[Graves' orbitopathy]. / Endokrine Orbitopathie.

BACKGROUND: Graves' orbitopathy (GO) is an autoimmune orbital disease which is mostly associated with Graves' disease and requires good interdisciplinary cooperation. To minimize irreversible damages a stage-adapted anti-inflammatory therapy is of great importance. MATERIAL AND METHODS: Discussion of the latest results of new findings of the pathogenesis, randomized controlled trials on anti-inflammatory treatments for Graves' orbitopathy and novel therapeutic concepts. RESULTS: In all patients with GO achieving euthyroidism, as well as cessation of smoking is very important to avoid prolongated diseases. Mild cases of GO can be treated with selenium supplementation and artificial tears. The moderate-to-severe, active form of GO requires primarily i. v. steroids in combination with orbital irradiation in case of impaired motility. In patients with insufficient therapeutic response after 6 weeks, treatment should be switched to other immunosuppressive agents. In severe sight-threatening cases even high-dose i. v. steroid treatments are often ineffective and bony orbital decompression is necessary. As latest research data have improved our understanding of the pathophysiology of GO, targeted therapies have been developed for GO. Teprotumumab, an IGF-1 receptor antibody, was shown effective in treating GO patients in a phase III trial and should soon be awarded approval for Europe. Inactive patients, who suffer from disturbing exophthalmos should be also treated with bony decompression before eye muscle or lid surgery. CONCLUSION: The current concept for Graves' orbitopathy is as follows: first anti-inflammatory therapy then surgical correction of the permanent defects. This might be modified in the future, due to the promising effects of targeted therapies.

A Prospective, Randomized, Double-blind, Placebo-controlled Study of Orbital Radiotherapy for Graves' Ophthalmopathy.

CONTEXT: Although widely used for more than 85 years, the efficacy of radiotherapy for Graves' ophthalmopathy (GO) has not been established convincingly. OBJECTIVE: To evaluate the efficacy of radiotherapy for GO. DESIGN: Prospective, randomized, internally controlled, double-blind clinical trial in a tertiary care academic medical center. PARTICIPANTS: The patients were ethnically diverse males and females over age 30 seen in a referral practice. The patients had moderate, symptomatic Graves' ophthalmopathy (mean clinical activity score, 6.2) but no optic neuropathy, diabetes, recent steroid treatment, previous decompression, or muscle surgery. Forty-two of 53 consecutive patients were enrolled after giving informed consent and fulfilling study entry criteria. Eleven eligible patients declined to participate because of inconvenience, desire for alternative therapy, or concern about radiation. INTERVENTION: One randomly selected orbit was treated with 20 Gy of external beam therapy; sham therapy was given to the other side. Six months later, the therapies were reversed. MAIN OUTCOME MEASURES: Every 3 months for 1 year, we measured the volume of extraocular muscle and fat, proptosis, range of extraocular muscle motion, area of diplopia fields, and lid fissure width. Effective treatment for GO will modify one or more of these parameters. RESULTS: No clinically or statistically significant difference between the treated and untreated orbit was observed in any of the main outcome measures at 6 months. At 12 months, muscle volume and proptosis improved slightly more in the orbit that was treated first. CONCLUSIONS: In this group of patients, representative of those for whom radiotherapy is frequently recommended, we were unable to demonstrate any beneficial therapeutic effect. The slight improvement noted in both orbits at 12 months may be the result of natural remission or of radiotherapy, but the changes are of marginal clinical significance.

Dose-Effect Analysis of Early Changes in Orbital Bone Morphology After Radiation Therapy for Rhabdomyosarcoma.

PURPOSE: In survivors of orbital embryonal rhabdomyosarcoma (ERMS), late effects include facial deformation and asymmetry. We sought to quantify orbital asymmetry in ERMS survivors and characterize the dose effect of radiation to the orbital bones. METHODS AND MATERIALS: We evaluated the most recent follow-up magnetic resonance imaging (MRI) in 17 children (≤21 years old) with stage 1 group III orbital ERMS treated with proton therapy between 2007 and 2018. For all patients, the orbital socket volumes were calculated and compared with the contralateral, unirradiated orbital socket. Patient age, orbital tumor quadrant, and the radiation dose delivered to the major orbital bones (maxillary, frontal, and zygomatic bones) were recorded and correlated with the orbital socket volume difference. RESULTS: The mean age at diagnosis was 5.4 years old (range, 1.1-9.7 years). All patients received a prescription dose of 45 GyRBE. The mean time interval between radiation and MRI was 2.9 years (range, 0.8-3.2 years). The mean age at most recent MRI was 8.4 years (range, 2.3-12.9 years). In 16 of 17 patients, the volume of the ipsilateral orbit was significantly smaller than the contralateral orbit on follow-up MRI (P ≤ .0001). In one patient with nonviable tumor in situ, the irradiated orbit was larger. The volume difference increased with follow-up time and did not correlate with age at treatment or age at MRI. A dose >40 GyRBE to all bones of the orbital rim was associated with a significant decrease in orbital volume (P < .05), but an isolated dose of >40 GyRBE to either the frontal, maxillary, or zygomatic bone was not. CONCLUSIONS: Despite the dosimetric precision of proton therapy, orbital asymmetry will develop after >40 GyRBE to multiple bones of the orbital rim. These data may be used to guide treatment planning and counsel patients on expected cosmesis.

Using an orbit shield during volume perfusion CT: is it useful protection or an obstacle?

AIM: To evaluate the image quality and artefacts resulting from in-plane orbit shielding during computed tomography (CT) perfusion and to assess the possibility of artefact reduction using the iterative metal artefact reduction (iMAR) algorithm. MATERIALS AND METHODS: Twenty-eight perfusion CT examinations obtained from 20 patients using orbit shields were included in this study. Source images and perfusion maps were analysed retrospectively to detect the type and extent of artefacts. Original images were compared with images processed using the iMAR algorithm. The extent of artefacts was categorised into three groups: orbital/frontal, middle fossa, and posterior fossa. Types of artefacts in source images were categorised as noise, streak, beam hardening, or a combination of those, and types of artefacts in perfusion maps were categorised as: noise, image distortion, areas with missing colour codes, or incorrect colour-coding. RESULTS: All source images evaluated showed artefacts related to orbit shielding and 85.7% reached the posterior fossa. In 92.8% of scans, perfusion maps showed artefacts, mostly as incorrect colour codes. Of the perfusion maps with artefacts, 92.3% reached the posterior fossa. After application of the iMAR algorithm, an increase in the extent of artefacts was observed in 93% of perfusion maps, and no improvement of image quality was noted. CONCLUSION: Orbit shields cause significant artefacts if used for in-plane shielding during whole-brain CT perfusion, and render areas at the level of the shield undiagnosable. Usage of an orbit shield during whole-brain CT perfusion is not recommended, so alternative methods for reducing the radiation dose are advisable.

Effects on Periocular Tissues after Proton Beam Radiation Therapy for Intraocular Tumors.

BACKGROUND: To present our experience on orbital and periorbital tissue changes after proton beam radiation therapy (PBRT) in patients with intraocular tumors, apart from treatment outcomes and disease control. METHODS: Medical records of 6 patients with intraocular tumors who had been treated with PBRT and referred to oculoplasty clinics of two medical centers (Seoul National University Hospital and Seoul Metropolitan Government-Seoul National University Boramae Medical Center) from October 2007 to September 2014 were retrospectively reviewed. The types of adverse effects associated with PBRT, their management, and progression were analyzed. In anophthalmic patients who eventually underwent enucleation after PBRT due to disease progression, orbital volume (OV) was assessed from magnetic resonance (MR) images using the Pinnacle3 program. RESULTS: Among the six patients with PBRT history, three had uveal melanoma, and three children had retinoblastoma. Two eyes were treated with PBRT only, while the other four eyes ultimately underwent enucleation. Two eyes with PBRT only suffered from radiation dermatitis and intractable epiphora due to canaliculitis or punctal obstruction. All four anophthalmic patients showed severe enophthalmic features with periorbital hollowness. OV analysis showed that the difference between both orbits was less than 0.1 cm before enucleation, but increased to more than 2 cm³ after enucleation. CONCLUSION: PBRT for intraocular tumors can induce various orbital and periorbital tissue changes. More specifically, when enucleation is performed after PBRT due to disease progression, significant enophthalmos and OV decrease can develop and can cause poor facial cosmesis as treatment sequelae.

Orbital radiotherapy plus three-wall orbital decompression in a patient with rare ocular manifestations of thyroid eye disease: case report.

BACKGROUND: Thyroid eye disease (TED) is a debilitating autoimmune orbital disease that is often a result of Graves' disease. Dysthyroid optic neuropathy (DON) is a rare but sight-threatening manifestation of TED with therapeutic challenges that can potentially lead to visual loss. CASE PRESENTATION: A 74-year-old man experienced active TED with extremely severe redness and swelling of the conjunctiva, loss of visual acuity and exacerbation of disfiguring proptosis. Computed tomography revealed the involvement of extraocular muscles resulting in optic nerve compression. He was in poor general condition and was intolerant to steroids. To achieve the optimal operating conditions for orbital decompression surgery, the patient was initially treated with orbital radiotherapy. The patient responded well, with improvements in clinical activity score and visual acuity. CONCLUSION: This case demonstrates a rare and severe case of DON with therapeutic challenges. To date, no cases has been reported of a patient with such severe and unusual ocular manifestations. Early awareness of the occurrence of optic nerve compression and prompt treatment are important to prevent irreversible outcomes. Orbital radiotherapy should be considered as a useful surgery-delaying alternative for DON, especially in patients who have contraindications to steroids.

Autologous fat graft in irradiated orbit postenucleation for retinoblastoma.

Autologous fat grafting has been extensively and successfully adopted in a number of pathologic conditions in regenerative surgery especially on irradiated fields in order to improve pain symptoms and tissue trophism promoting scar release. In the present study, we report our experience with autologous fat grafting for the treatment of postirradiation fibrosis and pain on three consecutive patients undergoing orbital enucleation for locally advanced retinoblastoma (RB) and subsequent radiotherapy. We selected three consecutive patients who underwent orbital enucleation for locally advanced RB and subsequent local radiotherapy showing severe reduction in orbital volume and eyelid length and retraction due to fibrosis, spontaneous local pain exacerbated after digital pressure with no possibility to place an ocular implant. They underwent autologous fat grafting in the orbital cavity and results were evaluated by clinical examination at 5 and 14 days, and 1, 3, 6 months, and 1 year after surgery. A significant release of scar retraction, reduction of fibrosis and orbital rim contraction together with an important improvement of pain symptoms was observed in all patients. The local changes observed enabled an ease placement of an ocular prosthetic implant (implant). No local or systemic complication occurred. Fat grafting is a promising treatment for patients showing radiotherapy related complication in the orbital area and it should be adopted by all oculoplastic surgeon in order to improve pain syndrome creating the ideal local conditions for the placement of an ocular prosthetic implant.

Clinical and Histological Studies of Suborbital Wrinkles Treated with Fractional Bipolar Radiofrequency.

Fractional bipolar radiofrequency (FRF) has been well established for facial rejuvenation, but there is no report showing its efficacy for the treatment of suborbital wrinkles. The aim of this study was to investigate and objectively evaluate the clinical efficacy and side effects of FRF for the treatment of suborbital wrinkles, including observation of histological changes of the suborbital skin along the therapy. Thirty-two female patients with suborbital wrinkles underwent three sessions of FRF at 3-week intervals with a follow-up period of 6 months after treatment. Two independent dermatologists with standardized photographs evaluated improvement grade. Most patients improved according to photographic assessments and the differences between results at 1 and 6 months were not statistically significant (p > 0.05). The median score of pain rated by patients using a visual analog scale (0-10 points) was 4.4 ± 1.2. Most patients rated themselves as satisfied (68.8%) and very satisfied (9.4%). Ten subjects (31.3%) experienced hyperpigmentation in 24 of all together 96 treatments (25.0%). Skin biopsies of three patients were routinely obtained, processed, and stained, and the histological changes had shown that 1-month after the end of the treatment, both the collagen and normal elastic fibers increased in accordance with the clinical efficacy. The study suggested that FRF is a safe and effective method to treat suborbital wrinkles.

Corneal complications after orbital radiotherapy for primary epithelial malignancies of the lacrimal gland.

PURPOSE: To review the long-term corneal complications after high-dose external beam orbital radiotherapy given to patients for lacrimal gland carcinomas. The impact of prophylactic measures to improve long-term ocular surface health is also assessed. DESIGN: Retrospective case series. PARTICIPANTS: Patients under the care of Moorfields Eye Hospital and receiving external beam radiotherapy for primary epithelial lacrimal gland carcinoma between 1975 and 2014. METHODS: Retrospective review of ophthalmic case notes at Moorfields Eye Hospital, and oncology and general physician records. MAIN OUTCOME MEASURES: The occurrence of corneal perforation, and time to perforation. RESULTS: Sixty-seven patients were included in this study, of whom nine (13%) developed corneal perforation at a median time of 10.4 months after radiotherapy (mean 35; range 3.2 months to 14.5 years); the majority (7/9; 78%) perforated within 36 months of radiotherapy. The mean follow-up interval of the whole cohort was 8.2 years (median 4.6; range, 2 months to 30.7 years). CONCLUSIONS: Although most patients with globe-sparing treatment of lacrimal gland carcinoma did not suffer corneal perforation, they usually require long-term therapy to maintain the ocular surface. The high-dose external beam radiotherapy needed for lacrimal gland carcinoma can produce significant ocular surface morbidity, and the 13% incidence of corneal perforation was greatest in the first 3 years after irradiation.

Combination Therapy of Intravenous Steroids and Orbital Irradiation is More Effective Than Intravenous Steroids Alone in Patients with Graves' Orbitopathy.

The aim of this study was to evaluate and compare the efficacy of intravenous (iv) glucocorticoids (GCs) with and without orbital radiotherapy (ORT) in a retrospective analysis of patients with active, moderate-to-severe Graves' orbitopathy (GO). Since diplopia has the strongest impact on quality of life, a careful work up of motility and binocular single vision (BSV) has been performed. The Essen-EUGOGO-Center database (n=3655) was screened for patients with untreated moderate-to-severe, active GO, onset ≤12 months. The inclusion criteria were met by 148 patients (n=76 ivGC, n=72 ivGC + ORT). We analyzed CAS (inactivation: ≤2), NOSPECS, lid-width, proptosis, motility, and field of BSV. To score the overall ophthalmic outcome, a severity-weighted-score (SOS) was compared with an established EUGOGO inflammation-weighted-score (IOS). Cumulative ivGCs dosages and duration of GO did not differ between the groups. Patients with combination therapy had a significantly more severe GO at baseline. Therefore, a subgroup with matched severity was additionally compared. In the IOS, both groups reached similar improvement rates (55.2 vs. 63.9%; p=0.31). However, in the SOS, the rates differed significantly (46.1 vs. 61.1%; p=0.03- unmatched and p=0.03 matched), despite similar rates of inactivation (65.8 vs. 63.8%). Impaired motility improved significantly more often after combination therapy (p=0.01 matched, p=0.004 unmatched). Treatment responders showed only partial improvement (proptosis: 2.5±0.5 mm; motility: 11.3±10.9°). In our retrospective analysis, combination therapy (ivGCs + ORT) was significantly more effective in reduction of severity and should therefore always be considered in moderate-to-severe GO stages, especially in the presence of motility disorders. However, the limited improvement in clinical parameters, despite the promising effect on inactivation of inflammation, has to be outlined to the patients.

Ultra-low-dose radiotherapy for definitive management of ocular adnexal B-cell lymphoma.

BACKGROUND: The purpose of this study was to report the response to and toxicity of ultra-low-dose radiotherapy (RT) for B-cell ocular adnexal lymphoma (OAL). METHODS: We conducted a retrospective review of patients with indolent B-cell and mantle cell OAL treated with 4 Gy to the orbit(s) in two 2-Gy fractions. Disease response was assessed clinically and/or radiographically at 2 to 4-month intervals after RT. Data collected included rates of overall response, complete response (CR), partial response (PR), and treatment-related toxic effects. RESULTS: Twenty-two patients (median age, 65 years) had the following histologic subtypes: mucosa-associated lymphoid tissue (MALT; 14 patients; 64%); follicular lymphoma (5 patients; 23%); mantle cell lymphoma (MCL; 2 patients; 9%); and unclassifiable (1 patient, 4%). The overall response rate was 100%; 19 patients (86%) had a CR and 3 patients (14%) had a PR. The only acute toxic effect was grade 1 dry eye syndrome in 1 patient. CONCLUSION: Ultra-low-dose RT in patients with OAL is associated with high response rates and minimal toxic effects, and is much shorter in duration and cost. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1095-1100, 2017.

Radiotherapy for the treatment of thyroid eye disease-a prospective comparison: Is orbital radiotherapy a suitable alternative to steroids?

BACKGROUND AND AIMS: To evaluate the efficacy of orbital radiotherapy (OR) for the treatment of thyroid eye disease (TED). METHODS: Thirty-five consecutive patients with active TED with contraindications to steroid therapy received a course of OR. Bilateral retrobulbar irradiation was performed with a total dose of 20 Gy. 7-points clinical activity score (7-CAS), ocular motility, visual acuity (VA), exophthalmos and eyelid retraction were prospectively evaluated at 3, 6 and 12 months and compared with baseline data. RESULTS: There was a statistically significant improvement in 7-CAS at 3, 6 and 12 months post-treatment (p < 0.05). Ocular motility disturbances improved at 6 and 12 months (p < 0.05). Visual acuity remained stable; there was no significant change in exophthalmos (mean 24 mm, SD 3 mm) or eyelid retraction (marginal reflex distance mean 6 mm, SD 1.5 mm) during the follow-up period. No side effects were registered. CONCLUSIONS: This study suggests that OR might be effective in reducing 7-CAS and ocular motility disturbances. No significant improvement in proptosis or eyelid retraction should be expected from this treatment. OR might be considered a suitable alternative treatment in TED for patients who cannot tolerate steroids.

Treatment of periorbital wrinkles using multipolar fractional radiofrequency in Korean patients.

A limited number of studies have evaluated the efficacy and safety of electrode pin fractional radiofrequency (FRF) for periorbital wrinkle treatment in Asian patients, but none have measured noninvasive methodological objective parameters such as periorbital wrinkle area. This study aimed to investigate the efficacy and safety of electrode pin multipolar FRF for the improvement of periorbital wrinkles in Korean patients by using a noninvasive methodological objective parameter. Seventy female subjects with periorbital wrinkles (age range, 40-60 years) participated in this study. Each patient underwent three sessions of FRF treatment to the periorbital region separated by 2-week intervals. The area of periorbital wrinkles was analyzed by using a Robo Skin Analyzer CS50 at 4 weeks after the final treatment session. Periorbital wrinkle area was significantly decreased at 1-month follow-up (75.77 ± 29.46 mm2) compared to baseline (94.74 ± 31.62 mm2). The improvement ratio of periorbital wrinkle area was 20.02 %. Side effects were limited to transient mild erythema, swelling, and crusts. Pain was tolerable without local anesthesia. Our findings suggest that the multipolar electrode pin FRF can be an effective and safe method for reducing periorbital wrinkles in Asian patients.

Conformal orbit sparing radiation therapy: a treatment option for advanced skin cancer of the parotid and ear region.

INTRODUCTION: New surgical methods have enabled resection of previously in-operable tumours in the region of the parotid gland and ear. This has translated to deeper target volumes being treated with adjuvant radiotherapy. Due to the limitations of existing conformal techniques, alternative planning approaches are required to cover the target volume with appropriate sparing of adjacent critical structures. Although intensity modulated radiation therapy (IMRT) may be able to achieve these goals compared with the existing conformal method, a new orbital sparing radiation therapy (OSRaT) technique was evaluated as an alternative conformal planning process. The study objective was to evaluate the dosimetry of three planning methods: pre-existing conformal, IMRT and OSRaT techniques. METHODS: Ten patients were planned retrospectively using the existing three-dimensional conformal radiotherapy (3DCRT), IMRT and OSRaT techniques. Dosimetry was analysed using the homogeneity index (HI), conformity index (CI), the volume of planning target volumes (PTV) under and over treated by the 95% isodose and dose to critical structures. RESULTS: OSRaT achieved superior 95% coverage of the high-dose PTV while delivering HI similar to IMRT for intermediate and high-dose PTVs. The CI for the high-dose PTV was comparable between the three techniques, however IMRT was statistically better for the low- and intermediate dose PTVs. All three techniques showed adequate orbital sparing, however OSRaT and IMRT achieved this with less under dosing of the PTVs. CONCLUSION: For the treatment of patients with advanced skin cancer of the parotid and ear, both IMRT and the OSRaT techniques are viable options.

The Effect of Systemic Steroids and Orbital Radiation for Active Graves Orbitopathy on Postdecompression Extraocular Muscle Volume.

PURPOSE: To evaluate the effect of orbital radiation prior to surgery on the clinical course and extraocular muscle (EOM) radiologic volume changes after decompression in Graves orbitopathy (GO). DESIGN: Retrospective, interventional case series. METHODS: The medical records of patients treated with orbital decompression for GO and who underwent postoperative orbital computed tomography were reviewed. Only patients who underwent rehabilitative decompression in the inactive phase and who received systemic corticosteroids alone (ST group) or combined orbital radiation and systemic corticosteroids (SRT group) in the active inflammatory phase of the disease were selected. The main outcome measure was the comparison of preoperative and postoperative EOM volumes. Secondary outcome measures were changes in proptosis and diplopia after decompression. RESULTS: Thirty-seven of 114 patients were selected for this study. There were no differences between the ST group (n = 22, 42 eyes) and SRT group (n = 15, 30 eyes) in terms of demographics or predecompression characteristics. After decompression surgery, the total EOM volume significantly increased by 15% in the ST group, but radiated EOMs in the SRT group did not expand, resulting in decreased induction of postoperative diplopia. The percentages of patients showing increased diplopia after decompression differed significantly between the groups (ST group, 40.9% vs SRT group, 13.3%, P = .04). However, there was no difference in exophthalmos reduction after decompression between the 2 groups. CONCLUSIONS: Orbital radiation prior to orbital decompression can reduce both the postoperative increase in EOM volume and deterioration in diplopia.

Efficacy of combined orbital radiation and systemic steroids in the management of Graves' orbitopathy.

PURPOSE: To compare the efficacy and safety of combination therapy with orbital irradiation and systemic steroids versus steroid monotherapy in the management of active Graves' orbitopathy (GO). METHODS: The clinical charts of 127 patients with active inflammation due to GO who received intravenous steroid pulse therapy as a first-line treatment with or without orbital radiotherapy between 2010 and 2014 were reviewed. Patients were divided into two treatment groups: 1) combined orbital radiotherapy and steroid pulse therapy (SRT group) and 2) steroid pulse therapy only (ST group). Primary outcome measures included clinical activity score (CAS); NOSPECS classification; ocular motility impairment; and exophthalmos at 1, 3, 6, and 12 months after treatment. The secondary outcome measure was the change in orbital, extraocular muscle (EOM), and fat volume after treatment measured by orbit computed tomography. RESULTS: Sixty-eight patients were included in the SRT group, and 59 patients were in the ST group. In both treatments, CAS and NOSPECS were significantly reduced. In the comparison of the degree of change from baseline between the groups, the SRT group demonstrated more improvement in NOSPECS and scores of ocular motility. Orbital, EOM, and fat volume significantly decreased in the SRT group; however, only fat volume was reduced in the ST group. Compressive optic neuropathy after treatment developed in 0 % of the SRT group and 3.4 % (2/59) of the ST group. Reactivation of inflammation occurred in 11.8 % (8/68) of the SRT group and 28.8 % (17/59) of the ST group. CONCLUSIONS: Orbital radiotherapy in combination with steroid treatment significantly improved ocular motility by reducing EOM volume in patients with active GO.

Development of a Novel Thyroid Function Fluctuated Animal Model for Thyroid-Associated Ophthalmopathy.

BACKGROUND: The establishment of a suitable and stable animal model is critical for research on thyroid-associated ophthalmopathy (TAO). In clinical practice, we found that patients treated with I-131 often exhibit TAO; therefore, we aimed to establish a novel thyroid function fluctuated animal model of TAO by simulating the clinical treatment process. METHODS: We treated SD rats with I-131 to damage the thyroid and then used sodium levothyroxine (L-T4) to supplement the thyroid hormone (TH) levels every seven days, leading to a fluctuating level of thyroid hormones that simulated the status of clinical TAO patients. Rats administered normal saline were considered as a control. The weight, intraocular pressure, and serum T3, T4, TSH and TRAb levels of the rats were measured, and the pathological changes were analyzed by H&E staining and transmission electron microscopy (TEM). RESULTS: The experimental rats (TAO group) exhibited significantly reduced weight and elevated intraocular pressure compared with the control rats. Meanwhile, the serum levels of T3 and T4 were up-regulated in the TAO group, but the TSH level decreased during the 10-week study. Moreover, increased numbers of blood vessels and inflammatory cell infiltrations were observed in the orbital tissues of the TAO rats, while no abnormal changes occurred in the control rats. The orbital myofibrils in the TAO rats appeared fractured and dissolved, with twisted structures. Mitochondrial swelling and vacuoles within the endoplasmic reticulum, swelling nerve fibers, shedding nerve myelin, and macrophages were found in the TAO group. CONCLUSION: Rats treated with I-131 and sodium levothyroxine exhibited characteristics similar to those of TAO patients in the clinic, providing an effective and simple method for the establishment of a stable animal model for research on the pathogenesis and treatment of TAO.

Orbital Radiation Therapy in Thyroid Eye Disease.

PURPOSE: To review the current literature summarizing the state of knowledge on the use of orbital radiation therapy (ORT) in thyroid eye disease. METHODS: A systematic review and analysis of the literature were performed. MEDLINE/PubMed, Cochrane Library databases, SCOPUS, and recent relevant journal articles were searched. RESULTS: Thyroid eye disease is an autoimmune disorder that has the propensity to affect multiple orbital tissues and can cause permanent vision loss. In moderate to severe disease, treatment may be warranted and can include multiple therapeutic modalities. Orbital radiation therapy is frequently used in this setting and may act to break the inflammatory cycle of glycosaminoglycan production and deposition. There has been a wealth of data regarding the effectiveness of ORT in thyroid eye disease resulting in the publication of treatment algorithms and management guidelines; however, there continues to be a lack of conformity among experts on the exact role of ORT in thyroid eye disease. CONCLUSION: The multiple different thyroid eye disease classification schemes and the concurrent use of other therapeutic modalities challenge the interpretation of studies evaluating the effectiveness of thyroid eye disease. Despite these limitations, the current literature indicates that ORT is generally safe and well tolerated. Orbital radiation therapy may have a modest effect on motility and proptosis early in the disease process. It is unclear whether ORT leads to improved quality of life. There are some data to support the use of ORT to prevent compressive optic neuropathy.

Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits.

PURPOSE: The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. METHODS: This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position the dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. RESULTS: (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R(2) = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o'clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and 43%, depending on the scan protocol used and the positioning of the phantom. Furthermore, the amount of dose reduction was significantly affected by the vertical position of the phantom, with the largest reduction in dose seen when the phantom was centered in the gantry. CONCLUSIONS: (1) An appropriate correction factor, specific to CT scanning, was developed to account for depletion and fading characteristics of the dosimeters. Additionally, an equation to convert dosimeter counts to absorbed dose was established. (2) The use of plastic safety glasses was validated as an appropriate positioning device when measuring dose to the lens of the eye. (3) The use of organ-based tube current modulation can reduce dose to the lens of the eye during CT scanning. The amount of dose reduction, however, is largely influenced by the positioning of the anatomy in the gantry.

Dose reduction in orthodontic lateral cephalography: dosimetric evaluation of a novel cephalographic thyroid protector (CTP) and anatomical cranial collimation (ACC).

OBJECTIVES: To test the dose-reducing capabilities of a novel thyroid protection device and a recently introduced cranial collimator to be used in orthodontic lateral cephalography. METHODS: Cephalographic thyroid protector (CTP) was designed to shield the thyroid while leaving the cervical vertebrae depicted. Using a RANDO(®) head phantom (The Phantom Laboratory, Salem, NY) equipped with dosemeters and a Proline XC (Planmeca, Helsinki, Finland) cephalograph, lateral cephalograms were taken, and the effective dose (ED) was calculated for four protocols: (1) without shielding; (2) with CTP; (3) with CTP and anatomical cranial collimator (ACC); and (4) with a thyroid collar (TC). RESULTS: The ED for the respective protocols was (1) 8.51; (2) 5.39; (3) 3.50; and (4) 4.97 µSv. The organ dose for the thyroid was reduced from 30.17 to 4.50 µSv in Protocols 2 and 3 and to 3.33 µSv in Protocol 4. CONCLUSIONS: The use of just the CTP (Protocol 2) resulted in a 36.8% reduction of the ED of a lateral cephalogram. This was comparable to the classical TC (Protocol 4). A 58.8% reduction of the ED was obtained when combining CTP and ACC (Protocol 3). The dose to the radiosensitive thyroid gland was reduced by 85% in Protocols 2 and 3 and by 89% in Protocol 4.