodosin. The patients given naftopidil showed an insufficient recovery in storage symptoms in naftopidil group in comparison with tamsulosin group at 3 months and with silodosin group at 6 and 9 months. Conclusions. In the management of LUT after brachytherapy, silodosin may provide a more favorable improvement. Silodosin and tamsulosin may have an advantage in improving not only voiding but also storage lower urinary tract symptoms after brachytherapy. PMID:25006516

A comparison study on various low energy sources in interstitial prostate brachytherapy

PubMed Central

Bakhshabadi, Mahdi; Ghorbani, Mahdi; Knaup, Courtney; Meigooni, Ali S.

2016-01-01

Purpose Low energy sources are routinely used in prostate brachytherapy. 125I is one of the most commonly used sources. Low energy 131Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125I, 103Pd, and 131Cs sources in interstitial brachytherapy of prostate. Material and methods ProstaSeed 125I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103Pd and 131Cs were simulated with the same geometry as the ProstaSeed 125I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103Pd source. Conclusions The higher initial absolute dose in cGy/(h.U) of 131Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103Pd source are advantages of this later brachytherapy source. Based on the total dose the 125I source has advantage over the others due to its longer half-life. PMID:26985200

SU-G-IeP4-14: Prostate Brachytherapy Activity Measurement and Source Localization by Using a Dual Photon Emission Computed Tomography System: A Feasibility Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, C; Lin, H; Chuang, K

2016-06-15

Purpose: To monitor the activity distribution and needle position during and after implantation in operating rooms. Methods: Simulation studies were conducted to assess the feasibility of measurement activity distribution and seed localization using the DuPECT system. The system consists of a LaBr3-based probe and planar detection heads, a collimation system, and a coincidence circuit. The two heads can be manipulated independently. Simplified Yb-169 brachytherapy seeds were used. A water-filled cylindrical phantom with a 40-mm diameter and 40-mm length was used to model a simplified prostate of the Asian man. Two simplified seeds were placed at a radial distance of 10more » mm and tangential distance of 10 mm from the center of the phantom. The probe head was arranged perpendicular to the planar head. Results of various imaging durations were analyzed and the accuracy of the seed localization was assessed by calculating the centroid of the seed. Results: The reconstructed images indicate that the DuPECT can measure the activity distribution and locate the seeds dwelt in different positions intraoperatively. The calculated centroid on average turned out to be accurate within the pixel size of 0.5 mm. The two sources were identified when the duration is longer than 15 s. The sensitivity measured in water was merely 0.07 cps/MBq. Conclusion: Preliminary results show that the measurement of the activity distribution and seed localization are feasible using the DuPECT system intraoperatively. It indicates the DuPECT system has potential to be an approach for dose-distribution-validation. The efficacy of acvtivity distribution measurement and source localization using the DuPECT system will evaluated in more realistic phantom studies (e.g., various attenuation materials and greater number of seeds) in the future investigation.« less

Dietary soy and tea mitigate chronic inflammation and prostate cancer via NFκB pathway in the Noble rat model

PubMed Central

Hsu, Anna; Bruno, Richard S.; Löhr, Christiane V.; Taylor, Alan W.; Dashwood, Rodrick H.; Bray, Tammy M.; Ho, Emily

2010-01-01

Chronic inflammation and nuclear factor-kappa B (NFκB) have been implicated in prostate cancer development; thus, dietary factors that inhibit NFκB may serve as effective chemo-preventative agents. Prostate cancer risk is significantly lower in Asian countries compared to the US, which has prompted interest in the potential chemopreventative action of Asian dietary components such as soy and green tea. This study examined the effects of dietary soy and tea on NFκB activation and inflammation in vivo using a hormone-induced rat model for prostate cancer. Male Noble rats implanted with estradiol and testosterone were divided into 4 dietary groups: control, soy, tea, or soy+ tea. NFκB activation and inflammatory cytokines were measured post implantation. The combination of soy and tea suppressed NFκB p50 binding activity and protein levels via induction of IκBα. Soy and tea also decreased prostate inflammatory infiltration, increased Bax/BcL2 ratio, and decreased protein expression of TNFα, IL-6 and IL1-β compared to control. Soy and tea attenuated prostate malignancy by decreasing prostate hyperplasia. These effects were not apparent in groups treated with soy or tea alone. The ongoing in vivo studies thus far suggest that combination of foods, such as soy and tea, may inhibit hormone-induced pro-inflammatory NFκB signals that contribute to prostate cancer development. PMID:20801632

Low dose rate brachytherapy (LDR-BT) as monotherapy for early stage prostate cancer in Italy: practice and outcome analysis in a series of 2237 patients from 11 institutions

PubMed Central

Fellin, Giovanni; Mirri, Maria A; Santoro, Luigi; Divan, Claudio; Mussari, Salvatore; Ziglio, Francesco; La Face, Beniamino; Barbera, Fernando; Buglione, Michela; Bandera, Laura; Ghedi, Barbara; Di Muzio, Nadia G; Losa, Andrea; Mangili, Paola; Nava, Luciano; Chiarlone, Renato; Ciscognetti, Nunzia; Gastaldi, Emilio; Cattani, Federica; Spoto, Ruggero; Vavassori, Andrea; Giglioli, Francesca R; Guarneri, Alessia; Cerboneschi, Valentina; Mignogna, Marcello; Paoluzzi, Mauro; Ravaglia, Valentina; Chiumento, Costanza; Clemente, Stefania; Fusco, Vincenzo; Santini, Roberto; Stefanacci, Marco; Mangiacotti, Francesco P; Martini, Marco; Palloni, Tiziana; Schinaia, Giuseppe; Lazzari, Grazia; Silvano, Giovanni; Magrini, Stefano; Ricardi, Umberto; Santoni, Riccardo; Orecchia, Roberto

2016-01-01

Objective: Low-dose-rate brachytherapy (LDR-BT) in localized prostate cancer is available since 15 years in Italy. We realized the first national multicentre and multidisciplinary data collection to evaluate LDR-BT practice, given as monotherapy, and outcome in terms of biochemical failure. Methods: Between May 1998 and December 2011, 2237 patients with early-stage prostate cancer from 11 Italian community and academic hospitals were treated with iodine-125 (125I) or palladium-103 LDR-BT as monotherapy and followed up for at least 2 years. 125I seeds were implanted in 97.7% of the patients: the mean dose received by 90% of target volume was 145 Gy; the mean target volume receiving 100% of prescribed dose (V100) was 91.1%. Biochemical failure-free survival (BFFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan–Meier method. Log-rank test and multivariable Cox regression were used to evaluate the relationship of covariates with outcomes. Results: Median follow-up time was 65 months. 5- and 7-year DSS, OS and BFFS were 99 and 98%, 94 and 89%, and 92 and 88%, respectively. At multivariate analysis, the National Comprehensive Cancer Network score (p < 0.0001) and V100 (p = 0.09) were correlated with BFFS, with V100 effect significantly different between patients at low risk and those at intermediate/high risk (p = 0.04). Short follow-up and lack of toxicity data represent the main limitations for a global evaluation of LDR-BT. Conclusion: This first multicentre Italian report confirms LDR-BT as an excellent curative modality for low-/intermediate-risk prostate cancer. Advances in knowledge: Multidisciplinary teams may help to select adequately patients to be treated with brachytherapy, with a direct impact on the implant quality and, possibly, on outcome. PMID:27384381

Low dose rate brachytherapy (LDR-BT) as monotherapy for early stage prostate cancer in Italy: practice and outcome analysis in a series of 2237 patients from 11 institutions.

PubMed

Fellin, Giovanni; Mirri, Maria A; Santoro, Luigi; Jereczek-Fossa, Barbara A; Divan, Claudio; Mussari, Salvatore; Ziglio, Francesco; La Face, Beniamino; Barbera, Fernando; Buglione, Michela; Bandera, Laura; Ghedi, Barbara; Di Muzio, Nadia G; Losa, Andrea; Mangili, Paola; Nava, Luciano; Chiarlone, Renato; Ciscognetti, Nunzia; Gastaldi, Emilio; Cattani, Federica; Spoto, Ruggero; Vavassori, Andrea; Giglioli, Francesca R; Guarneri, Alessia; Cerboneschi, Valentina; Mignogna, Marcello; Paoluzzi, Mauro; Ravaglia, Valentina; Chiumento, Costanza; Clemente, Stefania; Fusco, Vincenzo; Santini, Roberto; Stefanacci, Marco; Mangiacotti, Francesco P; Martini, Marco; Palloni, Tiziana; Schinaia, Giuseppe; Lazzari, Grazia; Silvano, Giovanni; Magrini, Stefano; Ricardi, Umberto; Santoni, Riccardo; Orecchia, Roberto

2016-09-01

Low-dose-rate brachytherapy (LDR-BT) in localized prostate cancer is available since 15 years in Italy. We realized the first national multicentre and multidisciplinary data collection to evaluate LDR-BT practice, given as monotherapy, and outcome in terms of biochemical failure. Between May 1998 and December 2011, 2237 patients with early-stage prostate cancer from 11 Italian community and academic hospitals were treated with iodine-125 ((125)I) or palladium-103 LDR-BT as monotherapy and followed up for at least 2 years. (125)I seeds were implanted in 97.7% of the patients: the mean dose received by 90% of target volume was 145 Gy; the mean target volume receiving 100% of prescribed dose (V100) was 91.1%. Biochemical failure-free survival (BFFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method. Log-rank test and multivariable Cox regression were used to evaluate the relationship of covariates with outcomes. Median follow-up time was 65 months. 5- and 7-year DSS, OS and BFFS were 99 and 98%, 94 and 89%, and 92 and 88%, respectively. At multivariate analysis, the National Comprehensive Cancer Network score (p < 0.0001) and V100 (p = 0.09) were correlated with BFFS, with V100 effect significantly different between patients at low risk and those at intermediate/high risk (p = 0.04). Short follow-up and lack of toxicity data represent the main limitations for a global evaluation of LDR-BT. This first multicentre Italian report confirms LDR-BT as an excellent curative modality for low-/intermediate-risk prostate cancer. Multidisciplinary teams may help to select adequately patients to be treated with brachytherapy, with a direct impact on the implant quality and, possibly, on outcome.

DTI and pathological changes in a rabbit model of radiation injury to the spinal cord after 125I radioactive seed implantation

PubMed Central

Cao, Xia; Fang, Le; Cui, Chuan-yu; Gao, Shi; Wang, Tian-wei

2018-01-01

Excessive radiation exposure may lead to edema of the spinal cord and deterioration of the nervous system. Magnetic resonance imaging can be used to judge and assess the extent of edema and to evaluate pathological changes and thus may be used for the evaluation of spinal cord injuries caused by radiation therapy. Radioactive 125I seeds to irradiate 90% of the spinal cord tissue at doses of 40–100 Gy (D90) were implanted in rabbits at T10 to induce radiation injury, and we evaluated their safety for use in the spinal cord. Diffusion tensor imaging showed that with increased D90, the apparent diffusion coefficient and fractional anisotropy values were increased. Moreover, pathological damage of neurons and microvessels in the gray matter and white matter was aggravated. At 2 months after implantation, obvious pathological injury was visible in the spinal cords of each group. Magnetic resonance diffusion tensor imaging revealed the radiation injury to the spinal cord, and we quantified the degree of spinal cord injury through apparent diffusion coefficient and fractional anisotropy. PMID:29623940

Targeting Discoidin Domain Receptors in Prostate Cancer

DTIC Science & Technology

2017-08-01

tumor incidence by bioluminescence. Thus, DDR1 may play a role in the initial seeding of tumor cells within the bone milieu. We are currently...conducting the quantitative analyses of bioluminescence and the histomorphometry analyses and evaluation of effects on bone remodeling. Studies on DDR1...regulation and function in culture cells is ongoing. 15. SUBJECT TERMS Prostate cancer, bone metastases, discoidin domain receptors, kinases

Influence of the neural microenvironment on prostate cancer

PubMed Central

Coarfa, Christian; Florentin, Diego; Putluri, NagiReddy; Ding, Yi; Au, Jason; He, Dandan; Ragheb, Ahmed; Frolov, Anna; Michailidis, George; Lee, MinJae; Kadmon, Dov; Miles, Brian; Smith, Christopher; Ittmann, Michael; Rowley, David; Sreekumar, Arun; Creighton, Chad J.

2017-01-01

Background Nerves are key factors in prostate cancer (PCa), but the functional role of innervation in prostate cancer is poorly understood. PCa induced neurogenesis and perineural invasion (PNI), are associated with aggressive disease. Method We denervated rodent prostates chemically and physically, before orthotopically implanting cancer cells. We also performed a human neoadjuvant clinical trial using botulinum toxin type A (Botox) and saline in the same patient, before prostatectomy. Result Bilateral denervation resulted in reduced tumor incidence and size in mice. Botox treatment in humans resulted in increased apoptosis of cancer cells in the Botox treated side. A similar denervation gene array profile was identified in tumors arising in denervated rodent prostates, in spinal cord injury patients and in the Botox treated side of patients. Denervation induced exhibited a signature gene profile, indicating translation and bioenergetic shutdown. Nerves also regulate basic cellular functions of non‐neoplastic epithelial cells. Conclusion Nerves play a role in the homeostasis of normal epithelial tissues and are involved in prostate cancer tumor survival. This study confirms that interactions between human cancer and nerves are essential to disease progression. This work may make a major impact in general cancer treatment strategies, as nerve/cancer interactions are likely important in other cancers as well. Targeting the neural microenvironment may represent a therapeutic approach for the treatment of human prostate cancer. PMID:29131367

Non-invasive imaging of prostate cancer progression in nude mice using iRFP gene reporter

NASA Astrophysics Data System (ADS)

Zhu, Banghe; Wu, Grace; Robinson, Holly; Wilganowski, Nathaniel; Sevick-Muraca, Eva M.

2013-03-01

Prostate cancer (PCa) is the second most common cancer in US men. Metastasis is the final step of tumor progression and remains the primary cause of PCa death. Hence preclinical, orthotopic models of PCa metastasis are necessary to develop new therapeutics against metastatic disease. Yet unlike irrelevant subcutaneous tumor models, the deployment of orthotopic models of cancer metastasis in drug research and development is limited by the inability to longitudinally monitor cancer progression/regression in response to administration of experimental pharmaceuticals. Recently, a nearinfrared fluorescent protein (iRFP) was created for deeper imaging [1]. Imaging prostate tumor growth and lymph node metastasis in nude mice therefore becomes possible using this new fluorescent gene reporter. In this study, we first developed an intensified CCD (ICCD)-based iRFP fluorescence imaging device. Then human PCa PC3 cell lines expressing iRFP gene reporter were orthotopically implanted in male Nu/Nu mice at 8-10 weeks old. After 6-10 weeks, in vivo, in situ and ex vivo fluorescence imaging was performed. In vivo iRFP fluorescence imaging showed that the detected fluorescence concentrated at the prostate and became stronger over time, indicating the growth of implanted PCa. Fluorescence was non-invasively detected at locations of prostate-draining lymph nodes as early as 5 weeks post implantation, indicating the metastasis to lymph nodes. In situ and ex vivo fluorescence imaging demonstrated that the detected signals from PCa and lymph nodes were correlated with cancer positive status of tissues as assessed through standard pathology.

Targeted Prostate Thermal Therapy with Catheter-Based Ultrasound Devices and MR Thermal Monitoring

NASA Astrophysics Data System (ADS)

Diederich, Chris; Ross, Anthony; Kinsey, Adam; Nau, Will H.; Rieke, Viola; Butts Pauly, Kim; Sommer, Graham

2006-05-01

Catheter-based ultrasound devices have significant advantages for thermal therapy procedures, including potential for precise spatial and dynamic control of heating patterns to conform to targeted volumes. Interstitial and transurethral ultrasound applicators, with associated treatment strategies, were developed for thermal ablation of prostate combined with MR thermal monitoring. Four types of multielement transurethral applicators were devised, each with different levels of selectivity and intended therapeutic goals: sectored tubular transducer devices with fixed directional heating patterns; planar and lightly focused curvilinear devices with narrow heating patterns; and multi-sectored tubular devices capable of dynamic angular control without applicator movement. These devices are integrated with a 4 mm delivery catheter, incorporate an inflatable cooling balloon (10 mm OD) for positioning within the prostate and capable of rotation via an MR-compatible motor. Similarly, interstitial devices (2.4 mm OD) have been developed for percutaneous implantation with fixed directional heating patterns (e.g., 180 deg.). In vivo experiments in canine prostate (n=15) under MR temperature imaging were used to evaluate the heating technology and develop treatment strategies. MR thermal imaging in a 0.5 T interventional MRI was used to monitor temperature contours and thermal dose in multiple slices through the target volume. Sectored transurethral devices produce directional coagulation zones, extending 15-20 mm radial distance to the outer prostate capsule. The curvilinear applicator produces distinct 2-3 mm wide lesions, and with sequential rotation and modulated dwell time can precisely conform thermal ablation to selected areas or the entire prostate gland. Multi-sectored transurethral applicators can dynamically control the angular heating profile and target large regions of the gland in short treatment times without applicator manipulation. Interstitial implants with

SU-G-201-02: Application of RayStretch in Clinical Cases: A Calculation for Heterogeneity Corrections in LDR Permanent I-125 Prostate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hueso-Gonzalez, F; Vijande, J; Ballester, F

Purpose: Tissue heterogeneities and calcifications have significant impact on the dosimetry of low energy brachytherapy (BT). RayStretch is an analytical algorithm developed in our institution to incorporate heterogeneity corrections in LDR prostate brachytherapy. The aim of this work is to study its application in clinical cases by comparing its predictions with the results obtained with TG-43 and Monte Carlo (MC) simulations. Methods: A clinical implant (71 I-125 seeds, 15 needles) from a real patient was considered. On this patient, different volumes with calcifications were considered. Its properties were evaluated in three ways by i) the Treatment planning system (TPS) (TG-43),more » ii) a MC study using the Penelope2009 code, and iii) RayStretch. To analyse the performance of RayStretch, calcifications located in the prostate lobules covering 11% of the total prostate volume and larger calcifications located in the lobules and underneath the urethra for a total occupied volume of 30% were considered. Three mass densities (1.05, 1.20, and 1.35 g/cm3) were explored for the calcifications. Therefore, 6 different scenarios ranging from small low density calcifications to large high density ones have been discussed. Results: DVH and D90 results given by RayStretch agree within 1% with the full MC simulations. Although no effort has been done to improve RayStretch numerical performance, its present implementation is able to evaluate a clinical implant in a few seconds to the same level of accuracy as a detailed MC calculation. Conclusion: RayStretch is a robust method for heterogeneity corrections in prostate BT supported on TG-43 data. Its compatibility with commercial TPSs and its high calculation speed makes it feasible for use in clinical settings for improving treatment quality. It will allow in a second phase of this project, its use during intraoperative ultrasound planning. This study was partly supported by a fellowship grant from the Spanish Ministry of

Quality assurance of HDR prostate plans: program implementation at a community hospital.

PubMed

Rush, Jennifer B; Thomas, Michael D

2005-01-01

Adenocarcinoma of the prostate is currently the most commonly diagnosed cancer in men in the United States, and the second leading cause of cancer mortality. The utilization of radiation therapy is regarded as the definitive local therapy of choice for intermediate- and high-risk disease, in which there is increased risk for extracapsular extension, seminal vesicle invasion, or regional node involvement. High-dose-rate (HDR) brachytherapy is a logical treatment modality to deliver the boost dose to an external beam radiation therapy (EBRT) treatment to increase local control rates. From a treatment perspective, the utilization of a complicated treatment delivery system, the compressed time frame in which the procedure is performed, and the small number of large dose fractions make the implementation of a comprehensive quality assurance (QA) program imperative. One aspect of this program is the QA of the HDR treatment plan. Review of regulatory and medical physics professional publications shows that substantial general guidance is available. We provide some insight to the implementation of an HDR prostate plan program at a community hospital. One aspect addressed is the utilization of the low-dose-rate (LDR) planning system and the use of existing ultrasound image sets to familiarize the radiation therapy team with respect to acceptable HDR implant geometries. Additionally, the use of the LDR treatment planning system provided a means to prospectively determine the relationship between the treated isodose volume and the product of activity and time for the department's planning protocol prior to the first HDR implant. For the first 12 HDR prostate implants, the root-mean-square (RMS) deviation was 3.05% between the predicted product of activity and time vs. the actual plan values. Retrospective re-evaluation of the actual implant data reduced the RMS deviation to 2.36%.

Differential Gene Expression Profiling of Functionally and Developmentally Distinct Human Prostate Epithelial Populations

PubMed Central

Liu, Haibo; Cadaneanu, Radu M; Lai, Kevin; Zhang, Baohui; Huo, Lihong; An, Dong Sun; Li, Xinmin; Lewis, Michael S; Garraway, Isla P

2015-01-01

BACKGROUND Human fetal prostate buds appear in the 10th gestational week as solid cords, which branch and form lumens in response to androgen 1. Previous in vivo analysis of prostate epithelia isolated from benign prostatectomy specimens indicated that Epcam+CD44−CD49fHi basal cells possess efficient tubule initiation capability relative to other subpopulations 2. Stromal interactions and branching morphogenesis displayed by adult tubule-initiating cells (TIC) are reminiscent of fetal prostate development. In the current study, we evaluated in vivo tubule initiation by human fetal prostate cells and determined expression profiles of fetal and adult epithelial subpopulations in an effort to identify pathways used by TIC. METHODS Immunostaining and FACS analysis based on Epcam, CD44, and CD49f expression demonstrated the majority (99.9%) of fetal prostate epithelial cells (FC) were Epcam+CD44− with variable levels of CD49f expression. Fetal populations isolated via cell sorting were implanted into immunocompromised mice. Total RNA isolation from Epcam+CD44−CD49fHi FC, adult Epcam+CD44−CD49fHi TIC, Epcam+CD44+CD49fHi basal cells (BC), and Epcam+CD44−CD49fLo luminal cells (LC) was performed, followed by microarray analysis of 19 samples using the Affymetrix Gene Chip Human U133 Plus 2.0 Array. Data was analyzed using Partek Genomics Suite Version 6.4. Genes selected showed >2-fold difference in expression and P < 5.00E-2. Results were validated with RT-PCR. RESULTS Grafts retrieved from Epcam+CD44− fetal cell implants displayed tubule formation with differentiation into basal and luminal compartments, while only stromal outgrowths were recovered from Epcam- fetal cell implants. Hierarchical clustering revealed four distinct groups determined by antigenic profile (TIC, BC, LC) and developmental stage (FC). TIC and BC displayed basal gene expression profiles, while LC expressed secretory genes. FC had a unique profile with the most similarities to adult TIC

Analysis of dose to patient, spouse/caretaker, and staff, from an implanted trackable radioactive fiducial for use in the radiation treatment of prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neustadter, David; Barnea, Gideon; Stokar, Saul

Purpose: A fiducial tracking system based on a novel radioactive tracking technology is being developed for real-time target tracking in radiation therapy. In this study, the authors calculate the radiation dose to the patient, the spouse/caretaker, and the medical staff that would result from a 100 {mu}Ci Ir192 radioactive fiducial marker permanently implanted in the prostate of a radiation therapy patient. Methods: Local tissue dose was calculated by Monte Carlo simulation. The patient's whole body effective dose equivalent was calculated by summing the doses to the sensitive organs. Exposure of the spouse/caretaker was calculated from the NRC guidelines. Exposure ofmore » the medical staff was based on estimates of proximity to and time spent with the patient. Results: The local dose is below 40 Gy at 5 mm from the marker and below 10 Gy at 10 mm from the marker. The whole body effective dose equivalent to the patient is 64 mSv. The dose to the spouse/caretaker is 0.25 mSv. The annual exposures of the medical staff are 0.2 mSv for a doctor performing implantations and 0.34 mSv for a radiation therapist positioning patients for therapy. Conclusions: The local dose is not expected to have any clinically significant effect on the surrounding tissue which is irradiated during therapy. The dose to the patient is small in comparison to the whole body dose received from the therapy itself. The exposure of all other people is well below the recommended limits. The authors conclude that there is no radiation exposure related contraindication for use of this technology in the radiation treatment of prostate cancer.« less

Suppression of BRCA2 by Mutant Mitochondrial DNA in Prostate Cancer

DTIC Science & Technology

2014-07-01

growth of prostatic epithelia both in vitro and in vivo To evaluate the impact of interaction between DAB2IP and Skp2 on cell growth , MTT assay and soft...determined using western blot and actin was used as a loading control. One thousand cells /well were seeded using 96-well plate. In vitro cell growth ...SEM. (E) 1 × 103 cells of C4-2 shSkp2 cells and its control were seeded at 96-well plate. In vitro cell growth was determined using

Reconstructing metastatic seeding patterns of human cancers

PubMed Central

Reiter, Johannes G.; Makohon-Moore, Alvin P.; Gerold, Jeffrey M.; Bozic, Ivana; Chatterjee, Krishnendu; Iacobuzio-Donahue, Christine A.; Vogelstein, Bert; Nowak, Martin A.

2017-01-01

Reconstructing the evolutionary history of metastases is critical for understanding their basic biological principles and has profound clinical implications. Genome-wide sequencing data has enabled modern phylogenomic methods to accurately dissect subclones and their phylogenies from noisy and impure bulk tumour samples at unprecedented depth. However, existing methods are not designed to infer metastatic seeding patterns. Here we develop a tool, called Treeomics, to reconstruct the phylogeny of metastases and map subclones to their anatomic locations. Treeomics infers comprehensive seeding patterns for pancreatic, ovarian, and prostate cancers. Moreover, Treeomics correctly disambiguates true seeding patterns from sequencing artifacts; 7% of variants were misclassified by conventional statistical methods. These artifacts can skew phylogenies by creating illusory tumour heterogeneity among distinct samples. In silico benchmarking on simulated tumour phylogenies across a wide range of sample purities (15–95%) and sequencing depths (25-800 × ) demonstrates the accuracy of Treeomics compared with existing methods. PMID:28139641

Factors influencing long-term urinary symptoms following prostate brachytherapy.

PubMed

Stone, Nelson N; Winoker, Jared S; Kaplan, Steven A; Stock, Richard G

2018-05-03

To determine which patient and treatment related factors were associated with increased AUA symptom score (AUASS) in men who presented with minimal symptoms prior to treatment for prostate cancer by permanent seed implantation. Of 1842 men with a minimum follow-up of 5 years (mean 9.4) 1110 (60.3%) had initial AUASS of 0-7 and were treated with BT alone (n=491) or BT with hormone therapy (NHT) and or external beam irradiation (EBRT, n=619). Median prostate volume (PV) was 37 cc. Data was prospectively collected on comorbidities. Initial AUASS was compared to last by student-t test (2-tailed). Freedom from increasing from minimal to moderate or severe symptoms was determined by Kaplan-Meier method with comparisons by log rank and Cox Hazard Rates (HR). The change from pre-treatment score for the minimal, moderate and severe symptom groups was: 3.6 to 7.3 (p<0.001), 11.6 to 11.3 (p=0.426) and 24.1 to 16.9 (p<0.001). For those with minimal symptoms the 10 and 15-year estimates for freedom from worse symptoms were 72.9 and 39.1%, respectively. Cox hazard rates were significant for EBRT boost (HR 1.45, p=0.004), radiation dose > 200 Gy (HR 1.25, p=0.024), hypertension (HR 1.37, p=0.006) and alcohol use (HR 1.46, p=0.001). A substantial number of men with initial low AUASS treated by BT experience worsening urinary symptoms with long-term follow. Use of EBRT, radiation dose, hypertension and alcohol use are risk factors for an increase in urinary symptom score. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

DTIC Science & Technology

2015-10-01

epididymis tumors, and performed implantation of testosterone pellets to continue support prostate tumor growth. Our recent data suggest that these...will eliminate the concerns on epididymis tumors. We also proposed to perform subcutaneous implantation of testosterone pellets to continue...USAMRMC ACURO. We have initiated performing the early castration and testosterone pellet implantation on the young PB-Cre4/CAG- SMIL/p53loxP/loxP

The Effect of Finasteride and Dutasteride on the Growth of WPE1-NA22 Prostate Cancer Xenografts in Nude Mice

PubMed Central

Opoku-Acheampong, Alexander B.; Nelsen, Michelle K.; Unis, Dave; Lindshield, Brian L.

2012-01-01

Background 5α-reductase 1 (5αR1) and 5α-reductase 2 (5αR2) convert testosterone into the more potent androgen dihydrotestosterone. 5αR2 is the main isoenzyme in normal prostate tissue; however, most prostate tumors have increased 5αR1 and decreased 5αR2 expression. Previously, finasteride (5αR2 inhibitor) treatment begun 3 weeks post-tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5αR1 expression or activity. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, whereas dutasteride (5αR1 and 5αR2 inhibitor) treatment would decrease tumor growth regardless of whether treatment was initiated before or after tumor implantation. Methodology/Principal Findings Sixty 8-week-old male nude mice were randomized to Control, Pre- and Post-Finasteride, and Pre- and Post-Dutasteride (83.3 mg drug/kg diet) diet groups. Pre- and post-groups began their treatment diets 1–2 weeks prior to or 3 weeks after subcutaneous injection of 1×105 WPE1-NA22 human prostate cancer cells, respectively. Tumors were allowed to grow for 22 weeks; tumor areas, body weights, and food intakes were measured weekly. At study's conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control; dutasteride intake significantly decreased seminal vesicle weights compared to finasteride intake. No differences were measured in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells and parent line RWPE-1 prostate epithelial cells were unaltered by treatment with testosterone, dihydrotestosterone, or mibolerone, suggesting that these cell lines are not androgen-sensitive. Conclusion The lack of response of WPE1-NA22 prostate cancer cells to androgen treatment may

A Stem Cell-Seeded Nanofibrous Scaffold for Auditory Nerve Replacement

DTIC Science & Technology

2015-10-01

guinea pigs . Initial results show improved electrically-evoked auditory brainstem responses in cell-seeded implants compared to control, cell-free...scaffold’s conduit, but the IAM of the guinea pig and limits imposed by the surgical approach make this difficult. Alternatives are being pursued...transplantation of the seeded nanofibrous scaffold Task 13. Group 1: Pilot deafening. Confirm efficacy of ß-bungarotoxin in guinea pig and time point of

The inhibiting effects of Urtica dioica root extracts on experimentally induced prostatic hyperplasia in the mouse.

PubMed

Lichius, J J; Muth, C

1997-08-01

Extracts of stinging nettle roots (Urtica dioica L. Urticaceae) are used in the treatment of benign prostatic hyperplasia (BPH). We established a BPH-model by directly implanting an urogenital sinus (UGS) into the ventral prostate gland of an adult mouse. Five differently prepared stinging nettle root extracts were tested in this model. The 20% methanolic extract was the most effective with a 51.4% inhibition of induced growth.

Selenomethionine and alpha-tocopherol do not inhibit prostate carcinogenesis in the testosterone plus estradiol-treated NBL rat model.

PubMed

Ozten, Nur; Horton, Lori; Lasano, Salamia; Bosland, Maarten C

2010-03-01

Previous studies with selenium and/or vitamin E in prostate carcinogenesis animal models have been negative, but these models may not involve oxidative stress mechanisms. In this study, we examined the potential of selenomethionine and alpha-tocopherol to modulate prostate cancer development in the testosterone plus estradiol-treated NBL rat, a model that does involve sex hormone-induced oxidative stress mechanisms and prostatic inflammation. One week following the implantation with hormone-filled Silastic implants, rats were fed diets containing l-selenomethionine (1.5 or 3.0 mg/kg), DL-alpha-tocopherol acetate (2,000 or 4,000 mg/kg), or a natural ingredient control diet (NIH-07). The development of prostate carcinomas was not affected by dietary treatment with either agent. Food intake, body weight, and mortality were also not affected. The high dose of selenomethionine reduced the severity of epithelial dysplasia in the lateral prostate that was not associated with inflammation, and alpha-tocopherol reduced in a dose-related fashion the incidence of marked inflammation and marked epithelial dysplasia in the lateral prostate, regardless of whether these lesions were associated with inflammation. alpha-Tocopherol significantly increased the incidence of adenocarcinomas of the mammary glands at both dietary concentrations. Collectively, our findings suggest that selenomethionine and alpha-tocopherol supplementation does not prevent prostate cancer in rats fed diets with nutritionally adequate levels of selenium and vitamin E. Importantly, the results of the current animal studies and those reported previously were fully predictive of the outcome of the Selenium and Vitamin E Cancer Prevention Trial.

Selenomethionine and α-Tocopherol do not Inhibit Prostate Carcinogenesis in the Testosterone plus Estradiol-Treated NBL Rat Model

PubMed Central

Özten, Nur; Horton, Lori; Lasano, Salamia; Bosland, Maarten C.

2009-01-01

Previous studies with selenium and/or vitamin E in prostate carcinogenesis animal models have been negative, but these models may not involve oxidative stress mechanisms. In this study, we examined the potential of selenomethionine and α-tocopherol to modulate prostate cancer development in the testosterone plus estradiol-treated NBL rat, a model that does involve sex-hormone induced oxidative stress mechanisms and prostatic inflammation. One week following implantation with hormone-filled Silastic implants, rats were fed diets containing L-selenomethionine (1. 5 or 3. 0 mg/kg), DL-α-tocopherol acetate (2,000 mg/kg or 4,000 mg/kg), or a natural ingredient control diet (NIH-07). Development of prostate carcinomas was not affected by dietary treatment with either agent. Food intake, body weight, and mortality were also not affected. The high dose of selenomethionine reduced the severity of epithelial dysplasia in the lateral prostate that was not associated with inflammation and α-tocopherol reduced in a dose-related fashion the incidence of marked inflammation and marked epithelial dysplasia in the lateral prostate, regardless of whether these lesions were associated with inflammation. α-Tocopherol significantly increased the incidence of adenocarcinomas of the mammary glands at both dietary concentrations. Collectively, our findings suggest that selenomethionine and α-tocopherol supplementation does not prevent prostate cancer in rats fed diets with nutritionally adequate levels of selenium and vitamin E. Importantly, the results of the current animal studies and those reported previously were fully predictive of the outcome of the SELECT trial. PMID:20179302

A Monte Carlo study of I-125 prostate brachytherapy with gold nanoparticles: dose enhancement with simultaneous rectal dose sparing via radiation shielding.

PubMed

Brivio, D; Nguyen, P L; Sajo, E; Ngwa, W; Zygmanski, P

2017-03-07

We investigate via Monte Carlo simulations a new 125 I brachytherapy treatment technique for high-risk prostate cancer patients via injection of Au nanoparticle (AuNP) directly into the prostate. The purpose of using the nanoparticles is to increase the therapeutic index via two synergistic effects: enhanced energy deposition within the prostate and simultaneous shielding of organs at risk from radiation escaping from the prostate. Both uniform and non-uniform concentrations of AuNP are studied. The latter are modeled considering the possibility of AuNP diffusion after the injection using brachy needles. We study two extreme cases of coaxial AuNP concentrations: centered on brachy needles and centered half-way between them. Assuming uniform distribution of 30 mg g -1 of AuNP within the prostate, we obtain a dose enhancement larger than a factor of 2 to the prostate. Non-uniform concentration of AuNP ranging from 10 mg g -1 and 66 mg g -1 were studied. The higher the concentration in a given region of the prostate the greater is the enhancement therein. We obtain the highest dose enhancement when the brachytherapy needles are coincident with AuNP injection needles but, at the same time, the regions in the tail are colder (average dose ratio of 0.7). The best enhancement uniformity is obtained with the seeds in the tail of the AuNP distribution. In both uniform and non-uniform cases the urethra and rectum receive less than 1/3 dose compared to an analog treatment without AuNP. Remarkably, employing AuNP not only significantly increases dose to the target but also decreases dose to the neighboring rectum and even urethra, which is embedded within the prostate. These are mutually interdependent effects as more enhancement leads to more shielding and vice-versa. Caution must be paid since cold spot or hot spots may be created if the AuNP concentration versus seed position is not properly distributed respect to the seed locations.

A Monte Carlo study of I-125 prostate brachytherapy with gold nanoparticles: dose enhancement with simultaneous rectal dose sparing via radiation shielding

NASA Astrophysics Data System (ADS)

Brivio, D.; Nguyen, P. L.; Sajo, E.; Ngwa, W.; Zygmanski, P.

2017-03-01

We investigate via Monte Carlo simulations a new 125I brachytherapy treatment technique for high-risk prostate cancer patients via injection of Au nanoparticle (AuNP) directly into the prostate. The purpose of using the nanoparticles is to increase the therapeutic index via two synergistic effects: enhanced energy deposition within the prostate and simultaneous shielding of organs at risk from radiation escaping from the prostate. Both uniform and non-uniform concentrations of AuNP are studied. The latter are modeled considering the possibility of AuNP diffusion after the injection using brachy needles. We study two extreme cases of coaxial AuNP concentrations: centered on brachy needles and centered half-way between them. Assuming uniform distribution of 30 mg g-1 of AuNP within the prostate, we obtain a dose enhancement larger than a factor of 2 to the prostate. Non-uniform concentration of AuNP ranging from 10 mg g-1 and 66 mg g-1 were studied. The higher the concentration in a given region of the prostate the greater is the enhancement therein. We obtain the highest dose enhancement when the brachytherapy needles are coincident with AuNP injection needles but, at the same time, the regions in the tail are colder (average dose ratio of 0.7). The best enhancement uniformity is obtained with the seeds in the tail of the AuNP distribution. In both uniform and non-uniform cases the urethra and rectum receive less than 1/3 dose compared to an analog treatment without AuNP. Remarkably, employing AuNP not only significantly increases dose to the target but also decreases dose to the neighboring rectum and even urethra, which is embedded within the prostate. These are mutually interdependent effects as more enhancement leads to more shielding and vice-versa. Caution must be paid since cold spot or hot spots may be created if the AuNP concentration versus seed position is not properly distributed respect to the seed locations.

Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants.

PubMed

Mavroidis, Panayiotis; Katsilieri, Zaira; Kefala, Vasiliki; Milickovic, Natasa; Papanikolaou, Nikos; Karabis, Andreas; Zamboglou, Nikolaos; Baltas, Dimos

2010-09-01

One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV), then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option. In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices. The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR) has been compared to alternative plans with HIPO and free modulation (without MR). All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs) involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P + and the biologically effective uniform dose ([Formula: see text]) were used for treatment plan evaluation and comparison. Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices. In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation restricted clinical

Impact of Concurrent Androgen Deprivation on Fiducial Marker Migration in External-beam Radiation Therapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiberi, David A.; Carrier, Jean-Francois; Beauchemin, Marie-Claude

2012-09-01

Purpose: To determine the extent of gold fiducial marker (FM) migration in patients treated for prostate cancer with concurrent androgen deprivation and external-beam radiation therapy (EBRT). Methods and Materials: Three or 4 gold FMs were implanted in 37 patients with prostate adenocarcinoma receiving androgen deprivation therapy (ADT) in conjunction with 70-78 Gy. Androgen deprivation therapy was started a median of 3.9 months before EBRT (range, 0.3-12.5 months). To establish the extent of FM migration, the distance between each FM was calculated for 5-8 treatments once per week throughout the EBRT course. For each treatment, the distance between FMs was comparedmore » with the distance from the digitally reconstructed radiographs generated from the planning CT. A total of 281 treatments were analyzed. Results: The average daily migration was 0.8 {+-} 0.3 mm, with distances ranging from 0.2 mm-2.6 mm. Two of the 281 assessed treatments (0.7%) showed migrations >2 mm. No correlation between FM migration and patient weight or time delay between ADT and start of EBRT was found. There was no correlation between the extent of FM migration and prostate volume. Conclusion: This is the largest report of implanted FM migration in patients receiving concomitant ADT. Only 0.7% of the 281 treatments studied had significant marker migrations (>2 mm) throughout the course of EBRT. Consequently, the use of implanted FMs in these patients enables accurate monitoring of prostate gland position during treatment.« less

Dosimetric differences between intraoperative and postoperative plans using Cs-131 in transrectal ultrasound–guided brachytherapy for prostatic carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Andrew, E-mail: aojones@geisinger.edu; Treas, Jared; Yavoich, Brian

2014-01-01

The aim of the study was to investigate the differences between intraoperative and postoperative dosimetry for transrectal ultrasound–guided transperineal prostate implants using cesium-131 ({sup 131}Cs). Between 2006 and 2010, 166 patients implanted with {sup 131}Cs had both intraoperative and postoperative dosimetry studies. All cases were monotherapy and doses of 115 were prescribed to the prostate. The dosimetric properties (D{sub 90}, V{sub 150}, and V{sub 100} for the prostate) of the studies were compared. Two conformity indices were also calculated and compared. Finally, the prostate was automatically sectioned into 6 sectors (anterior and posterior sectors at the base, midgland, and apex)more » and the intraoperative and postoperative dosimetry was compared in each individual sector. Postoperative dosimetry showed statistically significant changes (p < 0.01) in every dosimetric value except V{sub 150}. In each significant case, the postoperative plans showed lower dose coverage. The conformity indexes also showed a bimodal frequency distribution with the index indicating poorer dose conformity in the postoperative plans. Sector analysis revealed less dose coverage postoperatively in the base and apex sectors with an increase in dose to the posterior midgland sector. Postoperative dosimetry overall and in specific sectors of the prostate differs significantly from intraoperative planning. Care must be taken during the intraoperative planning stage to ensure complete dose coverage of the prostate with the understanding that the final postoperative dosimetry will show less dose coverage.« less

Alendronate decreases orthotopic PC-3 prostate tumor growth and metastasis to prostate-draining lymph nodes in nude mice

PubMed Central

Tuomela, Johanna M; Valta, Maija P; Väänänen, Kalervo; Härkönen, Pirkko L

2008-01-01

Background Metastatic prostate cancer is associated with a high morbidity and mortality but the spreading mechanisms are still poorly understood. The aminobisphosphonate alendronate, used to reduce bone loss, has also been shown to inhibit the invasion and migration of prostate cancer cells in vitro. We used a modified orthotopic PC-3 nude mouse tumor model of human prostate cancer to study whether alendronate affects prostate tumor growth and metastasis. Methods PC-3 cells (5 × 105) were implanted in the prostates of nude mice and the mice were treated with alendronate (0.5 mg/kg/day in PBS, s.c.) or vehicle for 4 weeks. After sacrifice, the sizes of tumor-bearing prostates were measured and the tumors and prostate-draining regional iliac and sacral lymph nodes were excised for studies on markers of proliferation, apoptosis, angiogenesis and lymphangiogenesis, using histomorphometry and immunohistochemistry. Results Tumor occurrence in the prostate was 73% in the alendronate-treated group and 81% in the control group. Mean tumor size (218 mm3, range: 96–485 mm3, n = 11) in the alendronate-treated mice was 41% of that in the control mice (513 mm3, range: 209–1350 mm3, n = 13) (p < 0.05). In the iliac and sacral lymph nodes of alendronate-treated mice, the proportion of metastatic area was only about 10% of that in control mice (p < 0.001). Immunohistochemical staining of tumor sections showed that alendronate treatment caused a marked decrease in the number of CD34-positive endothelial cells in tumors (p < 0.001) and an increase in that of ISEL positive apoptotic cells in tumors as well as in lymph node metastases (p < 0.05) compared with those in the vehicle-treated mice. The density of m-LYVE-1-stained lymphatic capillaries was not changed. Conclusion Our results demonstrate that alendronate treatment opposes growth of orthotopic PC-3 tumors and decreases tumor metastasis to prostate-draining lymph nodes. This effect could be at least partly explained by

Low Testosterone Alters the Activity of Mouse Prostate Stem Cells.

PubMed

Zhou, Ye; Copeland, Ben; Otto-Duessel, Maya; He, Miaoling; Markel, Susan; Synold, Tim W; Jones, Jeremy O

2017-04-01

Low serum testosterone (low T) has been repeatedly linked to worse outcomes in men with newly diagnosed prostate cancer (PC). How low T contributes to these outcomes is unknown. Here we demonstrate that exposure to low T causes significant changes in the mouse prostate and prostate stem cells. Mice were castrated and implanted with capsules to achieve castrate, normal, or sub-physiological levels of T. After 6 weeks of treatment, LC-MS/MS was used to quantify the levels of T and dihydrotestosterone (DHT) in serum and prostate tissue. FACS was used to quantify the percentages of purported prostate stem and transit amplifying (TA) cells in mouse prostates. Prostate tissues were also stained for the presence of CD68+ cells and RNA was extracted from prostate tissue or specific cell populations to measure changes in transcript levels with low T treatment. Despite having significantly different levels of T and DHT in the serum, T and DHT concentrations in prostate tissue from different T treatment groups were similar. Low T treatment resulted in significant alterations in the expression of androgen biosynthesis genes, which may be related to maintaining prostate androgen levels. Furthermore, the expression of androgen-regulated genes in the prostate was similar among all T treatment groups, demonstrating that the mouse prostate can maintain functional levels of androgens despite low serum T levels. Low T increased the frequency of prostate stem and TA cells in adult prostate tissue and caused major transcriptional changes in those cells. Gene ontology analysis suggested that low T caused inflammatory responses and immunofluorescent staining indicated that low T treatment led to the increased presence of CD68+ macrophages in prostate tissue. Low T alters the AR signaling axis which likely leads to maintenance of functional levels of prostate androgens. Low T also induces quantitative and qualitative changes in prostate stem cells which appear to lead to inflammatory

Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections.

PubMed

Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

2010-09-01

To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four 103Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selected from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. For the phantom study, seed localization error is (0.58 +/- 0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/ iteration on a 1 GHz processor. The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate approximately 1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.

Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.

2010-09-15

Purpose: To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. Methods: The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four {sup 103}Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selectedmore » from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. Results: For the phantom study, seed localization error is (0.58{+-}0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/iteration on a 1 GHz processor. Conclusions: The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate {approx}1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.« less

Differential gene expression profiling of functionally and developmentally distinct human prostate epithelial populations.

PubMed

Liu, Haibo; Cadaneanu, Radu M; Lai, Kevin; Zhang, Baohui; Huo, Lihong; An, Dong Sun; Li, Xinmin; Lewis, Michael S; Garraway, Isla P

2015-05-01

Human fetal prostate buds appear in the 10th gestational week as solid cords, which branch and form lumens in response to androgen 1. Previous in vivo analysis of prostate epithelia isolated from benign prostatectomy specimens indicated that Epcam⁺ CD44⁻ CD49f(Hi) basal cells possess efficient tubule initiation capability relative to other subpopulations 2. Stromal interactions and branching morphogenesis displayed by adult tubule-initiating cells (TIC) are reminiscent of fetal prostate development. In the current study, we evaluated in vivo tubule initiation by human fetal prostate cells and determined expression profiles of fetal and adult epithelial subpopulations in an effort to identify pathways used by TIC. Immunostaining and FACS analysis based on Epcam, CD44, and CD49f expression demonstrated the majority (99.9%) of fetal prostate epithelial cells (FC) were Epcam⁺ CD44⁻ with variable levels of CD49f expression. Fetal populations isolated via cell sorting were implanted into immunocompromised mice. Total RNA isolation from Epcam⁺ CD44⁻ CD49f(Hi) FC, adult Epcam⁺ CD44⁻ CD49f(Hi) TIC, Epcam⁺ CD44⁺ CD49f(Hi) basal cells (BC), and Epcam⁺ CD44⁻ CD49f(Lo) luminal cells (LC) was performed, followed by microarray analysis of 19 samples using the Affymetrix Gene Chip Human U133 Plus 2.0 Array. Data was analyzed using Partek Genomics Suite Version 6.4. Genes selected showed >2-fold difference in expression and P < 5.00E-2. Results were validated with RT-PCR. Grafts retrieved from Epcam⁺ CD44⁻ fetal cell implants displayed tubule formation with differentiation into basal and luminal compartments, while only stromal outgrowths were recovered from Epcam- fetal cell implants. Hierarchical clustering revealed four distinct groups determined by antigenic profile (TIC, BC, LC) and developmental stage (FC). TIC and BC displayed basal gene expression profiles, while LC expressed secretory genes. FC had a unique profile with the most similarities

A gEUD-based inverse planning technique for HDR prostate brachytherapy: Feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giantsoudi, D.; Department of Radiation Oncology, Francis H. Burr Proton Therapy Center, Boston, Massachusetts 02114; Baltas, D.

2013-04-15

Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the differentmore » dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D{sub 10} or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.« less

Evaluation of inductively heated ferromagnetic alloy implants for therapeutic interstitial hyperthermia.

PubMed

Paulus, J A; Richardson, J S; Tucker, R D; Park, J B

1996-04-01

Ferromagnetic alloys heated by magnetic induction have been investigated as interstitial hyperthermia delivery implants for over a decade, utilizing low Curie temperatures to provide thermal self-regulation. The minimally invasive method is attractive for fractionated thermal treatment of tumors which are not easily heated by focused microwave or ultrasound techniques. Past analyses of ferromagnetic seeds by other authors depict poor experimental correlation with theoretical heating predictions. Improvements in computer hardware and commercially available finite element analysis software have simplified the analysis of inductively heated thermal seeds considerably. This manuscript examines end effects of finite length implants and nonlinear magnetic material properties to account for previous inconsistencies. Two alloys, Ni-28 wt% Cu (NiCu) and Pd-6.15 wt% Co (PdCo), were used for comparison of theoretical and experimental calorimetric results. Length to diameter (L/d) ratios of over 20 for cylindrical seeds are necessary for minimization of end effects. Magnetic properties tested for alloys of NiCu and PdCo illustrate considerable nonlinearity of these materials in field strength ranges used for induction heating. Field strength dependent magnetic permeabilities and calorimetric data illustrate that more detailed material information must be included to accurately estimate induction power loss for these implants.

WE-FG-BRA-02: Docetaxel Eluting Brachytherapy Spacers for Local Chemo-Radiation Therapy in Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belz, J; Kumar, R; Sridhar, S

Purpose: We propose an innovative combinatorial treatment strategy of Local ChemoRadiation Therapy (LCRT) using a sustained drug delivery platform in the form of a spacer to locally radio-sensitize the prostate with Docetaxel (DTX) enabling a synergistic cure with the use of lower radiation doses. These biodegradable spacers are physically similar to the inert spacers routinely used in prostate brachytherapy but are now loaded with formulations of DTX. Methods: Spacers were loaded with ∼500µg Docetaxel (DTX) for prostate cancer studies. The implants were characterized in vitro using SEM and HPLC. The release kinetic studies were carried out in buffer (pH 6.0)more » at 37°C. Subcutaneous PC3 tumors were xenografted in nude mice. Prostate cancer studies were done with and without radiation using SARRP at 5Gy, 10Gy, and 15Gy. Drug-loaded implants were injected once intratumorally using an 18G brachytherapy needle. Results: The release study in vitro showed a highly sustained release for multiple weeks at therapeutically relevant doses. The monotherapy with local DTX spacer showed sustained tumor inhibition compared to empty implants and an equivalent DTX dose given systemically. At 40 days, 89% survival was observed for mice treated with DTX implants compared with 0% in all other treatment groups. The combined treatment with local DTX spacer and radiation (10Gy) showed the highest degree of tumor suppression (significant tumor growth inhibition by day 90). The control mice showed continuous tumor growth and were scarified by day 56. Groups of mice treated with DTX-spacer or radiation alone showed initial tumor suppression but growth continued after day 60. A larger experiment is ongoing. Conclusion: This approach provides localized delivery of the chemotherapeutic sensitizer directly to the tumor and avoids the toxicities associated with both brachytherapy and current systemic delivery of docetaxel. Sustained release of DTX is an effective chemotherapy option

Interfraction Prostate Movement in Bone Alignment After Rectal Enema for Radiotherapy

PubMed Central

Seo, Young Eun; Kim, Tae Hyo; Lee, Ki Soo; Cho, Won Yeol; Lee, Hyung-Sik; Hur, Won-Joo

2014-01-01

Purpose To assess the effect of a rectal enema on interfraction prostate movement in bone alignment (BA) for prostate radiotherapy (RT), we analyzed the spatial difference in prostates in a bone-matched setup. Materials and Methods We performed BA retrospectively with data from prostate cancer patients who underwent image-guided RT (IGRT). The prostate was identified with implanted fiducial markers. The setup for the IGRT was conducted with the matching of three fiducial markers on RT planning computed tomography images and those on two oblique kV x-ray images. Offline BA was performed at the same position. The coordinates of a virtual prostate in BA and a real prostate were obtained by use of the ExaxTrac/NovalisBody system, and the distance between them was calculated as the spatial difference. Interfraction prostate displacement was drawn from the comparison of the spatial differences. Results A total of 15 patients with localized prostate cancer treated with curative hypofractionated IGRT were enrolled. A total of 420 fractions were analyzed. The mean of the interfraction prostate displacements after BA was 3.12±2.00 mm (range, 0.20-10.53 mm). The directional difference was profound in the anterior-posterior and supero-inferior directions (2.14±1.73 mm and 1.97±1.44 mm, respectively) compared with the right-left direction (0.26±0.22 mm, p<0.05). The required margin around the clinical target volume was 4.97 mm with the formula of van Herk et al. Conclusions The interfraction prostate displacement was less frequent when a rectal enema was performed before the procedure. A rectal enema can be used to reduce interfraction prostate displacement and resulting clinical target volume-to-planning target volume margin. PMID:24466393

Impact of target area selection in 125 Iodine seed brachytherapy on locoregional recurrence in patients with non-small cell lung cancer.

PubMed

Yan, Wei-Liang; Lv, Jin-Shuang; Guan, Zhi-Yu; Wang, Li-Yang; Yang, Jing-Kui; Liang, Ji-Xiang

2017-05-01

Computed tomography (CT)-guided percutaneous implantation of 125 Iodine radioactive seeds requires the precise arrangement of seeds by tumor shape. We tested whether selecting target areas, including subclinical areas around tumors, can influence locoregional recurrence in patients with non-small cell lung cancer (NSCLC). We divided 82 patients with NSCLC into two groups. Target areas in group 1 (n = 40) were defined along tumor margins based on lung-window CT. Target areas in group 2 (n = 42) were extended by 0.5 cm in all dimensions outside tumor margins. Preoperative plans for both groups were based on a treatment plan system, which guided 125 I seed implantation. Six months later, patients underwent chest CT to evaluate treatment efficacy (per Response Evaluation Criteria in Solid Tumors version 1). We compared locoregional recurrences between the groups after a year of follow-up. We then used the treatment plan system to extend target areas for group 1 patients by 0.5 cm (defined as group 3 data) and compared these hypothetical group 3 planned seeds with the actual seed numbers used in group 1 patients. All patients successfully underwent implantation; none died during the follow-up period. Recurrence was significantly lower in group 2 than in group 1 ( P  < 0.05). Group 1 patients and group 3 data significantly differed in seed numbers ( P  < 0.01). Our results imply that extending the implantation area for 125 I seeds can decrease recurrence risk by eradicating cancerous lymph-duct blockades within the extended areas. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Clinical Significance of Accounting for Tissue Heterogeneity in Permanent Breast Seed Implant Brachytherapy Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mashouf, Shahram; Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario; Fleury, Emmanuelle

Purpose: The inhomogeneity correction factor (ICF) method provides heterogeneity correction for the fast calculation TG43 formalism in seed brachytherapy. This study compared ICF-corrected plans to their standard TG43 counterparts, looking at their capacity to assess inadequate coverage and/or risk of any skin toxicities for patients who received permanent breast seed implant (PBSI). Methods and Materials: Two-month postimplant computed tomography scans and plans of 140 PBSI patients were used to calculate dose distributions by using the TG43 and the ICF methods. Multiple dose-volume histogram (DVH) parameters of clinical target volume (CTV) and skin were extracted and compared for both ICF and TG43more » dose distributions. Short-term (desquamation and erythema) and long-term (telangiectasia) skin toxicity data were available on 125 and 110 of the patients, respectively, at the time of the study. The predictive value of each DVH parameter of skin was evaluated using the area under the receiver operating characteristic (ROC) curve for each toxicity endpoint. Results: Dose-volume histogram parameters of CTV, calculated using the ICF method, showed an overall decrease compared to TG43, whereas those of skin showed an increase, confirming previously reported findings of the impact of heterogeneity with low-energy sources. The ICF methodology enabled us to distinguish patients for whom the CTV V{sub 100} and V{sub 90} are up to 19% lower compared to TG43, which could present a risk of recurrence not detected when heterogeneity are not accounted for. The ICF method also led to an increase in the prediction of desquamation, erythema, and telangiectasia for 91% of skin DVH parameters studied. Conclusions: The ICF methodology has the advantage of distinguishing any inadequate dose coverage of CTV due to breast heterogeneity, which can be missed by TG43. Use of ICF correction also led to an increase in prediction accuracy of skin toxicities in most cases.« less

Clinical Significance of Accounting for Tissue Heterogeneity in Permanent Breast Seed Implant Brachytherapy Planning.

PubMed

Mashouf, Shahram; Fleury, Emmanuelle; Lai, Priscilla; Merino, Tomas; Lechtman, Eli; Kiss, Alex; McCann, Claire; Pignol, Jean-Philippe

2016-03-15

The inhomogeneity correction factor (ICF) method provides heterogeneity correction for the fast calculation TG43 formalism in seed brachytherapy. This study compared ICF-corrected plans to their standard TG43 counterparts, looking at their capacity to assess inadequate coverage and/or risk of any skin toxicities for patients who received permanent breast seed implant (PBSI). Two-month postimplant computed tomography scans and plans of 140 PBSI patients were used to calculate dose distributions by using the TG43 and the ICF methods. Multiple dose-volume histogram (DVH) parameters of clinical target volume (CTV) and skin were extracted and compared for both ICF and TG43 dose distributions. Short-term (desquamation and erythema) and long-term (telangiectasia) skin toxicity data were available on 125 and 110 of the patients, respectively, at the time of the study. The predictive value of each DVH parameter of skin was evaluated using the area under the receiver operating characteristic (ROC) curve for each toxicity endpoint. Dose-volume histogram parameters of CTV, calculated using the ICF method, showed an overall decrease compared to TG43, whereas those of skin showed an increase, confirming previously reported findings of the impact of heterogeneity with low-energy sources. The ICF methodology enabled us to distinguish patients for whom the CTV V100 and V90 are up to 19% lower compared to TG43, which could present a risk of recurrence not detected when heterogeneity are not accounted for. The ICF method also led to an increase in the prediction of desquamation, erythema, and telangiectasia for 91% of skin DVH parameters studied. The ICF methodology has the advantage of distinguishing any inadequate dose coverage of CTV due to breast heterogeneity, which can be missed by TG43. Use of ICF correction also led to an increase in prediction accuracy of skin toxicities in most cases. Copyright © 2016 Elsevier Inc. All rights reserved.

Prostate thermal therapy with catheter-based ultrasound devices and MR thermal monitoring

NASA Astrophysics Data System (ADS)

Diederich, Chris J.; Nau, Will H.; Kinsey, Adam; Ross, Tony; Wootton, Jeff; Juang, Titania; Butts-Pauly, Kim; Ricke, Viola; Liu, Erin H.; Chen, Jing; Bouley, Donna M.; Van den Bosch, Maurice; Sommer, Graham

2007-02-01

Four types of transurethral applicators were devised for thermal ablation of prostate combined with MR thermal monitoring: sectored tubular transducer devices with directional heating patterns; planar and curvilinear devices with narrow heating patterns; and multi-sectored tubular devices capable of dynamic angular control without applicator movement. These devices are integrated with a 4 mm delivery catheter, incorporate an inflatable cooling balloon (10 mm OD) for positioning within the prostate and capable of rotation via an MR-compatible motor. Interstitial devices (2.4 mm OD) have been developed for percutaneous implantation with directional or dynamic angular control. In vivo experiments in canine prostate under MR temperature imaging were used to evaluate the heating technology and develop treatment control strategies. MR thermal imaging in a 0.5 T interventional MRI was used to monitor temperature and thermal dose in multiple slices through the target volume. Sectored tubular, planar, and curvilinear transurethral devices produce directional coagulation zones, extending 15-20 mm radial distance to the outer prostate capsule. Sequential rotation and modulated dwell time can conform thermal ablation to selected regions. Multi-sectored transurethral applicators can dynamically control the angular heating profile and target large regions of the gland in short treatment times without applicator manipulation. Interstitial implants with directional devices can be used to effectively ablate the posterior peripheral zone of the gland while protecting the rectum. The MR derived 52 °C and lethal thermal dose contours (t 43=240 min) allowed for real-time control of the applicators and effectively defined the extent of thermal damage. Catheter-based ultrasound devices, combined with MR thermal monitoring, can produce relatively fast and precise thermal ablation of prostate, with potential for treatment of cancer or BPH.

Experimental and theoretical studies of implant assisted magnetic drug targeting

NASA Astrophysics Data System (ADS)

Aviles, Misael O.

One way to achieve drug targeting in the body is to incorporate magnetic nanoparticles into drug carriers and then retain them at the site using an externally applied magnetic field. This process is referred to as magnetic drug targeting (MDT). However, the main limitation of MDT is that an externally applied magnetic field alone may not be able to retain a sufficient number of magnetic drug carrier particles (MDCPs) to justify its use. Such a limitation might not exist when high gradient magnetic separation (HGMS) principles are applied to assist MDT by means of ferromagnetic implants. It was hypothesized that an Implant Assisted -- MDT (IA-MDT) system would increase the retention of the MDCPs at a target site where an implant had been previously located, since the magnetic forces are produced internally. With this in mind, the overall objective of this work was to demonstrate the feasibility of an IA-MDT system through mathematical modeling and in vitro experimentation. The mathematical models were developed and used to demonstrate the behavior and limitations of IA-MDT, and the in vitro experiments were designed and used to validate the models and to further elucidate the important parameters that affect the performance of the system. IA-MDT was studied with three plausible implants, ferromagnetic stents, seed particles, and wires. All implants were studied theoretically and experimentally using flow through systems with polymer particles containing magnetite nanoparticles as MDCPs. In the stent studies, a wire coil or mesh was simply placed in a flow field and the capture of the MDCPs was studied. In the other cases, a porous polymer matrix was used as a surrogate capillary tissue scaffold to study the capture of the MDCPs using wires or particle seeds as the implant, with the seeds either fixed within the polymer matrix or captured prior to capturing the MDCPs. An in vitro heart tissue perfusion model was also used to study the use of stents. In general, all

Edible seeds from Cucurbitaceae family as potential functional foods: Immense promises, few concerns.

PubMed

Patel, Seema; Rauf, Abdur

2017-07-01

Cucurbitaceae family members such as pumpkin and watermelon have seeds that are discarded as the by-products of food processing. However, they have been discovered to contain a rich repertoire of nutrients such as proteins, unsaturated fatty acids, phenolic acids, carotenoids, tocopherol, phytosterol, squalene etc. Biological assays have proven the seed extracts to exert antioxidative, hypoglycemic, anticancer, antihypertensive, cardioprotective, antilipemic, gynoprotective, and anthelmintic properties. Further, the seeds do not contain any major anti-nutrients. Phytoestrogens like β-sitosterol occur, which might be acting as agonists or antagonists of estrogen and testosterone, given their validated role in gyenic and prostate health. Few instances of intestinal bezoar, and allergy, following pumpkin seeds consumption have emerged. After the risk-benefit analysis though exhaustive literature search, it can be suggested that these seeds are underutilized and they can be used to formulate a myriad of nutraceuticals. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

ERRATUM: In vivo evaluation of a neural stem cell-seeded prosthesis In vivo evaluation of a neural stem cell-seeded prosthesis

NASA Astrophysics Data System (ADS)

Purcell, E. K.; Seymour, J. P.; Yandamuri, S.; Kipke, D. R.

2009-08-01

In the published article, an error was made in figure 5. Specifically, the three-month, NSC-seeded image is a duplicate of the six-week image, and the one-day, probe alone image is a duplicate of the three-month image. The corrected figure is reproduced below. Figure 5 Figure 5. Glial encapsulation of each probe condition over the 3 month time course. Ox-42 labeled microglia and GFAP labeled astrocytes are shown. Images are taken from probes implanted in the same animal at each time point. NSC seeding was associated with reduced non-neuronal density at 1 day post-implantation in comparison to alginate coated probes and at the 1 week time point in comparison to untreated probes (P < 0.001). Glial activation is at its overall peak 1 week after insertion. A thin encapsulation layer surrounds probes at the 6 week and 3 month time points, with NSC-seeded probes having the greatest surrounding non-neuronal density P < 0.001). Interestingly, microglia appeared to have a ramified, or `surveilling', morphology surrounding a neural stem cell-alginate probe initially, whereas activated cells with an amoeboid structure were found near an alginate probe in the same hemisphere of one animal (left panels).

Effect of Body Mass Index on Intrafraction Prostate Displacement Monitored by Real-Time Electromagnetic Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, Wayne M., E-mail: wbutler@wheelinghospital.org; Wheeling Jesuit University, Wheeling, West Virginia; Morris, Mallory N.

2012-10-01

Purpose: To evaluate, using real-time monitoring of implanted radiofrequency transponders, the intrafraction prostate displacement of patients as a function of body mass index (BMI). Methods and Materials: The motions of Beacon radiofrequency transponders (Calypso Medical Technologies, Seattle, WA) implanted in the prostate glands of 66 men were monitored throughout the course of intensity modulated radiation therapy. Data were acquired at 10 Hz from setup to the end of treatment, but only the 1.7 million data points with a 'beam on' tag were used in the analysis. There were 21 obese patients, with BMI {>=}30 and 45 nonobese patients in themore » study. Results: Mean displacements were least in the left-right lateral direction (0.56 {+-} 0.24 mm) and approximately twice that magnitude in the superior-inferior and anterior-posterior directions. The net vector displacement was larger still, 1.95 {+-} 0.47 mm. Stratified by BMI cohort, the mean displacements per patient in the 3 Cartesian axes as well as the net vector for patients with BMI {>=}30 were slightly less (<0.2 mm) but not significantly different than the corresponding values for patients with lower BMIs. As a surrogate for the magnitude of oscillatory noise, the standard deviation for displacements in all measured planes showed no significant differences in the prostate positional variability between the lower and higher BMI groups. Histograms of prostate displacements showed a lower frequency of large displacements in obese patients, and there were no significant differences in short-term and long-term velocity distributions. Conclusions: After patients were positioned accurately using implanted radiofrequency transponders, the intrafractional displacements in the lateral, superior-inferior, and anterior-posterior directions as well as the net vector displacements were smaller, but not significantly so, for obese men than for those with lower BMI.« less

Post-treatment PSA < or = 0.2 ng/mL defines disease freedom after radiotherapy for prostate cancer using modern techniques.

PubMed

Critz, F A; Williams, W H; Holladay, C T; Levinson, A K; Benton, J B; Holladay, D A; Schnell, F J; Maxa, L S; Shrake, P D

1999-12-01

The prostate-specific antigen (PSA) definition of disease freedom after radiotherapy for prostate cancer is still in dispute. This report focuses on the PSA nadir achieved in men treated by modern radiotherapy techniques. From 1984 to 1994, 489 consecutive men with clinical Stage T1 -T2 prostate cancer were treated by simultaneous radiation: prostate iodine-125 implant followed by external beam radiation. A transperineal implant was performed on 143 men with Stage T1-T2NX, the focus of this study; 346 men with Stage T1-T2N0 had a retropubic implant. The median pretreatment PSA was 8.3 ng/mL (range 0.3 to 188). A rising PSA was defined as one that rose on three consecutive occasions above whatever nadir was achieved. A minimum 5-year follow-up (range 5 to 15) was reached by 453 men. After a minimum 5-year follow-up, 336 men had a nonrising PSA, and of this group, 107 had undergone simultaneous radiation by the transperineal implant technique. A PSA nadir of 0.2 ng/mL or less was achieved by 97% of the transperineally implanted men, and 3% had a nadir of 0.3 to 1.0 ng/mL. Of the 489 men, those who had a nadir of 0.2 ng/mL or less had a 92% nonrising PSA rate (P = 0.001) 10 years after treatment compared with a 41% rate for men who had a nadir of 0.3 to 1.0 ng/mL. All men whose nadir was greater than 1.0 ng/mL had recurrence. The median time to achieve the PSA nadir of 0.2 ng/mL was 27 months (range 3 to 102). Primarily on the basis of the results from men treated with simultaneous radiation using the transperineal technique, the definition of disease freedom for radiotherapy should be men who achieve and maintain a PSA nadir of 0.2 ng/mL or less.

A novel approach for evaluation of prostate deformation and associated dosimetric implications in IGRT of the prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayyas, Essa, E-mail: emayyas1@hfhs.org, E-mail: ortonc@comcast.net; Kim, Jinkoo; Kumar, Sanath

2014-09-15

Purpose: Prostate deformation is assumed to be a secondary correction and is typically ignored in the planning target volume (PTV) margin calculations. This assumption needs to be tested, especially when planning margins are reduced with daily image-guidance. In this study, deformation characteristics of the prostate and seminal vesicles were determined, and the dosimetric impact on treatment plans with different PTV margins was investigated. Methods: Ten prostate cancer patients were retrospectively selected for the study, each with three fiducial markers implanted in the prostate. Two hundred CBCT images were registered to respective planning CT images using a B-spline-based deformable image registrationmore » (DIR) software. A manual bony anatomy-based match was first applied based on the alignment of the pelvic bones and fiducial landmarks. DIR was then performed. For each registration, deformation vector fields (DVFs) of the prostate and seminal vesicles (SVs) were quantified using deformation-volume histograms. In addition, prostate rotation was evaluated and compared with prostate deformation. For a patient demonstrating small and large prostate deformations, target coverage degradation was analyzed in each of three treatment plans with PTV margins of 10 mm (6 mm at the prostate/rectum interface), as well as 5, and 3 mm uniformly. Results: Deformation of the prostate was most significant in the anterior direction. Maximum prostate deformation of greater than 10, 5, and 3 mm occurred in 1%, 17%, and 76% of the cases, respectively. Based on DVF-histograms, DVF magnitudes greater than 5 and 3 mm occurred in 2% and 27% of the cases, respectively. Deformation of the SVs was most significant in the posterior direction, and it was greater than 5 and 3 mm in 7.5% and 44.9% of the cases, respectively. Prostate deformation was found to be poorly correlated with rotation. Fifty percent of the cases showed rotation with negligible deformation and 7% of the cases

Demonstration of a forward iterative method to reconstruct brachytherapy seed configurations from x-ray projections

NASA Astrophysics Data System (ADS)

Murphy, Martin J.; Todor, Dorin A.

2005-06-01

By monitoring brachytherapy seed placement and determining the actual configuration of the seeds in vivo, one can optimize the treatment plan during the process of implantation. Two or more radiographic images from different viewpoints can in principle allow one to reconstruct the configuration of implanted seeds uniquely. However, the reconstruction problem is complicated by several factors: (1) the seeds can overlap and cluster in the images; (2) the images can have distortion that varies with viewpoint when a C-arm fluoroscope is used; (3) there can be uncertainty in the imaging viewpoints; (4) the angular separation of the imaging viewpoints can be small owing to physical space constraints; (5) there can be inconsistency in the number of seeds detected in the images; and (6) the patient can move while being imaged. We propose and conceptually demonstrate a novel reconstruction method that handles all of these complications and uncertainties in a unified process. The method represents the three-dimensional seed and camera configurations as parametrized models that are adjusted iteratively to conform to the observed radiographic images. The morphed model seed configuration that best reproduces the appearance of the seeds in the radiographs is the best estimate of the actual seed configuration. All of the information needed to establish both the seed configuration and the camera model is derived from the seed images without resort to external calibration fixtures. Furthermore, by comparing overall image content rather than individual seed coordinates, the process avoids the need to establish correspondence between seed identities in the several images. The method has been shown to work robustly in simulation tests that simultaneously allow for unknown individual seed positions, uncertainties in the imaging viewpoints and variable image distortion.

Monte Carlo study of a new I‐125 brachytherapy prototype seed with a ceramic radionuclide carrier and radiographic marker

PubMed Central

Paixão, Lucas; Santos, Ana Maria M.; dos Santos, Adriano Márcio; Grynberg, Suely Epsztein

2012-01-01

In prostate cancer treatment, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported with high prices, which prohibit their use in public hospitals. A ceramic matrix that can be used as a radioisotope carrier and radiographic marker was developed at our institution. The ceramic matrix is distinguished by the characteristic of maintaining the radioactive material uniformly distributed in its surface. In this work, Monte Carlo simulations were performed in order to assess the dose distributions generated by this prototype seed model, with the ceramic matrix encapsulated in titanium, in the same way as the commercial 6711 seed. The obtained data was assessed, as described in the TG‐43U1 report by the American Association of Physicists in Medicine, for two seed models: (1) the most used model 6711 source — for validation and comparison, and (2) for the prototype model with the ceramic matrix. The dosimetric parameters dose rate constant, Λ, radial dose function, gL(r), and anisotropy function, F(r,θ), were derived from simulations by the Monte Carlo method using the MCNP5 code. A Λ 0.992 (±2.33%) cGyh−1U−1 was found for the prototype model. In comparison with the 6711 model, a lower dose fall‐off on transverse axis was found, as well as a lower dose anisotropy for the radius r= 0.25 cm. In general, for all distances, the prototype seed model presents a slightly larger anisotropy between 0° ≤ Θ < 50° and anisotropy similar to the 6711 model for Θ ≥ 50°. The dosimetric characteristics of the prototype model presented in this study suggest that its use is feasible. Because of the model's characteristics, seeds of lower specific activity iodine might be necessary which, on the other hand, would help to reduce costs. However, it has to be emphasized that the proposed source is a prototype, and the required (AAPM prerequisites) experimental study and tolerance

SU-F-T-09: In Phantom Full-Implant Validation of Plastic Scintillation Detectors for in Vivo Dosimetry During Low Dose Rate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Therriault-Proulx, F; Bruno, T; Beddar, S

Purpose: To validate in a water phantom the use of plastic scintillation detectors to measure dose to the urethra and the rectal wall during a clinically realistic low dose rate (LDR) brachytherapy implant. Methods: A template was designed to replicate a clinically realistic LDR brachytherapy prostate implant inside a water phantom. Twenty-two catheters were inserted, including one mimicking the urethra and another the rectal wall. The needles inserted in the remaining 20 catheters were composed of thin-walled nylon tubes in which I-125 radioactive seeds (Air Kerma Strengths of (0.328±0.020)U) were abutted together with plastic spacers to replicate a typical loading.more » A plastic scintillation detector (PSD) with a 5-mm long × 1-mm diameter sensitive element was first placed inside the urethra and 1-second measurements were performed for 60s after each needle implant. Measurements were also performed at multiple positions along the urethra once all the needles were inserted. The procedure was then repeated with the PSD placed at the rectal wall. Results: Individual dose-rates ranging from 0.07µGy/s to 1.5µGy/s were measured after each needle implant. The average absolute relative differences were (6.2±3.6)% and (6.9±6.5)% to the values calculated with the TG-43 formalism, for the urethra and rectal wall respectively. These results are within expectations from the error uncertainty budget once accounting for uncertainties in seeds’ strength and positioning. Interestingly, the PSD allowed for unplanned error detection as the study was performed. Finally, the measured dose after the full implant at different positions along the mimicked organs at risk were in agreement with TG-43 values for all of the positions tested. Conclusion: Plastic scintillation detectors could be used as in vivo detectors for LDR brachytherapy as they would provide accurate dose information after each needle implant as well as along the organs at risk at the end of the implant.« less

SU-F-T-43: Prediction of Dose Increments by Brain Metastases Resection Cavity Shrinkage Model with I-125 and Cs-131 LDR Seed Implantations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, D; Braunstein, S; Sneed, P

Purpose: This work aims to determine dose variability via a brain metastases resection cavity shrinkage model (RC-SM) with I-125 or Cs-131 LDR seed implantations. Methods: The RC-SM was developed to represent sequential volume changes of 95 consecutive brain metastases patients. All patients underwent serial surveillance MR and change in cavity volume was recorded for each patient. For the initial resection cavity, a prolate-ellipsoid cavity model was suggested and applied volume shrinkage rates to correspond to 1.7, 3.6, 5.9, 11.7, and 20.5 months after craniotomy. Extra-ring structure (6mm) was added on a surface of the resection volume and the same shrinkagemore » rates were applied. Total 31 LDR seeds were evenly distributed on the surface of the resection cavity. The Amersham 6711 I-125 seed model (Oncura, Arlington Heights, IL) and the Model Cs-1 Rev2 Cs-131 seed model (IsoRay, Richland, WA) were used for TG-43U1 dose calculation and in-house-programed 3D-volumetric dose calculation system was used for resection cavity rigid model (RC-RM) and the RC-SM dose calculation. Results: The initial resection cavity volume shrunk to 25±6%, 35±6.8%, 42±7.7%, 47±9.5%, and 60±11.6%, with respect to sequential MR images post craniotomy, and the shrinkage rate (SR) was calculated as SR=56.41Xexp(−0.2024Xt)+33.99 and R-square value was 0.98. The normal brain dose as assessed via the dose to the ring structure with the RC-SM showed 29.34% and 27.95% higher than the RC-RM, I-125 and Cs-131, respectively. The dose differences between I-125 and Cs-131 seeds within the same models, I-125 cases were 9.17% and 10.35% higher than Cs-131 cases, the RC-RM and the RC-SM, respectively. Conclusion: A realistic RC-SM should be considered during LDR brain seed implementation and post-implement planning to prevent potential overdose. The RC-SM calculation shows that Cs-131 is more advantageous in sparing normal brain as the resection cavity volume changes with the LDR seeds

[18F]fluoroethylcholine-PET/CT imaging for radiation treatment planning of recurrent and primary prostate cancer with dose escalation to PET/CT-positive lymph nodes.

PubMed

Würschmidt, Florian; Petersen, Cordula; Wahl, Andreas; Dahle, Jörg; Kretschmer, Matthias

2011-05-01

a previous treatment with TUR of the prostate and seed implantation. FEC-PET/CT planning could be helpful in dose escalation to lymph nodal sites of prostate cancer.

Presence of PSA auto-antibodies in men with prostate abnormalities (prostate cancer/benign prostatic hyperplasia/prostatitis).

PubMed

Lokant, M T; Naz, R K

2015-04-01

Prostate-specific antigen (PSA), produced by the prostate, liquefies post-ejaculate semen. PSA is detected in semen and blood. Increased circulating PSA levels indicate prostate abnormality [prostate cancer (PC), benign prostatic hyperplasia (BPH), prostatitis (PTIS)], with variance among individuals. As the prostate has been proposed as an immune organ, we hypothesise that variation in PSA levels among men may be due to presence of auto-antibodies against PSA. Sera from healthy men (n = 28) and men having prostatitis (n = 25), BPH (n = 30) or PC (n = 29) were tested for PSA antibody presence using enzyme-linked immunosorbent assay (ELISA) values converted to standard deviation (SD) units, and Western blotting. Taking ≥2 SD units as cut-off for positive immunoreactivity, 0% of normal men, 0% with prostatitis, 33% with BPH and 3.45% with PC demonstrated PSA antibodies. One-way analysis of variance (anova) performed on the mean absorbance values and SD units of each group showed BPH as significantly different (P < 0.01) compared with PC and prostatitis. All others were nonsignificant (P < 0.05). Men (33%) with BPH had PSA antibodies by ELISA and Western blot. These discoveries may find clinical application in differential diagnosis among prostate abnormalities, especially differentiating BPH from prostate cancer and prostatitis. © 2014 Blackwell Verlag GmbH.

Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants

PubMed Central

Katsilieri, Zaira; Kefala, Vasiliki; Milickovic, Natasa; Papanikolaou, Nikos; Karabis, Andreas; Zamboglou, Nikolaos; Baltas, Dimos

2010-01-01

Purpose One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV), then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option. In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices. Material and methods The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR) has been compared to alternative plans with HIPO and free modulation (without MR). All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs) involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose (D¯¯) were used for treatment plan evaluation and comparison. Results Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices. In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation

Anticarcinogenic Effect of Spices Due to Phenolic and Flavonoid Compounds-In Vitro Evaluation on Prostate Cells.

PubMed

Lackova, Zuzana; Buchtelova, Hana; Buchtova, Zaneta; Klejdus, Borivoj; Heger, Zbynek; Brtnicky, Martin; Kynicky, Jindrich; Zitka, Ondrej; Adam, Vojtech

2017-09-28

This study shows the effects of spices, and their phenolic and flavonoid compounds, on prostate cell lines (PNT1A, 22RV1 and PC3). The results of an MTT assay on extracts from eight spices revealed the strongest inhibitory effects were from black pepper and caraway seed extracts. The strongest inhibitory effect on prostatic cells was observed after the application of extracts of spices in concentration of 12.5 mg·mL -1 . An LC/MS analysis identified that the most abundant phenolic and flavonoid compounds in black pepper are 3,4-dihydroxybenzaldehyde and naringenin chalcone, while the most abundant phenolic and flavonoid compounds in caraway seeds are neochlorogenic acid and apigenin. Using an MTT assay for the phenolic and flavonoid compounds from spices, we identified the IC 50 value of ~1 mmol·L -1 PNT1A. The scratch test demonstrated that the most potent inhibitory effect on PNT1A, 22RV1 and PC3 cells is from the naringenin chalcone contained in black pepper. From the spectrum of compounds assessed, the naringenin chalcone contained in black pepper was identified as the most potent inhibitor of the growth of prostate cells.

A novel MSC-seeded triphasic construct for the repair of osteochondral defects.

PubMed

Marquass, B; Somerson, J S; Hepp, P; Aigner, T; Schwan, S; Bader, A; Josten, C; Zscharnack, M; Schulz, R M

2010-12-01

Mesenchymal stem cells (MSC) are increasingly replacing chondrocytes in tissue engineering based research for treatment of osteochondral defects. The aim of this work was to determine whether repair of critical-size chronic osteochondral defects in an ovine model using MSC-seeded triphasic constructs would show results comparable to osteochondral autografting (OATS). Triphasic implants were engineered using a beta-tricalcium phosphate osseous phase, an intermediate activated plasma phase, and a collagen I hydrogel chondral phase. Autologous MSCs were used to seed the implants, with chondrogenic predifferentiation of the cells used in the cartilage phase. Osteochondral defects of 4.0 mm diameter were created bilaterally in ovine knees (n = 10). Six weeks later, half of the lesions were treated with OATS and half with triphasic constructs. The knees were dissected at 6 or 12 months. With the chosen study design we were not able to demonstrate significant differences between the histological scores of both groups. Subcategory analysis of O'Driscoll scores showed superior cartilage bonding in the 6-month triphasic group compared to the autograft group. The 12-month autograft group showed superior cartilage matrix morphology compared to the 12-month triphasic group. Macroscopic and biomechanical analysis showed no significant differences at 12 months. Autologous MSC-seeded triphasic implants showed comparable repair quality to osteochondral autografts in terms of histology and biomechanical testing. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

A Dose–Response Analysis of Biochemical Control Outcomes After {sup 125}I Monotherapy for Patients With Favorable-Risk Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiraishi, Yutaka, E-mail: shiraishi@rad.med.keio.ac.jp; Department of Radiology, National Hospital Organization Tokyo Medical Center, Tokyo; Yorozu, Atsunori

Purpose: To define the optimal dose for {sup 125}I prostate implants by correlating postimplantation dosimetry findings with biochemical failure and toxicity. Methods and Materials: Between 2003 and 2009, 683 patients with prostate cancer were treated with {sup 125}I prostate brachytherapy without supplemental external beam radiation therapy and were followed up for a median time of 80 months. Implant dose was defined as the D90 (the minimal dose received by 90% of the prostate) on postoperative day 1 and 1 month after implantation. Therefore, 2 dosimetric variables (day 1 D90 and day 30 D90) were analyzed for each patient. We investigated the dosemore » effects on biochemical control and toxicity. Results: The 7-year biochemical failure-free survival (BFFS) rate for the group overall was 96.4% according to the Phoenix definition. A multivariate analysis found day 1 D90 and day 30 D90 to be the most significant factors affecting BFFS. The cutoff points for day 1 D90 and day 30 D90, calculated from ROC curves, were 163 Gy and 175 Gy, respectively. By use of univariate analysis, various dosimetric cutoff points for day 30 D90 were tested. We found that day 30 D90 cutoff points from 130 to 180 Gy appeared to be good for the entire cohort. Greater D90s were associated with an increase in late genitourinary or gastrointestinal toxicity ≥ grade 2, but the increase was not statistically significant. Conclusions: Improvements in BFFS rates were seen with increasing D90 levels. Day 30 D90 doses of 130 to 180 Gy were found to serve as cutoff levels. For low-risk and low-tier intermediate-risk prostate cancer patients, high prostate D90s, even with doses exceeding 180 Gy, achieve better treatment results and are feasible.« less

Synergistic interaction of benign prostatic hyperplasia and prostatitis on prostate cancer risk

PubMed Central

Hung, S-C; Lai, S-W; Tsai, P-Y; Chen, P-C; Wu, H-C; Lin, W-H; Sung, F-C

2013-01-01

Background: The incidence of prostate cancer is much lower in Asian men than in Western men. This study investigated whether prostate cancer is associated with prostatitis, benign prostatic hyperplasia (BPH), and other medical conditions in the low-incidence population. Methods: From the claims data obtained from the universal National Health Insurance of Taiwan, we identified 1184 patients with prostate cancer diagnosed from 1997 to 2008. Controls comprised 4736 men randomly selected from a cancer-free population. Both groups were 50 years of age or above. Medical histories between the two groups were compared. Results: Multivariate logistic regression analysis showed that prostatitis and BPH had stronger association with prostate cancer than the other medical conditions tested. Compared with men without prostatitis and BPH, a higher odds ratio (OR) for prostate cancer was associated with BPH (26.2, 95% confidence interval (CI) 20.8–33.0) than with prostatitis (10.5, 95% CI=3.36–32.7). Men with both conditions had an OR of 49.2 (95% CI=34.7–69.9). Conclusion: Men with prostate cancer have strong association with prostatitis and/or BPH. Prostatitis interacts with BPH, resulting in higher estimated relative risk of prostate cancer in men suffering from both conditions. PMID:23612451

Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

PubMed

Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

2009-08-01

Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers

Method of electroplating a conversion electron emitting source on implant

DOEpatents

Srivastava, Suresh C [Setauket, NY; Gonzales, Gilbert R [New York, NY; Adzic, Radoslav [East Setauket, NY; Meinken, George E [Middle Island, NY

2012-02-14

Methods for preparing an implant coated with a conversion electron emitting source (CEES) are disclosed. The typical method includes cleaning the surface of the implant; placing the implant in an activating solution comprising hydrochloric acid to activate the surface; reducing the surface by H.sub.2 evolution in H.sub.2SO.sub.4 solution; and placing the implant in an electroplating solution that includes ions of the CEES, HCl, H.sub.2SO.sub.4, and resorcinol, gelatin, or a combination thereof. Alternatively, before tin plating, a seed layer is formed on the surface. The electroplated CEES coating can be further protected and stabilized by annealing in a heated oven, by passivation, or by being covered with a protective film. The invention also relates to a holding device for holding an implant, wherein the device selectively prevents electrodeposition on the portions of the implant contacting the device.

Catheter-based ultrasound hyperthermia with HDR brachytherapy for treatment of locally advanced cancer of the prostate and cervix

NASA Astrophysics Data System (ADS)

Diederich, Chris J.; Wootton, Jeff; Prakash, Punit; Salgaonkar, Vasant; Juang, Titania; Scott, Serena; Chen, Xin; Cunha, Adam; Pouliot, Jean; Hsu, I. C.

2011-03-01

A clinical treatment delivery platform has been developed and is being evaluated in a clinical pilot study for providing 3D controlled hyperthermia with catheter-based ultrasound applicators in conjunction with high dose rate (HDR) brachytherapy. Catheter-based ultrasound applicators are capable of 3D spatial control of heating in both angle and length of the devices, with enhanced radial penetration of heating compared to other hyperthermia technologies. Interstitial and endocavity ultrasound devices have been developed specifically for applying hyperthermia within HDR brachytherapy implants during radiation therapy in the treatment of cervix and prostate. A pilot study of the combination of catheter based ultrasound with HDR brachytherapy for locally advanced prostate and cervical cancer has been initiated, and preliminary results of the performance and heating distributions are reported herein. The treatment delivery platform consists of a 32 channel RF amplifier and a 48 channel thermocouple monitoring system. Controlling software can monitor and regulate frequency and power to each transducer section as required during the procedure. Interstitial applicators consist of multiple transducer sections of 2-4 cm length × 180 deg and 3-4 cm × 360 deg. heating patterns to be inserted in specific placed 13g implant catheters. The endocavity device, designed to be inserted within a 6 mm OD plastic tandem catheter within the cervix, consists of 2-3 transducers × dual 180 or 360 deg sectors. 3D temperature based treatment planning and optimization is dovetailed to the HDR optimization based planning to best configure and position the applicators within the catheters, and to determine optimal base power levels to each transducer section. To date we have treated eight cervix implants and six prostate implants. 100 % of treatments achieved a goal of >60 min duration, with therapeutic temperatures achieved in all cases. Thermal dosimetry within the hyperthermia target

A simple ion implanter for material modifications in agriculture and gemmology

NASA Astrophysics Data System (ADS)

Singkarat, S.; Wijaikhum, A.; Suwannakachorn, D.; Tippawan, U.; Intarasiri, S.; Bootkul, D.; Phanchaisri, B.; Techarung, J.; Rhodes, M. W.; Suwankosum, R.; Rattanarin, S.; Yu, L. D.

2015-12-01

In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X-Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

Effect of cell-seeded hydroxyapatite scaffolds on rabbit radius bone regeneration.

PubMed

Rathbone, C R; Guda, T; Singleton, B M; Oh, D S; Appleford, M R; Ong, J L; Wenke, J C

2014-05-01

Highly porous hydroxyapatite (HA) scaffolds were developed as bone graft substitutes using a template coating process, characterized, and seeded with bone marrow-derived mesenchymal stem cells (BMSCs). To test the hypothesis that cell-seeded HA scaffolds improve bone regeneration, HA scaffolds without cell seeding (HA-empty), HA scaffolds with 1.5 × 10(4) BMSCs (HA-low), and HA scaffolds with 1.5 × 10(6) BMSCs (HA-high) were implanted in a 10-mm rabbit radius segmental defect model for 4 and 8 weeks. Three different fluorochromes were administered at 2, 4, and 6 weeks after implantation to identify differences in temporal bone growth patterns. It was observed from fluorescence histomorphometry analyses that an increased rate of bone infiltration occurred from 0 to 2 weeks (p < 0.05) of implantation for the HA-high group (2.9 ± 0.5 mm) as compared with HA-empty (1.8 ± 0.8 mm) and HA-low (1.3 ± 0.2 mm) groups. No significant differences in bone formation within the scaffold or callus formation was observed between all groups after 4 weeks, with a significant increase in bone regenerated for all groups from 4 to 8 weeks (28.4% across groups). Although there was no difference in bone formation within scaffolds, callus formation was significantly higher in HA-empty scaffolds (100.9 ± 14.1 mm(3) ) when compared with HA-low (57.8 ± 7.3 mm(3) ; p ≤ 0.003) and HA-high (69.2 ± 10.4 mm(3) ; p ≤ 0.02) after 8 weeks. These data highlight the need for a better understanding of the parameters critical to the success of cell-seeded HA scaffolds for bone regeneration. Copyright © 2013 Wiley Periodicals, Inc.

Accomplishments of the Oak Ridge National Laboratory Seed Money program

DOE R&D Accomplishments Database

1986-09-01

In 1974, a modest program for funding new, innovative research was initiated at ORNL. It was called the "Seed Money" program and has become part of a larger program, called Exploratory R and D, which is being carried out at all DOE national laboratories. This report highlights 12 accomplishments of the Seed Money Program: nickel aluminide, ion implantation, laser annealing, burn meter, Legionnaires' disease, whole-body radiation counter, the ANFLOW system, genetics and molecular biology, high-voltage equipment, microcalorimeter, positron probe, and atom science. (DLC)

Assessment of the feasibility of using transrectal ultrasound for postimplant dosimetry in low-dose-rate prostate brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davies, Rhian Siân, E-mail: rhian.s.davies@wales.nhs.uk; Perrett, Teresa; Powell, Jane

A study was performed to establish whether transrectal ultrasound (TRUS)-based postimplant dosimetry (PID) is both practically feasible and comparable to computed tomography (CT)-based PID, recommended in current published guidelines. In total, 22 patients treated consecutively at a single cancer center with low-dose-rate (LDR) brachytherapy for early-stage prostate cancer had a transrectal ultrasound performed immediately after implant (d0-TRUS) and computed tomography scan 30 days after implant (d30-CT). Postimplant dosimetry planning was performed on both image sets and the results were compared. The interobserver reproducibility of the transrectal ultrasound postimplant dosimetry planning technique was also assessed. It was noticed that there wasmore » no significant difference in mean prostate D{sub 90} (136.5 Gy and 144.4 Gy, p = 0.2197), V{sub 100} (86.4% and 89.1%, p = 0.1480) and V{sub 150} (52.0% and 47.8%, p = 0.1657) for d30-CT and d0-TRUS, respectively. Rectal doses were significantly higher for d0-TRUS than d30-CT. Urethral doses were available with d0-TRUS only. We have shown that d0-TRUS PID is a useful tool for assessing the quality of an implant after low-dose-rate prostate brachytherapy and is comparable to d30-CT PID. There are clear advantages to its use in terms of resource and time efficiency both for the clinical team and the patient.« less

Null effect of dietary restriction on prostate carcinogenesis in the Wistar-Unilever rat.

PubMed

McCormick, David L; Johnson, William D; Haryu, Todd M; Bosland, Maarten C; Lubet, Ronald A; Steele, Vernon E

2007-01-01

Chronic dietary restriction inhibits carcinogenesis in several sites in laboratory animals. To determine the effects of dietary restriction on prostate carcinogenesis, prostate cancers were induced in male Wistar-Unilever rats by a sequential regimen of cyproterone acetate (50 mg/day; 21 days); testosterone propionate (100 mg/kg/day; 3 days); N-methyl-N-nitrosourea [MNU; 30 mg/kg; single dose]; and testosterone (subcutaneous implants of 2 pellets containing 40 mg each). Dietary restriction (0% [ad libitum control], 15%, or 30%) was initiated 2 wk post-MNU, and continued until study termination at 12 mo. Dietary restriction induced a rapid suppression of body weight gain but conferred no protection against prostate carcinogenesis. 74% of carcinogen-treated ad libitum controls developed accessory sex gland cancers, versus cancer incidences of 64% and 72% in groups restricted by 15% and 30%, respectively. Similarly, 44% of dietary controls developed cancers limited to the dorsolateral/prostate, versus incidences of 45% and 53% in groups restricted by 15% and 30%. The results of the present study do not support the hypothesis that prostate carcinogenesis can be prevented by reducing caloric intake. Reducing mean body weight by up to 25% through chronic dietary restriction has no effect on the induction of prostate cancers in the Wistar-Unilever rat model.

Whitmore, Henschke, and Hilaris: The reorientation of prostate brachytherapy (1970-1987).

PubMed

Aronowitz, Jesse N

2012-01-01

Urologists had performed prostate brachytherapy for decades before New York's Memorial Hospital retropubic program. This paper explores the contribution of Willet Whitmore, Ulrich Henschke, Basil Hilaris, and Memorial's physicists to the evolution of the procedure. Literature review and interviews with program participants. More than 1000 retropubic implants were performed at Memorial between 1970 and 1987. Unlike previous efforts, Memorial's program benefited from the participation of three disciplines in its conception and execution. Memorial's retropubic program was a collaboration of urologists, radiation therapists, and physicists. Their approach focused greater attention on dosimetry and radiation safety, and served as a template for subsequent prostate brachytherapy programs. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Prostate-Specific Antigen: Nonspecific in Deceased Organ Donors.

PubMed

Pabisiak, K; Ostrowski, M; Kram, A; Safranow, K; Myślak, M; Sieńko, J; Sulikowski, T; Ciechanowski, K

2016-06-01

Currently, there is no clear position regarding the donation of organs from donors with prostate carcinoma (CaP) in European countries, except Italy. The lengthening of life expectancy increases the probability of prostate cancer among potential organ donors. The concentration of prostate-specific antigen (PSA) >2 ng/mL at 60 years of age is related to the increasing possibility of identifying an advanced form of CaP. In recent years in Poland, the recommendation has been to determine tumor markers in potential donors. In the first year of the recommendation, 10% of potential male cadaveric donors were disqualified in West Pomerania, Poland, on the basis of elevated PSA levels (>10 ng/mL). To avoid reduction of the actual donor pool, each potential male donor reported to the center since January 2010 undergoes a routine histologic evaluation of the whole prostate, regardless of the PSA level, before organ implantation. In the study group (N = 52), histopathologic evaluation revealed 6 cases of CaP (12%). In CaP positive group Gleason score range from 2+2 to 3+4. In CaP donors PSA level have been noticed in range 1.79 ng/mL - 7.66 ng/mL. There was no correlation between histologically confirmed CaP and the PSA level. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of image fusion technology of radioactive particles implantation before and after the planning target and dosimetry].

PubMed

Jiang, Y L; Yu, J P; Sun, H T; Guo, F X; Ji, Z; Fan, J H; Zhang, L J; Li, X; Wang, J J

2017-08-01

Objective: To compare the post-implant target volumes and dosimetric evaluation with pre-plan, the gross tumor volume(GTV) by CT image fusion-based and the manual delineation of target volume in CT guided radioactive seeds implantation. Methods: A total of 10 patients treated under CT-guidance (125)I seed implantation during March 2016 to April 2016 were analyzed in Peking University Third Hospital.All patients underwent pre-operative CT simulation, pre-operative planning, implantation seeds, CT scanning after seed implantation and dosimetric evaluation of GTV.In every patient, post-implant target volumes were delineated by both two methods, and were divided into two groups. Group 1: image fusion pre-implantation simulation and post-operative CT image, then the contours of GTV were automatically performed by brachytherapy treatment planning system; Group 2: the contouring of the GTV on post-operative CT image were performed manually by three senior radiation oncologists independently. The average of three data was sets. Statistical analyses were performed using SPSS software, version 3.2.0. The paired t -test was used to compare the target volumes and D(90) parameters in two modality. Results: In Group 1, average volume of GTV in post-operation group was 12-167(73±56) cm(3). D(90) was 101-153 (142±19)Gy. In Group 2, they were 14-186(80±58)cm(3) and 96-146(122±16) Gy respectively. In both target volumes and D(90), there was no statistical difference between pre-operation and post-operation in Group 1.The D(90) was slightly lower than that of pre-plan group, but there was no statistical difference ( P =0.142); in Group 2, between pre-operation and post-operation group, there was a significant statistical difference in the GTV ( P =0.002). The difference of D(90) was similarly ( P <0.01). Conclusion: The method of delineation of post-implant GTV through fusion pre-implantation simulation and post-operative CT scan images, the contours of GTV are automatically

Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicolae, Alexandru; Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario; Morton, Gerard

Purpose: This work presents the application of a machine learning (ML) algorithm to automatically generate high-quality, prostate low-dose-rate (LDR) brachytherapy treatment plans. The ML algorithm can mimic characteristics of preoperative treatment plans deemed clinically acceptable by brachytherapists. The planning efficiency, dosimetry, and quality (as assessed by experts) of preoperative plans generated with an ML planning approach was retrospectively evaluated in this study. Methods and Materials: Preimplantation and postimplantation treatment plans were extracted from 100 high-quality LDR treatments and stored within a training database. The ML training algorithm matches similar features from a new LDR case to those within the trainingmore » database to rapidly obtain an initial seed distribution; plans were then further fine-tuned using stochastic optimization. Preimplantation treatment plans generated by the ML algorithm were compared with brachytherapist (BT) treatment plans in terms of planning time (Wilcoxon rank sum, α = 0.05) and dosimetry (1-way analysis of variance, α = 0.05). Qualitative preimplantation plan quality was evaluated by expert LDR radiation oncologists using a Likert scale questionnaire. Results: The average planning time for the ML approach was 0.84 ± 0.57 minutes, compared with 17.88 ± 8.76 minutes for the expert planner (P=.020). Preimplantation plans were dosimetrically equivalent to the BT plans; the average prostate V150% was 4% lower for ML plans (P=.002), although the difference was not clinically significant. Respondents ranked the ML-generated plans as equivalent to expert BT treatment plans in terms of target coverage, normal tissue avoidance, implant confidence, and the need for plan modifications. Respondents had difficulty differentiating between plans generated by a human or those generated by the ML algorithm. Conclusions: Prostate LDR preimplantation treatment plans that have equivalent quality to plans

Repair of traumatic skeletal muscle injury with bone-marrow-derived mesenchymal stem cells seeded on extracellular matrix.

PubMed

Merritt, Edward K; Cannon, Megan V; Hammers, David W; Le, Long N; Gokhale, Rohit; Sarathy, Apurva; Song, Tae J; Tierney, Matthew T; Suggs, Laura J; Walters, Thomas J; Farrar, Roger P

2010-09-01

Skeletal muscle injury resulting in tissue loss poses unique challenges for surgical repair. Despite the regenerative potential of skeletal muscle, if a significant amount of tissue is lost, skeletal myofibers will not grow to fill the injured area completely. Prior work in our lab has shown the potential to fill the void with an extracellular matrix (ECM) scaffold, resulting in restoration of morphology, but not functional recovery. To improve the functional outcome of the injured muscle, a muscle-derived ECM was implanted into a 1 x 1 cm(2), full-thickness defect in the lateral gastrocnemius (LGAS) of Lewis rats. Seven days later, bone-marrow-derived mesenchymal stem cells (MSCs) were injected directly into the implanted ECM. Partial functional recovery occurred over the course of 42 days when the LGAS was repaired with an MSC-seeded ECM producing 85.4 +/- 3.6% of the contralateral LGAS. This was significantly higher than earlier recovery time points (p < 0.05). The specific tension returned to 94 +/- 9% of the contralateral limb. The implanted MSC-seeded ECM had more blood vessels and regenerating skeletal myofibers than the ECM without cells (p < 0.05). The data suggest that the repair of a skeletal muscle defect injury by the implantation of a muscle-derived ECM seeded with MSCs can improve functional recovery after 42 days.

Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model

PubMed Central

Parajuli, Keshab Raj; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2016-01-01

Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer. PMID:26840261

Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model.

PubMed

Parajuli, Keshab Raj; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2016-03-01

Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer.

The Stromal Contribution to the Development of Resistance to New-Generation Drugs by Castration-Resistant Prostate Cancer

DTIC Science & Technology

2015-10-01

against PCa, such as Enzalutamide or Abiraterone (abi), which target the AR or cytochrome p450 (CYP17)A1, respectively (4). By the way of the “seed and...Castration-Resistant Prostate Cancer PRINCIPAL INVESTIGATOR: Amy Lubik RECIPIENT: University of British Columbia Vancouver, BC Canada V6H 3Z6 REPORT...Generation Drugs by Castration-Resistant Prostate Cancer 5b. GRANT NUMBER W81XWH-13-1-0379 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Lubik, Amy Anne, PhD 5d

Neointimal hyperplasia on a cell-seeded polytetrafluoroethylene graft is promoted by transfer of tissue plasminogen activator gene and inhibited by transfer of nitric oxide synthase gene.

PubMed

Yu, Hong; Dai, Wangde; Yang, Zhe; Romaguera, Rita L; Kirkman, Paul; Rowe, Vincent L

2005-01-01

The objective of this study was to examine the effect of tissue plasminogen activator (tPA) and endothelial nitric oxide synthase (eNOS) on thrombosis and neointimal hyperplasia on a polytetrafluoroethylene (PTFE) graft seeded with smooth muscle cells (SMCs). SMCs retrovirally transduced with tPA and eNOS genes were seeded on PTFE grafts and then implanted into the infrarenal rabbit aorta. Thrombosis and neointimal hyperplasia on the grafts were examined after 30 and 100 days of implantation. At 30 days of implantation, thrombus was observed on the luminal surface of both unseeded and SMC seeded control grafts, whereas grafts seeded with SMCs secreting tPA were nearly free of thrombus. At 100 days, the neointima on grafts seeded with tPA transduced SMCs was significantly thicker (925 +/- 150 microm, n = 5) than neointima on the other grafts (range, 132 to 374 microm; P < .001). Neointima thickness on grafts seeded with eNOS transduced SMCs (154 +/- 27 microm) was similar to that of unseeded grafts (132 +/- 16 microm, P > .05); both were thinner than those on grafts seeded with SMCs transduced with only lacZ gene (287 +/- 35 microm). The ratio of seeded cells in the neointima was significantly higher on SMC/tPA grafts (46% +/- 8%) than SMC/NOS grafts (21% +/- 6%, P < .05), indicating tPA transduced cells proliferated more than eNOS transduced cells. Engineered tPA expression in seeded SMCs causes significantly more neointimal hyperplasia, despite the favorable inhibition of luminal thrombus. eNOS expression in the seeded cells inhibits neointimal hyperplasia.

Optical biopsy of the prostate: can we TRUST (trans-rectal ultrasound-coupled spectral tomography)?

NASA Astrophysics Data System (ADS)

Piao, Daqing; Jiang, Zhen; Bartels, Kenneth E.; Holyoak, G. Reed; Ritchey, Jerry W.; Rock, Kendra; Ownby, Charlotte L.; Bunting, Charles F.; Slobodov, Gennady

2011-03-01

Needle-based core-biopsy to locate prostate cancer relies heavily upon trans-rectal ultrasound (TRUS) imaging guidance. Ultrasonographic findings of classic hypoechoic peripheral zone lesions have a low specificity of ~28%, a low positive predictive value of ~29%, and an overall accuracy of ~43%, in prostate cancer diagnosis. The prevalence of isoechoic or nearly invisible prostate cancers on ultrasonography ranges from 25 to 42%. As a result, TRUS is useful and convenient to direct the needle trajectory following a systematic biopsy sampling template rather than to target only the potentially malignant lesion for focal-biopsy. To address this deficiency in the first-line of prostate cancer imaging, a trans-rectal ultrasound-coupled spectral tomography (TRUST) approach is being developed to non-invasively resolve the likely optical signatures of prostate malignancy. The approach has evolved from using one NIR wavelength to two NIR bands, and recently to three bands of NIR spectrum information. The concept has been evaluated on one normal canine prostate and three dogs with implanted prostate tumor developed as a model. The initial results implementing TRUST on the canine prostate tumor model includes: (1) quantifying substantially increased total hemoglobin concentration over the time-course of imaging in a rapidly growing prostate tumor; (2) confirming hypoxia in a prostatic cystic lesion; and (3) imaging hypoxic changes of a necrotic prostate tumor. Despite these interesting results, intensive technologic development is necessary for translating the approach to benefiting clinical practice, wherein the ultimate utility is not possibly to eliminate needle-biopsy but to perform focal-biopsy that is only necessary to confirm the cancer, as well as to monitor and predict treatment responses.

Polyethylene glycol hydrogel rectal spacer implantation in patients with prostate cancer undergoing combination high-dose-rate brachytherapy and external beam radiotherapy.

PubMed

Yeh, Jekwon; Lehrich, Brandon; Tran, Carolyn; Mesa, Albert; Baghdassarian, Ruben; Yoshida, Jeffrey; Torrey, Robert; Gazzaniga, Michael; Weinberg, Alan; Chalfin, Stuart; Ravera, John; Tokita, Kenneth

2016-01-01

To present rectal toxicity rates in patients administered a polyethylene glycol (PEG) hydrogel rectal spacer in conjunction with combination high-dose-rate brachytherapy and external beam radiotherapy. Between February 2010 and April 2015, 326 prostate carcinoma patients underwent combination high-dose-rate brachytherapy of 16 Gy (average dose 15.5 Gy; standard deviation [SD] = 1.6 Gy) and external beam radiotherapy of 59.4 Gy (average dose 60.2 Gy; SD = 2.9 Gy). In conjunction with the radiation therapy regimen, each patient was injected with 10 mL of a PEG hydrogel in the anterior perirectal fat space. The injectable spacer (rectal spacer) creates a gap between the prostate and the rectum. The rectum is displaced from the radiation field, and rectal dose is substantially reduced. The goal is a reduction in rectal radiation toxicity. Clinical efficacy was determined by measuring acute and chronic rectal toxicity using the National Cancer Center Institute Common Terminology Criteria for Adverse Events v4.0 grading scheme. Median followup was 16 months. The mean anterior-posterior separation achieved was 1.6 cm (SD = 0.4 cm). Rates of acute Grade 1 and 2 rectal toxicity were 37.4% and 2.8%, respectively. There were no acute Grade 3/4 toxicities. Rates of late Grade 1, 2, and 3 rectal toxicity were 12.7%, 1.4%, and 0.7%, respectively. There were no late Grade 4 toxicities. PEG rectal spacer implantation is safe and well tolerated. Acute and chronic rectal toxicities are low despite aggressive dose escalation. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.