Probable risk of tumour induction after retro-orbital irradiation for Graves' ophthalmopathy

Low- vs. high-dose radiotherapy in Graves' ophthalmopathy: a retrospective comparison of long-term results

Purpose

Radiotherapy represents an effective treatment option in Graves’ ophthalmopathy (GO), leading to palliation of clinical symptoms. However, there are only a limited number of trials comparing the effectiveness of low- vs. high-dose radiotherapy.

Methods

We analyzed 127 patients treated with radiotherapy for stage 3/4 GO (NOSPECS classification). Patients were treated with single doses of 2.0 Gy (cumulative dose 20 Gy) until 2007, afterwards a single dose of 0.8 Gy (cumulative dose 4.8 Gy) was applied. With a median follow-up-time of 9.0 years, the treatment efficacy (overall improvement, sense of eye pressure, lid edema, ocular motility, exophthalmos, subjective vision, and diplopia) and adverse effects were analyzed by a standardized survey.

Results

Overall, 63.8% described improvement of symptoms after radiotherapy. No significant differences in overall treatment response and improvement of main outcome measures between low- or high-dose radiotherapy treatments are detectable, while low-dose radiotherapy leads significantly more often to retreatment (13.1% vs. 1.7%, p = 0.016). The main independent predictor of treatment response is the presence of lid edema (odds ratio, OR, 3.53; p = 0.006).

Conclusion

At long-term follow-up, the majority of patients reported palliation of symptoms with limited adverse effects, suggesting clinical effectiveness of radiotherapy for amelioration of GO symptoms independent of low- or high-dose radiotherapy.

Thyroid eye disease survey: An anonymous web-based survey in the Indian subcontinent

Purpose

To evaluate the current practice patterns in the treatment of thyroid eye disease (TED) in Indian subcontinent through a web-based survey of members of Oculoplastics Association of India (OPAI).

Methods

This was an online web-based questionnaire survey disseminated via monkeysurvey.com to all ratified active members of OPAI between May 1, 2016 and June 30, 2016. Questions encompassed the background, training, region, and experience of oculoplastic surgeons along with the management protocol of TED.

Results

Of the 435 emails sent to OPAI members, 9 bounced and 180 (42.3%) responded within the study period. A large majority (96%) of respondents were oculoplastic surgeons practicing in India and the remaining practiced within South-East Asia. Two-thirds of respondents were oculoplastic surgeons with less than 10 years of clinical experience; 82% were fellowship trained in Oculoplasty. Almost all (99%) favored a multidisciplinary management of TED. A large majority routinely grade the severity (89%) and activity (87%) of disease before management. While corticosteroid remained the treatment of choice, 54% preferred immune-modulators as the second-line of therapy for recalcitrant TED. Three-quarters did not use orbital radiotherapy as a management modality in active TED owing to concerns over its efficacy and/or safety.

Conclusion

The survey gives useful insights to the practice patterns of TED management in Indian subcontinent. Multidisciplinary approach and grading of disease severity and activity were the rule rather than exception among OPAI members. Immune modulation was the preferred steroid-sparing agent in recalcitrant disease. Orbital radiotherapy was an uncommon treatment choice.

Teprotumumab: a novel therapeutic monoclonal antibody for thyroid-associated ophthalmopathy

INTRODUCTION

Thyroid-associated ophthalmopathy (TAO) is a disfiguring, potentially blinding, and sub-optimally managed autoimmune condition. Current therapy of active TAO consists most frequently of glucocorticoid steroids, orbital radiation, or B-cell depletion; all of which are associated with substantial side effects. Teprotumumab (Tepezza) is a human monoclonal antibody against the insulin-like growth factor type I receptor (IGF-IR), recently evaluated in two clinical trials for active moderate-to-severe TAO that was recently approved by the United States Food and Drug Administration (FDA) for use in TAO.

AREAS COVERED

This article reviews phase II and III placebo-controlled, double-masked, prospective, multicenter studies assessing the efficacy and safety of teprotumumab for the treatment of active, moderate-to-severe TAO.

EXPERT OPINION

Teprotumumab has demonstrated substantial and rapid improvement in Clinical Activity Score and proptosis reduction in TAO compared to placebo. Subjective diplopia and quality of life were also improved in both clinical trials. Teprotumumab exhibited a favorable safety profile, with transient hyperglycemia, muscle cramps, and auditory side effects being associated with the drug; these were usually transient. The trial findings indicate that teprotumumab is a promising, potential first-line therapy for treating TAO.

Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.

Risk of developing radiogenic cancer following photon-beam radiotherapy for Graves' orbitopathy

PURPOSE

The objective of this study was to estimate the probability for cancer development due to radiotherapy for Graves' orbitopathy with 6 MV x rays.

METHODS

Orbital irradiation was simulated with the MCNP code. The radiation dose received by 10 out-of-field organs having a strong disposition for carcinogenesis was calculated with Monte Carlo methods. These dose calculations were used to estimate the organ-dependent lifetime attributable risk (LAR) for cancer induction in 30- and 50-yr-old males and females on the basis of the linear model suggested by the BEIR-VII report. Differential dose-volume histograms derived from patients' three-dimensional (3D) radiotherapy plans were employed to determine the organ equivalent dose (OED) of the brain which was partly exposed to primary radiation. The OED and the relevant LAR for brain cancer development were assessed with the plateau, bell-shaped and mechanistic models. The radiotherapy-induced cancer risks were compared with the lifetime intrinsic risk (LIR) values for unexposed population.

RESULTS

The radiation dose range to organs excluded from the treatment volume was 0.1-91.0 mGy for a target dose of 20 Gy. These peripheral organ doses increased the LIRs for cancer development of unexposed 30- and 50-yr-old males up to 1.0% and 0.2%, respectively. The corresponding elevations after radiotherapy of females were 2.0% and 0.4%. The use of nonlinear models gave an OED range of the brain of 482.0-562.5 mGy depending upon the model used for analysis and the patient's gender. The elevation of the LIR for developing brain malignancies after radiotherapy of 30-yr-old males and females reached to 13.3% and 16.6%, respectively. The corresponding increases after orbital irradiation at the age of 50 yr were 6.7% and 8.3%.

CONCLUSIONS

The level of the LIR increase attributable to radiation therapy for GO varied widely by the organ under examination and the age and gender of the exposed subject. This study provides the required data to quantify the elevation of these baseline cancer risks following orbital irradiation.

Radiotherapy for Active Thyroid Eye Disease

PURPOSE

To critically review the published literature on orbital radiotherapy as a treatment modality for thyroid eye disease (TED).

METHODS

A systematic review and analysis of the relevant published literature was performed.

RESULTS

Thyroid eye disease is an autoimmune condition that is amenable to treatments that modulate the immune response, including orbital radiotherapy (ORT). Ideal candidates for ORT are patients in the early, active phase of TED with moderate to severe, or rapidly progressive, disease, including patients with significant motility deficits and compressive optic neuropathy. Patients with progressive strabismus may also benefit. Patients with mild or inactive disease will not benefit from ORT when compared with the natural history of the disease. Orbital radiotherapy should generally be used in conjunction with corticosteroid therapy, with response to corticosteroids demonstrating the immunomodulatory therapeutic potential of ORT. When treating TED-compressive optic neuropathy, ORT may help obviate the need for urgent surgical decompression, or postpone it until the stable, inactive phase of the disease. Orbital radiotherapy treatment doses should approach 20 Gy in most cases, but lower doses may be considered in younger patients without significant dysmotility. The safety profile of ORT is well established, and side effects are minimal in appropriately selected patients.

CONCLUSIONS

Radiotherapy is a safe and effective treatment for active TED in appropriately selected patients.

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.

Secondary malignancy following radiotherapy for thyroid eye disease

AIM

To describe the first case of a secondary meningioma in a patient after radiation treatment for thyroid eye disease (TED). Secondarily to identify any additional cases of secondary malignancy resulting from radiotherapy for thyroid eye disease from our institutional experience.

BACKGROUND

Thyroid eye disease (TED) is a self-limiting auto-immune disorder causing expansion of orbital soft tissue from deposition of glycosaminoglycans and collagen, leading to significant cosmetic and functional morbidity. Established management options for TED include: glucocorticosteroids, orbital radiotherapy, and surgical orbital decompression. Two large series on radiotherapy for TED have been reported without any cases of secondary malignancy.

MATERIALS AND METHODS

The case of a patient with visual failure, found to have a sphenoid wing meningioma after previous TED radiotherapy is described. We then reviewed 575 patients with at least 3-year follow-up receiving radiotherapy for TED at British Columbia Cancer Agency to identify other possible secondary malignancies.

RESULTS

The patient had postoperative improvement in her vision without any identified complications. Three additional cases of hematologic malignancy were identified. The calculated risk in our population of developing a radiation-induced meningioma after TED with at least 3 years of follow-up of is 0.17% (1/575); with hematopoetic malignancies the risk for secondary malignancy is 0.7% (4/575).

CONCLUSIONS

Our calculated risk for secondary malignancy (0.17%, 0.7%) is similar to the reported theoretical risk published in the literature (0.3-1.2%). There is real risk for the development of a secondary malignancy after radiotherapy treatment of TED and treatment options should include consideration for this potential.

[Thyroid orbitopathy, an overview with special attention to the role of radiotherapy]

Thyroid orbitopathy is the most prevalent non-thyroid symptom in Graves' syndrome. It has a high incidence and particularly affects young women. Smoking is clearly involved in its development and progress, and in its response to different treatments. This autoimmune condition usually has a benign course, independent from hyperthyroidism, but its severe, progressive forms represent a major therapeutic challenge. Clinical evaluation poses great difficulties, as there is no truly objective rating scale representing disease activity. New molecular or inflammation markers may prove to be useful in this regard. This review reports new findings about its pathophysiology and the different techniques used for treatment over time. Discussion particularly focuses on the immunomodulatory role of radiotherapy, as well as on its role together with corticosteroids.

Orbital radiotherapy for thyroid eye disease

PURPOSE OF REVIEW

Orbital radiotherapy has been used for over 60 years to treat thyroid eye disease (TED) alone or in conjunction with glucocorticoids or orbital decompression surgery. However, numerous observational and randomized controlled trials have yielded conflicting results concerning its efficacy. This review highlights recent systematic reviews concerning the use of radiotherapy for TED.

RECENT FINDINGS

Three recent systematic analyses have drawn different conclusions about its efficacy. This relates to the varied nature of the disease, the different selection criteria, and different outcome measures (often focussing on global indices or clinical activity scores rather than subjective quality of life scores and individual disease parameters as specified by the VISA Classification).

SUMMARY

Radiotherapy should only be offered in the early active phase, is most effective in combination with glucocorticoids, and may have specific indications for dysthyroid optic neuropathy (DON), inflammatory periocular changes, or progressive motility disturbance. Future research may study its potential benefit in preventing or treating DON and compare the ability of combination radiotherapy/intravenous (i.v.) glucocorticoids versus i.v. glucocorticoids monotherapy for limiting complications from progressive TED.

Radiotherapy in the treatment of Graves ophthalmopathy-to do it or not?

To the objective of this study is to evaluate the role and toxicity of radiotherapy in the treatment of Graves ophthalmopathy. In the years 2000-2003, 121 patients with malignant exophthalmos were treated with radiotherapy of the retrobulbar area to the total dose of 20 Gy in ten fractions with a 6 MeV photon beam. The treatment was performed by the team of the Clinic of Oncology of the Jagiellonian University Medical College in Cracow. The radiotherapy was preceded by intravenous steroid therapy: methylprednisolone acetate administered at the dose of 2 g/week for four consecutive weeks. The highest efficacy, expressed as improvement of all ocular symptoms, was observed for the combined treatment. Female and non-diabetic patients responded positively to the combined treatment. Radiotherapy combined with steroid therapy in the treatment of Graves ophthalmopathy seems to be an effective treatment for strictly defined indications. In the treatment of Graves-Basedow disease, radiotherapy is a well-tolerated treatment modality. Diabetes is a factor that worsens prognosis in Graves ophthalmopathy and female sex is a favourable factor for this condition.

No changes in serum concentrations of interleukin 10 (IL-10) and interferon gamma (IF-gamma) before and after treatment of the thyroid eye disease (TED)

TED is a severe eye disease leading in rare cases to decrease of sight, optic nerve compression and blindness. Recently, significant progresses in understanding the disease have been done. Nevertheless, the treatment of the disease, especially in its severe form remains challenging. Glucocorticoids (GC) have been the basis of the treatment for a long time. Orbital irradiation (OI) and optical decompression (OD) are also used in managing the severe forms of TED. Somatostatin, intravenous immunoglobulin have been also used, with conflicting results. Regarding the potential for the treatment of TED with cytokine antagonists, controlled clinical studies are not available. Since cytokines play an important role in the pathogenesis of the TED, they seemed to be logical choice for modern TED treatment. It has been shown that both Th1 (interleukin-2, tumor necrosis factor gamma, interleukin gamma) and Th2 (interleukin -4, -5, -10) profile T cells are activated in the TED. We therefore measured interleukin-gamma, IF-gamma and interleukin -10 (IL-10)(Th1 and Th2 pattern) to assess its relationship to the course of the disease. This paper shows that both Th1 (IL-2) and Th2 (IF-gamma) pathways represented by those two cytokines are not involved (IL-10 before 2.29+/-5.23 and after treatment 3.77+/-8.44; IF gamma before 0.50+/-0.24 and after treatment 0.35+/-0.19). No relationship to the response to treatment was found. GC resulted in positive response in 8/22 patients, OI (12 patients) given after CS therapy, resulted in a response in all patients. Increase in proptosis, loss of visual acuity is spite of CS treatment prompted OD in two patients, who both recovered visual acuity and proptosis fell under 25 mm Hertel.

Ophthalmic and adnexal complications of radiotherapy

The role of radiotherapy in ophthalmic practice continues to grow. This growth has seen an expansion of indications for radiotherapy, a refinement of the modalities that can be used and a reduction in the ocular and adnexal complications that result from this form of therapy. The compendium of indications for radiotherapy in ophthalmology continues to grow and now includes many conditions such as the treatment of lid and adnexal disease, ocular surface disorders and both benign and malignant disease of the posterior segment and optic pathways. The radiotherapeutic modalities employed to manage these conditions are numerous and include both radioactive plaques (brachytherapy) and external beam radiation techniques. New techniques such as stereotactic radiosurgery are delivering benefits in the management of conditions such as optic nerve sheath meningioma, where the treatment of this blinding and occasionally life-threatening intracranial neoplasm now results in fewer adverse affects. The purpose of this review is to give a brief overview of the indications and treatment modalities, and a more in-depth discussion of the potential side-effects when radiotherapy is used for ocular and periorbital disease.

Estimation of the carcinogenic risk of radiotherapy of benign diseases from shoulder to heel

BACKGROUND AND PURPOSE

To estimate risk on fatal tumour induction in patients by radiotherapy of benign diseases at various body sites, including heterotopic ossification, omarthritis, gonarthrosis, heel spurs and hidradenitis suppurativa.

MATERIAL AND METHODS

The carcinogenic risk is estimated by applying the effective dose concept from the ICRP with the average risk factor of 10% per Sv for high dose and high dose rate. Although, the concept of effective dose for the present study has limitations, its use is considered acceptable for a fairly rough risk estimate. The organ doses are calculated using a Monte Carlo radiation transport code and anthropomorphic mathematical phantoms. Special risk modifying factors like patient's age at exposure and gender are taken into account.

RESULTS

For the treatment of heterotopic ossification, omarthritis, gonarthrosis, heel spurs and hidradenitis suppurativa the effective dose is in the range of 5-400 mSv. For an average-aged population, the estimated number of radiation-induced fatal tumours due to these treatments is assessed to be between 0.5 and 40 persons per 1000 patients treated. At higher ages the risks are reduced.

CONCLUSIONS

The range of effective doses found for the various types of treatment at various body sites is large. There are several possibilities to optimise the treatment protocols resulting in reduced effective doses and related radiation risks.

Orbital irradiation for Graves' ophthalmopathy: Is it safe? A long-term follow-up study

PURPOSE

We evaluated the frequency of long-term complications of orbital irradiation (radiation-induced tumors, cataract, and retinopathy) in comparison with glucocorticoids.

DESIGN

We conducted a follow-up study in a cohort of 245 Graves' ophthalmopathy patients who had been treated with retrobulbar irradiation (20 Gy in 2 weeks) and/or oral glucocorticoids between 1982 and 1993 in our institution. Irradiated patients were compared with nonirradiated patients.

METHODS

Data on mortality and cause of death were obtained. Living patients were invited to participate in a follow-up study. Possible retinopathy was assessed in a masked fashion and defined as the presence of > or =1 hemorrhages and/or microaneurysms on red-free retina photographs. If >5 lesions were present, patients were categorized as suffering from definite retinopathy. Cataract was assessed using the Lens Opacity Classification System II score.

MAIN OUTCOME MEASURES

Mortality, prevalence of retinopathy, prevalence of cataract, and type of cataract.

RESULTS

Thirty-seven of the 245 patients had died, none of them from an intracranial tumor. Mortality was similar in the irradiated (27/159 [17%]) and nonirradiated patients (10/86 [12%]; P = 0.264). One hundred fifty-seven of the 208 living patients (75%) consented to participate in a follow-up ophthalmologic investigation; the mean follow-up time (+/- standard deviation) was 11+/-3 years. Possible retinopathy was present in 15% of patients, 22 of the irradiated and 1 of the nonirradiated patients (P = 0.002). In 5 patients (all had been irradiated), definite retinopathy (i.e., >5 retinal lesions) was present. Of these, 3 had diabetes mellitus, and 1 had hypertension. Diabetes was associated with both possible (P = 0.029) and definite (P = 0.005) retinopathy, with a relative risk of 21 (95% confidence interval, 3-179). The prevalence and severity of cataract were similar in the radiotherapy group (29%) and the glucocorticoid group (34%); it should be noted that 88 of 104 of the irradiated patients were also treated with oral glucocorticoids.

CONCLUSION

The data suggest that orbital irradiation for Graves' ophthalmopathy is a safe treatment modality, except possibly for diabetic patients.

Cancer prevention and therapy: strategies and problems

During the next years, molecular diagnostic science and the pharmaceutical industry will face increasing demand for personalized medicine. Therapeutic treatments should be tailored to the needs of individual patient. Patients will inquire for information about potential tumor detection at an early stage when disease can be more likely to be arrested or cured with specific regimens of drug therapy. To respond to this demand, science and industry need to modulate therapeutic approaches to the continuous development of cancer. Now more than ever, it is necessary to fill the knowledge hiatus between the "beginning" and the "end" of cancer development, i.e we need to critically analyze the extensive multi-step process of cancer development that still remains poorly understood.

The risk of radiation-induced carcinogenesis after external beam radiotherapy of Graves' orbitopathy

PURPOSE

In order to estimate the risk of radiation-induced carcinogenesis after external beam radiotherapy of Graves' orbitopathy, we made dosimetric measurements with thermoluminescent dosimeters in a male Rando phantom using our treatment technique.

METHODS

We produced dose-volume histograms from 5-mm CT slices using our treatment planning system. In this way we estimated the irradiation dose received by the main surrounding organs such as the brain, the bone and the eyeball. We use 6-MV X-ray for the treatment of Graves' orbitopathy and our total dose is 2,000 cGy, 200 cGy per fraction. Clinical target volume was limited to the retrobulbar orbital content and medial rectus muscle, sparing the lenses, lacrimal glands and the sella turcica. All dosimetric measurements with thermoluminescent dosimeters were made 3 times.

RESULTS

We found that the dose to the right lens was 101.6 mGy and to left lens 103.4 mGy. Average absorbed doses to red bone marrow, thyroid, lung, esophagus, bone surface, skin and brain, respectively, were estimated to be 523, 21, 4, 5, 81, 29, 47 mGy. Then, using tissue weighting factors specified by the International Commission of Radiation Protection, the resulting total effective dose was calculated to be 66.8 mSv.

CONCLUSION

The risk factor for fatal cancer development derived from human epidemiological data is presently assumed to be 10% per Gy. In patients treated by our method of retro-orbital external beam radiotherapy for Graves' orbitopathy, there is a 0.0067 (or 7 per 1,000 persons or 0.7%) risk of developing fatal radiation-induced cancer.

Retrobulbar irradiation for thyroid-associated orbitopathy: double-blind comparison between 2.4 and 16 Gy

PURPOSE

Retrobulbar irradiation is used as a standard therapy for thyroid-associated orbitopathy. The evidence of its effectiveness is, however, scarce. Doses from 2.5 to 20 Gy have been recommended.

METHODS

Forty-three patients with active thyroid-associated orbitopathy were irradiated with 2.4 Gy and 43 with 16 Gy. Five measures of outcome were used: (1) appearance of the eye region, documented with photographs; (2) Hertel exophthalmometry; (3) range of vertical eye movements; (4) eye muscle thickness (sum of three MRI sections across the eight rectus eye muscles); and (5) complaints, indicated on a visual analog scale.

RESULTS

At 3 and 6 months after irradiation, no difference between 2.4 and 16 Gy was found in any of the five outcome measures (p between 0.099 and 0.993; Kruskal-Wallis test, Holm correction). Most outcome measures were slightly, but not significantly, improved in both the 2.4 and the 16 Gy groups. Patient complaints had improved significantly in both groups and the eye muscle thickness was significantly reduced in the 2.4 Gy group after 6 months.

CONCLUSION

The lack of a difference between 2.4 and 16 Gy is compatible with four different interpretations: (1) the irradiation could be ineffective; (2) the maximal effect could be already reached at 2.4 Gy; (3) the maximal effect could lie between 2.4 and 16 Gy; and (4) the effect could increase beyond a threshold of >or=16 Gy. From general experience with inflammatory disease, the last two possibilities are unlikely; only the first two interpretations carry some probability. Although the design of the study did not allow a distinction between these two possibilities, we conclude that retrobulbar irradiation for thyroid-associated orbitopathy should not exceed 2.4 Gy.

The aftermath of orbital radiotherapy for graves' ophthalmopathy

OBJECTIVE

To determine whether long-term improvement could be observed after orbital radiotherapy for Graves' disease; in addition, to evaluate ancillary treatments needed for those who have received radiotherapy, to search for late-emerging adverse consequences of radiotherapy, and to relate orbital changes to serum levels of thyroid-stimulating immunoglobulin (TSI).

DESIGN

Three-year follow-up of noncomparative interventional case series.

PARTICIPANTS

Forty-two patients.

INTERVENTION

All patients had received orbital radiotherapy within 6 months of study entry. Twelve months after study entry, patients were free to select any additional treatment for their ophthalmopathy.

MAIN OUTCOME MEASURES

Need for surgery, steroid therapy, volume of extraocular muscles and fat, proptosis, area of diplopia fields and range of extraocular muscle motion, volume changes after decompression and correlations of eye findings with serum TSI levels, retinal status.

RESULTS

Half of the patients elected to have a surgical procedure on their eyes or orbits. Among patients who were not decompressed, we found only slight improvement in some of the main outcome measures. TSI did not positively correlate with baseline status or with any observed change in major outcome measures. After orbital decompression, the volumes of both muscle and fat increase, but bony orbital volume increases more and proptosis diminishes. Retinal microvascular abnormalities consistent with radiation retinopathy developed de novo in five eyes of three patients within 3 years of radiation therapy.

CONCLUSIONS

In this 3-year uncontrolled follow-up phase, limited evidence for a clinically significant improvement was observed, which may be the result of treatment or of natural remission. In either case, the changes are of little clinical significance. Because it is neither effective nor innocuous, radiotherapy does not seem to be indicated for treatment of mild to moderate ophthalmopathy.

Graves' ophthalmopathy: a rational approach to treatment

The past decade has witnessed great progress in our understanding of Graves' opthalmopathy (GO), although its precise immunopathogenesis remains an enigma. Several clinical studies have provided a more rational basis for treatment of this distressing disease, which significantly lowers the quality of life. A management plan tailored to the patient's needs can be devised according to the severity and activity of the eye disease. In active GO, immunosuppression might be considered. The combination of intravenous pulses of methylprednisolone and retrobulbar irradiation improves eye changes in 88% of patients, and is well tolerated. Once the disease has become inactive, rehabilitative surgery could be performed (orbital decompression, strabismus surgery and eyelid surgery, in that order). The patient should be reassured that functional and cosmetic improvement of eye changes is feasible, but restoration can require one to two years. To a certain extent, refraining from smoking prevents the development or worsening of GO.

Orbital radiotherapy for Graves' ophthalmopathy

Orbital radiotherapy is a well-established method of treatment for severe Graves' ophthalmopathy, because of its anti-inflammatory and locally immunosuppressive effects. It has been used for 60 years. Conventional external x-ray and cobalt therapy have been abandoned, and most groups now use supervoltage linear accelerators (4-6 MeV). Cumulative doses may vary, but in most studies a cumulative dose of 20 Gy delivered over 2 weeks was utilized. Successful outcome depends on the selection of patients, because recent onset, active ophthalmopathy is much more favorably affected than longstanding, inactive disease. Inflammatory signs, recent onset eye muscle dysfunction, and optic neuropathy respond well to orbital radiotherapy, while proptosis and longstanding eye muscle restriction respond poorly. Overall, favorable responses have been reported, with few exceptions, in approximately 60% of cases. Combination of irradiation with high-dose systemic glucocorticoids provides better results than either treatment alone. Orbital radiotherapy is well tolerated and safe. Preexisting retinopathy (e.g., in patients with diabetes) is a contraindication to this treatment for the risk of further retinal damage. No case of radiation-induced tumors has so far been described after orbital radiotherapy for Graves' ophthalmopathy.

[Radiotherapy of endocrine orbitopathy--state of the art]

Since several decades, radiotherapy is included in the multimodal treatment concept of Graves' disease. By using orbital irradiation alone or in combination with oral corticosteroids up to two thirds of the patients respond to the treatment and achieve improvement of soft tissue signs and extraocular muscle impairment.

A long-term follow-up study after retro-orbital irradiation for Graves' ophthalmopathy

PURPOSE

The aim of this retrospective analysis was to find out whether low-dose radiation, which is used in the treatment of Graves' ophthalmopathy, could cause radiation-induced cancer, which would in turn adversely affect the survival of the irradiated population and cause an increase in the cancer-specific death rate.

METHODS AND MATERIALS

From 1963 to 1978, 250 patients received bilateral orbital irradiation for a progressive Graves' ophthalmopathy. Median age was 49 years. Overall survival and causes of death were evaluated with the help of patients still living, registration offices, medical records, referring physicians, and relatives. Survival curves were calculated with the Kaplan-Meier method. The outcome for each patient was compared with data from life tables regarding gender, age, and calendar period-specific person-years at risk. In addition, treatment outcome for living patients was evaluated with a questionnaire.

RESULTS

After a median follow-up of 31 years, 102 patients are still alive, 123 patients have died, and 25 patients have been lost to follow-up. The 10-year, 20-year, and 30-year survival rates were 89%, 68%, and 49%, compared with the age-adapted survival rate of the normal population of 92%, 76%, and 52%. Evaluation of cancer-specific survival was possible in 166 cases. The 10-year, 20-year, and 30-year cancer-specific survival rates were 98%, 92%, and 88%, compared with 97%, 93%, and 87% in the normal population. Treatment response was evaluable in 94 cases. A complete response was reported in 41 patients, a partial response in 39 patients, and no change in 14 patients.

CONCLUSIONS

No significant evidence of radiation-induced cancer death was seen in this small cohort of patients treated with radiotherapy for Graves' ophthalmopathy. The long-term treatment results seem to be satisfactory. Studies with greater numbers of patients are necessary to examine the risks and benefits more precisely.

Long-term results of irradiation for patients with progressive Graves' ophthalmopathy

PURPOSE

To determine the long-term outcome of radiotherapy (RT) in patients with progressively symptomatic thyroid eye disease and to evaluate the potential long-term sequelae.

METHODS AND MATERIALS

Four hundred fifty-three patients provided written informed consent and received retrobulbar RT for Graves' ophthalmopathy at Stanford University Medical Center; 197 with 1 year of follow-up were retrospectively analyzed. Of the 197 patients, 189 received RT to the bilateral retrobulbar regions, and 4 received unilateral RT. The technical information was unavailable for 4 patients. Patients were assessed by chart review, telephone interview, questionnaire, and multidisciplinary physician examination. Eye impairment was scored using the SPECS system. The end point review included the before and after treatment SPECS score, surgical intervention, and patient satisfaction. Potential complications, including cataract development, retinopathy, and tumor formation, were investigated. Multivariate analyses were performed to assess the prognostic variables.

RESULTS

Improvement or resolution was 89% for soft-tissue findings; 70% for proptosis; 85% for extraocular muscle dysfunction; 96% for corneal abnormalities; and 67% for sight loss. The response to RT may take >6 months to stabilize. Factors predictive of response varied in the individual SPECS categories but included the initial SPECS score, pretreatment thyroid status, female gender, a 20-Gy RT dose, and a history of hypertension. Nonpredictive factors included a history of tobacco use, diabetes mellitus, steroids, and prior cataracts. Only 16% required surgical intervention to preserve their vision or restore binocular vision. Twenty-two patients (12%) developed cataracts after irradiation (median 11 years). No patient developed a tumor within the RT field during the follow-up period (range 1-29 years). Ninety-eight percent of patients were pleased with their results, and 2% believed their symptoms progressed despite RT.

CONCLUSIONS

Retrobulbar irradiation (20 Gy) is safe and effective treatment for progressive Graves' ophthalmopathy, with a 96% overall response rate, 98% patient satisfaction rate, and no irreparable long-term sequelae, with follow-up extending 29 years. The most common late effect observed was cataract development, which occurred more frequently in older patients and was reversible with extraction. Elective surgical intervention after RT should be withheld until patients have demonstrated a plateau in response.

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.

An evidence-based approach to the treatment of Graves' ophthalmopathy

A recent survey demonstrated considerable controversy about the therapeutic approach to a patient with Graves' ophthalmopathy. Among various reasons for this disagreement is the lack of an accepted way to assess the outcome of a given therapeutic intervention. An evidence-based approach requires an objective and meaningful assessment of therapeutic outcomes in prospective, randomized studies in which confounding factors (e.g., smoking, disease activity, and state of the thyroid) are accounted for and controlled. On the basis of the available studies, a treatment approach can be selected.

Management of Graves' ophthalmopathy: reality and perspectives

Graves' ophthalmopathy is an debilitating disease impairing the quality of life of affected individuals. Despite recent progress in the understanding of its pathogenesis, treatment is often not satisfactory. In mild cases, local therapeutic measures (artificial tears and ointments, sunglasses, nocturnal taping of the eyes, prisms) can control symptoms and signs. In severe forms of the disease (3-5%), aggressive measures are required. If the disease is active, high-dose glucocorticoids and/or orbital radiotherapy, or orbital decompression represent the mainstay of treatment. If the disease is severe but inactive, orbital decompression is preferred. Novel treatments such as somatostatin analogs or intravenous immunoglobulins are under evaluation. Rehabilitative (extraocular muscle or eyelid) surgery is often needed after treatment and inactivation of eye disease. Correction of both hyper- and hypothyroidism is crucial for the ophthalmopathy. Antithyroid drugs and thyroidectomy do not influence the course of the ophthalmopathy, whereas radioiodine treatment may cause the progression of preexisting ophthalmopathy, especially in smokers. The exacerbation, however, is prevented by glucocorticoids. In addition, thyroid ablation may prove beneficial for the ophthalmopathy in view of the pathogenetic model relating eye disease to autoimmune reactions directed against antigens shared by the thyroid and the orbit.

Low- versus high-dose radiotherapy for Graves' ophthalmopathy: a randomized, single blind trial

Orbital radiotherapy (Rx) is a commonly used treatment for Graves' ophthalmopathy (GO), but controlled clinical trials evaluating different Rx doses and application forms have not been performed. In euthyroid patients with moderately severe GO, we randomly compared the efficacy and tolerability of three Rx protocols. Orbital Rx (telecobalt) was administered either in 20 divided fractions of 1 Gray (Gy) weekly over 20 weeks (group A) or in 10 fractions of 1 Gy (B) and 2 Gy (C) daily over 2 weeks. Before and 24 weeks after starting Rx, ophthalmic investigation and magnetic resonance imaging were performed. Response to therapy, defined as a significant amelioration of three objective parameters, was noted in 12 A (67%), 13 B (59%), and 12 C (55%) subjects (C vs. A, P = 0.007). Ophthalmic symptoms and signs regressed most in group A; changes in lid fissure width were -1.5, -0.5, and 0 mm in the A, B, and C groups, respectively (A vs. C, P = 0.005), whereas changes in intraocular pressure (upgaze) were -3, +1, and -1.5 mm Hg, respectively (A vs. B, P = 0.002). The median decreases in proptosis were -2 mm (A, P = 0.0001), -1.5 mm (B, P = 0.02), and -1 mm (C, P = 0.007; A vs. C, P = 0.0380. Visual acuity (+0.15; P = 0.02) and eye muscle motility (bulbar elevation, 30 degrees vs. 37 degrees, P = 0.03, A vs. C, P = 0.0020; abduction, 45 vs. 49 degrees, P = 0.02; A vs. C, P = 0.017) improved in group A only. A significant change in all rectus muscle areas was noted in 14 A (78%), 12 B (55%), and 9 C (41%) subjects (C vs. A, P = 0.002). A decrease in the NOSPECS classes was observed in 12 A (67%), 13 B (59%), and 13 C (59%) patients (A vs. B/C, P = 0.01). Rx-induced conjunctivitis was not observed in group A, but was seen in 4 B (18%) and 8 C (36%) subjects (C vs. A, P = 0.003). At 24 weeks, satisfaction rates were 67%, 59%, and 55% in the A, B, and C groups, respectively (C vs. A, P = 0.008). Thus, in patients with moderately severe GO, similar response rates were observed for low and high Rx doses, but the 1 Gy/week protocol was more effective and better tolerated than the short arm regimens.

Assessment of a carcinogenic risk for treatment of Graves' ophthalmopathy in dependence on age and irradiation geometry

In view of the probable carcinogenic risk due to the irradiation of Graves' ophthalmopathy in young patients the effective dose was assessed for two geometries. Adjusting the field to the conical outline of the orbit resulted in appreciable reduction in dose to uninvolved areas such as brain and bone marrow. In Leiden and in Essen the initial target dose was 20 Gy in 10 fractions of 2 Gy. Since 1996 the target dose in Essen was lowered to 10 fractions of 1.6 Gy with equal positive results. The combined effect of field optimization and 20% reduction in target dose has lowered the effective dose from 65 to 34 mSv. The attributable lifetime risk for fatal malignancies of 0.3% as a population average will be considerably reduced when the exposure occurs at older age.

Radiation therapy for benign disease of the orbit

Benign diseases of the orbit can cause significant impairment of visual function through direct effects on the eye or supporting orbital tissues. Persistent moderate-to-severe inflammatory symptoms, diplopia, and visual loss may prompt therapeutic intervention. Low doses of external-beam irradiation (20 Gy in 2-Gy fractions) have an efficacy equivalent to corticosteroid medications in the treatment of both Graves' ophthalmopathy and orbital pseudotumor, with response rates of 50% to 80%. Appropriate patient selection, coordination with other medical subspecialties, and careful treatment planning are important in maximizing benefit from radiation therapy. In the case of Graves' ophthalmopathy, quantitative assessment of orbital disease severity and thyroid status as well as attainment of cross-sectional imaging should be performed before treatment. Patients whose thyroid disease is controlled but who have moderate-to-severe active orbital involvement can be offered orbital radiation therapy with a high likelihood of response. Stability of disease is generally obtained within 6 months; surgical correction of residual abnormalities may be required. For orbital pseudotumor, attainment of histological material before treatment is important in excluding benign or malignant systemic diseases, including malignant lymphoma. Genotypic abnormalities may exist in patients with reactive lymphoid hyperplasia, some of whom ultimately develop systemic lymphoma. Within the dose range recommended for treatment of Graves' ophthalmopathy and pseudotumor, late radiation effects on the retina or optic nerve should be nonexistent. Adequate lens shielding is required, however, to prevent cataract formation. This may require individualized treatment planning with computed tomography at the time of simulation. Pterygia recurrence after bare sclera excision occurs in at least 30% of cases, usually within 6 months of surgery. Radiation of the surgical bed using a strontium-90 source, beginning within 24 hours postoperatively, reduces the risk of recurrence substantially. Late scleral complications have been associated with large single-fraction treatments. To achieve maximal efficacy with minimal complications, fractionated treatment should be given by radiation oncologists experienced with the technique using sources calibrated by the National Bureau of Standards.

Place of radiotherapy in the treatment of Graves' orbitopathy

PURPOSE

The aim of this study is to evaluate the response of Graves' orbitopathy to irradiation, and to specify the prognostic factors allowing one to better define the indications of orbital radiotherapy.

METHODS AND MATERIALS

From 1977 to 1996, 199 patients received bilateral orbital irradiation delivering 20 Gy in 10 fractions and 2 weeks for a progressive Graves' orbitopathy. 195 patients were seen between 1 and 6 months after radiotherapy. The different symptoms were studied and their response to radiation was analyzed. Factors such as age, sex, evolution of thyroid disease, history of symptoms, and previous or combined treatments were analyzed.

RESULTS

The results revealed that 50 patients (26%) had a good or excellent response, 98 (50%) had a partial response, 37 (19%) were stable, 10 (5%) had a progression of disease. The signs that best responded to radiotherapy were the infiltration of soft tissues and the corneal involvement. Responses of proptosis or oculomotor disorders were more complete when these signs were not advanced at the time of treatment. Irradiation seemed to have the same efficacy when applied as first-line treatment or after failure of corticosteroids. Neither modality of treatment of hyperthyroidism nor thyroid status at the time of orbital irradiation modified the results. The best results were recorded for early or moderately advanced presentation (p = 0.05). Patients treated within a delay of 7 months after the beginning of the ophthalmopathy had better responses than patients treated later (p = 0.10).

CONCLUSION

Radiation therapy was successful in Graves' orbitopathy by stopping the progression of disease in almost all cases, by improving the comfort of patients, by obtaining objective responses, and by avoiding surgical treatments particularly when signs were moderate.

[Endocrine orbitopathy: comparison of the long-term result and classification after radiotherapy]

BACKGROUND

This study compares 4 classifications in patients with progressive refractory Graves orbitopathy (GO) and examines their prognostic value in long-term follow-up.

PATIENTS AND METHODS

From 1984 to 1994, 60 consecutive patients (49 female, 11 male) received 20 Gy (10 x 2 Gy) radiotherapy with 6 MV Linac photons. Ocular symptoms and functional impairment was evaluated according to 4 GO-classification systems: Werner-, modified ATA- and Stanford-Score and Ophthalmopathy-Index (OI) according to Grussendorf. In addition, all patients noted their subjective response on a linear scale (0 to 100%).

RESULTS

Improvement was achieved within 1 year after radiotherapy according to the Werner-Score in 28 (47%) patients in > or = 1 symptom category, according to the modified ATA-score in 48 (80%), the Stanford-score in 47 (78%) and the OI-Score in 55 (92%) patients (reduction of > 2 points). The Werner-Score correlated less to the other scores (coefficient r < 0.5) than the other scores among themselves (r approximately 0.9). The ATA-Score improved in the different symptom categories between 47% (stage VI) and 87% (stage V). The OI-Score was reduced by a mean of 6 points. The patients reached a mean subjective improvement of +70 +/- 25%. Acute or chronic side effects were not observed. In multivariate analysis the "male gender" (p = 0.08), a "symptom duration prior to radiotherapy > 1 year" (p = 0.14) and a "high symptom category" (p = 0.11) indicated a negative prognostic trend.

CONCLUSIONS

External radiotherapy is effective for severe, progressive GO after pretreatment. A minimum follow-up of at least 12 months and standardized classification and success criteria are required.

Indications and treatment schedules for irradiation of benign diseases: a survey

BACKGROUND

The interest in the treatment of benign diseases with radiotherapy has grown particularly in the Western part of the world. Questions about the effectiveness and risks of radiotherapy for these disorders have to be answered in the light of new information from clinical research, dose calculations and risk estimates. New indications for irradiation of non-malignant diseases, e.g. vascular disorders, such as macular degeneration and prevention of stent restenosis, are appearing. As a starting point for further discussions and publications in this area, the authors, with the help of the European Society for Therapeutic Radiology and Oncology (ESTRO), performed a survey of current practice and of opinion amongst ESTRO members.

METHODS

A questionnaire was circulated in 1996 to 1348 institutes listed in the 1995 ESTRO directory asking whether the respondents considered a list of the 28 most common benign disorders as being a good indication for radiotherapy. Details of the frequency of such treatments and of treatment schedules used were requested.

RESULTS AND CONCLUSIONS

A large variation in indications and treatment schedules was detected throughout the world. This variation confirms the inadequate information on which such treatments are based and stresses the importance of careful clinical studies and trials as well as clear understanding of any risks involved.

Treating severe Graves' ophthalmopathy

Most patients with Graves' disease have some evidence of ocular involvement, but this is commonly mild, requiring only local measures. A minority of patients (3-5%) have severe Graves' ophthalmopathy, for which the three main treatment procedures are represented by high-dose glucocorticoids, orbital radiotherapy and orbital decompression. Favourable results with medical treatment have been reported in approximately 60% of patients, with particular regard to inflammatory changes, newly developed eye muscle dysfunction and optic neuropathy. Orbital decompression is indicated in severe eye disease not responsive to glucocorticoids and/or irradiation, particularly in the presence of marked proptosis and optic neuropathy. Not conclusive or unsatisfactory results have been obtained with other medical treatment procedures, including immunosuppressive drugs, intravenous immunoglobulins and plasmapheresis. Recently favourable responses have been reported with somatostatin analogues. Rehabilitative surgery involving either the eye muscles or the eyelids is not infrequently required after medical treatment or decompression. Permanent control of thyroid hyperfunction by radioiodine or thyroidectomy is advisable when severe ophthalmopathy is present. Exacerbation of ophthalmopathy following radioiodine may occur but can be prevented by concomitant administration of glucocorticoids. Smoking deleteriously influences the course of ophthalmopathy and its response to treatment.