O our Asa: A hard decision

This week's EUA didn't turn out the way we'd hoped.

"The right eye has relapsed," the doctors told us after they examined Asa.

"Areas we've treated many times with cryo and with chemo, … last time they looked stable and avascular.

Today they're growing.

More cryo is not the answer. We've done a lot of it, and it's not controlling things.

Second-line chemo held things at bay, but also in the longer term is not working.

I'm afraid we are recommending radiotherapy.

We don't have another option."

Radiotherapy

In the past months we've thought about radiotherapy -- it was clear that it would be on the cards if another relapse occurred -- and we tried to prepare ourselves psychologically.

Last week I spoke with a friend who received radiotherapy for Rb as a child, and asked her how she felt about the treatment -- its effectiveness in attacking her tumours, versus the side effects.

When she'd been treated, radiotherapy was the only treatment for Rb -- that or enucleation.

"Increased risk of second cancers is the main concern," she'd said immediately.

Radiotherapy is very effective at killing active tumours but it also damages other tissues, raising the risk that other cancers will develop, later in life.

The key questions are, By how much is this risk raised?

And how much sight is the treatment likely to preserve?

There's no point in giving radiotherapy -- and incurring that extra risk of later cancer -- to eyes that won't provide useful vision.

Asa's vision

As anyone who's spent much time with Asa can attest, he has very useful vision.

Just the other weekend, when we visited the London Aquarium, he was running around confidently in its dimly lit rooms and tunnels.

At the London Aquarium, July 6, 2013

But we realise now more clearly than ever before that he's in danger of losing his sight completely.

On Wednesday, the doctors for the first time raised enucleation as a possibility for the left eye, because they can't tell what's going on behind the cataract.

Ultrasound provides some information on what's going on there, but only on a gross scale -- "we can't see subtle changes," they said.

Let's consider in more detail, then, what radiotherapy involves.

What we know about radiotherapy

What we know about the treatment that's been recommended is this:

It's external beam radiotherapy (a beam of radiation directed at the eyes from outside).

Since the tumours in Asa's eyes are diffuse, they can't use the gentler forms of radiotherapy; instead they would have to treat the whole of both eyes.
It's given under general anaesthetic, with a mask to immobilise the face.

This stops the patient moving around, which would decrease precision.

A mesh template for a mask used in radiotherapy.
Image from the Macmillan website

The course of treatment is usually one month.

Treatments would be given from Monday to Friday, with a break on weekends -- i.e. 20 sessions in total.
And, unlike with chemo, it's very rare to carry out further courses of radiotherapy after the initial course.

It either works or it doesn't.

What we don't know

There is of course a lot we don't know about radiotherapy.

We’ve heard that whole-eye radiotherapy sometimes affects the lacrimal gland (the tear duct), producing a debilitating "dry eye" syndrome that may be permanent.

How likely is it that Asa would suffer that?

And how high is the risk of second cancers?

The answer to this question depends in part on

how much long-term follow-up has been done
and how much of that long-term follow-up involves children who've received equivalent doses of radiation, with equivalent precision, to what Asa would be getting.

The doctors at the Royal London deflected some of our questions on Wednesday, encouraging us to ask the radiotherapists at Barts who carry out the treatments.

If anyone has relevant information on any of these questions, we'd be grateful if you would contact us.

A hard decision

What the choice seems to boil down to is this:

Certain blindness (double enucleation), with a lower risk of later-life suffering, or possible sight (radiotherapy), with a higher risk of later-life suffering.

At the moment it’s very difficult to evaluate those risks.

As the doctors are wont to say, "We don't have a crystal ball" to see the future.

Walk with Asa

In September we will again walk across London at night, to raise money for retinoblastoma research.

We do this in hope:

that research may identify better treatment options than what’s available right now;
that other families may be spared the hard decisions we have to make;
and that other children with retinoblastoma may be spared Asa's suffering.