Intra-arterial Chemotherapy With Melphalan for the Treatment of Retinoblastoma (RTB) in Advanced Intraocular Stage

An Open, Single-centre Non-randomized Phase II Clinical Trial on Intra-arterial Chemotherapy With Melphalan for the Treatment of Retinoblastoma (RTB) in Advanced Intraocular Stage

For selected cases with advanced Retinoblastoma (RTB) intraocular involvement(stage V of the Reese-Ellsworth classification) in which enucleation would usually be the standard therapeutic approach, in this project the investigators propose an alternative conservative treatment using intra-arterial chemotherapy with melphalan, via direct administration by catheterization of the ophthalmic artery.

Retinoblastoma (RTB) is the most frequent tumour of the eye in early childhood and the commonest cancer in the first year of life. Approximately 60% of cases are sporadic and unilateral. Unilateral tumours are usually diagnosed in the advanced intraocular stage and the most frequent treatment prescribed is enucleation. This prevents disease progression but has an important visual risk, and also constitutes a mutilation, with potentially devastating psychological effects on patients and their relatives.

At diagnosis, patients affected with RTB and their relatives are faced with the important effects of this disease, such as a threat to life, although rare in developed countries, and the risk of losing their sight, which depends on the uni- or bilateral nature of the tumour, the topography of the tumour or tumours, and the still prevalent need for enucleation as a treatment. In fact, almost all advanced stage unilateral RTBs are treated with enucleation. In addition to the risk to life and the patient's sight associated with this treatment, it is also important to take into account the risk to the eye itself. For selected cases with advanced intraocular involvement (stage V of the Reese-Ellsworth classification) in which enucleation would usually be the standard therapeutic approach, in this project we propose an alternative conservative treatment using intra-arterial chemotherapy with melphalan, via direct administration by catheterization of the ophthalmic artery.

The treatment aims to preserve the eye ball and visual acuity as much as possible in these patients, and has been demonstrated to be extremely effective at achieving volumetric reduction of tumours, which permits, if necessary, the subsequent conservative treatment, mainly with brachytherapy for anterior tumours or thermotherapy with laser diode for posterior tumours. In cases of retinal detachment, significant volume reduction, such as that achieved after injection with melphalan would, in most cases, permit retinal reapplication that would favour visual prognosis.

This technique was first described by David H. Abramson in the Sloan-Kettering Cancer Center Memorial Hospital of New York (A Phase I/II Study of direct Intra-arterial (Ophthalmic Artery) Chemotherapy with Melphalan for Intraocular Retinoblastoma). Here, in this study we propose using this technique for the first time outside New York city, in our own clinical setting (Retinoblastoma Unit, affiliated to the Oncology Development Department and the Ophthalmology Department of the Sant Joan de Déu Hospital in Barcelona).

The attainment of positive results, in addition to those previously obtained by the New York project, could consolidate this treatment as an alternative to enucleation in most cases of advanced intraocular RTB, and open the way for the future indication of this technique in other stages of RTB.

Inclusion Criteria:

1. Patients with unilateral RTB.

2. Patients with advanced intraocular involvement, corresponding to Stage D of the International Classification , selected by the Tumour Committee of the Retinoblastoma Unit.

   By contrast to most other cancers, histological confirmation is contraindicated in RTB prior to onset of treatment and, in our study, any biopsy of the tumour practiced was considered as an exclusion criterion.

3. The only alternative to treatment is enucleation.

4. Over six months old at diagnosis and younger than six years old.

5. Informed consent of the parents or legal representative.

Exclusion Criteria:

1. Under 6 months old at diagnosis.
2. Impaired kidney function, with creatinine clearance lower than 80 mL/min/1.73m2 or serum creatinine higher than 0.7 mg/dL.
3. Impaired liver function, normal function being defined as presenting total bilirubin levels lower than 1.5 times the limit of normal for that age and ALT lower than 5 times the limit of normal for that age.
4. Patients with some type of coagulation disorder that could contraindicate the procedure or with a previous diagnosis of any thrombotic condition.
5. Congenital cerebral anomalies diagnosed previously or detected by angioresonance prior to treatment for extraocular involvement by RTB shown by image techniques, cerebrospinal fluid (CSF) cytology or cytomorphology of bone marrow aspirates (BMA), or positive expression of GD2 synthase in CSF or BMA.
6. Patients with heart disease, arterial hypertension, or diseases of the nervous system not referred to in point 5, or with active infections that the Anaesthesiology Service responsible for the procedure have studied and consider to contraindicate the procedure.
7. Not having been selected for intra-arterial chemotherapy through the ophthalmic artery for any other reason than those given by the Tumour Committee of the RTB Unit of the HSJD.
8. Concurrent administration of any other anti-cancer treatment.
9. Any surgical or non-surgical procedure that could have changed the structure of the eye and, therefore, facilitate risk of dissemination, including histological confirmation prior to treatment.
10. Participation in another clinical trial.