Radiation-Induced Ocular Surface Disorders and Retinopathy: Ocular Structures and Radiation Dose-Volume Effect

Orbital cavernous venous malformation shrinkage during fractionated stereotactic radiotherapy contributing to the development of radiation retinopathy

BACKGROUND

Posterior movement of ocular tissue secondary to orbital cavernous venous malformation shrinkage from fractionated stereotactic radiotherapy can allow healthy structures to move into the radiation field during treatment. This may carry an increased risk of radiation-induced retinopathy.

METHODS

We present a case of a young female whose radiotherapy treatment for an orbital cavernous venous malformation resulted in a 3 mm reduction in proptosis and subsequent retinopathy.

RESULTS

The severity of the patient's radiation-induced radiotherapy exceeded expectations. The venous malformation shrinkage during treatment and ensuing posterior movement of the globe suggested an increased involvement of ocular tissue in the radiation field, prompting consideration of interval neuroimaging and tumour mapping.

CONCLUSIONS

We describe and suggest a protocol of onboard neuroimaging during the radiation therapy course to better target tumour volumes and minimise collateral tissue damage. To our knowledge, this has not been previously described in the ophthalmic literature.

Radiation retinopathy vs. ocular ischemic syndrome: how to reach the diagnosis?

We present a case of diagnostic interest; we present the differential diagnosis and the complementary tests necessary to reach it, in addition to highlighting the importance of a correct collection of background and clinical history. A 54-year-old woman with a history of carcinoma of the floor of the mouth treated with radiotherapy and chemotherapy develops ischemic retinopathy. It was necessary to perform a systemic study and differential diagnosis with entities such as ocular ischemic syndrome and radiation retinopathy, due to the similarity in the clinical findings found. Radiation retinopathy should be ruled out in any patient with visual impairment and a history of radiotherapy treatment. A broad differential diagnosis and systemic study are required to rule out entities such as ocular ischemic syndrome and diabetic retinopathy, in addition to early treatment to avoid possible complications.

New Frontiers in the Treatment of Patients with HER2+ Cancer and Brain Metastases: Is Radiotherapy Always Useful?

Brain metastases (BM) pose a significant challenge in the management of HER2+ breast cancer since almost 50% of patients with HER2+ breast cancer develop brain tumors. The complex process of brain metastases involves genetic mutations, adaptations and mechanisms to overcome the blood-brain barrier. While radiotherapy is still fundamental in local therapy, its use is associated with cognitive adverse effects and limited long-term control, necessitating the exploration of alternative treatments. Targeted therapies, including tyrosine kinase inhibitors, monoclonal antibodies, and antibody-drug conjugates, offer promising options for HER2+ breast cancer patients with BM. Clinical trials have demonstrated the efficacy of these agents in controlling tumor growth and improving patient outcomes, posing the question of whether radiotherapy is always the unique choice in treating this cancer. Ongoing research into novel anti-HER2 antibodies and innovative combination therapies holds promise for advancing treatment outcomes and enhancing patient care in this clinical scenario. This narrative review provides a comprehensive overview of traditional medical treatments, molecularly targeted therapy and investigational agents in the management of HER2+ breast cancer with BM, highlighting the evolving landscape and potential future directions in treatment strategies to improve patient survival and quality of life.

Ocular surface changes in patients who have undergone head and neck radiation therapy

PURPOSE

Dry eye syndrome (DES) is a familiar sequelae of radiation therapy (RT) for head and neck cancers (HNC). Ocular surface changes such as DES occur due to injury to the conjunctival epithelium, goblet cells, corneal surface, lacrimal glands, and meibomian glands. This study aimed at the evaluation and early detection of changes in ocular surface parameters in patients receiving RT for extraocular HNC.

METHODS

Forty-two eyes of 21 patients undergoing HNC RT were evaluated. Radiation technique and dose of radiation to the lens and eye were recorded. Subjects were evaluated for meibomian gland changes by meiboscore grading, ocular surface disease index (OSDI) questionnaire, Schirmer's test, tear film break-up time (TBUT), and slit-lamp examination before RT, immediately post RT, and 6 weeks post RT. A comparison of the ipsilateral eye on the irradiated side to the contralateral eye was done.

RESULTS

A significant reduction in TBUT was seen immediately post RT and 6 weeks post RT ( P < 0.001 and 0.008, respectively), with an increase in meiboscore at both visits ( P < 0.001). An OSDI score of >13 was seen in 23.80% of patients post RT, with a significant difference from baseline ( P < 0.001). On comparing ipsilateral and contralateral eye groups, a significant difference from baseline was seen in TBUT ( P < 0.001 and 0.033, respectively) and meiboscore ( P < 0.001 for both eyes). A significant change of >1 second in TBUT and >1.7 in meiboscore was seen with a mean dose of around 8 Gy to the lens.

CONCLUSION

All patients undergoing HNC RT should be followed up for ocular surface and meibomian gland changes. The contralateral eye should also be evaluated. Patients receiving lower doses to the ocular structures should also be kept under follow-up.

Efficacy of Intravitreal Injections Anti-Vascular Endothelial Growth Factor Treatment for Radiation Retinopathy: A Systematic Review and Meta-analysis

PURPOSE

This study aims to appraise the therapeutic effectiveness of intravitreal injections anti-vascular endothelial growth factor (anti-VEGF) vs alternative therapies in managing radiation retinopathy (RR).

DESIGN

Systematic review and meta-analysis.

METHODS

We obtained comprehensive data retrieval using PubMed, Embase, Web of Science, Scopus, and the Cochrane Library from their inception until December 15, 2023. This review included randomized controlled trials (RCTs) and nonrandomized studies (NRSs) reporting on best-corrected visual acuity (BCVA) among RR patients treated with intravitreal anti-VEGF. Study selection and data extraction were meticulously performed by 2 independent reviewers. The Cochrane Risk of Bias Tool 2.0 (RoB 2.0) and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) scales were utilized for bias risk assessment. Quantification of heterogeneity was executed using Q, H, and I2 statistics. The primary endpoint was the BCVA at the final observation point of each study. Secondary endpoints included central retinal thickness (CRT), foveal avascular zone (FAZ) area, and capillary density (CD) at the level of superficial capillary plexus. Subgroup analyses were undertaken to explore potential heterogeneity sources possibly due to treatment duration and study design. Sensitivity analyses were conducted to ascertain result stability.

RESULTS

This analysis incorporated 7 studies (including 3 RCTs) encompassing 922 patients afflicted with RR. Relative to other treatment modalities, intravitreal anti-VEGF therapy was associated with a statistically significant mean decrease in BCVA of -0.34 logMAR (95% CI, -0.39 to -0.30 logMAR; I2 = 87.70%; P < .001), and a substantial reduction in CRT of -34.65 µm (95% CI, -50.70 to -18.60 µm; I2 = 30.40%; P < .001). Additionally, a reduction in the FAZ area by -0.69 mm² (95% CI, -0.91 to -0.46 mm², I2 = 0%; P < .001) was observed. A positive tendency was noted in CD at the superficial capillary plexus between anti-VEGF and other therapeutic interventions.

CONCLUSIONS

Intravitreal anti-VEGF injections, in comparison to other treatments, demonstrate superior efficacy in enhancing BCVA and reducing CRT, thereby underscoring the potential of anti-VEGF in ameliorating radiation retinopathy outcomes. However, the conclusions are constrained by the incorporation of data from some NRSs and the small sample sizes.

Biomaterials-mediated radiation-induced diseases treatment and radiation protection

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field.

Neurological complications of modern radiotherapy for head and neck cancer

Radiotherapy is one of the mainstay treatment modalities for the management of non-metastatic head and neck cancer (HNC). Notable improvements in treatment outcomes have been observed in the recent decades. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and charged particle therapy, have significantly improved tumor target conformity and enabled better preservation of normal structures. However, because of the intricate anatomy of the head and neck region, multiple critical neurological structures such as the brain, brainstem, spinal cord, cranial nerves, nerve plexuses, autonomic pathways, brain vasculature, and neurosensory organs, are variably irradiated during treatment, particularly when tumor targets are in close proximity. Consequently, a diverse spectrum of late neurological sequelae may manifest in HNC survivors. These neurological complications commonly result in irreversible symptoms, impair patients' quality of life, and contribute to a substantial proportion of non-cancer deaths. Although the relationship between radiation dose and toxicity has not been fully elucidated for all complications, appropriate application of dosimetric constraints during radiotherapy planning may reduce their incidence. Vigilant surveillance during the course of survivorship also enables early detection and intervention. This article endeavors to provide a comprehensive review of the various neurological complications of modern radiotherapy for HNC, summarize the current incidence data, discuss methods to minimize their risks during radiotherapy planning, and highlight potential strategies for managing these debilitating toxicities.

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.

Dosimetric impact of applying a model-based dose calculation algorithm for skin cancer brachytherapy (interventional radiotherapy)

Purpose

Brachytherapy (BT, interventional radiotherapy) is a well-established radiotherapy technique capable of delivering high doses to tumors while sparing organs at risk (OARs). Currently, the clinically accepted dose calculation algorithm used is TG-43. In the TG-186 report, new model-based dose calculation algorithms (MBDCA), such as Elekta's advanced collapsed cone engine (ACE), have been introduced, although their clinical application is yet to be fully realized. This study aimed to investigate two aspects of TG-186: firstly, a comparison of dose distributions calculated with TG-43 and TG-186 for skin tumors; and secondly, an exploration of the impact of using a water bolus on the coverage of clinical target volume (CTV) and OARs.

Material and methods

Ten treatment plans for high-dose-rate IRT were developed. All plans were initially calculated using the TG-43 algorithm, and were subsequently re-calculated with TG-186. In addition, one of the treatment plans was assessed with both TG-43 and TG-186, using 10 different water bolus thicknesses ranging from 0 to 5 cm. To assess dose variations, the following dose-volume histogram (DVH) parameters were compared: D2cc and D0.01cc for OARs, and V150, V100, V95 and V90 for CTV coverage.

Results and conclusions

The average dosimetric results for CTV and OARs, as calculated by both algorithms, revealed statistically significant lower values for TG-186 when compared with TG-43. The presence of a bolus was observed to enhance CTV coverage for the TG-186 algorithm, with a bolus thickness of 2 cm being the point at which ACE calculations matched those of TG-43. This study identified significant differences in dosimetric parameters for skin tumors when comparing the TG-43 and TG-186 algorithms. Moreover, it was demonstrated that the inclusion of a water bolus increased CTV coverage in TG-186 calculations.

Efficacy and Safety of Radiotherapy Combined with Pyrotinib in the Treatment of HER2-Positive Breast Cancer with Brain Metastases

Purpose

To explore the efficacy and safety of pyrotinib combined with different radiotherapy modes in human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) patients with brain metastasis (BM).

Patients and Methods

This study is a retrospective analysis of patients diagnosed with BM who underwent treatment with pyrotinib between November 2018 and April 2023. A total of 66 patients were administered radiotherapy in conjunction with pyrotinib (Group A), while 26 patients received pyrotinib as a standalone treatment (Group B). Within Group A, 18 patients underwent conventional fractionated radiotherapy (2Gy/F), while 48 patients received hyperfractionated radiotherapy (HFRT) (≥3Gy/F). The primary endpoints were intracranial progression-free survival (IC-PFS) and overall survival (OS). The secondary endpoints were objective response rate (ORR) and clinical benefit rate (CBR).

Results

The ORR of Group A was 54.5% (36/66), while the ORR of Group B was 34.6% (9/26) (P= 0.047). The CBR of Group A was 89.4% (59/66) and that of Group B was 69.2% (18/26) (P= 0.041). The IC-PFS between Group A and Group B were 12 months and 8 months, respectively (P< 0.001), and the OS were 20 months and 16 months, respectively (P= 0.065). In Group A, the IC-PFS and OS between the conventional fractionation radiotherapy group and the HFRT group were 10 months and 12 months, respectively (P= 0.001) and 16 months and 24 months, respectively (P< 0.001). No serious adverse reactions were observed in Group A and Group B.

Conclusion

For HER2-positive BC patients with BM, it is recommended to adopt the treatment mode of HFRT combined with pyrotinib, which can improve the local control and survival of patients.

Case Report: Optical coherence tomography angiography findings in radiation retinopathy

We reported the observation of a 31-year-old female followed for a nasopharyngeal carcinoma since 2009, treated by locoregional radiotherapy, with a cumulative dose of 75 Gray. The patient presented with a progressive decline in bilateral vision. Ophthalmologic examination revealed bilateral dry eye, posterior subcapsular cataract, radiation retinopathy, and optic neuropathy. The patient presented all ocular complications of radiotherapy. The most severe was radiation retinopathy. Performing optic coherence tomography angiography (OCT-A) earlier could have speeded up the diagnosis and led to a better prognosis. The OCT-A showed more pronounced macular edema in the right eye, and revealed enlargement of the central avascular zone and loss of the deep and superficial retinal vascular network. The patient received three consecutive monthly intravitreal injections of anti-vascular endothelial growth factor. Yet, we noted a non-improved visual acuity. The aim of this case report was to present the contribution of OCT-A in the diagnosis of radiation maculopathy and attribute these changes to ischemia at the level of the retinal vascular network.

Radiation-Induced Retinopathy and Optic Neuropathy after Radiation Therapy for Brain, Head, and Neck Tumors: A Systematic Review

Background: Patients with brain, head, and neck tumors experience a decline in their quality of life due to radiation retinopathy and optic neuropathy. Little is known about the dose–response relationship and patient characteristics. We aimed to systematically review the prevalence of radiation retinopathy and optic neuropathy. Method: The primary outcome was the pooled prevalence of radiation retinopathy and optic neuropathy. The secondary outcome included the effect of the total radiation dose prescribed for the tumor according to the patient’s characteristics. Furthermore, we aimed to evaluate the radiation dose parameters for organs at risk of radiation retinopathy and optic neuropathy. Results: The pooled prevalence was 3.8%. No retinopathy was reported for the tumor’s prescribed dose of <50 Gy. Optic neuropathy was more prevalent for a prescribed dose of >50 Gy than <50 Gy. We observed a higher prevalence rate for retinopathy (6.0%) than optic neuropathy (2.0%). Insufficient data on the dose for organs at risk were reported. Conclusion: The prevalence of radiation retinopathy was higher compared to optic neuropathy. This review emphasizes the need for future studies considering retinopathy and optic neuropathy as primary objective parameters.

Comparable meibomian gland changes in patients with and without ocular graft-versus-host disease after hematopoietic stem cell transplantation

PURPOSE

To compare the presentation and severity of meibomian gland dysfunction (MGD) in patients with and without chronic ocular graft-versus-host disease (coGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

This prospective cross-sectional study included 79 patients (47 with coGVHD and 32 without) after allo-HSCT. All participants completed ocular surface disease index questionnaire, and received slit lamp, ocular surface interferometer, meibography and confocal microscopy examination. The prevalence and severity of MGD were compared between two groups and related factors were analyzed. Main outcome measures were lipid layer thickness (LLT) and meiboscore.

RESULTS

Similarly high prevalence of MGD was detected in coGVHD and non-coGVHD groups (87.2% vs 84.4%, P = 0.977). Among those with MGD, although patients without coGVHD had longer noninvasive break-up time [5.54 (2.87, 9.37) vs 2.29 (0.00, 3.82) s, P < 0.001], patients in two groups presented similarly decreased LLT (53.5 ± 22.3 vs 47.1 ± 25.2 nm, P = 0.286), increased meiboscore (2.7 ± 1.5 vs 3.5 ± 1.8, P = 0.060) and enlarged acinar unit area (1647.7 ± 942.9 vs 1808.8 ± 1211.5 μm², P = 0.592). Meibomian gland inflammation and fibrosis were observed in both groups, but more predominant in coGVHD group. Results were consistent when patients within a comparable post-HSCT time interval were compared. Regression analysis revealed neither LLT nor meiboscore was associated with coGVHD severity. LLT was positively correlated with systemic immunosuppressant use (β = 12.0, P = 0.044), while meiboscore was positively correlated with lymphoma (β = 1.78, P = 0.040) and matched unrelated donor (β = 1.59,P = 0.008).

CONCLUSIONS

MGD was common and evident in patients after allo-HSCT. MGD is not different between coGVHD and non-coGVHD patients except more inflammation and fibrosis in the former.

Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options

In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.