Ophthalmic and adnexal complications of radiotherapy

Risk of dry eye syndrome in patients treated with whole-brain radiotherapy

With improvements in systemic therapy, patients with cancer treated with whole-brain radiotherapy (WBRT) are living long enough to develop late toxicities, including dry eye syndrome. In general practice, dose to the lacrimal gland (LG) is not constrained (maximum constraint <40 Gy) in WBRT. The purpose of this study was to measure dose to the LG in WBRT and determine methods for reducing radiation exposure. We conducted a retrospective review of 70 3-dimensional (3D) conformal plans; thirty-six plans with a radiation prescription of 30 Gy in 10 fractions and 34 plans with a prescription of 37.5 Gy in 15 fractions. LGs were contoured in accordance with Freedman and Sidani (2015). Biological effective dose (BED)3 maximum constraints were calculated from 40 Gy and 20 Gy to be 32.17 Gy (30 Gy) and 36.70 Gy (37.5 Gy). Both regimens demonstrated supraorbital blocking by 3 methods: T1, bordering the supraorbital ridge; T2, no contact with supraorbital ridge; and T3, coverage of the supraorbital ridge. Mean dose for the plans with a 30-Gy prescription and the plans with a 37.5-Gy prescription was 27.5 Gy and 35.2 Gy, respectively (p ≤ 0.0001). BED3 maximum constraint (D_max) was violated 16 of 26 (61.5%) in T1 (average D_max: 32.2 Gy), 13 of 28 (46.4%) in T2 (average D_max: 32.1 Gy), and 5 of 18 (27.8%) in T3 (average D_max: 31.8 Gy) for the 30-Gy prescription. D_max was violated in 32 of 32 (100%) in T1 (average D_max: 40.1 Gy), 22 of 22 (100%) in T2 (average D_max: 40.3 Gy), and 14 of 14 (100%) in T3 (average D_max: 39.4) for the 37.5 Gy prescription. Average D_max for the 37.5-Gy prescription was highly significant in favor of T3 (p = 0.0098). Patients who receive WBRT may develop dry eye syndrome as a late toxicity. Constraints are commonly violated with a prescription of 37.5 Gy. Methods to reduce dose include T3 supraorbital blocking, an easily implementable change that may dramatically improve patient quality of life.

TFOS DEWS II pathophysiology report

The TFOS DEWS II Pathophysiology Subcommittee reviewed the mechanisms involved in the initiation and perpetuation of dry eye disease. Its central mechanism is evaporative water loss leading to hyperosmolar tissue damage. Research in human disease and in animal models has shown that this, either directly or by inducing inflammation, causes a loss of both epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film breakup and amplifies hyperosmolarity via a Vicious Circle. Pain in dry eye is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity. Increased friction targets damage to the lids and ocular surface, resulting in characteristic punctate epithelial keratitis, superior limbic keratoconjunctivitis, filamentary keratitis, lid parallel conjunctival folds, and lid wiper epitheliopathy. Hybrid dry eye disease, with features of both aqueous deficiency and increased evaporation, is common and efforts should be made to determine the relative contribution of each form to the total picture. To this end, practical methods are needed to measure tear evaporation in the clinic, and similarly, methods are needed to measure osmolarity at the tissue level across the ocular surface, to better determine the severity of dry eye. Areas for future research include the role of genetic mechanisms in non-Sjögren syndrome dry eye, the targeting of the terminal duct in meibomian gland disease and the influence of gaze dynamics and the closed eye state on tear stability and ocular surface inflammation.

Aqueous Deficient Dry Eye Syndrome Post Orbital Radiotherapy: A 10-Year Retrospective Study

Purpose

Despite advances in orbital radiotherapy (XRT), a significant proportion of patients develop ophthalmic complication like dry eye syndrome (DES). The study evaluates the prevalence of aqueous deficient DES (ADDE) and lacrimal gland (LG) changes through histologic evaluation and ex-vivo expansion potential postorbital XRT.

Methods

With the approval of the institutional review board, medical records of patients who underwent orbital XRT as management protocol were reviewed for evidence of ADDE using DEWS (Dry Eye Workshop) 2007 criteria (n = 51). HuLG was harvested from three of these patients who underwent subsequent orbital exenteration and used for histological studies/ex-vivo culture.

Results

ADDE was noted in 47.07% of the patients, status postorbital XRT, with a prediction of nearly 50% developing it within 0.5 to 2.9 years. ADDE severity was grade 2 (18%), grade 3 (14%), and grade 4 (17%). Other comorbidities were radiation retinopathy (33.4%), radiation-induced cataract (24.9%), and radiation keratopathy (20.8%). Multivariate and univariate analysis showed that fraction of radiation and dose of radiation/fraction were significant risk factors; male gender and young age were protective factors. The post-XRT exenterated HuLG showed near-total effacement of histoarchitecture with intra/periductal and intra/interlobular fibrosis, loss of acini, and reduced secretory activity. The potential of the LG to expand and grow in culture was impaired with loss of stem cells as compared to normal HuLG.

Conclusion

This study documents that orbital-XRT is associated with morphological and functional loss of lacrimal function in nearly 50% of the patients with a prediction of two-third developing ADDE by the end of 5 years.

Translational Relevance

The study provides objective clinical evidence for DES development due to architectural/functional damage to the LG postorbital XRT. Based on recent findings that the LG can be cultured in-vitro, with preservation of stem cells and secretory potential, it would be logical to harvest a portion of LG before radiation, and expand and transplant it to rescue the damaged gland if indicated.

Acute and late toxicity of bilateral orbital irradiation in the management of primary intraocular lymphoma

Primary intraocular lymphoma (PIOL) is a rare malignancy with poor outcomes. Concerns regarding toxicity lead some clinicians to exclude orbital radiation therapy (RT). We aimed to quantify the ocular toxicity of RT in 11 PIOL patients treated with chemoimmunotherapy and bilateral orbital RT (median 36 Gy). A multidisciplinary team, including an ocular oncologist, followed patients for a median of 42 months after RT. Common adverse events included dermatitis (100%), conjunctivitis (82%), xerophthalmia (64%), and keratopathy (45%). All phakic eyes developed cataracts (100%); correction resulted in good vision recovery. New, visually significant retinopathy was observed in only one eye (<5%) and affected a patient with preexisting diabetes. This report suggests that severe, vision-threatening complications following orbital RT are uncommon. In the absence of comorbidities, orbital RT should not be withheld due to fear of vision-threatening toxicity. The risk of toxicity may be augmented by comorbidities, so an individualized approach is recommended.

Photodynamic Therapy for Choroidal Metastasis

PURPOSE

To evaluate the effectiveness of photodynamic therapy (PDT) in the management of choroidal metastasis.

DESIGN

Retrospective, interventional case series.

METHODS

Patients with choroidal metastasis treated with PDT at a single institution were reviewed. PDT was applied with verteporfin at a dose of 6 mg/m(2) body surface area and a 689 nm diode laser for 83 seconds. Visual acuity, tumor basal diameter, tumor thickness by ultrasonography, and enhanced depth imaging optical coherence tomography (EDI-OCT), as well as associated features including subretinal fluid, were recorded before PDT and during follow-up examinations.

RESULTS

Twenty-one tumors in 13 eyes of 10 patients were included. Eight tumors were treated with a single session of PDT, 11 tumors received 2 sessions, 1 tumor received 3 sessions, and 1 tumor received 5 sessions. At the end of a mean follow-up of 12 months (range, 3-42 months), 9 eyes (69%) had stable or improved visual acuity, while 4 eyes (31%) had decreased visual acuity. Mean logMAR change in visual acuity was -0.09 (range, -1.3 to 0.8). Seventeen of 21 tumors (81%) were flat at last follow-up. The mean decrease in ultrasound-measured thickness was 0.83 mm (range, 2.6 mm decrease to 1.4 mm increase), while the decrease in EDI-OCT-measured thickness was 400 μm (range, 1280 μm decrease to 280 μm increase). Eighteen tumors (86%) had complete resolution of subretinal fluid. There were no PDT-related complications.

CONCLUSIONS

Photodynamic therapy may be an effective therapeutic option for the management of choroidal metastasis in selected cases.

Monte Carlo Simulation of the Treatment of Eye Tumors with (106)Ru Plaques: A Study on Maximum Tumor Height and Eccentric Placement

BACKGROUND/AIMS

Ruthenium plaques are used for the treatment of ocular tumors. There is, however, a controversy regarding the maximum treatable tumor height. Some advocate eccentric plaque placement, without a posterior safety margin, to avoid collateral damage to the fovea and optic disc, but this has raised concerns about marginal tumor recurrence. There is a need for quantitative information on the spatial absorbed dose distribution in the tumor and adjacent tissues. We have overcome this obstacle using an approach based on Monte Carlo simulation of radiation transport.

METHODS

CCA and CCB (106)Ru plaques were modeled and their geometry embedded in a computerized tomography scan of the eye of a patient. Different tumor sizes and locations were simulated with the general-purpose Monte Carlo code PENELOPE.

RESULTS

Cumulative dose-volume histograms were obtained for the tumors and the tissues at risk considered. Plots of isodose lines for both plaques were obtained in a computerized tomography study.

CONCLUSIONS

Ruthenium eye plaques are an adequate treatment option for tumors up to around 5 mm in height. According to our results, assuming a correct placement of the plaque, a tumor of 6.5 mm apical height is about the maximum size that can be treated safely with the large CCB plaque.

Management of conjunctival malignant melanoma: a review and update

Conjunctival malignant melanoma is a pigmented lesion of the ocular surface. It is an uncommon but potentially devastating tumor that may invade the local tissues of the eye, spread systemically through lymphatic drainage and hematogenous spread, and recur in spite of treatment. Despite its severity, the rarity of available cases has limited the evidence for diagnosis and management. This review will provide an overview of the epidemiology, presentation, diagnosis, management, and surveillance of conjunctival melanoma, with an emphasis on recent advances in biological therapies to treat this disease.

Human lacrimal gland regeneration: Perspectives and review of literature

The human lacrimal gland is an essential component of the lacrimal functional unit (LFU). Any perturbation of this unit can lead to the debilitating morbid condition called the dry eye syndrome (DES). The current line of therapy available for dry eye remains supportive and palliative with the patient being dependent on life long and frequent administration of lubricating eye drops. Even advanced therapies like punctual plugs, cyclosporine B administration, and salivary gland auto-transplantation have led to a limited success. Under these scenarios, the option of cell based therapy needs to be explored to provide better and long term relief to these patients. This review gives an overview of the efforts in lacrimal gland regeneration and examines the past and ongoing research in cell based therapies in animals as well as human lacrimal gland cultures. The authors discuss their first of its kind functionally viable human lacrimal gland in vitro culture system from fresh exenteration specimens. A brief overview of research in near future and the potential implications of lacrimal gland regenerative therapies have been discussed.

Clinical-dosimetric relationship between lacrimal gland dose and ocular toxicity after intensity-modulated radiotherapy for sinonasal tumours

OBJECTIVE

To characterise the relationship between lacrimal gland dose and ocular toxicity among patients treated by intensity-modulated radiotherapy (IMRT) for sinonasal tumours.

METHODS

40 patients with cancers involving the nasal cavity and paranasal sinuses were treated with IMRT to a median dose of 66.0 Gy. Toxicity was scored using the Radiation Therapy Oncology Group morbidity criteria based on conjunctivitis, corneal ulceration and keratitis. The paired lacrimal glands were contoured as organs at risk, and the mean dose, maximum dose, V10, V20 and V30 were determined. Statistical analysis was performed using logistic regression and the Akaike information criterion (AIC).

RESULTS

The maximum and mean dose to the ipsilateral lacrimal gland were 19.2 Gy (range, 1.4-75.4 Gy) and 14.5 Gy (range, 11.1-67.8 Gy), respectively. The mean V10, V20 and V30 values were 50%, 25% and 17%, respectively. The incidence of acute and late Grade 3+ toxicities was 23% and 19%, respectively. Based on logistic regression and AIC, the maximum dose to the ipsilateral lacrimal gland was identified as a more significant predictor of acute toxicity (AIC, 53.89) and late toxicity (AIC, 32.94) than the mean dose (AIC, 56.13 and 33.83, respectively). The V20 was identified as the most significant predictor of late toxicity (AIC, 26.81).

CONCLUSION

A dose-response relationship between maximum dose to the lacrimal gland and ocular toxicity was established. Our data suggesting a threshold relationship may be useful in establishing dosimetric guidelines for IMRT planning that may decrease the risk of acute and late lacrimal toxicities in the future.

ADVANCES IN KNOWLEDGE

A threshold relationship between radiation dose to the lacrimal gland and ocular toxicity was demonstrated, which may aid in treatment planning and reducing the morbidity of radiotherapy for sinonasal tumours.

Cyclosporine 0.05% ophthalmic emulsion for the treatment of radiation-associated dry eye in children

Dry eye disease is a well-known late complication of radiation therapy and is often difficult to treat. We evaluated the usefulness of cyclosporine 0.05% ophthalmic emulsion for the treatment of radiation-associated dry eye in children. Eleven children received cyclosporine 0.05% emulsion twice daily after failure of conventional therapy. After 6 months, dry eye manifestations improved in three children (27.3%). The remaining eight children showed no improvement with cyclosporine 0.05% ophthalmic emulsion. These results suggest that twice-daily cyclosporine 0.05% ophthalmic emulsion has limited use in children with refractory radiation-associated chronic dry eye.

Madarosis: a marker of many maladies

Madarosis is a terminology that refers to loss of eyebrows or eyelashes. This clinical sign occurs in various diseases ranging from local dermatological disorders to complex systemic diseases. Madarosis can be scarring or non-scarring depending upon the etiology. Appropriate diagnosis is essential for management. Follicular unit transplantation has been found to be a useful method of treating scarring madarosis and the procedure relevant to eyebrow and eyelash reconstruction has been discussed. A useful clinical approach to madarosis has also been included for bedside diagnosis. The literature search was conducted with Pubmed, Medline, and Google scholar using the keywords madarosis, eyebrow loss, and eyelash loss for articles from 1960 to September 2011. Relevant material was also searched in textbooks and used wherever appropriate.

Preliminary results of helical tomotherapy in patients with complex-shaped meningiomas close to the optic pathway

Meningiomas are the most common benign intracranial tumor. Meningiomas close to the optic pathway represent a treatment challenge both for surgery and radiotherapy. The aim of this article is to describe early results of helical tomotherapy treatment in complex-shaped meningiomas close to the optic pathway. Twenty-eight patients were consecutively treated. All patients were immobilized with a thermoplastic head mask and planned with the aid of a magnetic resonance imaging-computed tomography fusion. All treatments included daily image guidance. Pretreatment symptoms and acute toxicity were recorded. Median age was 57.5 years, and 92.8% patients had Eastern Cooperative Oncology Group performance status scale ≤1. The most common localizations were the sella turcica, followed by the cavernous sinus and the sphenoid. The most common symptoms were derived from cranial nerve deficits. Tomotherapy was administered as primary treatment in 35.7% of patients, as an adjuvant treatment in 32.4%, and as a rescue treatment after postsurgical progression in 32.1% patients. Most patients were either inoperable or Simpson IV. Total dose varied between 5000 and 5400 cGy; fractionation varied between 180 and 200 cGy. Median dose to the planning target volume was 51.7 Gy (range, 50.2-55.9 Gy). Median coverage index was 0.89 (range, 0.18-0.97). Median homogeneity index was 1.05 (range, 1-1.12). Acute transient toxicity was grade 1 and included headache in 35.7% patients, ocular pain/dryness in 28.5%, and radiation dermatitis in 25%. Thus far, with a maximal follow-up of 3 years, no late effects have been seen and all patients have a radiological stabilization of the disease. Helical tomotherapy offered a safe and effective therapeutic alternative for patients with inoperable or subtotally resected complex-shaped meningiomas close to the optic pathway. Acceptable coverage and homogeneity indexes were achieved with appropriate values for maximal doses delivered to the eyes, lenses, and chiasm, despite the proximity of the tumor to these structures.

Large particle hyaluronic Acid gel for the treatment of lower eyelid retraction associated with radiation-induced lipoatrophy

A 42-year-old female with a remote history of a left maxillary sinus tumor treated with excision and radiation therapy was referred for dry eye symptoms. Ophthalmic examination revealed left-sided exposure keratopathy, lagophthalmos, lower eyelid retraction, and fat atrophy of inferior periorbital tissue with associated hollowing. Large particle hyaluronic acid gel was injected to expand and reinforce the lower eyelid. After treatment, there was significant improvement in lagophthalmos, inferior scleral show, and periorbital hollowing. Excellent symmetry with the fellow eye was achieved. The patient reported markedly reduced dry eye symptoms. No adverse side effects were observed. The use of large particle hyaluronic acid gel shows promise as a novel nonsurgical therapy in the management of lower eyelid retraction associated with radiation-induced lipoatrophy. Additionally, large particle hyaluronic acid gel may provide better soft tissue expansion and retention than small particle hyaluronic acid gel, increasing the longevity of treatment.

Late onset of subfoveal choroidal neovascularisation following cerebral radiotherapy

A report of choroidal neovascularisation (CNV) associated with radiation retinopathy. A 43-year-old Caucasian man presented with a 4-week history of sudden loss of central vision in the left eye, 8.5 years following radical radiotherapy for left tempero-parietal anaplastic astrocytoma. His visual acuity was 6/6 in the right eye and 6/60 in the left eye. Ophthalmoscopy of the left eye showed central macular pigmented area surrounded by subretinal fluid, haemorrhage and exudates. Fundus fluorescein angiography revealed left subfoveal CNV with surrounding macular oedema and peripheral retinal ischaemia. Radiation retinopathy associated CNV is a late ocular complication of cerebral radiotherapy. It should be investigated as a possible aetiology of severe visual loss in long-term survivors of cerebral tumours who have previously received radiotherapy.

Ocular adnexal lymphomas: a review

Ocular adnexal lymphomas comprise 1% to 2% of all non-Hodgkin lymphomas and about 8% of extranodal lymphomas. They are a heterogeneous group of malignancies, the majority of which are primary extranodal lymphoma with most (up to 80%) of the marginal zone of mucosa associated lymphoid tissue type (MALT lymphoma). This review will encompass the incidence, histology, immunophenotyping, recent advances in molecular and cytogenetics, clinical features including outcome, and prognostic factors. The association with Chlamydia psittaci and the very recently recognized occurrence in the context of IgG4-related sclerosing disease will be discussed. Finally, traditional (surgery, radiotherapy, chemotherapy) and newer forms of therapy (immunotherapy and radioimmunotherapy) will be reviewed.

[Late neurotoxicity after nasopharyngeal carcinoma treatment]

PURPOSE

A retrospective analysis of risk factors for late neurological toxicity after nasopharyngeal carcinoma radiotherapy.

PATIENTS AND METHODS

Between 1993 and 2004, 239 patients with non metastatic nasopharyngeal carcinoma were treated by radiotherapy associated or not to chemotherapy. Radiotherapy was delivered with two modalities: hyperfractionated for 82 patients and conventional fractionation for 157 patients. We evaluated the impact of tumour stage, age, gender, radiotherapy schedule and chemotherapy on neurological toxicity.

RESULTS

After a mean follow-up of 107 months (35-176 months), 21 patients (8.8%) developed neurological complications, such as temporal necrosis in nine cases, brain stem necrosis in five cases, optics nerve atrophy in two cases and myelitis in one case. Five- and ten-year free of toxicity survival was 95 and 84% respectively. Young patients had greater risk of temporal necrosis, and hyperfractionated radiotherapy was associated with a significantly higher risk of neurological complications (14.6% vs 5.7%, p=0.02). On multivariate analysis, hyperfractionation and age were insignificant.

CONCLUSION

Late neurological toxicity after radiotherapy for nasopharyngeal carcinoma was rare. Younger age and hyperfractionation were considered as risk factors of neurological toxicity in our study.

Estimation of yttrium-90 Zevalin tumor-absorbed dose in ocular adnexal lymphoma using quantitative indium-111 Zevalin radionuclide imaging

OBJECTIVE

The purpose of this investigation was to estimate radiation-absorbed dose in orbital tumors from yttrium-90 ibritumomab tiuxetan (Zevalin) radioimmunotherapy of ocular adnexal lymphoma.

METHODS

Three patients participating in a prospective research protocol involving treatment of ocular adnexal lymphoma with yttrium-90 Zevalin consented to quantitative radionuclide imaging to estimate tumor radiation-absorbed doses. Each patient received 185 MBq of indium-111 Zevalin, followed by serial planar whole-body scanning, to derive an activity versus time curve for the tumor. Single photon emission computed tomography (SPECT) and computed tomography (CT) imaging, including a calibration source, were performed at 24 h on a SPECT/CT scanner, to obtain a SPECT estimate of the radioactivity (in megabequerels) in the tumor and correct the planar curve, as well as estimate the tumor mass (M) from CT. The curve was then converted to that for yttrium-90 at the prescribed activity, and absorbed dose estimated from the area under the curve multiplied by the Medical Internal Radiation Dose S value (Gy per MBq-h) for a sphere of mass M.

RESULTS

A right orbital tumor in one patient was visualized in both the planar and SPECT/CT images, with an estimated absorbed dose of 3.57 Gy. Tumor uptake in the other two patients was not visualized.

CONCLUSION

The radiation dose to the orbit and ocular structures during radioimmunotherapy of ocular adnexal lymphoma is well below the threshold for significant radiation-induced ocular toxicity and about 10 times lower than that delivered during external beam radiotherapy.

Multisession CyberKnife radiosurgery for optic nerve sheath meningiomas

Optic nerve sheath meningiomas (ONSMs) are benign lesions originating from the dural sheath of the optic nerve. Progressive growth can lead to gradual loss of vision and exophthalmos. Loss of vision following microsurgical resection is not uncommon, and although stereotactic fractionated radiotherapy can be a safe alternative to control tumor growth and preserve vision, it may also lead to complications. Frame-based stereotactic radiosurgery has only been rarely used because single-fraction high-dose treatments of intrinsic optic nerve lesions may induce unacceptably high toxicity. New frameless radiosurgery devices such as the robotic CyberKnife, an image-guided radiosurgery system, can provide the extremely tight conformality and submillimetric accuracy of frame-based systems combined with the possibility of delivering radiation in several sessions. In the present report the authors review the clinical presentation and management of ONSMs and describe their preliminary experience using multisession radiosurgery to treat these lesions.