Dual-source strength seed loading for eye plaque brachytherapy using eye physics eye plaques: A feasibility study.

Thumbnail Image



Journal Title

Journal ISSN

Volume Title

Repository Usage Stats


Citation Stats



This study quantifies the dosimetric impact of incorporating two iodine-125 (125I) seed source strengths in Eye Physics eye plaques for treatment of uveal melanoma.

Material and methods

Plaque Simulator was used to retrospectively plan 15 clinical cases of three types: (1) Shallow tumors (< 5.5 mm) with large base dimensions (range, 16-19 mm); (2) Tumors near the optic nerve planned with notched plaques; and (3) Very shallow (< 3.0 mm) tumors with moderate base dimensions (range, 13.5-15.5 mm) planned with larger plaques than requested by the ocular oncologist. Circular plaques were planned with outer ring sources twice the source strength of inner sources, and notched plaques with the six seeds closest to the notch at twice the source strength.


In cases of type (1), the dual-source strength plan decreased prescription depth, and doses to critical structures were lower: inner sclera -25% ±2%, optic disc -7% ±3%, and fovea -6% ±3%. In four out of five cases of type (2), the dual-source strength plan decreased prescription depth, and dose to inner sclera was lower (-22% ±5%), while dose to optic disc (17% ±7%) and fovea (20% ±12%) increased. In cases of type (3), a smaller dual-source strength plaque was used, and scleral dose was lower (-45% ±3%), whereas dose to optic disc (1% ±14%) and fovea (5% ±5%) increased.


Dual-source strength loading as described in this study can be used to cover tumor margins and decrease dose to sclera, and therefore the adjacent retina, but can either decrease or increase radiation dose to optic disc and fovea depending on location and size of the tumor. This technique may allow the use of a smaller plaque, if requested by the ocular oncologist. Clinical determination to use this technique should be performed on an individual basis, and additional QA steps are required. Integrating the use of volumetric imaging may be warranted.





Published Version (Please cite this version)


Publication Info

Meltsner, Sheridan G, David G Kirsch, Miguel A Materin, Yongbok Kim, Yang Sheng and Oana Craciunescu (2022). Dual-source strength seed loading for eye plaque brachytherapy using eye physics eye plaques: A feasibility study. Journal of contemporary brachytherapy, 14(6). pp. 590–600. 10.5114/jcb.2022.123979 Retrieved from https://hdl.handle.net/10161/26672.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.



Sheridan Griffin Meltsner

Assistant Professor of Radiation Oncology

David Guy Kirsch

Adjunct Professor in the Department of Radiation Oncology

My clinical interests are the multi-modality care of patients with bone and soft tissue sarcomas and developing new sarcoma therapies. My laboratory interests include utilizing mouse models of cancer to study cancer and radiation biology in order to develop new cancer therapies in the pre-clinical setting.


Miguel Angel Materin

Professor of Ophthalmology

Ocular oncologist Miguel Materin, MD joined Duke Eye Center as Professor of Ophthalmology and Director of Ophthalmic Oncology in September 2016. He joins Duke from Yale University School of Medicine where he was an Associate Professor of Ophthalmology & Visual Science. Prior to his appointment at Yale, he was at Wills Eye Hospital at Thomas Jefferson University in Philadelphia, where he served as Director of Diagnostic Studies for the Ocular Oncology Service.

Dr. Materin’s clinical practice involves diagnosis and treatment of patients with ocular tumors, including benign and malignant tumors of the eye. He has special interests in ocular melanoma, retinoblastoma, choroidal hemangiomas, retinal hemangioblastomas, metastases, astrocytic tumors and tumors related to other conditions or syndromes, like von Hippel Lindau disease, Tuberous Sclerosis among others. 

He is an internationally recognized ocular oncologist, who has served as a member of the International Advisory Board (Ocular Oncology) for the Canadian Journal of Ophthalmology. Dr. Materin has published extensively in the peer-reviewed literature, including journals and book chapters. He has been invited as visiting professor in US, Canada, Israel, Spain, Brazil, Puerto Rico, Argentina, and gave lectures worldwide.

Dr. Materin has received the Achievement Award from the American Academy of Ophthalmology and he is a Member of Merit of Clinica Barraquer (Barcelona, Spain). He has served as Director of Diagnostic Studies at the Ocular Oncology Service at Wills Eye Hospital for 7 years. He is an active member of the International Society of Ocular Oncology, American Academy of Ophthalmology, Pan American Association of Ophthalmology and Argentine Society of Ophthalmology.

Dr. Materin serves on the education committee of the American Association of Ocular Oncology and Pathology and is the President Elect for the Pan American Society of Ocular Oncology.


Yongbok Kim

Professor of Radiation Oncology

Yang Sheng

Assistant Professor of Radiation Oncology

My research interest focuses on machine learning and AI application in radiation oncology treatment planning, including prostate cancer, head-and-neck cancer and pancreatic cancer etc.


Oana Craciunescu

Professor of Radiation Oncology

Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.