Intra-Arterial Chemo Works for Retinoblastoma, but With Side Effects

June 20, 2011

By Genevra Pittman

NEW YORK (Reuters Health) Jun 17 - Intra-arterial chemotherapy for retinoblastoma can produce a "dramatic response," but it also comes with the risk of both mild and severe side effects, according to a new report.

"We were surprised to find that our tumor control is very good either when (tumors were) described as intermediate or advanced," Dr. Carol Shields told Reuters Health. "In a couple of children, the intra-arterial chemotherapy was used after they failed other methods. In those cases, these children are facing enucleation" and intra-arterial chemotherapy (IAC) likely saved the eye, she added.

Dr. Shields of the Wills Eye Institute in Philadelphia and her colleagues used IAC to treat 17 kids with retinoblastoma, age 4 to 74 months, and saw a complete response from the main tumor in 14 cases. Ten of those children were followed for at least a year afterward, and all remained tumor-free, the authors reported June 13th in Archives of Ophthalmology.

Catheterization was successful in all but one case. The final 16 eyes had a median retinoblastoma basal dimension of 20 mm, and a mean thickness of 9 mm. The protocol called for three rounds of IAC at monthly intervals, but researchers didn't do additional chemotherapy cycles if tumors showed complete regression.

Chemotherapy was the primary treatment in 12 eyes, and it allowed globe salvage in 8 of those - including all eyes that were classified as C or D by the International Classification of Retinoblastoma (scale: A to E; E most severe). Globe salvage was also achieved in 2 of 4 eyes managed with IAC as secondary treatment. Main tumors regressed a median of 31% in basal dimension and 56% in thickness following chemotherapy.

Tumors recurred in 3 globes - once as a solid tumor, once as subretinal seeds, and once as vitreous or anterior chamber seeds. Enucleation was needed for 6 eyes, external beam radiotherapy twice and plaque radiotherapy once.

IAC has a number of advantages over other treatments for retinoblastoma, the authors note -- namely its small chemotherapy dose, delivered in a single day, which minimizes toxic effects to the rest of the body while having a greater biological effect at the site.

However, Dr. Shields and her colleagues caution that the procedure is technically challenging, and that kids much be watched closely for serious side effects. They devoted a second report to describing those complications.

Mild transient side effects included eyelid edema (in 13 eyes at 1 month), blepharoptosis (10 eyes), and orbital congestion (12 eyes), which all resolved within 6 months.

More serious complications included ophthalmic artery stenosis (3 permanent cases and 1 temporary case) and retinal artery occlusion (2 permanent, 1 temporary).

The authors advise centers performing IAC to use fluorescein angiography to study ocular blood flow, lest choroidal atrophy be overlooked. They diagnosed 5 cases in their patients.

"The implications of choroidal atrophy on ultimate visual acuity in children could be profound," the authors note. "However, it should be realized that most of these eyes would have otherwise been enucleated and had complete loss of vision."

There were no cases of visible emboli in arteries, metastases, neurological defects, internal carotid or femoral artery occlusion, or stroke.

"This is a new and exciting way to focally treat retinoblastoma with only two or three cycles of chemotherapy, but it's not for everybody," Dr. Shields concluded. "The results are so good, but the complications can be very serious."

SOURCES:

http://bit.ly/jdKhLk

http://bit.ly/iIGcHt

Arch Ophthalmol 2011.

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