Burri, Christian; Dysli, Chantal; Salzmann, Simon Adrian; Povazay, Boris; Meier, Christoph; Frenz, Martin; Zinkernagel, Martin; Wolf, Sebastian (27 April 2023). Dosimetry of selective retina therapy using optical coherence tomography: first results from the CENTAURUS study In: ARVO Annual Meeting 2023. New Orleans. 23.04.2023 - 27.04.2023.
Purpose : Assessment of the SPECTRALIS CENTAURUS device for real-time feedback-controlled dosimetry (RFD) of selective retina therapy (SRT). Evaluation of optical coherence tomography (OCT) data for future real-time dosimetry applications. Methods : A test pattern (single pulse) for damage threshold determination as well as a specified laser treatment pattern for RFD simulation (ramped up pulse sequence, maximal 30 pulses, 100 Hz) were applied in 3 patients with diabetic retinopathy using the SPECTRALIS CENTAURUS device (HuCE-optoLab, BFH-TI, CH). This device consists of a modified imaging platform (SPECTRALIS HRA+OCT, Heidelberg Engineering, DE) extended with a prototype laser (Meridian Medical; wavelength: 532 nm; peak power: 30 W) for SRT. Laser pulses of 8 µs duration with a maximum pulse energy of 170 µJ were used. OCT M-scan data recorded during treatment was analyzed post-treatment to investigate OCT-RFD. The patterns were evaluated binary for retinal pigment epithelium (RPE) damage based on fluorescence angiography (FA), overtreatment based on color fundus photography (CFP), as well as OCT M-scans fringe washouts (visually / dedicated algorithm). Probit analysis was used to calculate the ED-values (median-effective dose), the therapeutic window (TW = ED50-CFP / ED50-FA), and the safety range (SR = ED16-CFP / ED84-FA) for SRT. Results : Probit analysis for the test pattern shows an RPE damage threshold of 57 µJ (ED50-FA) and a threshold towards overtreatment of 95 µJ (ED50-CFP). Furthermore, a TW of 1.7 and a SR of 1.2 for SRT was found. For all lesions, OCT M-scan feedback (detectable fringe washouts) is guaranteed with 50% probability from 47 µJ on (visual evaluation), respectively 53 µJ (algorithm). At the lower SR limit (ED84-FA = 75 µJ), visually evaluated dosimetry could provide feedback with 98% and the algorithm with 95% probability. At the upper SR limit (ED16-CFP = 92 µJ), both methods could provide feedback with 99% probability. A statistical evaluation of the RFD simulation pattern shows that over all a sensitivity of 83% and a specificity of 93% was achieved for the dosimetry algorithm. Conclusions : OCT-RFD of SRT using the SPECTRALIS CENTAURUS device is feasible in patients with diabetic retinopathy, indicating that controlled retinal treatment is possible. Applying the algorithm in real-time would have reduced the applied energy dose for certain lesions by 30%.
Item Type: |
Conference or Workshop Item (Poster) |
|---|---|
Division/Institute: |
School of Engineering and Computer Science > Institute for Human Centered Engineering (HUCE) School of Engineering and Computer Science > Institute for Human Centered Engineering (HUCE) > HUCE / Laboratory for Optics School of Engineering and Computer Science |
Name: |
Burri, Christian 0000-0003-2690-7527; Dysli, Chantal; Salzmann, Simon Adrian 0000-0001-5453-8808; Povazay, Boris 0000-0001-5571-5116; Meier, Christoph; Frenz, Martin; Zinkernagel, Martin and Wolf, Sebastian |
Subjects: |
R Medicine > R Medicine (General) R Medicine > RE Ophthalmology T Technology > T Technology (General) |
Language: |
English |
Submitter: |
Christian Burri |
Date Deposited: |
07 Jul 2023 11:38 |
Last Modified: |
07 Jul 2023 11:38 |
URI: |
https://arbor.bfh.ch/id/eprint/19560 |
Actions (login required)
 |
View Item |