Radiation Therapy for Orbital Tumors: Concepts, Current Use, and Ophthalmic Radiation Side Effects

An Overview of Cancer Biology, Pathophysiological Development and It's Treatment Modalities: Current Challenges of Cancer anti-Angiogenic Therapy

A number of conditions and factors can cause the transformation of normal cells in the body into malignant tissue by changing the normal functions of a wide range of regulatory, apoptotic, and signal transduction pathways. Despite the current deficiency in fully understanding the mechanism of cancer action accurately and clearly, numerous genes and proteins that are causally involved in the initiation, progression, and metastasis of cancer have been identified. But due to the lack of space and the abundance of details on this complex topic, we have emphasized here more recent advances in our understanding of the principles implied tumor cell transformation, development, invasion, angiogenesis, and metastasis. Inhibition of angiogenesis is a significant strategy for the treatment of various solid tumors, that essentially depend on cutting or at least limiting the supply of blood to micro-regions of tumors, leading to pan-hypoxia and pan-necrosis inside solid tumor tissues. Researchers have continued to enhance the efficiency of anti-angiogenic drugs over the past two decades, to identify their potential in the drug interaction, and to discover reasonable interpretations for possible resistance to treatment. In this review, we have discussed an overview of cancer history and recent methods use in cancer therapy, focusing on anti-angiogenic inhibitors targeting angiogenesis formation. Further, this review has explained the molecular mechanism of action of these anti-angiogenic inhibitors in various tumor types and their limitations use. In addition, we described the synergistic mechanisms of immunotherapy and anti-angiogenic therapy and summarizes current clinical trials of these combinations. Many phase III trials found that combining immunotherapy and anti-angiogenic therapy improved survival. Therefore, targeting the source supply of cancer cells to grow and spread with new anti-angiogenic agents in combination with different conventional therapy is a novel method to reduce cancer progression. The aim of this paper is to overview the varying concepts of cancer focusing on mechanisms involved in tumor angiogenesis and provide an overview of the recent trends in anti-angiogenic strategies for cancer therapy.

Unilateral conjunctival Classic Kaposi Sarcoma following a COVID 19 booster

Purpose

We describe a case of Classic Kaposi's sarcoma in a functionally monocular patient following a COVID19 vaccine booster and provide compelling evidence that suggests the booster was a relevant co-factor in the initiation of the disease process.

Observations

The patient presented with red, irritated conjunctival area described as "bubbling" in her right eye. While her past medical history includes hypercholesterolemia and hypertension, she had no history of a compromised immune system. Her ophthalmologic history is more complex including treatment for glaucoma. The patient has 20/20 uncorrected vision OD and LP OS. Due to her ocular co-morbidities, the patient initially received interferon alpha 2-B qid for 6 weeks. However, topical therapy failed to decrease the size of the conjunctival lesions. After referral to Radiation Oncology, the right eye/orbit was treated with electron beam therapy for 1 month which caused a marked decrease in the size and vascularity of the conjunctival lesions. A slow improvement continued during followup.

Conclusion and importance

In that the vaccine booster preceded the cancer, it appears etiologic to the appearance of Kaposi's sarcoma. The patient's monocular vision and glaucoma complicated her treatment. This case expands on current concepts of cofactors needed for the development of Kaposi's sarcoma in that vaccine booster administration was relevant to tumor progression and both clinical and mechanistic evidence is presented to support this hypothesis.

Personalized treatment for patients with lacrimal sac squamous cell carcinoma

OBJECTIVE

Lacrimal sac squamous cell carcinoma (LSSCC) is a rare and poor prognosis malignancy. We aimed to investigate the predictive factors for prognosis and to discuss the optimal treatment mode.

METHODS

This retrospective study comprised 84 patients with LSSCC who accepted multidisciplinary treatment. We analyzed the potential prognostic factors and the efficiency of different treatment modes in univariate and multivariate analyses.

RESULTS

The 5-year overall survival (OS), progression-free survival (PFS), regional failure-free survival (RFS), and distant metastasis-free survival (DMFS) rates for the entire cohort were 83.7%, 76.3%, 77.2%, and 83.7%, respectively. On univariate analysis, orbital bone erosion, lymph node metastasis, and advanced clinical stage were poor prognostic factors. Multivariate Cox regression analysis showed that orbital bone erosion was a uniquely poor predictor for OS; orbital bone erosion, positive cervical lymph nodes, and old age were poor predictors for PFS. Chemotherapy significantly improved the 5-year OS (90.4% vs. 69.6%, p = 0.03), PFS (82.1% vs. 63.6%, p = 0.036), and DMFS (90.4% vs. 69.6%, p = 0.013), except for RFS (82.5% vs. 65.6%, p = 0.15). Surgery did not improve the 5-year OS (85.6% vs. 79.3%, p = 0.062), PFS (76.0% vs. 76.2%, p = 0.41), RFS (76.1% vs. 79.5%, p = 0.54), and DMFS (85.6% vs. 79.5%, p = 0.096). However, the pre-operative radiotherapy conferred a slightly better OS (p = 0.13) and DMFS (p = 0.16) than post-operative radiotherapy and definitive radiotherapy, but without statistical significance.

CONCLUSIONS

Orbital bone erosion and lymph node metastasis were poor prognostic factors in LSSCC. Chemoradiotherapy was vital and effective. Although surgery did not improve survival, multidisciplinary treatment, including surgery, was recommended for LSSCC.

Influence of Post-radiation Ocular Surface Disorder on Ocular Surgery: A Case Report and Review of the Literature

BACKGROUND

Ocular surface disorder after ocular radiation therapy, even though commonly reported, is often overlooked. Any delay in diagnosis may lead to complications that threaten vision. The presented case highlights the clinical outcome of a severe post-radiation disorder of the ocular surface, the importance of intensive therapy, and the limitations of further surgical interventions.

CASE PRESENTATION

A 34-year-old woman was referred for a second opinion due to a years-long history of pain and redness in her right eye (OD) after proton beam therapy for recurrent iris melanoma. The patient then developed post-radiation retinopathy with macula edema, secondary glaucoma, cataract, as well as a severe ocular surface disorder with corneal decompensation and band keratopathy. Several surgical treatments have been attempted, including phacoemulsification with IOL implantation and trabeculectomy with mitomycin C. Due to refractory glaucoma, Baerveldt glaucoma drainage was then necessary. Given the worsening clinical presentation of post-radiation ocular surface disorder with progressing band keratopathy, the possibility of penetrating keratoplasty (PKP) was discussed.

CONCLUSION

The continuous worsening of clinical symptoms of the disorder of the ocular surface after proton beam radiotherapy can be the result of a post-radiation syndrome. Gradual expansion of ischemia, vasculitis, and inflammatory mediators compresses the retinal tissue, leading to recurrent macular edema as well as to secondary glaucoma and corneal decompensation. Band keratopathy is occasionally noted and seems to result from severe post-radiation disorder of the ocular surface. However, PKP would typically be indicated in cases of corneal perforation, uncontrolled infectious keratitis, or for improving vision in the presence of corneal opacification, none of which applied to our patient. Furthermore, post-radiation keratopathy implies compromised corneal stromal lymphogenesis and angiogenesis, both of which are now considered essential conditions for allograft rejection. Moreover, a previously performed Baerveldt glaucoma drainage surgery can affect the survival rate of the endothelial cells of the recipient cornea. Therefore, a penetrating or endothelial keratoplasty should be viewed as a high-risk procedure. In this instance, the rigorous treatment of the severe ocular surface disorder was crucial. We managed our patient's complex situation by following the latest guidelines set by the Tear Film & Ocular Surface Society and aimed to alleviate the symptoms as effectively as possible. In conclusion, careful decision-making regarding surgical treatment options should be considered, taking into account the complexities and potential risks involved.

Ophthalmic Manifestations in Patients with Blood Malignancies

Ocular complications can occur in up to 90% of patients with blood malignancies. Such complications range from direct infiltration to local hemostatic imbalance and treatment-related toxicity. This narrative review is based on a systematic computerized search of the literature conducted until January 2024 and examines the common ocular complications associated with blood cancers. Ocular complications from primary disease include mass effects from ocular adnexal lymphomas and intraocular lymphomas, with B-cell lymphomas accounting for 95% of primary ocular presentations. Secondary disease involvement from systemic hematological malignancies can lead to a wide range of ocular manifestations, such as leukemic retinopathy. Furthermore, toxicity from antineoplastic therapies and ocular graft versus host disease (oGVHD) after hematopoietic stem cell transplantation present additional risks to ocular health. In conclusion, ocular complications in blood cancer patients are an integral part of patient management, requiring regular ophthalmic evaluations and close collaboration between oncologists and ophthalmologists. Advances in therapy and an increased focus on early symptom recognition are essential for preserving vision and enhancing patient quality of life.

Metastatic squamous cell carcinoma masquerading as acute retinal necrosis

Purpose

To describe a case of retinal and optic nerve metastases masquerading as acute retinal necrosis secondary to primary squamous cell carcinoma of the lung.

Observations

A 66-year-old male with a history of Stage IV lung cancer, actively on chemotherapy, presented with right eye vision loss, an afferent pupillary defect, and partial visual field deficiencies. Exam revealed vitritis, macula-involving infiltrative retinitis, optic neuritis, and vasculitis of the right eye. The patient was treated empirically for acute viral retinitis with intravitreal foscarnet and ganciclovir injections and oral acyclovir and trimethoprim-sulfamethoxazole. A diagnostic pars plana vitrectomy with vitreous biopsy, intravitreal antivirals and silicone oil fill was performed. The resulting cytology was positive for malignant squamous cell carcinoma.

Conclusions and importance

We present a unique case of primary squamous cell carcinoma metastasizing to the retina and optic nerve which masqueraded as an acute viral retinitis. To date, there have not been any reported cases on Pubmed or Google Scholar at publication time of known squamous cell carcinoma metastases to the retina that demonstrated interval growth leading to emergent elevations in intraocular pressure (IOP). This case demonstrates the importance of considering metastasis when encountering an atypical acute retinal necrosis case, as well as bring awareness to the possibility that elevated IOP may be the first sign of interval metastases, despite surgical debulking, in cases involving known tumor metastases to the retina.

Occult anterior uveal melanomas presenting as extrascleral extension

OBJECTIVE

To describe the management of patients with occult anterior uveal melanomas presenting with extrascleral extension.

METHODS AND ANALYSIS

Retrospective case series including five patients with small pigmented nodular mass on the episclera. Each lesion was documented by slit-lamp photography and measured with high-frequency ultrasound imaging (ultrasound biomicroscopy). Diagnosis of uveal melanoma was confirmed by biopsy with lamellar sclerectomy. Immediate scleral patch graft repair was performed. Later, each tumour was treated with palladium-103 ophthalmic plaque brachytherapy. The mean plaque diameter was 12 mm (median, 12; range, 10-14). A mean apex prescription dose of 87 Gy (median, 84.5; range, 82.3-99.2) to a tumour depth of 2 mm from the inner sclera delivered over 7 continuous days. The main outcome measures were best-corrected visual acuity, changes in tumour and scleral characteristics and complications.

RESULTS

During each surgery, residual tumour was visualised within an emissary passageway at the deep plane of scleral resection. At a mean of 80 months (median, 57; range, 24-159) follow-up, no patients experienced graft infection, scleromalacia or rejection. Biopsy was required to establish the diagnosis, transillumination failed, and therefore ultrasound measurements were used to determine the plaque size required to treat the relatively occult intraocular component. Despite these challenges, there were no cases of local tumour recurrence, secondary enucleation or metastatic disease. Attributed to cataract surgery, visual acuities improved in three patients and two were stable.

CONCLUSION

Extrascleral uveal melanoma extension can occur with undetectable, occult intraocular tumours. In these cases, plaque radiation effectively induced local tumour control, preserved vision and prevented metastasis.

Choroidal metastasis: Radiation and bevacizumab at presentation

Purpose

To reveal early intervention outcomes for patients describing with choroidal metastasis.

Methods

A retrospective interventional case series on 27 eyes of 22 patients treated for choroidal metastasis with external beam radiation therapy (EBRT) With and without intravitreal injections. The prescribed radiation dose was a mean and median 30 Gy (range of 30-40 Gy in 180-200 cGy daily fractions). Outcome measures included change in tumor thickness, subretinal fluid, visual acuity, radiation oculopathy, and survival.

Results

Decreased vision was the most common presenting symptom (n = 20/27, 74%). Pre-treatment vision for subfoveal lesions was a mean 20/400, median 20/200, and range 20/40 to hand motions (HM). Pre-treatment vision for extrafoveal tumors were a mean 20/40, median 20/25, range 20/20 to counting fingers (CF) which improved to a mean 20/32, median 20/20, range 20/12.5 to 20/200. Local control, with ultrasonographic height regression (44.5%; mean: 2.7-1.5 mm), was observed in all eyes at mean follow-up of 16 months (range: 1-72 months). Intravitreal anti-vascular endothelial growth factor (anti-VEGF) was given in nine cases (n = 9/27, 33%) to slow the growth of the metastasis and suppress their exudative detachments and to treat radiation maculopathy in 10 cases (n = 10/27, 37%). Late radiation complications included keratoconjunctivitis sicca in four cases (n = 4/27, 15%), exposure keratopathy in two cases (n = 2/27, 7%), and radiation retinopathy in 10 cases (n = 10/27, 37%). Of the 23 phakic eyes, four (n = 4, 17%) developed cataract.

Conclusion

Radiation therapy with or without intravitreal anti-VEGF injections was a safe and effective treatment for choroidal metastasis. It was associated with local tumor control, reduction of secondary retinal detachments, and vision preservation.

Orthovoltage X-ray Minibeam Radiation Therapy for the Treatment of Ocular Tumours-An In Silico Evaluation

(1) Background: Radiotherapeutic treatments of ocular tumors are often challenging because of nearby radiosensitive structures and the high doses required to treat radioresistant cancers such as uveal melanomas. Although increased local control rates can be obtained with advanced techniques such as proton therapy and stereotactic radiosurgery, these modalities are not always accessible to patients (due to high costs or low availability) and side effects in structures such as the lens, eyelids or anterior chamber remain an issue. Minibeam radiation therapy (MBRT) could represent a promising alternative in this regard. MBRT is an innovative new treatment approach where the irradiation field is composed of multiple sub-millimetric beamlets, spaced apart by a few millimetres. This creates a so-called spatial fractionation of the dose which, in small animal experiments, has been shown to increase normal tissue sparing while simultaneously providing high tumour control rates. Moreover, MBRT with orthovoltage X-rays could be easily implemented in widely available and comparably inexpensive irradiation platforms. (2) Methods: Monte Carlo simulations were performed using the TOPAS toolkit to evaluate orthovoltage X-ray MBRT as a potential alternative for treating ocular tumours. Dose distributions were simulated in CT images of a human head, considering six different irradiation configurations. (3) Results: The mean, peak and valley doses were assessed in a generic target region and in different organs at risk. The obtained doses were comparable to those reported in previous X-ray MBRT animal studies where good normal tissue sparing and tumour control (rat glioma models) were found. (4) Conclusions: A proof-of-concept study for the application of orthovoltage X-ray MBRT to ocular tumours was performed. The simulation results encourage the realisation of dedicated animal studies considering minibeam irradiations of the eye to specifically assess ocular and orbital toxicities as well as tumour response. If proven successful, orthovoltage X-ray minibeams could become a cost-effective treatment alternative, in particular for developing countries.

Effects of Irradiation on Brain Tumors Using MR-Based Electrical Conductivity Imaging

Ionizing radiation delivers sufficient energy inside the human body to create ions, which kills cancerous tissues either by damaging the DNA directly or by creating charged particles that can damage the DNA. Recent magnetic resonance (MR)-based conductivity imaging shows higher sensitivity than other MR techniques for evaluating the responses of normal tissues immediately after irradiation. However, it is still necessary to verify the responses of cancer tissues to irradiation by conductivity imaging for it to become a reliable tool in evaluating therapeutic effects in clinical practice. In this study, we applied MR-based conductivity imaging to mouse brain tumors to evaluate the responses in irradiated and non-irradiated tissues during the peri-irradiation period. Absolute conductivities of brain tissues were measured to quantify the irradiation effects, and the percentage changes were determined to estimate the degree of response. The conductivity of brain tissues with irradiation was higher than that without irradiation for all tissue types. The percentage changes of tumor tissues with irradiation were clearly different than those without irradiation. The measured conductivity and percentage changes between tumor rims and cores to irradiation were clearly distinguished. The contrast of the conductivity images following irradiation may reflect the response to the changes in cellularity and the amounts of electrolytes in tumor tissues.

Chrysin Induces Apoptosis via the MAPK Pathway and Regulates ERK/mTOR-Mediated Autophagy in MC-3 Cells

Chrysin is a flavonoid found abundantly in substances, such as honey and phytochemicals, and is known to exhibit anticancer effects against various cancer cells. Nevertheless, the anticancer effect of chrysin against oral cancer has not yet been verified. Furthermore, the mechanism underlying autophagy is yet to be clearly elucidated. Thus, this study investigated chrysin-mediated apoptosis and autophagy in human mucoepidermoid carcinoma (MC-3) cells. The change in MC-3 cell viability was examined using a 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide cell viability assay, as well as 40,6-diamidino-2-phenylindole, annexin V, and propidium iodide staining. Western blotting was used to analyze the proteins related to apoptosis and the mitogen-activated protein kinase (MAPK) pathway. In addition, the presence or absence of autophagy and changes in the expression of related proteins were investigated using acridine orange staining and Western blot. The results suggested that chrysin induced apoptosis and autophagy in MC-3 oral cancer cells via the MAPK/extracellular signal-regulated kinase pathway. Moreover, the induced autophagy exerted a cytoprotective effect against apoptosis. Thus, the further reduced cell viability due to autophagy as well as apoptosis induction highlight therapeutic potential of chrysin for oral cancer.

Early anti-VEGF treatment for radiation maculopathy and optic neuropathy: lessons learned

Radiation therapy has saved both sight and life for eye cancer patients. The most common methods include ophthalmic plaque brachytherapy and external beam techniques. However, subsequent dose-dependent radiation vasculopathy invariably occurs within and around the targeted zone. In 2006, Finger discovered that periodic intravitreal anti-vascular endothelial growth factor (anti-VEGF) bevacizumab could reverse and suppress intraocular radiation vasculopathy. At first, it was administered at the onset of radiation-related vision loss. Though bevacizumab induced regression of macular oedema, retinal haemorrhages and cotton-wool infarcts, most patients were left with residual retinal damage, manifest as metamorphopsia and loss of vision. These results led to earlier and earlier anti-VEGF interventions: first after signs of progressive radiation retinopathy, and then for signs of radiation maculopathy, and finally for high-risk eyes with no clinical signs of retinopathy. Earlier initiation of intravitreal anti-VEGF therapy typically resulted in greater restoration and preservation of macular anatomy, reductions of retinal haemorrhages, resolution of cotton-wool spots and vision preservation. Recent research on optical coherence tomography angiography (OCT-A) has revealed that radiation vasculopathy occurs prior to clinical ophthalmic signs or symptoms. Therefore, it seemed reasonable to consider treating high-risk patients (considered certain to eventually develop radiation maculopathy) to prevent or delay vision loss. Herein, we describe the evolution of treatment for radiation maculopathy as well as recent research supporting anti-VEGF treatment of high-risk patients immediately following radiation to maximize vision outcomes.

The Role of Radiotherapy in Orbital Pseudotumor: A Systematic Review of Literature

PURPOSE

Orbital pseudotumor (or pseudotumor orbitae) is a benign entity, also known as idiopathic orbital inflammatory syndrome (IOIS), which encompasses a wide range of non-tumoral, space occupying lesions of the orbit. In selected cases of refractory disease or presence of side effects or even comorbidities that limit systemic therapies, radiotherapy could play a role in the management because it has been demonstrated that irradiation is effective in suppressing the inflammatory process.

METHODS

A systematic review of the literature about the main scientific databases was launched and the time interval included all published articles present in the databases from their inception until September 2020.

RESULTS

We were able to identify 19 studies eligible for inclusion in this review from 1978 to 2018. Overall the data of 241 patients were collected and are presented in this systematic review. The response rate varied between 74% and 100% with a median recurrence rate of 10%. The median total dose was 20 Gy whereas the mean total dose was 21 Gy with a range from 4 to 36 Gy. Regarding the fractionation, 2 Gy/fraction daily was the most widely used.

CONCLUSIONS

Radiotherapy seemed to achieve good response rates however, in most of the studies, inclusion criteria and outcome parameters are not uniform and therefore the results are difficult to compare. Often important parameters such as chronic pain and permanent functional deficits are not assessed in the outcome. Therefore, prospective studies, with good cohort characteristics and a clear definition of the outcome, are required.

Ocular complications with the use of radium-223: a case series

Background

Radium-223 is used for the treatment of osseous metastases in castrate-resistant prostate cancer, and has been shown to increase time to the first skeletal-related event, reduce the rate of hospitalization, and improve quality of life. It is well tolerated, with hematologic toxicity as the main adverse event. Thus far, no ocular complication has been reported in the literature after initial administration of radium-223 with a single case reported of ocular complications after a patient’s second course of radium-223.

Case presentations

We present three cases of ocular complications after the use of radium-223 in patients with metastatic prostatic adenocarcinoma. Ocular complications presented as blurry vision, and formal diagnosis included uveitis and hyphema.

Conclusions

Documentation of adverse events is exceedingly important due to the high incidence of metastatic prostate cancer and increasing interest for the use of radium-223 in other osteoblastic disease. The authors postulate that these ocular complications may be a result of radiation’s potential effect on neovascularization, polypharmacy, or the biomolecular effects of radium-223 on integral signaling proteins, potentially coupled with poor underlying ocular health.

Modulating the Antioxidant Response for Better Oxidative Stress-Inducing Therapies: How to Take Advantage of Two Sides of the Same Medal?

Oxidative stress-inducing therapies are characterized as a specific treatment that involves the production of reactive oxygen and nitrogen species (RONS) by external or internal sources. To protect cells against oxidative stress, cells have evolved a strong antioxidant defense system to either prevent RONS formation or scavenge them. The maintenance of the redox balance ensures signal transduction, development, cell proliferation, regulation of the mechanisms of cell death, among others. Oxidative stress can beneficially be used to treat several diseases such as neurodegenerative disorders, heart disease, cancer, and other diseases by regulating the antioxidant system. Understanding the mechanisms of various endogenous antioxidant systems can increase the therapeutic efficacy of oxidative stress-based therapies, leading to clinical success in medical treatment. This review deals with the recent novel findings of various cellular endogenous antioxidant responses behind oxidative stress, highlighting their implication in various human diseases, such as ulcers, skin pathologies, oncology, and viral infections such as SARS-CoV-2.

Ocular, Orbital, and Adnexal Toxicity With High-dose Volumetric Modulated Arc Radiation Therapy for Orbital Malignancies

PURPOSE

Conventional modalities of external-beam radiation therapy (EBRT) are associated with high incidences of severe vision-threatening ocular and orbital toxicities when used to treat orbital malignancies. We investigate toxicities associated with high-dose volumetric modulated arc therapy (VMAT), a commonly used contemporary treatment modality for these tumors.

METHODS

Retrospective analysis of malignant orbital tumors managed with adjuvant high-dose VMAT preceded by globe-salvaging surgical therapy (GST) or exenteration. Dosimetric quantitation of target volumes and critical structures was performed. Incidence and severity of ocular, orbital, and adnexal toxicities were evaluated and assessed with regard to conventional EBRT toxicities for orbital malignancies described in the literature.

RESULTS

Eighty-four subjects (mean age = 65.9 ± 9.7 years) were included (N = 48 and N = 36 in GST and exenteration subgroups, respectively). Mean dose was 64.8 ± 2.1 Gy to the planning target volume. Dosing to critical structures typically did not surpass known tissue tolerance limits. Median follow up was 18.3 months. Visual acuity in the GST subgroup was not significantly different after VMAT (0.25 ± 0.06) compared with baseline (0.23 ± 0.02; P = 0.302). Whereas severe toxicities reported by major systematic analyses in the literature with older EBRT modalities were relatively common-for example, retinopathy (16-40%), optic neuropathy (16%), and corneal perforation (13%)-toxicities with VMAT were typically mild and less common. The most common toxicities with VMAT were mild dry eye (81.3%; 39/48), cataract (21.1%; 8/38 phakic eyes), and periocular dermatitis (15.5%; 13/84). Vision-threatening toxicities, including severe corneal pathologies, retinopathy, or optic neuropathy, were rare. There were no contralateral ocular or adnexal toxicities.

CONCLUSIONS

High-dose VMAT for orbital malignancies demonstrated low incidence and severity of eye-related toxicity, in contradistinction to adverse events reported from conventional forms of radiotherapy.

Non-Cancer Effects following Ionizing Irradiation Involving the Eye and Orbit

Simple Summary

The irradiation of tumors involving the eye or orbit represents a complex therapeutic challenge due to the proximity between the tumor and organs that are susceptible to radiation. The challenges include tumor control, as it is often a surrogate for survival; organ (usually the eyeball) preservation; and the minimization of damage of sensitive tissues surrounding the tumor in order to preserve vision. Anticipation of the spectrum and severity of radiation-induced complications is crucial to the decision of which technique to use for a given tumor. The aim of the present review is to report the non-cancer effects that may occur following ionizing irradiation involving the eye and orbit and their specific patterns of toxicity for a given radiotherapy modality. The pros and cons of conventional and advanced forms of radiation techniques and their clinical implementation are provided with a clinical perspective.

Abstract

The eye is an exemplarily challenging organ to treat when considering ocular tumors. It is at the crossroads of several major aims in oncology: tumor control, organ preservation, and functional outcomes including vision and quality of life. The proximity between the tumor and organs that are susceptible to radiation damage explain these challenges. Given a high enough dose of radiation, virtually any cancer will be destroyed with radiotherapy. Yet, the doses inevitably absorbed by normal tissues may lead to complications, the likelihood of which increases with the radiation dose and volume of normal tissues irradiated. Precision radiotherapy allows personalized decision-making algorithms based on patient and tumor characteristics by exploiting the full knowledge of the physics, radiobiology, and the modifications made to the radiotherapy equipment to adapt to the various ocular tumors. Anticipation of the spectrum and severity of radiation-induced complications is crucial to the decision of which technique to use for a given tumor. Radiation can damage the lacrimal gland, eyelashes/eyelids, cornea, lens, macula/retina, optic nerves and chiasma, each having specific dose–response characteristics. The present review is a report of non-cancer effects that may occur following ionizing irradiation involving the eye and orbit and their specific patterns of toxicity for a given radiotherapy modality.

Optic disc cupping after circumpapillary Pd-103 slotted plaque radiation therapy

OBJECTIVE

To investigate vascular and morphologic optic disc changes after slotted plaque radiation therapy for choroidal melanoma involving the optic disc.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Thirty-nine patients with choroidal melanoma involving the optic nerve.

METHODS

Each melanoma was treated with palladium-103 slotted plaque brachytherapy (incorporating and/or surrounding the optic nerve sheath) between 2005 and 2019. Imaging of the optic nerve before and after radiation allowed for documentation and evaluation of optic nerve pallor and cup-to-disc ratio (CDR) changes. Optical coherence tomography (OCT) CDR measurements and intraocular pressure (IOP) were recorded pretreatment and at follow-up. Of these patients, 22 also had OCT angiography (OCT-A) images with sufficient quality for evaluation of blood vessel density and length. Differences in cup-to-disc measurements were correlated with changes in OCT-A-measured vessel density and length.

RESULTS

Following slotted plaque radiation therapy, there was no significant increase in IOP or optic nerve pallor. OCT and colour photography revealed significant increases (both p < 0.001) in CDR from pretreatment to the last follow-up. Increased CDRs on OCT were significantly correlated to OCT-A-measured change in vessel length (p = 0.027). Similarly, increased CDR ratios on fundus photography were significantly correlated with OCT-A-measured change in vessel density (p = 0.043) and length (p = 0.019).

CONCLUSION

Fundus photography and OCT measurements revealed increased optic disc cupping following slotted plaque radiation therapy. Cupping was associated with OCT-A evidence of synchronous progressive peripapillary vascular occlusion and attenuation. Therefore, slotted plaque radiation-induced peripapillary and papillary ischemia was associated with increased CDR ratios and optic disc cupping.

Radiobiological evaluation of organs at risk for electronic high-dose-rate brachytherapy in uveal melanoma: a radiobiological modeling study

Purpose

The objective of this study was to examine feasibility of single- or hypo-fraction of high-dose-rate (HDR) electronic brachytherapy (eBT) in uveal melanoma treatment.

Material and methods

Biologically effective doses (BED) of organs at risk (OARs) were compared to those of iodine-125-based eye plaque low-dose-rate brachytherapy (¹²⁵I LDR-BT) with vitreous replacement (VR). Single- or hypo-fractionated equivalent physical doses (SFEDs or HFEDs) for tumor were calculated from tumor BED of ¹²⁵I LDR-BT using linear-quadratic (LQ) and universal survival curve (USC) models. BED OARs doses to retina opposite the implant, macula, optic disc, and lens were calculated and compared among SFED, HFED, and ¹²⁵I LDR-BT. Electronic BT of 50 kVp was considered assuming dose fall-off as clinically equivalent to ¹²⁵I LDR-BT. All OARs BEDs were analyzed with and without silicone oil VR.

Results

For a single-fraction incorporating VR, the median/interquartile range of LQ (USC)-based BED doses of the retina opposite the implant, macula, optic disc, and lens were 16%/1.2% (33%/4%), 35%/19.5% (64%/17.7%), 37%/19% (75%/17.8%), and 27%/7.9% (68%/23.2%) of those for ¹²⁵I LDR-BT, respectively. SFED tumor values were 29.8/0.2 Gy and 51.7/0.5 Gy when using LQ and USC models, respectively, which could be delivered within 1 hour. SFED can be delivered within 1 hour using a high-dose-rate eBT. Even four-fraction delivery of HFED without VR resulted in higher OARs doses in the macula, optic disc, and lens (135 ~ 159%) than when using ¹²⁵I LDR-BT technique. A maximum p-value of 0.005 was observed for these distributions.

Conclusions

The simulation of single-fraction eBT, including vitreous replacement, resulted in significantly reduced OARs doses (16 ~ 75%) of that achieved with ¹²⁵I LDR-BT.

Interstitial Brachytherapy for Orbital Sebaceous Carcinoma

Sebaceous carcinoma is characterized by its aggressive local tumor behavior and ability to metastasize. Small periocular sebaceous carcinoma are typically treated by excision with cryotherapy. Larger tumors often require adjuvant external beam radiotherapy (EBRT) and/or exenteration surgery. When used alone, EBRT techniques typically exceed the tolerance of critical normal ocular structures. The interstitial orbital brachytherapy-boost technique permits dose escalation to the tumor bed, while minimizing radiation dose to critical normal ocular structures. Here, we present a case of orbital sebaceous carcinoma treated with excision, cryotherapy, and super-thick amniotic membrane fornix reconstruction. Then, after 3 weeks of healing, adjuvant-combined electron interstitial high-dose rate brachytherapy-boost was added to electron-beam radiotherapy to optimize the orbital radiation dose distribution, increase dose to inferonasal orbit, and allow relative sparing of orbital tissues. At 1-year follow-up, there was no evidence of orbital tumor, no significant eye lash loss, normal ocular motility, no radiation retinopathy, optic neuropathy and a visual acuity of 20/20.

Radiation Retinopathy: Detection and Management Strategies

A gradual shift in trend from primary enucleation to globe salvaging radiation therapy for the management of ocular tumors has resulted in the rise of several post-treatment ocular complications including radiation retinopathy. Radiation retinopathy is a chronic, progressive, and occlusive vasculopathy that can manifest anytime between 1 month to 15 years after starting radiation therapy. The aim of treatment in most of these cases is to prevent further vision loss. Treatment options such as laser photocoagulation, anti-vascular endothelial growth factor and intraviral steroids have been described. However, despite several advances in diagnostic and therapeutic modalities, a significant proportion of eyes with radiation retinopathy eventually go blind. This review summarises some of the clinical features, investigative modalities, and recent therapeutic strategies used in the management of radiation retinopathy.

OCT-A evaluation of radiation vasculopathy following slotted plaque brachytherapy

PURPOSE

To determine a reliable diagnostic method to reveal and monitor subclinical progression of neural and perineural radiation vasculopathy.

METHODS

A retrospective cross-sectional study, where optical coherence tomography angiography (OCT-A) imaging data was collected and analyzed from 22 consecutive patients that had been treated with circumneural slotted plaque brachytherapy for peripapillary, juxtapapillary, or circumpapillary choroidal melanomas. Pre-operative dosimetry of palladium-103 radiation dose to the optic nerve and fovea were collected. Quantified differences in OCT-A-measured vessel density and length in treated verses untreated contralateral control eyes were collected. Vessel density and length were correlated to radiation dose, plaque slot depth, visual acuity outcomes, and circumpapillary retinal nerve fiber layer thickness.

RESULTS

Patients had post-irradiation follow-up of median 39 months, interquartile range 62 months). The mean optic disc radiation dose was 89.9 Gy ± 39.2 (86.5, 30.8-189.0). In comparison to controls, OCT-A imaging revealed significant differences in radial peripapillary capillary vessel density (18 μm² in case eyes, 34 μm² in control eyes; p < 0.001) and length (10 μm in case eyes, 14 μm in control eyes; p < 0.001). Change in vessel density did not show a significant correlation to radiation dose, slot depth, or visual acuity. However, change in vessel length was significantly correlated to radiation dose (p = 0.049) and change in visual acuity (p < 0.001).

CONCLUSIONS

OCT-A imaging revealed that radial peripapillary capillary vessel density and length were significantly reduced after circumneural irradiation for choroidal melanoma. Therefore, OCT-A imaging can be used to monitor progression of papillary vasculopathy associated with radiation optic neuropathy.

Gamma Knife Stereotactic Radiosurgery for Conjunctival Squamous Cell Carcinoma Invading the Anterior Orbit: A Case Series

Introduction

The aim of the study was to report our experience in the use of Gamma Knife Stereotactic Radiosurgery (GKSTRS) for conjunctival squamous cell carcinoma (SCC) invading the orbit, as an alternative to exenteration surgery.

Patients and Methods

Patients who had GKSTRS for conjunctival SCC invading the orbit but sparing the bone (AJCC eighth ed. T4a) with a minimum of 1-year follow-up were included. Treatment failure was defined as no decrease in tumour size 3 months post-treatment, or further growth during the follow-up period. Patients were followed up 3-monthly for 2 years and 6-monthly afterwards with a minimum of yearly MR Imaging of orbit.

Results

Six patients met the inclusion criteria. MR imaging was used to identify the extent of orbital involvement of SCC. Stereotactic radiosurgery utilizing the Leksell Gamma Knife® Perfexion was delivered in a single session in which patients received 18-20 Gy to the 45-50% isodose. The median follow-up was 29 months. Four patients responded to the treatment and had no evidence of recurrence at their most recent follow-up. The treatment failed in 2 patients, in 1 of whom the tumour was larger and extended deeper into the orbit. The other patient developed a recurrence away from the treated area at 9 months, suggesting a multifocal disease. Both patients had poorly differentiated SCC.

Conclusion

GKSTRS is a potential alternative to orbital exenteration surgery for conjunctival SCC extending into the anterior orbit in a selected group of patients refusing orbital exenteration or has a second blind eye. Nevertheless, the disease is more likely to recur than with exenteration surgery, hence lifelong monitoring and low threshold for surgical intervention or retreatment is prudent.

High-Dose-Rate Interstitial Brachytherapy (Interventional Radiotherapy) for Conjunctival Melanoma with Orbital Extension

Purpose

To evaluate local control and functional and cosmetic outcomes of postoperative high-dose-rate interventional radiotherapy (HDR-IRT) in patients affected by conjunctival melanoma with orbit invasion.

Methods

A retrospective study was conducted in 2 patients affected by conjunctival melanoma infiltrating the orbit, treated with surgical excision and HDR-IRT. The treatment procedures consisted of surgical excision of the orbital infiltrating nodule followed, 1 month after surgery, by adjuvant HDR-IRT. A target dose of 34 Gy was delivered in 10 twice-a-day fractions over 5 consecutive days. Data analysis included local tumor control and metastatic rate, acute and late toxicity, functional and aesthetic results.

Results

In both patients, treatment was well tolerated, and there was no orbital recurrence at a median follow-up of 37-40 months. There was an excellent functional outcome, without no significant acute or late side effects.

Conclusions

HDR-IRT could be considered a promising, feasible, successful, and well-tolerated option for selected patients affected by ocular tumors with orbital invasion.

Detection of radiotherapy-related damage in head and neck cancer patients by evaluating volumetric changes in lacrimal gland, nasolacrimal duct and computed tomography attenuation changes in lens

PURPOSE

In our study, we aimed to evaluate the change in attenuation of lens in CT images, volumetric changes, in lacrimal gland (LG) and nasolacrimal duct (NLD) of the patients receiving radiotherapy for brain or head & neck tumor. Additionally, the correlation between these changes and radiation dose data were investigated.

METHODS

Patient simulation CT images and control CT images were used to evaluate the volume and attenuation changes. Pre- and post-treatment MR and CT images were used to evaluate radiation-induced volumetric alterations in NLD and LG, respectively. Radiation therapy was given to a total dose of 54-70 Gy with conventional fractionated scheme using intensity-modulated radiotherapy technique (IMRT). Dose volume parameters were evaluated via dose volume histograms (DVHs).

RESULTS

Dose volume parameters, volume and densities of 59 lenses (L), 60 LG and 60 NLD of 30 patients were retrospectively assessed. The median LG volume was significantly lower in the post-treatment images (p < 0.001), whereas the median volumes of NLD in pre- and post-RT images were similar. The Hounsfield unit (HU) numbers of lenses were significantly lower on post-RT CT images (p < 0.001). No statistically significant correlation was found between dose parameters and volume or HU changes (p = 0.054-0.817).

CONCLUSION

It was observed that the attenuation of lenses and lacrimal gland volume significantly lowers following radiation. However, these alterations were not found to be correlated with dose.

Using patient-specific bolus for pencil beam scanning proton treatment of periorbital disease

Purpose

A unique mantle cell lymphoma case with bilateral periorbital disease unresponsive to chemotherapy and with dosimetry not conducive to electron therapy was treated with pencil beam scanning (PBS) proton therapy. This patient presented treatment planning challenges due to the thin target, immediately adjacent organs at risk (OAR), and nonconformal orbital surface anatomy. Therefore, we developed a patient‐specific bolus and hypothesized that it would provide superior setup robustness, dose uniformity and dose conformity.

Materials/Methods

A blue‐wax patient‐specific bolus was generated from the patient's face contour to conform to his face and eliminate air gaps. A relative stopping power ratio (RSP) of 0.972 was measured for the blue‐wax, and the HUs were overridden accordingly in the treatment planning system (TPS). Orthogonal kV images were used for bony alignment and then to ensure positioning of the bolus through fiducial markers attached to the bolus and their contours in TPS. Daily CBCT was used to confirm the position of the bolus in relation to the patient's surface. Dosimetric characteristics were compared between (a) nonbolus, (b) conventional gel bolus and (c) patient‐specific bolus plans. An in‐house developed workflow for assessment of daily treatment dose based on CBCT images was used to evaluate inter‐fraction dose accumulation.

Results

The patient was treated to 24 cobalt gray equivalent (CGE) in 2 CGE daily fractions to the bilateral periorbital skin, constraining at least 50% of each lacrimal gland to under 20 Gy. The bolus increased proton beam range by adding 2–3 energy layers of different fields to help achieve better dose uniformity and adequate dose coverage. In contrast to the plan with conventional gel bolus, dose uniformity was significantly improved with patient‐specific bolus. The global maximum dose was reduced by 7% (from 116% to 109%). The max and mean doses were reduced by 6.0% and 7.7%, respectively, for bilateral retinas, and 3.0% and 13.9% for bilateral lacrimal glands. The max dose of the lens was reduced by 2.1%. The rigid shape, along with lightweight, and smooth fit to the patient face was well tolerated and reported as “very comfortable” by the patient. The daily position accuracy of the bolus was within 1 mm based on IGRT marker alignment. The daily dose accumulation indicates that the target coverage and OAR doses were highly consistent with the planning intention.

Conclusion

Our patient‐specific blue‐wax bolus significantly increased dose uniformity, reduced OAR doses, and maintained consistent setup accuracy compared to conventional bolus. Quality PBS proton treatment for periorbital tumors and similar challenging thin and shallow targets can be achieved using such patient‐specific bolus with robustness on both setup and dosimetry.

Clinical Spectrum and Outcomes of Ocular and Periocular Complications following External-Beam Radiotherapy for Inoperable Malignant Maxillary Sinus Tumors

Purpose

To highlight the clinical spectrum, management, and outcomes of ocular/periocular complications following high-dose external-beam radiotherapy (EBRT) for inoperable malignant maxillary sinus-involving tumors (MMST).

Methods

A retrospective, interventional case series. All patients who were diagnosed with inoperable MMST (with orbital involvement) and treated with high-dose fractionated EBRT (65 Gy in 30 fractions) at James Cook University Hospital, UK, were included.

Results

Seven patients with advanced MMST (T4aN0M0-T4bN2cM0) were included and were followed up for 23.8 ± 10.2 months. Severe lid margin disease, dry eye, and neurotrophic keratopathy were universally observed. Other complications included cicatricial conjunctivitis (71%), corneal perforation (57%), limbal stem cell deficiency (LSCD; 43%), glaucoma (29%), and superimposed candida keratitis (14%). Amniotic membrane transplant (AMT; 71%), tarsorrhaphy (43%), tectonic keratoplasty (29%), and evisceration (14%) were warranted. Intact corneal epithelium was observed in all patients and good corrected-distance visual acuity (≥20/60) was observed in 3 (43%) patients at final follow-up.

Conclusion

High-dose EBRT for inoperable MMST can lead to a wide array of severe ocular/periocular complications. AMT serves as a potentially useful treatment modality to restore the ocular surface integrity after severe radiation keratopathy. We advocate active monitoring for any evolving ophthalmic complications during and after EBRT to enable timely intervention.

Proton beam radiotherapy of locally advanced or recurrent conjunctival squamous cell carcinoma: experience of the CATANA Centre

Aim:

Conjunctival squamous cell carcinoma (SCC) is a rare tumour of the ocular region and microscopic radical surgical is difficult. There are no single guidelines for therapeutic management and the role of radiation therapy is not clearly defined although conventionally photon or electron beams are used. Proton beam radiotherapy (PBRT) is a new option for a conservative approach and allows good sparing of the organs at risk.

Materials and methods:

After surgical resection, we collected 15 cases treated at our institution with PBRT. The dose delivered was between 48 and 60 Gy relative biological effectiveness (RBE), with fractions of 12–15 Gy RBE.

Results:

After an average period of 48 months, the patients achieved excellent disease control (overall survival and disease-free survival: 86·6%), with minimal acute and late toxicity.

Findings:

In this work, we present our experience on the use of PBRT technique in SCC treatment. A larger sample of patients is needed to draw conclusions about the impact of this treatment on disease recurrence and overall survival.

Monte Carlo Computation of Dose-Volume Histograms in Structures at Risk of an Eye Irradiated with Heterogeneous Ruthenium-106 Plaques

Background/Aims

The aim of this work is to compare Monte Carlo simulated absorbed dose distributions obtained from ¹⁰⁶Ru eye plaques, whose heterogeneous emitter distribution is known, with the common homogeneous approximation. The effect of these heterogeneities on segmented structures at risk is analyzed using an anthropomorphic phantom.

Methods

The generic CCA and CCB, with a homogeneous emitter map, and the specific CCA1364 and CCB1256 ¹⁰⁶Ru eye plaques are modeled with the Monte Carlo code PENELOPE. To compare the effect of the heterogeneities in the segmented volumes, cumulative dose-volume histograms are calculated for different rotations of the aforementioned plaques.

Results

For the cornea, the CCA with the equatorial placement yields the lowest absorbed dose rate while for the CCA1364 in the same placement the absorbed dose rate is 33% higher. The CCB1256 with the hot spot oriented towards the cornea yields the maximum dose rate per unit of activity while it is 44% lower for the CCB.

Conclusions

Dose calculations based on a homogeneous distribution of the emitter substance yield the lowest absorbed dose in the analyzed structures for all plaque placements. Treatment planning based on such calculations may result in an overdose of the structures at risk.

Contour Variability in Thyroid Eye Disease with Compressive Optic Neuropathy Treated with Radiation Therapy

Purpose

Few studies have evaluated the methodology by which radiation therapy (RT) for thyroid eye disease and compressive optic neuropathy is performed. The objective of this study was to retrospectively review our experience from a radiation planning standpoint and to determine whether current treatment methods provide adequate dose to target and collateral structures.

Methods

A retrospective review of 52 patients (104 orbits) with bilateral thyroid eye disease and compressive optic neuropathy treated with RT (20 Gy in 10 fractions) at our institution. RT plans were analyzed for target volumes and doses. Visual fields, color plates, and visual acuity were assessed pretreatment and at last available follow-up post RT. A standardized, anatomic contour of the retro-orbital space was applied to these retrospective plans to determine dose to the entire space, rather than the self-selected target structure.

Results

Compared with the anatomic retro-orbital space, the original contour overlapped by only 68%. Maximum and mean dose was 2134 cGy and 1910 cGy to the anatomic retro-orbital space. Consequently, 39.8% of the orbits had a mean dose <19 Gy (<17 Gy 16.4%, <18 Gy 27.6% <19 Gy 37.8%, <20 Gy 59.2%, 20-21 Gy 35.8%, >21 Gy 5%). There was no significant association of improvement in color plates (P = .07), visual fields (P = .77), and visual acuity (P = .62), based on these dose differences. When beam placement was retrospectively adjusted to include a space of 0.5 cm between the lens and the anterior beam edge, there was a 39.4% and 20.3% decrease in max and mean dose to the lens.

Conclusions

Without a standardized protocol for contouring in thyroid eye disease, target delineation was found to be rather varied, even among the same practitioner. Differences in dose to the anatomic retro-orbital space did not affect outcomes in the follow-up period. Although precise contouring of the retro-orbital space may be of little clinical consequence overall, a >0.5 cm space from the lens may significantly reduce or delay cataractogenesis.

Surgical Techniques and the Choice of Operative Approach for Cranioorbital Lesions

Objectives  Cranioorbital lesions present a great challenge for neurosurgeons and ophthalmologists. There is no consensus on the choice of surgical approach. The aims of this study were to investigate 49 cases of cranioorbital lesions and evaluate surgical approaches and outcomes. Patients and Methods  A retrospective study was done on 49 patients (51 operations) from 2009 to 2018. Information about the lesion was used to decide whether the supraorbital eyebrow approach (SEA) or pterional approach (PA) was performed. Results  Twenty-eight patients had surgical resection using SEA, 21 patients received PA, each group included one case of recurrence, who underwent reoperation via the same approach. SEA provided better cosmetic satisfaction, and a shorter incision than PA ( p  < 0.05). There was no significant difference in total resection rates, visual outcomes, recovery of ptosis, and other new surgical-related complications between SEA group and PA group ( p  > 0.05). Forty-nine cases of proptosis (94.1%, 49/51) were improved. Thirty-three patients (33/37, 89.2%) who underwent follow-up for longer than 12 weeks had a modified Rankin Scale (mRS) score ≤ 3. Conclusion  Surgery is the preferred treatment for cranioorbital lesions, but total resection is difficult. SEA may be a more minimally invasive option for some more limited lesions superior to optic nerve. PA may be more reasonable for the lesion with obvious hyperostosis and more extensive lesions.

Metastasis of advanced gastric cancer to the extraocular muscle: a case report

BACKGROUND

Metastatic tumors in the orbit, especially from gastric cancer, are rare. We present a rare case of extraocular muscle metastasis from gastric cancer and raise consideration of metastasis to extraocular muscle as a differential diagnosis of proptosis/lid swelling in a patient with history of malignancy.

CASE PRESENTATION

A 54-year-old Japanese woman presented with proptosis, lid swelling, diplopia, and retro-orbital pain in her left eye, which she had been experiencing for 1 day. She had a medical history of poorly differentiated adenocarcinoma of the stomach, which had metastasized to several organs. A computed tomography scan showed enlargement of the medial rectus muscle in her left eye. She was diagnosed as having gastric cancer metastasis to the medial rectus muscle of her left eye, and received a total of 20 Gy radiation therapy to the orbit, which resulted in resolution of her ocular symptoms. She died 3 months after her initial visit to our ophthalmic department.

CONCLUSIONS

Metastasis from malignancy should be considered in the differential diagnosis of a patient presenting with proptosis or lid swelling who has a history of gastric cancer. Radiation therapy of metastases in the orbit may be an effective treatment in such cases.

Checkpoint inhibition immunotherapy for advanced local and systemic conjunctival melanoma: a clinical case series

Background

Herein, we describe the use of systemic immunotherapy for both locally advanced and metastatic conjunctival melanoma. Current treatments for advanced conjunctival melanoma typically result in poor local control leading to disfiguring orbital exenteration surgery. Locoregional spread of conjunctival malignant melanoma typically requires pre-auricular and cervical lymph node dissection with post-operative adjuvant radiation therapy. In addition, classic systemic chemotherapy has been unsuccessful in the treatment of metastatic disease.

Methods

This is a retrospectively analyzed clinical case series of 5 patients with biopsy proven conjunctival melanoma who were treated with checkpoint inhibition therapy. Of these, 3 patients were treated for residual ocular disease present after failing multiple local therapies and refusing orbital exenteration surgery and two (with local ocular control) for metastatic conjunctival melanoma. Both those with locally advanced disease and patients with metastatic disease received an anti-PD1 agent in combination with another immunotherapeutic agent. All 5 were given multiple cycles of systemic anti-PD1 therapy, 1 was initially treated with single agent ipilimumab (3 mg/kg) prior to approval of anti-PD1 agents and two received interferon eye drops. As part of each ophthalmic examination, photographs of all conjunctival and eyelid surfaces were obtained. Systemic evaluations involved initial staging scans as well as periodic re-imaging.

Results

All cases have shown responses. Of the 2 complete responses, 1 was a patient with systemic disease. No patients developed ocular toxicity or loss of vision. However, systemic adverse effects included adrenal insufficiency, Grade-III colitis, Grade-II dermatitis, Grade-II hepatotoxicity and Grade-II pneumonitis.

Conclusions

This report suggests that systemic immunotherapy with or without topical interferon is effective in treatment of malignant melanoma of the conjunctiva. Therefore, it can be considered for patients with advanced local conjunctival melanoma, those who refuse orbital exenteration surgery and those with systemic metastasis.

Animal models of radiation retinopathy - From teletherapy to brachytherapy

Radiation retinopathy is a serious vision-impairing complication of radiation therapy used to treat ocular tumors. Characterized by retinal vasculopathy and subsequent retinal damage, the first sign of radiation retinopathy is the preferential loss of vascular endothelial cells. Ensuing ischemia leads to retinal degradation and late stage neovascularization. Despite the established disease progression, the pathophysiology and cellular mechanisms contributing to radiation retinopathy remain unclear. Clinical experience and basic research for other retinal vasculopathies, such as diabetic retinopathy and retinopathy of prematurity, can inform our understanding of radiation retinopathy; however, the literature investigating the fundamental mechanisms in radiation retinopathy is limited. Treatment trials have shown modest success but, ultimately, fail to address the cellular events that initiate radiation retinopathy. Animal models of radiation retinopathy could provide means to identify effective therapies. Here, we review the literature for all animal models of radiation retinopathy, summarize anatomical highlights pertaining to animal models, identify additional physiological factors to consider when investigating radiation retinopathy, and explore the use of clinically relevant tests for studying in vivo models of radiation retinopathy. We encourage further investigation into the mechanistic characterization of radiation retinopathy in the hope of discovering novel treatments.

Long-term follow-up in patients treated with electrochemotherapy for non-melanoma skin cancer in the head and neck area

BACKGROUND

Electrochemotherapy (ECT) is a cancer treatment modality where the intracellular accumulation of chemotherapeutic agents is enhanced by an applied electrical field.

AIMS/OBJECTIVES

To evaluate the long-term efficacy, safety and functional outcome after ECT treatment in high-risk non-melanoma skin cancer (NMSC) with curative intent.

MATERIALS AND METHODS

Seven patients with SCC or BCC in the head and neck area were treated with ECT with intratumoral bleomycin administration.

RESULTS

Five patients were cured by ECT as a mono-modality treatment after a median 10-year follow-up period. Two patients had recurrences and/or persisting tumors after treatment that required salvage surgery and radiotherapy. In two patients, the eye was spared with no visual impairment. In another patient, full facial nerve function was spared.

CONCLUSIONS

ECT can be a curative as well as an organ and function-sparing mono modality treatment in high-risk NMSC.

SIGNIFICANCE

Today ECT is mostly used as a palliative treatment. Its curative potential should be further investigated. Randomized studies comparing ECT with standard treatment is needed. Hopefully, this small study can encourage such studies.

Orbital metastases of invasive lobular breast carcinoma

Breast cancer is the main site of origin of orbital metastatic disease. Although invasive lobular breast carcinoma accounts for 10-15% of all breast cancer cases, it has been noticed that it metastasizes to the orbit more often compared to breast cancer of no special type (NST). The pathogenesis of this metastasis is not entirely understood; however, it seems that the unique tissue-specific characteristics of orbital microenvironment might contribute to metastatic disease in this particular site. Given the increasing survival of breast cancer patients and the prolonged metastatic potential of invasive lobular breast carcinoma, it is possible that the incidence of this rare metastasis might increase in the future. The purpose of this review is to present clinical manifestations, immunohistochemical characteristics and therapeutic options for orbital metastases from invasive lobular carcinoma.

Metastasis to the extraocular muscles: a case report, literature review and pooled data analysis

Metastasis to the extraocular muscles (EOM) is rare. The existing literature comprises only of isolated case reports therefore a summative description of these lesions is lacking. This study presents a case of bilateral rectus muscle metastasis from malignant melanoma. Furthermore a literature review and pooled data analysis is undertaken with 43 articles encompassing 77 patients and 101 eyes. Mean age was 53 years, 54% were male, 66% had unilateral involvement and 34% had bilateral involvement. The primary malignancies were melanoma (n = 17, 22%), breast (n = 15, 15%) and carcinoid (n = 11, 14%). A single muscle was involved in 56 eyes (67%) and multiple muscles in 27 eyes (33%). Lateral rectus was most commonly affected (n = 44, 53%). Presenting symptoms included restricted eye movements (n = 48, 62%), proptosis (n = 45, 58%), diplopia (n = 27, 35%) and pain (n = 18, 23%). Scattered case reports have previously made it difficult to characterise this phenomenon thus a pooled data analysis is presented.

Trends in Radiation Practices for Female Ocular Oncologists in North America: A Collaborative Study of the International Society of Ocular Oncology

Background

The aim of this study was to determine the known radiation exposure, attitudes, and consequent risk modifications among female ocular oncologists in North America who routinely administer radioactive plaque brachytherapy treatment and are members of the International Society of Ocular Oncology.

Methods

Nineteen female ocular oncologists completed an anonymous 17-question radiation exposure survey.

Results

Eleven of the participants chose to routinely wear lead protection during surgery; 8 did not. Fifteen of 19 participants reported using an unloaded "nonactive" template to prepare for plaque implantation. During pregnancy, 11 of 13 participants continued to perform plaque brachytherapy. Eight of these 11 undertook measures to decrease radiation exposure self-reported as lead wear and other. The average reported anxiety regarding fertility was 2.1 (SD, 2.2) on a scale from 1 to 10.

Conclusion

This study corroborates prior literature that surgeons' exposure to radiation during plaque brachytherapy is minimal. Nonetheless, there remains some anxiety regarding exposure risk to women, due to potential effects on fertility and fetal health. We found variability in exposure monitoring, required training, and precautions during pregnancy amongst this group of surgeons. Improved education and clearer pregnancy guidelines may equip female ocular oncologists with optimal knowledge regarding risk of radiation exposure.

Meibomian Gland Dysfunction Associated With Periocular Radiotherapy

PURPOSE

To investigate the influence of periocular radiotherapy on meibomian glands.

METHODS

We evaluated 28 patients (40 eyes) who received radiotherapy (RT group) for conjunctival or orbital lymphoma and 30 age-matched control subjects (60 eyes). Subjects underwent slit-lamp examination of the eyelids, Schirmer test, meibography, and evaluation of tear film breakup time (TBUT), Ocular Surface Disease Index (OSDI) scores, meibomian glands evaluation (meiboscore, meibum expressibility, and lid margin abnormality scores), and tear film lipid layer thickness using an ocular surface interferometer. These parameters were compared between subjects in the RT and control groups.

RESULTS

Meiboscores as well as meibum expressibility and OSDI scores in the RT group were significantly higher compared with those in the control group (1.6 ± 0.9 vs. 0.4 ± 0.6, 1.6 ± 1.0 vs. 0.2 ± 0.4, and 48.1 ± 21.4 vs. 6.2 ± 4.4, respectively, P < 0.001, all), whereas the Schirmer value (9.2 ± 5.1 vs. 12.3 ± 5.2, P = 0.004), TBUT (4.2 ± 2.5 vs. 6.4 ± 2.6, P = 0.001), and lipid layer thickness (61.0 ± 29.3 vs. 85.2 ± 20.0, P < 0.001) in the RT group were lower compared with those in the control group. The percentage of meibomian gland dropout was significantly correlated with age (P = 0.025) and total radiation dose (P = 0.012), regardless of the target location of irradiation. Even low-dose irradiated eyes (<30 Gy) exhibited significantly higher meiboscores (P < 0.001) and shorter TBUT (P = 0.005) compared with control eyes.

CONCLUSIONS

Eyes that received periocular radiotherapy exhibited relatively high tear film instability induced by meibomian gland dysfunction, contributing to the high severity of dry eye symptoms.

Orbital Apex Metastasis from Adenoid Cystic Carcinoma: Acute Loss of Vision and Subsequent Recovery with the Radiation

Orbital apex metastasis from adenoid cystic carcinoma (ACC) is rare. We present a patient with known metastatic ACC presented with a rapidly declining vision with visual acuity oculus dexter (OD) equal to counting fingers at two feet. On imaging, she was found to have a right orbital apex tumor causing compressive optic neuropathy. She received the intensity modulated radiation therapy (IMRT). After completion of the therapy, she had regained essentially a full vision with visual acuity OD of 20/30 without corrective lenses. The treatment rationale and pertinent literature are discussed in this article.

Interstitial brachytherapy for orbital soft tissue sarcoma: an innovative technique

Purpose

To report an innovative technique of interstitial brachytherapy developed for treatment of orbital soft tissue tumors.

Material and methods

A 4-month-old child diagnosed with rhabdomyosarcoma of orbit was treated with multiagent chemotherapy (CTh) and brachytherapy. Pre-planning computed tomography (CT) images were obtained and clinical target volume (CTV) was defined using the pre-treatment magnetic resonance imaging (MRI). Brachytherapy plan was generated for deciding optimal catheter placement. With the child under general anesthesia, catheter entry points were extrapolated and marked on the skin as determined from the pre-planning CT scan. Implantation of catheters was performed as per pre-determined catheter position and depths. Brachytherapy plan was generated and evaluated using dose volume histograms (DVH). A comparative external beam radiotherapy (EBRT) plan using RapidArc was also generated for the CTV with a 3 mm margin as the planning target volume (PTV).

Results

The mean CTV dose with brachytherapy was 158% compared to 101% with RapidArc. The CTV V₁₀₀ was 90% for brachytherapy vs. 95% for RapidArc. The mean dose to Lt Lens were 51% and 60%, respectively for brachytherapy and RapidArc, while the corresponding mean doses to the bony orbit were 39% and 68%, respectively. Follow-up MRI at 3 months showed complete response of the tumor.

Conclusions

Interstitial brachytherapy for orbit using this innovative technique is a safe and effective modality of local treatment for appropriately selected orbital soft tissue tumors. Brachytherapy resulted in excellent disease control with significant reduction of dose to surrounding ocular structures compared to EBRT.