International Journal of Radiation Oncology*Biology*Physics
Clinical InvestigationsDiode-light transillumination for ophthalmic plaque localization around juxtapapillary choroidal melanomas☆
Introduction
Transillumination of an eye containing an intraocular tumor can reveal the tumors shadow on the sclera. To aid radioactive plaque insertion, the edges of the shadow are marked on the sclera with tissue dye. Then the radioactive eye-plaque is sewn onto the sclera as to cover the tumor shadow, plus a 2- to 3-mm shadow-free margin. This is the most commonly used technique for radioactive plaque localization 1, 2, 3. This type of transillumination works well for intraocular tumors with borders that extend anterior to the eyes equator. However, small posterior and juxtapapillary tumors can be more difficult or impossible to transilluminate 1, 4. When standard transillumination fails, localization of radioactive-plaques usually requires the use of ophthalmoscopy with scleral depression and/or ultrasonographic localization techniques 4, 5, 6, 7. The increased incidence of failure of plaque radiotherapy of juxtapapillary tumors may be attributed (in part) to difficulties with plaque placement 1, 4, 8, 9, 10. Most ocular tumor specialists agree that accurate plaque placement is critical to successful radiation therapy and that failure of local control may reduce a patient’s chance of survival 1, 11, 12, 13. These factors underscore the need for methods to ensure and document proper plaque placement.
We have developed a system of plaque-mounted diode-lights for localization of episcleral plaques beneath juxtapapillary tumors (14). This study is unique in that 4 lights were attached to the eye plaque, implanted, illuminated, and photographed with digital imaging. We describe DLT-plaque construction, insertion, illumination, and photographic documentation.
Section snippets
DLT-plaque construction
Four non-heat producing, light-emitting diode-lights [Lumex SSL-LXA228SRC-TR1125 (Palatine, IL, USA), angle of dispersion:25 degrees, clear lens, 170mcd @20ma, 660 nanometers)] were affixed to gold eye-plaques with their apertures flush with the episcleral rim (Fig. 1). Then, a 2 conductor female-connector with wires (Nanoseries-2, Omnetics Connector, Inc., Minneapolis, MN, USA) was affixed flush with the posterior wall of the plaque and above the suture eyelets. The wires were connected to
Results
DLT light intensity was modulated such that 4 distinct point sources could be visualized (Fig. 2). By the end of plaque insertion, the results of standard transillumination, ultrasound, and DLT were all consistent with optimum plaque placement.
Indirect ophthalmoscopy with video imaging could be optimized if the light from the indirect ophthalmoscope was minimized. We found that DLT was also affected by plaque-scleral contact. Plaque-tilt and episcleral soft tissue would diffuse the light,
Discussion
Ophthalmic plaque positioning has been studied utilizing a number of radiographic and ultrasound techniques 4, 5, 6, 7, 16, 17, 18. While each modality offers unique perspectives, only plaque-mounted DLT allows for direct visualization and photodocumentation of the plaque-edges surrounding the intraocular tumor.
References (20)
Radiation therapy for choroidal melanoma
Surv Ophthalmol
(1997)- et al.
Ultrasound determination of the relationship of radioactive plaques to the base of choroidal melanomas
Ophthalmology
(1989) - et al.
Enucleation versus plaque irradiation for choroidal melanoma
Ophthalmology
(1988) - et al.
Impact of improved local control on survival
Int J Radiat Oncol Biol Phys
(1986) - et al.
Impact of local tumor relapse on patient survival after cobalt-60 plaque radiotherapy
Ophthalmology
(1991) - et al.
Palladium-103 (103Pd) plaque radiotherapy for choroidal melanomaResults of a 7-year study
Ophthalmology
(1999) - et al.
MR technique for localization and verification procedures in episcleral brachytherapy
Int J Radiat Oncol Biol Phys
(1989) - et al.
A technique for accurate placement of episcleral iodine-125 plaques
Am J Ophthalmol
(1987) - et al.
Radiation therapy of choroidal melanoma
Trans Ophthalmol Soc UK
(1977) Radiotherapy for malignant melanoma of the choroid
Br J Ophthalmology
(1966)
Cited by (13)
MRI and dual-energy CT fusion anatomic imaging in Ru-106 ophthalmic brachytherapy
2021, BrachytherapyCitation Excerpt :A variety of methods have so far been used to accurately locate the tumor intraoperatively and thus accurately position the plaque over the tumor with adequate tumor-free margins around it and decide whether a temporary muscle insertion extirpation may be necessary. Such methods include indirect fundoscopy with or without scleral depression, transpupillary or transcleral transillumination (6), two- and three-dimensional intraoperative ultrasonography (7) or plaque-mounted light-emitting diode illumination (8,9). The detection of the so-called Cerenkov luminescence, a weak light emitted through the interaction of electrons with tissues, has also been proposed (10).
Plaque radiotherapy for juxtapapillary choroidal melanoma: Tumor control in 650 consecutive cases
2011, OphthalmologyCitation Excerpt :The cases described in the current series all underwent careful localization with intraoperative indirect ophthalmoscopy for secure plaque placement. A variety of intraoperative techniques have been devised to assist localization, such as methods of ultrasound or plaque-mounted transillumination.17–19 In this report, Kaplan-Meier analysis disclosed local tumor recurrence of 14% at 5 years and 21% at 10 years.
The American Brachytherapy Society recommendations for brachytherapy of uveal melanomas
2003, International Journal of Radiation Oncology Biology PhysicsPlaque radiation therapy for malignant melanoma of the iris and ciliary body
2001, American Journal of OphthalmologyCitation Excerpt :In such cases, the posterior margin of the ciliary body band was used as the posterior tumor margin. Because of their anterior location, these cases were poor candidates for three-dimensional ultrasound and diode-light localization techniques.31,32,34 All patients received one plaque radiation that started at insertion and continued until the prescribed dose was delivered to the tumor apex (defined as the point of deepest intraocular tumor extension after dilation).23
Intraoperative echographic localization of iodine-125 episcleral plaque for brachytherapy of choroidal melanoma
2000, American Journal of OphthalmologyIntraoperative echographic localization of iodine-125 episcleral plaque for brachytherapy of choroidal melanoma [2] (multiple letters)
2000, American Journal of Ophthalmology
- ☆
Supported in part by The EyeCare Foundation, Inc., New York City.
- 1
The authors have no proprietary interest in the device described in this study.