Dosimetry parameters of BARC OcuProsta I-125 seed source

Sharma, S. D.; Basu, M.; Shanta, A; Selvam, T. Palani; Tripathi, U B; Bhatt, B.C.

doi:10.1007/bf03178859

Cited by 12 publications

(22 citation statements)

References 18 publications

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“…Significant differences in g L (r) values between the Symmetra source and the other sources are observed, which are attributed to significant differences in the source design of the Symmetra seed (the active source core is consists of ceramic). The values of g L (r) of each seed model were compared with the published work [9][10][11][12][13]. A good agreement (within 2%) in g L (r) values between our study and the published work is observed for the Oncura and Symmetra seed sources [10,11].…”

Section: Radial Dose Functionsupporting

confidence: 58%

“…This is due to the fact that the dosimetry studies for these sources are based on an updated photon cross-section dataset. However, a similar comparison for the OcuProsta and EchoSeed source models showed significant differences because the dosimetry studies of these sources [12,13] are based on an old photon cross-section dataset. For the SelectSeed, the agreement is reasonably good (within 2%) for most distances, with a maximum deviation of 3.6% at r = 1 mm.…”

Section: Radial Dose Functionmentioning

confidence: 89%

“…All five sources were cylindrically symmetrical and had similar outer dimensions (*4.5 mm length and 0.8 mm diameter). The geometry and source materials for each model were obtained from published papers [9][10][11][12][13].…”

Section: I Radioactive Source Modelsmentioning

confidence: 99%

“…In the present study, we investigated the influence of Ti K-shell X-rays on S k and K for several models of 125 I sources such as SelectSeed, Oncura seed, Symmetra seed, OcuProsta, and EchoSeed [9][10][11][12][13]. The study also includes the calculation of a radial dose function for each seed.…”

Section: Introductionmentioning

confidence: 98%

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An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

Sridhar

Selvam

2009

Radiol Phys Technol

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Titanium-encapsulated (125)I brachytherapy sources are in use for treatment of the eye, brain, and head and neck region, and for early stage prostate cancer. The photoelectric interaction of (125)I photons with titanium encapsulation generates Ti K X-rays (approximately 5 keV). According to the National Institute of Standards and Technology (NIST) 1999 air-kerma strength, S(k), standard, these X-rays should be excluded from S (k). We used the EGSnrc Monte Carlo code system to calculate the S(k) (including the contribution of approximately 5-keV X-rays), dose rate constant, and radial dose function for five different (125)I source models. Depending upon the source model, the contribution of 5-keV Ti X-rays to S(k) varies between 17.1 and 18.7%. Including these X-rays as part of S(k) would result in underestimation of the dose rate constant by up to 19%. The radial dose functions of the investigated sources are comparable to published studies that are based on an updated photon cross-section dataset.

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Section: Radial Dose Functionsupporting

confidence: 58%

Section: Radial Dose Functionmentioning

confidence: 89%

Section: I Radioactive Source Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

Sridhar

Selvam

2009

Radiol Phys Technol

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“…[9] We describe our initial experience and learning curve using ‘BARC 125 I Ocu-Prosta seed’ for the treatment of intraocular tumors.…”

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confidence: 99%

Episcleral plaque brachytherapy using ′BARC I-125 Ocu-Prosta seeds′ in the treatment of intraocular tumors: A single-institution experience in India

Shah

Narendran

Selvaraj

et al. 2012

Indian J Ophthalmol

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Context:To analyze the results of episcleral plaque brachytherapy using indigenous Bhabha Atomic Research Centre (BARC) Iodine-125 Ocu-Prosta seeds for the management of intraocular tumors from a single institute.AIM:To report our initial experience and learning curve on the use of ‘BARC I-125 Ocu-Prosta seeds’ for the management of intraocular tumors such as choroidal melanomas, retinoblastomas and vasoproliferative tumors (VPT).Materials and Methods:We retrospectively reviewed 13 eyes of 13 patients who underwent ophthalmic brachytherapy between May 2008 to March 2012. Nine cases had choroidal melanomas; three had retinoblastomas while one case had VPT.Results:For choroidal melanomas the average apical diameter before brachytherapy was 7.6 mm and average largest basal diameter was 12.1 mm, respectively, which reduced to 4.2 mm and 7.7 mm after the procedure at an average follow-up of 24 months (range 10-43 months). Retinoblastoma and VPT also showed good regression after brachytherapy.Conclusion:Plaque radiotherapy using 125I seeds can be performed under peribulbar anesthesia and provides a viable option for the management of intraocular cancer with minimal invasiveness and surgical complications. Patients in our studies experienced excellent local tumor control. With the availability of indigenous ‘BARC I-125 Ocu-Prosta seeds’ locally, cost effective ophthalmic brachytherapy can be performed in India.

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Monte Carlo‐based dosimetry of proposed bi‐radionuclide (¹²⁵I and ¹⁰⁶Ru/¹⁰⁶Rh) eye plaque: A feasibility study

Mishra,

Selvam,

Sahoo

et al. 2024

Medical Physics

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BackgroundCombining the sharp dose fall off feature of beta‐emitting 106Ru/106Rh radionuclide with larger penetration depth feature of photon‐emitting125I radionuclide in a bi‐radionuclide plaque, prescribed dose to the tumor apex can be delivered while maintaining the tumor dose uniformity and sparing the organs at risk. The potential advantages of bi‐radionuclide plaque could be of interest in context of ocular brachytherapy.PurposeThe aim of the study is to evaluate the dosimetric advantages of a proposed bi‐radionuclide plaque for two different designs, consisting of indigenous 125I seeds and 106Ru/106Rh plaque, using Monte Carlo technique. The study also explores the influence of other commercial 125I seed models and presence or absence of silastic/acrylic seed carrier on the calculated dose distributions. The study further included the calculation of depth dose distributions for the bi‐radionuclide eye plaque for which experimental data are available.MethodsThe proposed bi‐radionuclide plaque consists of a 1.2‐mm‐thick silver (Ag) spherical shell with radius of curvature of 12.5 mm, 20 µm‐thick‐106Ru/106Rh encapsulated between 0.2 mm Ag disk, and a 0.1‐mm‐thick Ag window, and water‐equivalent gel containing 12 symmetrically arranged 125I seeds. Two bi‐radionuclide plaque models investigated in the present study are designated as Design I and Design II. In Design I, 125I seeds are placed on the top of the plaque, while in Design II 106Ru/106Rh source is positioned on the top of the plaque. In Monte Carlo calculations, the plaque is positioned in a spherical water phantom of 30 cm diameter.ResultsThe proposed bi‐radionuclide eye plaque demonstrated superior dose distributions as compared to 125I or 106Ru plaque for tumor thicknesses ranges from 5 to 10 mm. Amongst the designs, dose at a given voxel for Design I is higher as compared to the corresponding voxel dose for Design II. This difference is attributed to the higher degree of attenuation of 125I photons in Ag as compared to beta particles. Influence of different 125I seed models on the normalized lateral dose profiles of Design I (in the absence of carrier) is negligible and within 5% on the central axis depth dose distribution as compared to the corresponding values of the plaque that has indigenous 125I seeds. In the presence of a silastic/acrylic seed carrier, the normalized central axis dose distributions of Design I are smaller by 3%–12% as compared to the corresponding values in the absence of a seed carrier. For the published bi‐radionuclide plaque model, good agreement is observed between the Monte Carlo‐calculated and published measured depth dose distributions for clinically relevant depths.ConclusionRegardless of the type of 125I seed model utilized and whether silastic/acrylic seed carrier is present or not, Design I bi‐radionuclide plaque offers superior dose distributions in terms of tumor dose uniformity, rapid dose fall off and lesser dose to nearby critical organs at risk over the Design II plaque. This shows that Design I bi‐radionuclide plaque could be a promising alternative to 125I plaque for treatment of tumor sizes in the range 5 to 10 mm.

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Dosimetry parameters of BARC OcuProsta I-125 seed source

Cited by 12 publications

References 18 publications

An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

Episcleral plaque brachytherapy using ′BARC I-125 Ocu-Prosta seeds′ in the treatment of intraocular tumors: A single-institution experience in India

Monte Carlo‐based dosimetry of proposed bi‐radionuclide (¹²⁵I and ¹⁰⁶Ru/¹⁰⁶Rh) eye plaque: A feasibility study

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Dosimetry parameters of BARC OcuProsta I-125 seed source

Cited by 12 publications

References 18 publications

An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

An EGSnrc investigation of the air-kerma strength, dose rate constant, and radial dose function of 125I brachytherapy sources

Episcleral plaque brachytherapy using ′BARC I-125 Ocu-Prosta seeds′ in the treatment of intraocular tumors: A single-institution experience in India

Monte Carlo‐based dosimetry of proposed bi‐radionuclide (125I and 106Ru/106Rh) eye plaque: A feasibility study

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Monte Carlo‐based dosimetry of proposed bi‐radionuclide (¹²⁵I and ¹⁰⁶Ru/¹⁰⁶Rh) eye plaque: A feasibility study