Intra-arterial chemotherapy for retinoblastoma: the dosimetric impact

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.

Retinoblastoma Is Characterized by a Cold, CD8+ Cell Poor, PD-L1- Microenvironment, Which Turns Into Hot, CD8+ Cell Rich, PD-L1+ After Chemotherapy

Purpose

To investigate the impact of chemotherapy (CHT) on human retinoblastoma (RB) tumor microenvironment (TME).

Cases and Methods

Ninety-four RBs were studied, including 44 primary RBs treated by upfront surgery (Group 1) and 50 primary RBs enucleated after CHT (CHT), either intra-arterial (IAC; Group 2, 33 cases) or systemic (S-CHT; Group 3, 17 cases). Conventional and multiplexed immunohistochemistry were performed to make quantitative comparisons among the three groups, for the following parameters: tumor-infiltrating inflammatory cells (TI-ICs); programmed cell death protein 1 (PD-1) positive TI-ICs; Ki67 proliferation index; gliosis; PD-1 ligand (PD-L1) protein expression; vessel number. We also correlated these TME factors with the presence of histological high-risk factors (HHRF+) and RB anaplasia grade (AG).

Results

After CHT, a decrease in both RB burden and Ki67 positivity was observed. In parallel, most subsets of TI-ICs, PD-1+ TI-ICs, gliosis, and PD-L1 protein expression significantly increased (P < 0.001, P = 0.02, P < 0.001, respectively). Vessel number did not significantly vary. Age, HHRFs+ and AG were significantly different between primary and chemoreduced RBs (P < 0.001, P = 0.006, P = 0.001, respectively) and were correlated with most TME factors.

Conclusions

CHT modulates host antitumor immunity by reorienting the RB TME from anergic into an active, CD8+, PD-L1+ hot state. Furthermore, some clinicopathological characteristics of RB correlate with several factors of TME. Our study adds data in favor of the possibility of a new therapeutic scenario in human RB.

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.

Selective Ophthalmic Artery Chemotherapy with Melphalan in the Management of Unilateral Retinoblastoma: A Prospective Study

PURPOSE

To determine prospectively the efficacy and to assess potential side effects of melphalan selective ophthalmic artery chemotherapy (SOAC) as first-line treatment for unilateral retinoblastoma.

DESIGN

Phase 2 nonrandomized, prospective study.

PARTICIPANTS

Patients with unilateral retinoblastoma group B, C, or D of the International Classification for Intraocular Retinoblastoma (IRC). Group D eyes with massive vitreous seeding were not eligible.

METHODS

Melphalan SOAC associated with diode laser thermotherapy, cryotherapy, or both at 4-week intervals (3-6 cycles). For persistent vitreous seeding, intravitreal melphalan chemotherapy also was used.

MAIN OUTCOME MEASURES

The primary outcome was globe preservation rate. Secondary outcomes were tumor relapse rate, occurrence of ocular or systemic adverse events, and measurement of the dose area product (DAP).

RESULTS

Between 2012 and 2017, 39 patients (39 eyes) with unilateral retinoblastoma were included prospectively. Three included patients did not receive SOAC (2 catheterization failures and 1 case of viral syndrome) and were considered failures. At diagnosis, IRC groups for the 36 treated patients were: B, n = 4 (11%); C, n = 13 (36%); and D, n = 19 (53%); median age was 21.5 months (range, 3.2-61.6 months). Median number of SOAC cycles was 3.9 (range, 1-6 cycles), and median melphalan dose was 4.9 mg/procedure. The median DAP was 1.24 Gy.cm²/procedure. Median follow-up was 63 months (range, 34-93 months). SOAC was associated with local treatments for 31 patients (86%): diode laser thermotherapy for all of them and cryotherapy or intravitreal chemotherapy for 10 (32%) and 9 patients (25%), respectively. SOAC treatment was interrupted in 5 patients because of severe ophthalmic (ptosis, n = 2; retinal ischemia, n = 2) or systemic (hypotension, n = 1) adverse events. At the cutoff date analysis, all patients were alive without metastasis. The 18-month eye preservation rate was 80% (range, 68.6%-94.6%). After a follow-up of at least 30 months, the ocular preservation rate was 69% (n = 24 preservations).

CONCLUSIONS

This first prospective trial demonstrated that SOAC with melphalan alone as first-line treatment for retinoblastoma is efficient and well tolerated with no metastatic events, although ocular ischemic complications were observed.

Radiation dose reduction during intra-arterial chemotherapy for retinoblastoma: a retrospective analysis of 96 consecutive pediatric interventions using five distinct protocols

BACKGROUND

Intra-arterial chemotherapy (IAC) represents a mainstay of retinoblastoma treatment in children. Patients with retinoblastoma are uniquely at risk for secondary malignancies and are sensitive to the ionizing effects of radiation.

OBJECTIVE

To retrospectively review a single institution's experience with IAC for retinoblastoma and the effect of variable intra-procedural imaging techniques on radiation exposure.

MATERIALS AND METHODS

Twenty-four consecutive patients, with a mean age of 30.8±16.3 months (range: 3.2-83.4 months), undergoing IAC for retinoblastoma between May 2014 and May 2020 (72 months) were included. No patients were excluded. The primary outcome was radiation exposure and secondary outcomes included technical success and procedural adverse events. Technical success was defined as catheterization of the ophthalmic or meningolacrimal artery and complete delivery of chemotherapy. Each procedure was retrospectively reviewed and categorized as one of five imaging protocol types. Protocol types were characterized by uniplanar versus multiplanar imaging and digital subtraction angiographic versus roadmap angiographic techniques. Radiation exposure, protocol utilization, the association of protocol and radiation exposure were assessed.

RESULTS

During 96 consecutive interventions, 109 ocular treatments were performed. Thirteen of the 96 (15.5%) treatments were bilateral. Ocular technical success was 106 of 109 (97.2%). All three treatment failures were successfully repeated within a week. Mean fluoroscopy time was 6.4±6.2 min (range: 0.7-31.1 min). Mean air kerma was 36.2±52.2 mGy (range: 1.4-215.0 mGy). There were two major (1.8%) complications and four (3.7%) minor complications. Of the 96 procedures, 10 (10.4%), 9 (9.4%), 13 (13.5%), 28 (29.2%) and 36 (37.5%) were performed using protocol types A, B, C, D and E, respectively. For protocol type A, mean fluoroscopy time was 10.3±6.8 min (range: 3.0-25.4 min) and mean air kerma was 118.2±61.2 mGy (range: 24.5-167.3 mGy). For protocol type E, mean fluoroscopy time was 3.1±3.2 min (range: 0.7-15.1 min) and mean air kerma was 5.4±4.2 mGy (range: 1.4-19.5 mGy). Fluoroscopy time and air kerma decreased over time, corresponding to the reduced use of multiplanar imaging and digital subtraction angiography. In the first quartile (procedures 1-24), 8 (33.3%), 7 (29.2%), 2 (8.3%), 6 (25.0%) and 1 (4.2%) were performed using protocol types A, B, C, D and E, respectively. Mean fluoroscopy time was 10.5±8.2 min (range: 2.4-28.1 min) and mean air kerma was 84.2±71.6 mGy (range: 12.8-215.0 mGy). In the final quartile (procedures 73-96), 24 (100%) procedures were performed using protocol type E. Mean fluoroscopy time was 3.5±4.0 min (range: 0.7-15.1 min) and mean air kerma was 5.0±4.3 mGy (range: 1.4-18.0 mGy), representing 66.7% and 94.1% reductions from the first quartile, respectively. Technical success in the second half of the experience was 100%.

CONCLUSION

Sequence elimination, consolidation from biplane imaging to lateral-only imaging, and replacing digital subtraction with roadmap angiography dramatically reduced radiation exposure during IAC for retinoblastoma without adversely affecting technical success or safety.

The Role of Intraarterial Chemotherapy in the Management of Retinoblastoma

Introduction. Retinoblastoma is the most common primary intraocular neoplasm in children. With the advances in medicine, the armamentarium of available treatment modalities has grown. Intraarterial chemotherapy is a relatively new treatment method with promising outcomes. The purpose of this literature review is to evaluate its role in the management of retinoblastoma.