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Liakopoulos DA, Perisinakis K, Solomou G, Kouvidakis A, Drakonaki EE, Bontzos G, Papadaki E, Detorakis ET. Individualized dosimetry in Ru-106 ophthalmic brachytherapy based on MRI-derived ocular anatomical parameters. Brachytherapy 2022; 21:904-911. [PMID: 35995724 DOI: 10.1016/j.brachy.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/01/2022] [Accepted: 07/01/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE To estimate ocular geometry-related inaccuracies of the dosimetric plan in Ru-106 ophthalmic brachytherapy. METHODS AND MATERIALS Thirty patients with intraocular lesions were treated with brachytherapy using a Ru-106 plaque-shell of inner radius of 12 mm. Magnetic resonance imaging was employed to determine the external scleral radius at tumor site and the tumor margins. A mathematical model was developed to determine the distance between the external sclera and the internal surface of the plaque associated with the tangential application of the plaque on the treated eye. Differences in delivered dose to the tumor apex, sclera and tumor margins as derived by considering the default eye-globe of standard size (external sclera radius = 12 mm) against the individual-specific eye globe were determined. RESULTS The radius of external sclera at the tumor site was found to range between 10.90 and 13.05 mm for the patient cohort studied. When the patient specific eye-globe/tumor geometry is not taken into account, the delivered dose was found to be overestimated by 8.1% ± 4.1% (max = 15.3%) at tumor apex, by 1.5% ± 2.8% (max = 5.7%) at anterior tumor margin, by 16.6% ± 7.5% (max = 36.4%) at posterior tumor margin and 8.1% ± 3.8% (max = 13.2%) at central sclera of eyes with lower than the default radius. The corresponding dose overestimations for eyes with higher than the default radius was 13.5% ± 4.3% (max = 22.3%), 1.5% ± 2.8% (max = 5.7%), 12.6% ± 4.5% (max = 20.0%), and 15.1% ± 5.0% (max = 24.4%). CONCLUSIONS The proposed patient-specific approach for Ru-106 brachytherapy treatment planning may improve dosimetric accuracy. Individualized treatment planning dosimetry may prevent undertreatment of intraocular tumors especially for highly myopic or hyperopic eyes.
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Affiliation(s)
| | - Kostas Perisinakis
- Department of Medical Physics, University of Crete, Medical School, Heraklion, Crete, Greece; Computational BioMedicine Laboratory (CBML), Foundation for Research and Technology-Hellas (FORTH), Heraklion, Greece
| | - Georgia Solomou
- Department of Medical Physics, University of Crete, Medical School, Heraklion, Crete, Greece
| | | | | | | | - Efrosini Papadaki
- Department of Radiology, University Hospital of Heraklion, Crete, Greece
| | - Efstathios T Detorakis
- Department of Ophthalmology, Medical School, University of Crete, Heraklion, Crete, Greece
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Oare C, Sun S, Dusenbery K, Reynolds M, Koozekanani D, Gerbi B, Ferreira C. Analysis of dose to the macula, optic disc, and lens in relation to vision toxicities - A retrospective study using COMS eye plaques. Phys Med 2022; 101:71-78. [PMID: 35981450 DOI: 10.1016/j.ejmp.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/08/2022] [Accepted: 08/03/2022] [Indexed: 11/28/2022] Open
Abstract
PURPOSE The aim of this study was to relate common toxicity endpoints with dose to the macula, optic disc, and lens for uveal melanoma patients treated with Iodine-125 Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy. METHODS A cohort of 52 patients treated at a single institution between 2005 and 2019 were retrospectively reviewed. Demographics, dosimetry, and clinical outcomes were recorded. Univariate, relative risk, and Kaplan-Meier analyses were performed to relate dose to toxicity endpoints including retinopathy, vision decline, and cataracts. RESULTS By the end of follow up (Median = 3.6 years, Range = 0.4 - 13.5 years), 65 % of eyes sustained radiation retinopathy, 40 % demonstrated moderate vision decline (>5 Snellen lines lost), and 56 % developed cataracts. Significant (p < 0.05) risk estimates exist for retinopathy and VA decline for doses >52 Gy to the macula and >42 Gy to the optic disc. Moreover, dose to the lens > 16 Gy showed a significant risk for cataract formation. Kaplan-Meier analysis demonstrated significantly different incidence of radiation retinopathy for > 52 Gy to the macula and > 42 Gy to the optic disc. In addition, the Kaplan-Meier analysis showed significantly different incidence of cataract formation for patients with lens dose > 16 Gy. CONCLUSIONS Dose-effect relationships exist for the macula and optic disc with respect to the loss of visual acuity and the development of retinopathy. To better preserve vision after treatment, further research is needed to reduce macula, optic disc, and lens doses while maintaining tumor control.
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Affiliation(s)
- Courtney Oare
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States.
| | - Susan Sun
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
| | - Kathryn Dusenbery
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
| | - Margaret Reynolds
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
| | - Dara Koozekanani
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
| | - Bruce Gerbi
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
| | - Clara Ferreira
- University of Minnesota Medical School, 420 Delaware St SE, MMC 494, Minneapolis, MN 55455, United States
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On measuring the 3D dose distribution for notched and circular Ru-106 plaque shapes through Gafchromic film dosimetry approach. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Buonanno F, Conson M, de Almeida Ribeiro C, Oliviero C, Itta F, Liuzzi R, Pacelli R, Cella L, Clemente S. Local tumor control and treatment related toxicity after plaque brachytherapy for uveal melanoma: A systematic review and a data pooled analysis. Radiother Oncol 2021; 166:15-25. [PMID: 34774654 DOI: 10.1016/j.radonc.2021.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 01/02/2023]
Abstract
Uveal melanoma (UM) represents the most common primary intraocular tumor, and nowadays eye plaque brachytherapy (EPB) is the most frequently used visual acuity preservation treatment option for small to medium sized UMs. The excellent local tumor control (LTC) rate achieved by EPB may be associated with severe complications and adverse events. Several dosimetric and clinical risk factors for the development of EPB-related ocular morbidity can be identified. However, morbidity predictive models specifically developed for EPB are still scarce. PRISMA methodology was used for the present systematic review of articles indexed in PubMed in the last sixteen years on EPB treatment of UM which aims at determining the major factors affecting local tumor control and ocular morbidities. To our knowledge, for the first time in EPB field, local tumor control probability (TCP) and normal tissue complication probability (NTCP) modelling on pooled clinical outcomes were performed. The analyzed literature (103 studies including 21,263 UM patients) pointed out that Ru-106 EPB provided high local control outcomes while minimizing radiation induced complications. The use of treatment planning systems (TPS) was the most influencing factor for EPB outcomes such as metastasis occurrence, enucleation, and disease specific survival, irrespective of radioactive implant type. TCP and NTCP parameters were successfully extracted for 5-year LTC, cataract and optic neuropathy. In future studies, more consistent recordings of ocular morbidities along with accurate estimation of doses through routine use of TPS are needed to expand and improve the robustness of toxicity risk prediction in EPB.
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Affiliation(s)
- Francesca Buonanno
- University Federico II, Post Graduate School in Medical Physics, Department of Advanced Biomedical Sciences, Napoli, Italy
| | - Manuel Conson
- University Federico II, Department of Advanced Biomedical Sciences, Napoli, Italy
| | | | - Caterina Oliviero
- University Hospital Federico II, Unit of Medical Physics and Radioprotection, Napoli, Italy
| | - Francesca Itta
- University Federico II, Post Graduate School in Medical Physics, Department of Advanced Biomedical Sciences, Napoli, Italy
| | - Raffaele Liuzzi
- National Research Council (CNR), Institute of Biostructures and Bioimaging, Napoli, Italy
| | - Roberto Pacelli
- University Federico II, Department of Advanced Biomedical Sciences, Napoli, Italy
| | - Laura Cella
- National Research Council (CNR), Institute of Biostructures and Bioimaging, Napoli, Italy.
| | - Stefania Clemente
- University Hospital Federico II, Unit of Medical Physics and Radioprotection, Napoli, Italy
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Bakshi AK, Shrivastava V, Chattaraj A, Samuel K, Palani Selvam T, Sapra BK, Sinharoy P, Banerjee D, Sugilala G, Manohar S, Kaushik CP. Surface dose rate variations in planar and curved geometries of 106Ru/ 106Rh plaque sources for ocular tumors. Phys Med 2021; 89:200-209. [PMID: 34399207 DOI: 10.1016/j.ejmp.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Investigation of surface dose rate variation with respect to the source configuration of 106Ru/106Rh eye plaque. To explore an alternate way to determine activity of brachytherapy plaques. METHODS The surface dose rates of 106Ru/106Rh plaque developed indigenously were measured by extrapolation chamber. To rule out possibility of any error in the activity distribution and quantity, same source was used in two different configurations namely planar and curved. EBT3 Gafchromic film was used for determination of uniformity in activity. Monte Carlo-based Codes EGSnrc and FLUKA were used to calculate dose rate in tissue, percentage depth dose and for determination of activity. Parameters and correction factors were estimated using simulations. RESULTS The measured reference absorbed dose rates for planar and curved 106Ru/106Rh eye plaques are found to be 589 ± 29 mGy/h and 560 ± 28 mGy/h, respectively. The difference in the reference absorbed dose rate of curved eye plaque is about ~5% as compared to planar configuration. The FLUKA-calculated dose values are almost independent of cavity length of the extrapolation chamber for both eye plaques. The FLUKA-based dose rates per μCi 106Ru/106Rh are about 17.28 ± 0.08 mGy/h and 16.48 ± 0.06 mGy/h, respectively for planar and curved eye plaques which match well with the measurements. The calculated activities for planar and curved eye plaques are 34.08 μCi and 33.98 μCi, respectively. CONCLUSIONS Surface dose rates for a prototype 106Ru/106Rh eye plaque with different configurations were estimated using simulations and measured experimentally. An alternate way to determine activity of beta-gamma brachytherapy plaque has been proposed.
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Affiliation(s)
- A K Bakshi
- Radiological Physics & Advisory Division, India; Homi Bhabha National Institute, Mumbai 400 094, India.
| | | | | | | | - T Palani Selvam
- Radiological Physics & Advisory Division, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - B K Sapra
- Radiological Physics & Advisory Division, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - Prithwish Sinharoy
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - Dayamoy Banerjee
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - G Sugilala
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - Smitha Manohar
- Radiological Physics & Advisory Division, India; Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute, Mumbai 400 094, India
| | - C P Kaushik
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute, Mumbai 400 094, India
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