Hemodynamic and Anatomic Variations Require an Adaptable Approach during Intra-Arterial Chemotherapy for Intraocular Retinoblastoma: Alternative Routes, Strategies, and Follow-Up

Absorbable gelatin compressed sponge (Gelfoam) embolization of distal external carotid artery branches in intra-arterial chemotherapy for retinoblastoma

BACKGROUND

In intra-arterial chemotherapy for retinoblastoma, a backflow from unreachable external carotid artery branches in the ophthalmic artery can be challenging.

OBJECTIVE

To describe a new endovascular technique using Gelfoam pledgets to temporarily occlude distal branches of the external carotid artery to reverse the competitive backflow into the ophthalmic artery in order to perform intra-arterial chemotherapy via the ostium of the ophthalmic artery in selected cases.

METHODS

We queried our prospectively collected database of 327 consecutive patients treated for retinoblastoma by intra-arterial chemotherapy and identified those employing Gelfoam pledgets. We describe this new technique with emphasis on feasibility and safety.

RESULTS

We treated 11 eyes with 14 infusions of intra-arterial chemotherapy using Gelfoam pledgets to occlude the distal branches of the external carotid artery. We report no perioperative complications due to this occlusion technique. At the ophthalmologic follow-up 1 month after the injection of Gelfoam pledgets, all cases showed tumor regression or stable disease. Two injections into the same eye as the rescue intra-arterial chemotherapy infusion resulted in a transient exudative retinal detachment, and one injection in a heavily pretreated case was followed by iris neovascularization and retinal ischemia. None of the pledget injections led to irreversible vision-threatening intraocular complications.

CONCLUSIONS

Intra-arterial chemotherapy in retinoblastoma using Gelfoam to transiently occlude the distal branches of the external carotid artery and reverse the backflow into the ophthalmic artery seems feasible and safe. Larges series will help to confirm the effectiveness of this new technique.

Angiographic characteristics and treatment approach in patients undergoing intra-arterial chemotherapy for retinoblastoma

PURPOSE

To identify the specific clinical and angiographic variables that determine the success of intra-arterial chemotherapy (IAC) in a patient with retinoblastoma.

METHODS

Medical records from patients undergoing intra-arterial chemotherapy for the treatment of retinoblastoma between January 2015 and June 2020 within a large academic ocular oncology practice were retrospectively reviewed. Demographics were recorded together with clinical, ocular, and angiographic variables such as the diameter of the ophthalmic artery (OA), angle of ophthalmic artery takeoff, and branching pattern of ophthalmic vasculature.

RESULTS

Forty-four eyes from 33 patients with retinoblastoma treated with IAC were identified. Over the total 32 mean months of follow-up, these patients received 144 total catheterizations and a mean of 3.2 IAC cycles for each eye. The number of IAC cycles and the chemotherapeutic agent used did not vary significantly with worsening International Classification of Retinoblastoma (ICRB) groups (P > 0.1). Cumulative dose did not vary with the ICRB group for eyes treated with melphalan, topotecan, or carboplatin (P > 0.1). A higher ICRB group was associated with a smaller mean ophthalmic artery diameter across all procedures (P = 0.016), and femoral artery diameter did not vary significantly between ICRB groups (P = 0.906). A higher cumulative dose of IAC was significantly associated with a smaller takeoff angle of the OA (melphalan, P = 0.011; topotecan, P = 0.009; carboplatin, P = 0.031) in patients who underwent successful IAC procedures. Ophthalmic artery diameter and femoral artery diameter did not have a significant association (P > 0.1) with higher IAC doses in successful IACs. Cumulative IAC dose was not significantly associated with ophthalmic vasculature branching pattern, presence of choroidal blush, temporary OA vasospasm reported during the procedure, and OA occlusion upon microcatheter placement.

CONCLUSION

In this study, neurosurgical angioanatomy appeared to influence the cumulative dose of chemotherapy needed during IAC for retinoblastoma. In the future, these anatomic variables may be used to guide the frequency of monitoring, dosing, and estimation of recurrence risk.

Risk factors for cataract in retinoblastoma management

AIMS

To investigate the risk factors for cataract following eye-preserving therapies for retinoblastoma.

METHODS

This retrospective, single-centre cohort study included patients diagnosed with retinoblastoma receiving eye-preserving therapies between January 2017 and June 2021. Cataract by the end of the follow-up was the main outcome.

RESULTS

Cataract was found in 31 of 184 (16.8%) included eyes during a mean follow-up of 27.6 months. The cataract and control groups were similar regarding patients' laterality, sex and disease stage. Eyes in the cataract group were more likely to present with endophytic retinoblastoma (p=0.02) and greater intraocular pressure (p=0.001). Competing risk regression analysis (univariate Fine-Gray model) showed that the growth pattern (p=0.01), intraocular pressure (p=0.01), number of intra-arterial chemotherapy (IAC) cycles (p=0.001), melphalan dose per IAC cycle (p=0.001) and number of intravitreous chemotherapy (IvitC) cycles (p=0.001) were associated with cataract occurrence. Multivariate analysis included higher intraocular pressure (p=0.003), a higher melphalan dose per IAC cycle (p=0.001) and an increasing number of IvitC cycles (p=0.04) as independent risk factors for cataract.

CONCLUSIONS

Repeated IAC and/or IvitC with melphalan were the most common eye-preserving therapies that induced cataract formation. The toxic effect of melphalan was an essential factor in cataract development, as indicated by the association of cataract occurrence with the melphalan dose.

Comparing internal versus external carotid artery branch delivery of intraarterial chemotherapy for the treatment of retinoblastoma

PURPOSE

The goal of this study was to compare the efficacy of intraarterial chemotherapy (IAC) for retinoblastoma delivered via the ophthalmic artery (OA) division of the internal carotid artery (ICA) versus alternative branches of the external carotid artery (ECA).

METHODS

We performed a retrospective chart review of patients receiving IAC for retinoblastoma at a single institution. Subjects were divided into three groups: those that received IAC solely through the OA branch of the ICA, those that initially received IAC through the OA branch of the ICA but were later switched to the ECA, and those that only received IAC through the ECA. The main outcomes compared included globe salvage rate and reduction in tumor thickness and size.

RESULTS

A total of 30 eyes from 26 patients were included. A total of 91 (58%) sessions of IAC were performed through the OA division of the ICA and 65 (42%) were performed through branches of the ECA. Eleven eyes (37%) solely received IAC through the OA branch of the ICA, 16 eyes (53%) were converted to ECA treatment, and 3 eyes solely received IAC through branches of the ECA. Statistical analysis did not show any significant difference in globe salvage rate or reduction in tumor thickness and size.

CONCLUSION

The use of alternative approaches for IAC when the OA branch of the ICA catheterization is not feasible allows for safe continued delivery of highly effective IAC, leading to similar outcomes in terms of globe salvage and reduction in tumor size.

Angiographic analysis of ophthalmic artery flow direction in children undergoing chemosurgery for retinoblastoma compared to age-matched controls

PURPOSE

Catheter-based intra-arterial chemotherapy (IAC) has revolutionized the treatment of retinoblastoma (RB). Variability in ophthalmic artery (OA) flow, either retrograde from external carotid artery branches, or anterograde from the internal carotid artery, necessitates multiple IAC techniques. We evaluated the direction of OA flow and identify OA flow reversal events over the course of IAC treatment as well in comparison to OA flow direction in non-RB children.

MATERIALS AND METHODS

We performed a retrospective analysis of OA flow direction in all RB patients treated with IAC, along with an age-matched control group who underwent cerebral angiography at our center from 2014 to 2020.

RESULTS

IAC was administered to a total of 18 eyes (15 patients). Initial anterograde OA flow was demonstrated in 66% (n  =  12) of eyes. Five OA reversal events were identified (3/5 anterograde-to-retrograde). All five events were in patients receiving multiagent chemotherapy. No correlation was found between OA flow reversal events and the initial IAC technique. A control group of 88 angiograms representing 82 eyes (41 patients) was utilized. The anterograde flow was observed in 76 eyes (86.4%). Our control group included 19 patients with sequential angiograms. One OA flow reversal event was identified.

CONCLUSION

OA flow direction is dynamic in IAC patients. Anterograde and retrograde OA directional switches do occur and may necessitate delivery technique variation. In our analysis, all OA flow reversal events were associated with multiagent chemotherapy regimens. Both anterograde and retrograde OA flow patterns were observed in our control cohort, suggesting bidirectional flow can occur in non-RB children.

Ocular survival after intra-arterial chemotherapy for retinoblastoma improves with accrual of experience and programmatic evolution

BACKGROUND

Intra-arterial chemotherapy (IAC) for the treatment of intraocular retinoblastoma has gained recognition as a method to improve ocular salvage; however, there is a paucity of evidence supporting treatment factors prognosticating ocular survival.

METHODS

All patients with retinoblastoma treated with IAC at a single institution between December 2008 and December 2019 were evaluated. Patient demographics, tumor classification, prior treatments, procedural data, other non-IAC therapies, adverse reactions, procedural complications, ocular outcomes, and overall survival were assessed via retrospective chart review. Factors suggestive of increased ocular survival were identified via univariate and multivariate analyses. The impact of accrued treatment experience was evaluated by grouping eyes by the respective year, IAC treatment was initiated.

RESULTS

Forty-nine eyes of 43 patients were treated for retinoblastoma with IAC (256 total procedures). At least grade 3 neutropenia was observed following 19% of IAC procedures. The risk of neutropenia was not statistically different between single or multidrug IAC. Comparing those who received balloon-assisted intra-arterial chemotherapy (bIAC) in more than two-thirds of cycles to those who did not, the risk of arterial access site complications was not statistically different. Multivariate analysis revealed a significantly lower risk of enucleation associated with treatment era in years (hazard ratio [HR] = 0.52-1.00, p < .05) and laser therapies (HR = 0.02-0.60, p < .05).

CONCLUSIONS

Ocular survival rates in patients treated with IAC for retinoblastoma at our institution have increased over time. Accrued treatment experience and programmatic changes have likely contributed. Larger, prospective series may lead to a better understanding of factors that consistently contribute to better ocular salvage.

Prospective Determination of Orbital Perfusion Dominance before Intra-Arterial Chemotherapy for Retinoblastoma Using Time-of-Flight Magnetic Resonance Angiography

Purpose Intra-arterial chemotherapy (IAC) represents a mainstay in the treatment of retinoblastoma. In a minority of cases, the external carotid artery (ECA) serves as the dominant supply to the central retinal artery and is associated with prolonged fluoroscopy times and higher intraprocedural radiation doses. The aim of this study was to evaluate the utility of time-of-flight (TOF) magnetic resonance angiography (MRA) for prospective determination of internal (ICA) versus ECA dominance for procedural planning.

Technique Between April 2017 and December 2020 (44 months), staging MR prior to IAC for retinoblastoma included variant spatial saturation band position TOF angiography. Exams were then retrospectively reviewed for concordance of ICA versus ECA dominance between the two modalities. Eight consecutive patients were included in the study. Mean patient age at time of diagnosis was 20.3 ± 10.7 months (range: 2.7–33.2 months). Ten affected eyes were included (2 cases of bilateral disease), with stage D disease in eight eyes and stage B disease in two eyes. MRA techniques demonstrated antegrade ophthalmic artery (OA) flow in 9/10 (90%) of affected eyes. Subsequent catheter angiography confirmed ICA dominant supply in 9/9 (100%). For a single affected eye (10%), the OA was demonstrated as orthotopic by T2 flow void, nonvisualized on anterior saturation TOF sequences, and faintly visualized on posterior saturation TOF sequences. Aggregate MRA to catheter angiographic concordance was 10/10 (100%).

Conclusion Variant saturation TOF MRA predicts ICA versus ECA dominant supply to the central retinal artery in retinoblastoma.

Intraarterial Chemotherapy for Retinoblastoma - Initial Experiences of a German Reference Centre

BACKGROUND

Adequate management of retinoblastoma requires a multidisciplinary and individual approach to treatment. Intraarterial chemotherapy (IAC) is one of the most commonly used treatment modalities, and enables supraselective application of chemotherapy via the ophthalmic artery and is now established in almost all treatment centres. However, published treatment success rates are heterogeneous. There are some unanswered issues regarding sight-threatening ocular complications and the long-term occurrence of secondary malignancies and metastatic disease. The objective of the present study is to analyse the results of a German national reference centre.

METHODS

Retrospective analysis of all children with an indication for at least one IAC from April 2010 to April 2020. IAC was used either as primary or recurrence therapy. Obligatory follow-up was at least 6 months.

RESULTS

137 eyes of 127 children with an indication for IAC could be included. 12 eyes with a follow-up of less than 6 months and 37 eyes in which IAC was technically not feasible were excluded. In summary, 88 eyes of 79 children were finally analysed. Mean follow-up was 38 months, ranging from 7 to 117 months. In total, 195 procedures were completed. In 30 eyes (34.1%) IAC was conducted as primary and in 58 (65.9%) as secondary therapy. There was an initial IAC treatment response in 75 eyes (85.2%) with a recurrence-free rate of 61.3%. Eye salvage rate was 68.1% with 28 enucleated eyes in total. Ocular complications were observed in 36 eyes (40.9%), with 19 eyes (21.6%) showing severe sight-threatening and 11 eyes (12.5%) presenting minor non-sight-threatening toxic reactions. During follow-up, 1 child developed a secondary malignancy, 1 child developed metastasis and 1 child died as a consequence of trilateral retinoblastoma.

CONCLUSION

In summary, IAC is a potent modality for retinoblastoma treatment and has been very successful, even in advanced disease and heavily pretreated eyes. However, ocular complications should be taken in consideration, especially when the only seeing eye is treated. Long term incidences of secondary malignancies and metastatic diseases should be further investigated in prospective studies.

Comparison of Intra-Arterial Chemotherapy Efficacy Delivered Through the Ophthalmic Artery or External Carotid Artery in a Cohort of Retinoblastoma Patients

Purpose: To evaluate the efficacy of an external carotid artery (ECA) alternative route in intra-arterial chemotherapy (IAC) for treatment of retinoblastoma.

Methods: In this retrospective, single-centre, case-control study, 98 retinoblastoma patients who received successful IAC were included. The drug delivery routes were the primary ophthalmic artery (OA) route and the ECA route when OA catheterization was not feasible.

Results: A total of 337 successful IAC procedures were performed in our study, of which 32 (9.5%) procedures were performed through the ECA route. Eighteen eyes (18.4%) accepted at least one IAC through branches of the ECA. Statistical analysis showed that there was no significant difference in ocular clinical results (enucleation, death, recurrence and event-free) between the ECA and OA routes. No significant association was found between the route of drug delivery and the ocular survival time (p = 0.69). The use of ECA catheterization in at least one IAC cycle was not a predictor of enucleation (HR: 1.58; 95% CI: 0.56–4.46, p = 0.39). The increasing number of procedures through the ECA route did not increase the risk of enucleation (HR: 1.64; 95% CI: 0.42–6.39, p = 0.48).

Conclusion: The ECA alternative route did not affect the efficacy of IAC in retinoblastoma. When the standard OA approach is not feasible, ECA system catheterization should be considered.

The Use of Alternative Routes for the Delivery of Intra-Arterial Chemotherapy for Retinoblastoma

BACKGROUND

The introduction of intra-arterial chemotherapy (IAC) for treatment of retinoblastoma considerably changed the paradigm by which this disease is managed, with event-free survival rates being above 70%.

OBJECTIVE

To analyze efficacy of IAC treatment using alternative approaches to ophthalmic artery catheterization (OAC), such as external carotid artery approach or balloon-assisted drug delivery.

METHODS

This is a retrospective chart review for subjects receiving IAC for retinoblastoma. The primary approach was OAC. In cases in which selective OAC was not feasible, alternative routes including catheterization of the external carotid artery or use of a balloon-assisted drug infusion were used.

RESULTS

This study included 197 consecutive patients with 207 retinoblastomas who underwent 658 IAC procedures overall. The mean age at diagnosis was 24 mo, and 54.5% of the study population was male. Success rate with IAC was 97% (639). Alternative approaches to OAC were, in total, 42 cases (6.4%)-external carotid artery catheterization and use of ICA balloon were performed in 22 (3.3%) and 20 (3%) cases, respectively. A mean of 3.1 IAC cycles were performed for each patient. In total, there were 23 technical failures of the primary OAC technique (3.4%). Periprocedural adverse events occurred in 4 procedures (0.6%). Use of an alternative technique for chemotherapy delivery other than selective OAC in at least one IAC cycle was not a predictor of enucleation.

CONCLUSION

IAC is a safe and effective treatment option for retinoblastoma. Chemotherapy delivery using alternative techniques is as effective as selective OAC.

Correlation of Technical and Adjunctive Factors with Quantitative Tumor Reduction in Children Undergoing Selective Ophthalmic Artery Infusion Chemotherapy for Retinoblastoma

BACKGROUND AND PURPOSE

Selective ophthalmic artery infusion chemotherapy has improved ocular outcomes in children with retinoblastoma. Our aim was to correlate quantitative tumor reduction and dichotomous therapeutic response with technical and adjunctive factors during selective ophthalmic artery infusion chemotherapy for retinoblastoma. An understanding of such factors may improve therapeutic efficacy.

MATERIALS AND METHODS

All patients with retinoblastoma treated by selective ophthalmic artery infusion chemotherapy at a single center during a 9-year period were reviewed. Only first-cycle treatments for previously untreated eyes were studied. Adjunctive factors (intra-arterial verapamil, intranasal oxymetazoline external carotid balloon occlusion) and technical factors (chemotherapy infusion time, fluoroscopy time) were documented by medical record review. Quantitative tumor reduction was determined by blinded comparison of retinal imaging acquired during examination under anesthesia before and 3-4 weeks after treatment. The dichotomous therapeutic response was classified according to quantitative tumor reduction as satisfactory (≥ 50%) or poor (<50%).

RESULTS

Twenty-one eyes met the inclusion criteria. Patients ranged from 2 to 59 months of age. Adjuncts included intra-arterial verapamil in 15, intranasal oxymetazoline in 14, and external carotid balloon occlusion in 14. Quantitative tumor reduction ranged from 15% to 95%. Six showed poor dichotomous therapeutic response. A satisfactory dichotomous therapeutic response was correlated with intra-arterial verapamil (P = .03) in the aggregate cohort and in a subgroup undergoing treatment with single-agent melphalan at a dose of <5 mg (P = .02). In the latter, higher average quantitative tumor reduction correlated with intra-arterial verapamil (P < .01).

CONCLUSIONS

Intra-arterial verapamil during selective ophthalmic artery infusion chemotherapy is correlated with an improved therapeutic response, particularly when treating with lower doses of single-agent melphalan.

Ophthalmic artery chemosurgery for retinoblastoma: an initial 3-year experience from two major institutes in Egypt

Background

Intra-arterial chemotherapy has shown promising results and improved the prognosis of retinoblastoma in the developed countries. Here, we aim to report our initial experience, in Egypt, in the treatment of all stages of naïve retinoblastoma with ophthalmic artery chemosurgery (OAC), using melphalan.

Results

The technique was successful in 23 out of 26 eyes. Overall, a total of 63 treatment sessions were performed. Ophthalmic artery catheterization was performed in 59 treatment sessions, whereas middle meningeal artery catheterization was performed in 4 treatment sessions. Adequate tumor control was achieved in 95.6%. Progression has developed in one eye after the third OAC session. The mean follow-up period was 18.5 months. Recurrence of the main tumor as well as vitreous and subretinal seeds was reported in one eye after 19-month duration. A globe salvage rate of 91.3% was attained. No metastasis was recorded, and all patients were alive within the stated follow-up period.

Conclusion

A high globe salvage rate along with metastasis free survival and mild complications were achieved. Therefore, our initial experience with OAC in primary retinoblastoma proved to be safe and effective.

Angiographic investigation of orbital vascular variations in the rabbit and implications for endovascular intra-arterial chemotherapy models

BACKGROUND

The New Zealand White rabbit (NZWR) is the first small-animal experimental model of intra-arterial chemotherapy (IAC) for retinoblastoma treatment. The NZWR has dual ophthalmic arteries (OA): the external OA (EOA) arises from the external carotid artery and the internal OA (IOA) from the internal carotid artery. We describe the technique that we have refined for OA catheterization in rabbits, and describe the angioanatomical variations in the OA supply to the NZWR eye and implications for IAC delivery, which were identified as part of a larger project exploring IAC effects in a rabbit retinoblastoma model.

METHODS

We developed techniques to perform angiography of the external and internal carotid arteries and superselective angiography of the EOA and IOA in NZWR using transfemoral access and a microwire/microcatheter system. EOA and IOA supply to the eye was determined angiographically and recorded before selective OA catheterization and angiography.

RESULTS

114 rabbits underwent carotid angiographic evaluation and OA catheterization (161 total eyes evaluated, 112 right, 49 left). Most eyes had a single dominant arterial supply; either IOA or EOA. EOA was dominant in 73% (118/161), and IOA was dominant in 17% (27/161). Co-dominant supply was seen in 10% (16/161). Of the rabbits with bilateral OA catheterization, 25/47 (53%) had bilateral dominant EOA.

CONCLUSION

Successful catheterization of the OA in the NZWR can be readily accomplished with nuanced technique. The external OA is the dominant arterial supply in the majority of NZWR eyes. These findings allow for successful reproduction of OA catheterization studies of IAC for retinoblastoma in NZWR.

Evaluation of the anastomoses between the ophthalmic artery and the middle meningeal artery by superselective angiography

PURPOSE

There are three anastomoses between the ophthalmic artery (OA) and the middle meningeal artery (MMA): the anastomotic branch with MMA, the recurrent meningeal branch and the anterior falx artery. We aimed to evaluate the anastomotic branches between the OA and the MMA on superselective angiograms of pediatric patients with retinoblastoma.

MATERIALS AND METHODS

We evaluated 126 angiographies performed on children with retinoblastoma. The mean diameter and angiographic visibility percentage of the anastomotic branches between the OA and the MMA were examined according to age group and sex.

RESULTS

The mean diameter of anastomotic branch with MMA was measured 0.58 ± 0.13 mm and we found this branch in 15 of 126 angiographic images (11.9%). We detected the recurrent meningeal branch in 47 of total images (37.3%). The recurrent meningeal branch arose 85.1% from the lacrimal artery, 8.5% from the anastomotic branch with MMA and 6.4% directly from the OA. The mean diameter of this artery was measured 0.21 ± 0.06 mm. Anterior falx artery was found in 86 of 126 angiographic peocedures (68.3%) and the mean diameter was measured 0.22 ± 0.06 mm.

CONCLUSION

Knowledge of the anastomoses between the OA and the MMA system are all necessary to perform safe and successful endovascular and surgical procedures involving the orbital region.

Initial experience with the Scepter Mini dual-lumen balloon for transophthalmic artery embolization of anterior cranial fossa dural arteriovenous fistulae

BACKGROUND

Precise delivery of liquid embolic agents (LEAs) remains a challenge in the endovascular treatment of dural arteriovenous fistulae (dAVFs) and cerebral arteriovenous malformations (cAVMs). Despite significant advances in the past decade, LEA reflux and catheter navigability remain shortcomings of current endovascular technology, particularly in small and tortuous arteries. The Scepter Mini dual-lumen balloon microcatheter aims to address these issues by decreasing the distal catheter profile (1.6 French) while allowing for a small (2.2 mm diameter) balloon at its tip.

METHODS

We report our initial experience with the Scepter Mini in two patients with anterior cranial fossa dAVFs that were treated with transophthalmic artery embolization.

RESULTS

In both patients, the Scepter Mini catheter was able to be safely advanced into the distal ophthalmic artery close to the fistula site, and several centimeters past the origins of the central retinal and posterior ciliary arteries. A single Onyx injection without any reflux resulted in angiographic cure of the dAVF in both cases, and neither patient suffered any vision loss.

CONCLUSIONS

These initial experiences suggest that the Scepter Mini represents a significant advance in the endovascular treatment of dAVFs and cAVMs and will allow for safer and more efficacious delivery of LEAs into smaller and more distal arteries while diminishing the risk of LEA reflux.

Orbital infarction syndrome after mechanical thrombectomy in acute ischaemic stroke

Orbital infarction syndrome (OIS) encompasses the ischaemic infarction of all intraorbital and intraocular structures (optic nerve, extraocular muscles and orbital fat) which leads to a painful loss of visual acuity, ophthalmoparesis, chemosis, proptosis and ptosis. The rich anastomotic orbital vascularisation from internal carotid artery (ICA) and external carotid artery makes this disorder a rare cause of visual loss in stroke patients. We describe a case of a woman who suffered an acute occlusion of her right ICA and developed an OIS after mechanical thrombectomy.

Ophthalmic artery catheterization for retinoblastoma treatment: does reflux affect tumor response?

Background

Intra-arterial chemotherapy (IAC) for retinoblastoma (Rb) has been established as a primary treatment for the disease. To determine whether the presence of reflux into the ICA is associated with tumor response or with any other adverse events in pediatric retinoblastoma patients.

Methods

A retrospective chart review was performed for patients diagnosed with Rb and managed with ophthalmic artery catheterization (OAC).

Results

The total study cohort included 205 Rb tumors of 205 eyes in 194 consecutive patients who underwent 624 successful intra-arterial chemotherapy infusions using OAC. Of the 205 eyes, 65 eyes (32.7%) underwent 157 OAC procedures constituted group A (no reflux), 64 eyes (31.2%) underwent 236 OAC procedures constituted group B (variable pattern), and 74 eyes (36.1%) underwent 231 OAC procedures constituted group C (reflux). There was no significant difference in baseline characteristics between the three cohorts. Also, there was no significant difference in tumor characteristics between the three groups, except for genetic status. There was no significant difference between the three groups in terms of tumor response at completion of the treatment regimen. Complete tumor response was achieved at 70.2% in Group A, at 83.3% in Group B, and at 78.5% in group C (P=0.39). Similarly, eye enucleation occurred at 38.5% in group A, 31.8% in group B, and 31.5% in group C. None of the patients in both groups had any neurological adverse events or new onset of seizures.

Conclusions

The presence of reflux, which may complicate the procedure and prolong it, was not associated with poor outcomes in our analysis.

Unusual ophthalmic artery origin: Implications for intraarterial chemotherapy of retinoblastoma

We report two pediatric retinoblastoma patients with unusual ophthalmic artery (OA) origins who were referred to our interventional neuroradiology department for intraarterial chemotherapy. The first patient had double OAs arising from the ipsilateral internal carotid artery and a central retinal artery (CRA) arising from the more cranially located artery, whereas the second patient had an OA originating from the A1 segment of the ipsilateral anterior cerebral artery. In both cases the CRA arose from the artery entering the orbit through the optic foramen. Both patients tolerated the procedures well. To the best of our knowledge, our retinoblastoma patients with unusual OA origins are the first in the literature in which detailed knowledge of the orbital vasculature and especially CRA origin carried immediate clinical implications, altering access strategies. These variations were proved both by flat-panel detector computed tomography findings and superselective injections of OAs with unusual origins. Our results show that in patients with retinoblastoma, a detailed angiographic work-up may be necessary to evaluate the orbital vasculature and possible abnormal origin of the OA. Recognition of possible variations of OA origin and its branching patterns is of the utmost importance for successful treatment and avoidance of adverse events among retinoblastoma patients.

Intra-arterial chemotherapy in retinoblastoma - A paradigm change

Intra-arterial chemotherapy (IAC), also known as superselective ophthalmic artery chemotherapy or chemosurgery, is currently widely accepted as one of the primary treatment modalities for intraocular retinoblastoma worldwide. Following the introduction of the technique in 1998, IAC has evolved over the past decades to be safer and more effective. Accumulated evidence shows that IAC is more effective in providing eye salvage in group D and E retinoblastoma as compared to conventional systemic intravenous chemotherapy (IVC). In contrast to IVC, IAC has the added benefits of reduced overall treatment duration and minimal systemic toxicity. This review provides a comprehensive update on the history, technique, indications, contraindications, and outcome of IAC. We have also identified the strengths, weaknesses, opportunities and threats (SWOT analysis) of the technique in this review.

Intra-arterial chemotherapy for retinoblastoma: the dosimetric impact

PURPOSE

Purposes are (1) to measure main radiation parameters and (2) to propose a method to estimate the absorbed doses of internal organs starting from DAP values. Measuring the exposition of internal organs by repeated irradiations on an anthropomorphic phantom with the same settings used in vivo, we could establish correlations between (1) DAP and the dose recorded by a dosimeter placed along the X-ray beam entrance pathway; (2) the dose recorded by the same dosimeter and the absorbed dose in internal organs.

METHODS

Forty-four consecutive patients (16 males, 28 females) (mean age 35.4 months) treated at our institution with IAC (216 procedures: 196 via the ICA and 20 into branches of the ECA) were included in this prospective study. IAC was divided into 5 phases. Fluoroscopic time, DAP, and ESD were measured.

RESULTS

The mean DAP was 595 ± 445 cGy cm² and the mean fluoroscopic time was 540 ± 403 s. ESD was on average 9.59 mGy (range 0.8-165 mGy). The absorbed dose was lower than 12.1 mGy in the left retina (the more exposed organ) in 75% of single treatments and lower than 25 mGy in 95% of treatments. In the cases of 3 and 6 sessions, the left retina of 75% of patients absorbed respectively less than 36.3 and 72.7 mGy, whereas the left retina of 95% of patients received less than 75.2 and 150.4 mGy. Other organs were less exposed.

CONCLUSION

This paper describes a method of absorbed dose estimation providing ranges used clinically in a single practice and the basis for further prospective studies.

Effectiveness of alternative routes of intra-arterial chemotherapy administration for retinoblastoma: Potential for response and complications

OBJECTIVE

Intra-arterial chemotherapy (IAC) is now the first line treatment for selected patients with retinoblastoma (Rb). Typically, IAC is infused following the selective catheterization of the ophthalmic artery (OA) on the affected side. However, in some patients, the OA alone may not provide vascular supply to the tumor, whereas in other instances the efficacy of IAC could be compromised due to the presence of prominent collateral vessels from the external carotid artery (ECA). We report our experience with catheterizing vessels other than the OA for IAC treatment for Rb.

METHODS

After institutional review board approval, a retrospective analysis was conducted of electronic medical records and imaging of our Rb population.

RESULTS

We identified 13 patients who received IAC for Rb treatment. Of these, five patients required alternative methods of chemotherapy delivery other than through the OA, totaling 17 treatments. Two patients needed balloon-assisted occlusion of the ECA, two patients required selective catheterization of the middle meningeal artery, and one patient had no internal carotid artery supply to the choroidal blush, thus the superficial temporal artery provided access for IAC. Total globe salvage rate was 76% and 80% with the alternative route subset.

CONCLUSIONS

Alternatives to the OA may be necessary to deliver IAC for selected cases of Rb. These routes can be safe and effective. However, thorough understanding of the orbital blood supply is essential. Whether these alternative IAC methods result in similar outcomes to OA infusions has not been established.

Middle meningeal artery occlusion for intra-arterial chemotherapy of retinoblastoma

We report the intentional occlusion of the middle meningeal artery arising from the lacrimal artery, a novel technique to improve drug delivery in a 14-month-old boy with a history of right sporadic unilateral cavitary retinoblastoma group D. The patient was referred to our institution for intra-arterial chemotherapy after two systemic chemotherapy treatments. The digital subtraction angiography showed a large middle meningeal artery arising from the right lacrimal artery and decrease choroidal enhancement thus decreased flow to the tumor. The ophthalmological examination after the first intra-arterial chemotherapy observed no tumor regression. Assuming a vascular steal, in the second intra-arterial chemotherapy session, the origin of the middle meningeal artery was occluded. Following this treatment, a significant response was observed at ophthalmological follow up. In the presented case, the efficacy of intra-arterial chemotherapy was improved after occlusion of a meningeal branch arising from the lacrimal artery, which was responsible for the vascular steal.

Recent advances and challenges in the management of retinoblastoma

The treatment of retinoblastoma (Rb) has improved significantly in recent times. Worldwide, there is an increasing trend to use conservative treatment modalities that aim to preserve the globe as well as vision with minimum morbidity. Recently, the use of targeted delivery of chemotherapy to the eye in the form of selective intra-arterial and intravitreal chemotherapy has shown promising results. Radiotherapy is beneficial in selected cases, either in the form of plaque brachytherapy or as external beam radiotherapy. Orbital disease carries a poor prognosis for survival. However, a multimodal treatment protocol has improved survival in children with extraocular disease. Nevertheless, challenges remain, especially for the developing world. This review aims to highlight recent advances in the management of Rb that have contributed towards improving treatment outcomes and also discuss the challenges ahead, with special reference to the Indian scenario.

An update on the variations of the orbital blood supply and hemodynamic

Purpose

Several variations of the arterial blood supply of the orbit have been reported over the years. This review is aimed to provide an update focusing on three important issues: (a) variations of the ophthalmic artery origin; (b) contribution of the external carotid artery to the orbital blood supply; (c) orbital hemodynamic.

Methods

A PubMed and Google search was carried out with the following keywords: ophthalmic artery origin, ophthalmic artery anastomoses and ophthalmic artery anatomy.

Results

The site of origin of the ophthalmic artery displays a limited number of variations. However they are important as they are also associated with course variations. Anastomoses between the ophthalmic artery and the external carotid artery are numerous and many of them can acquire clinical relevance. Records on their anatomic frequency are limited. Orbital hemodynamic variations are a poorly studied subject. Recent investigations in children have unveiled unexpected variability and instability in the way the blood flows through the orbit.

Conclusions

The orbit shows several possible arterial variations. Some of them have a profound influence on its hemodynamic at least in children. More studies are required to ascertain if the hemodynamic variability observed in children can be pinpointed also in adults.