Evaluation of the Radiation Dose–Volume Effects of Optic Nerves and Chiasm by Psychophysical, Electrophysiologic Tests, and Optical Coherence Tomography in Nasopharyngeal Carcinoma

Akagündüz, Özlem Özkaya; Yılmaz, Suzan Güven; Yalman, Deniz; Yüce, Berna; Biler, Elif Demirkilinc; Afrashi, Filiz; Esassolak, Mustafa

doi:10.1177/1533034617711613

Cited by 13 publications

(19 citation statements)

References 24 publications

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“…Usually the dose constraint for Dmax is between 54 et 60Gy (EQD2). But in the study published by Ozkaya et al 4 , visual field and contrast sensitivity were affected significantly with a volume receiving more than 55Gy (V55) >50% of the OAR volume, and a Dmean > 50Gy. Visual evoked potential latency was affected significantly with Dmean > 50Gy, D5% > 55Gy, and Dmax > 60Gy.…”

Section: Discussionmentioning

confidence: 92%

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

Lecornu

Lesueur²,

Salleron³

et al. 2021

Front. Oncol.

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PurposeProton therapy (PT) can be a good option to achieve tumor control while reducing the probability of radiation induced toxicities compared to X-ray-based radiotherapy. However, there are still uncertainties about the effects of PT on the organs in direct contact with the irradiated volume. The aim of this prospective series was to report 6-month follow-up of clinical and functional optic neuropathy rates of patients treated by proton therapy using a standardized comprehensive optic examination.Methods and MaterialsStandardized ophthalmological examinations were performed to analyze subclinical anomalies in a systematic way before treatment and 6 months after the end of proton therapy with: Automatic visual field, Visual evoked potential (VEP) and optic coherence of tomography (OCT).ResultsFrom October 2018 to July 2020 we analyzed 81 eyes. No significant differences were found in the analysis of the clinical examination of visual functions by the radiation oncologist. However, considering VEP, the impairment was statistically significant for both fibers explored at 30’angle (p:0.007) and 60’angle (p <0.001). In patients with toxicity, the distance of the target volume from the optical pathways was more important with a p-value for 30’VEP at 0.035 and for 60’VEP at 0.039.ConclusionsThese results confirm uncertainties concerning relative biological effectiveness of proton therapy, linear energy transfer appears to be more inhomogeneous especially in areas close to the target volumes. The follow-up of patients after proton therapy is not an easy process to set up but it is necessary to improve our knowledges about the biological effects of proton therapy in real life. Our study which will continue during the coming years, suggests that follow-up with in-depth examinations such as VEP as a biomarker could improve the detection of early abnormalities.

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Section: Discussionmentioning

confidence: 92%

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

Lecornu

Lesueur²,

Salleron³

et al. 2021

Front. Oncol.

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“…Unlike glaucoma and optic neuritis, most of the VF defects patterns were irregular and lacked distinguishable characteristics. Ozkaya et al ( 33 ) found that VF and contrast sensitivity were significantly affected with a mean dose of more than 50 Gy in NPC patients. According to Ferguson ( 34 ), no significant correlation for other risk factors was identified in RON when a lower radiation dosage was applied in EBRT.…”

Section: Discussionmentioning

confidence: 99%

Radiation-Induced Optical Coherence Tomography Angiography Retinal Alterations in Patients With Nasopharyngeal Carcinoma

Zhan

Xiao

et al. 2021

Front. Med.

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Aim: The aim of the study was to investigate the early neurovascular alterations of the retina in radiation encephalopathy (RE) patients with normal-ranged visual acuity after radiotherapy for nasopharyngeal carcinoma.Methods: Fifty-five RE patients and 54 healthy age-matched subjects were enrolled in this retrospective cross-sectional case–control study. The best corrected visual acuity (LogMAR) of the included eye should not be more than 0. The vessel density and thickness of different locations in the retina were acquired automatically using optical coherence tomography angiography (OCTA). The data were then compared between the RE patients and the controls. The location included the whole retina, the superficial vascular plexus (SVP)/the ganglion cell complex (GCC), the deep vascular plexus (DVP), and the choroid in the macular area, as well as the inside disc and peripapillary area in the optic nerve head (ONH). The risk factors in OCTA retinal impairments were analyzed using a backward multiple linear regression. The relationships between mean deviation (MD) and pattern standard deviation (PSD) in the visual field (VF) and the OCTA parameters were also analyzed in RE patients.Results: The vessel density of the GCC was significantly reduced in RE patients compared with controls (p = 0.018), and the reductions were mainly shown in the parafoveal (p = 0.049) and perifoveal fields (p = 0.006). The thickness of the GCC was correspondingly reduced (whole image GCC mean thickness: p = 0.044; parafoveal thickness: p = 0.038; perifoveal thickness: p = 0.038). In addition, the sub-foveal choroidal thickness (p = 0.039) was also reduced in RE patients. The vessel density of the GCC (R2 = 0.643) and DVP (R2 = 0.777) had a significant positive correlation with high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (ApoA1) and had a significant negative correlation with age (GCC: HDL-C, β = 29.89, p = 0.005; ApoA1, β = 78.92, p = 0.002; age, β = −0.886, p = 0.001; DVP: HDL-C, β = 40.09, p = 0.003; ApoA1, β = 62.65, p = 0.013; age, β = −1.31, p = 0.001). The vessel density of the GCC also had a significant negative correlation with apolipoprotein B (ApoB) (β = −32.18, p = 0.006). In the VF, MD had a significant positive correlation with the vessel density inside disc (R2 = 0.241, β = 0.304, p = 0.045), whereas PSD showed a significant negative correlation with the vessel density inside disc and the average GCC thickness, respectively (R2 = 0.437; vessel density inside disc, β = −0.358, p = 0.004; average GCC thickness, β = −0.510, p < 0.001).Conclusion: With the aid of OCTA, we found that neurovascular alterations of the retina may exist in RE patients with normal-ranged visual acuity. Herein, we suggest the implementation of OCTA to assist ophthalmologists in the early detection and consistent monitoring of radiation-related eye diseases to avoid delayed diagnosis.

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“…Remarkably, the first diagnosis of NPC usually occurs at an advanced stage because the clinical symptoms are atypical and hardly detected ( 3 ). Locoregionally advanced NPCs often infiltrate important areas, including the skull base, the cavernous sinus, the orbit, and the neuro-optic structures (optic nerve and optic chiasm; NOS) ( 4 ). Dose restriction of planning target volumes (PTVs) is a clinically common solution to protect organs at risk (OARs) undergoing radiotherapy ( 5 ).…”

Section: Introductionmentioning

confidence: 99%

Loosening Neuro-Optic Structures Dosimetric Constraints Provides High 5-Year Local Recurrence-Free Survival With Acceptable Toxicity in T4 Nasopharyngeal Carcinoma Patients Treated With Intensity-Modulated Radiotherapy

Zhang

et al. 2021

Front. Oncol.

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ObjectiveWhether the original dosimetric constraints of neuro-optic structures (NOS) are appropriate for patients with nasopharyngeal carcinoma (NPC) undergoing intensity-modulated radiotherapy (IMRT) remains controversial. The present study compared the survival rates and radiation-induced optic neuropathy (RION) occurrence between T4 NPC patients whose NOS were irradiated with a near maximum dose received by 2% of the volume (D2%) >55 Gy and ≤55 Gy. Moreover, the NOS dosimetric parameters and their correlation with RION occurrence were also evaluated.MethodsIn this retrospective study, 256 T4 NPC patients treated with IMRT between May 2009 and December 2013 were included. Patient characteristics, survival rates, dosimetric parameters, and RION incidence were compared between the D2% ≤55 Gy and D2% >55 Gy groups.ResultsThe median follow-up durations were 87 and 83 months for patients in the D2% >55 Gy and D2% ≤55 Gy groups, respectively. The 5-year local recurrence-free survival rates were 92.0 and 84.0% in the D2% >55 Gy and D2% ≤55 Gy groups (P = 0.043), respectively. There was no significant difference in the 5-year overall survival (OS) between both groups (D2% >55 Gy, 81.6%; D2% ≤55 Gy, 79.4%; P = 0.586). No patients developed severe RION (Grades 3–5), and there was no significant difference (P = 0.958) in the incidence of RION between the two groups. The maximum dose of NOS significantly affected the RION incidence, with a cutoff point of 70.77 Gy.ConclusionAppropriately loosening NOS dosimetric constraints in order to ensure a more sufficient dose to the target volume can provide a better 5-year local recurrence-free survival and acceptable neuro-optic toxicity in T4 NPC patients undergoing IMRT.

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Evaluation of the Radiation Dose–Volume Effects of Optic Nerves and Chiasm by Psychophysical, Electrophysiologic Tests, and Optical Coherence Tomography in Nasopharyngeal Carcinoma

Cited by 13 publications

References 24 publications

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

Radiation-Induced Optical Coherence Tomography Angiography Retinal Alterations in Patients With Nasopharyngeal Carcinoma

Loosening Neuro-Optic Structures Dosimetric Constraints Provides High 5-Year Local Recurrence-Free Survival With Acceptable Toxicity in T4 Nasopharyngeal Carcinoma Patients Treated With Intensity-Modulated Radiotherapy

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