Proton Treatment Plan | thinkingshrinking

Proton Therapy

Sam's treatment will comprise 30 days of radiation treatment which is the same number of treatments he would have received for standard photon radiation in the UK.

Sam's first treatment was on 1st July after receiving the all clear that the tumour shows no evidence of having spread to other areas of his body via the spinal column.

Sam has had a mesh mask made that he'll be bringing home with him which is attached to his treatment bed via clips & his face via a gumshield. Sam's position for the treatment has to be spot on to minimise the collatoral damage to the healthy areas of his brain so the specific position of his head is guided by the alignment of the bed, the mask, several laser guided beams & 2 x-ray machines that extend from the main body of the proton machine.

Proton Chamber

Left - A picture of the proton chamber with one of the excellent staff from the University of Florida Proton Institute for scale ...

This is just the treatment chamber. The particle accelerator & the rest of the kit takes up multiple floors behind the machine & costs a fortune which is why the UK doesn't have any to the required specifications ... yet.

The patient lies on the flat black bed which is then rotated around to receive treatment (as shown). The bed can be adjusted in any plane to receive treatment depending on ease of delivery.

The two rectangular blocks come out from the back wall of the chamber & contain x-ray machines to ensure the patient is aligned properly.

The whole circular back wall of the chamber also rotates to align correctly.

The large block to the upper left of the pic is what they call the 'snout'. The snout is effectively the barrel & muzzle. Apertures of the correct size are attached & various accentuators ensure the correct doses of radiation are delivered.

Once it's all set up with the patient clippled in, masked up & aligned properly, the x-ray machines retract & the beam is delivered (after any staff beat a hasty retreat). Then the next beam is set up!

Lots of people have been asking for specific information on Sam's treatment. For obvious reasons it's quite often hard to discuss such things, but we appreciate we put ourselves in the public domain to attract all the wonderful practical & emotional support from everyone so we can't really shy away now. The information below isn't intended to glorify the treatment, or for any other self serving reason. It's just to give everyone the same information & to make sure we don't have to keep going through the issues attached to having to explain things over & again. If you don't want the less glamourous details, then I'd strongly suggest you don't read below. Many of Sam's peers read this site so information has been tailored appropriately.

Pilocytic Astrocytoma

Sam is luckier than many who have more aggressive tumours of high grade. Sam's is a low grade (grade 1) tumour. It's the location of the tumour that's made it impossible for Sam's to be even partially removed.

It's on Sam's mid-brain, at the top of his brain stem, close to, or at areas of the brain that are vital to many of the most important functional areas of the brain.

So - he can't have it removed, either completely or partially.

He has had 2 years of chemotherapy (carboplatin & vincristine for anyone interested) which successfully stalled the progress of the tumour growth for a while, allowing Sam's brain to finish maturing (though I'm not sure mature is the word I'd use for Sam's brain).

Since the start of 2012 scans have shown Sam's tumour to be progressing again to the extent that Sam needed radiation treatment to halt the progression or the outlook would not be favourable. Standard radiation treatment available in the UK is in the form of photon (x-ray) treatment that irradiates the whole of Sam's brain. The effects were impossible to acurately predict, but safe to say, not pleasant either in the short or long term. It would effectively treat the tumour though.

Proton radiation treatment that Sam is receiving in the USA results in less exposure to healthy tissue & hopefully less negative impact. Both types are just as effective at tumour treatment.

The mask looks pretty much like this ...

Sam's Treatment Plan

These pictures show the way the proton beams are delivered to Sam's head.

There are 3 beams.

This one shows 2 beams going into Sam's head from above each ear, at a slightly downward angle to attack the tumour mass.

The tumour area itself can just about be seen by looking at the centre of the picture & following the green line.

The red, yellow, green & blue colouring of the beam dose represents the intensity of the radiation that Sam's brain is exposed to. In the case of these 2 beams, they enter from the top left & right, attack the tumour mass & lose intensity extremely quickly without continuing through the other side of Sam's head.

This third beam comes from the back of Sam's head, behind the cerebellum. For biologists, the thick grey chord coming out of the treated area to the bottom of the picture is the bottom of the brain stem, leading to the top of the spinal column.

Because of the location of the tumour, there will be unavoidable exposure to the medulla, pons & hypothallamus regions of the midbrain that are the cause of major concern to the medical team. We won't go into any more details of the implications of this here.

A decision has been made to restrict this beam on the final (30th) day of treatment. The medical team hope that by this time, the key area will have been irradiated enough to ensure the required outcome for the tumour so are taking a chance to try to reduce the negative effects on the most vital areas of the brain.

This picture shows the same beam from above.

The positive aspects of this treatment plan for Sam are:

The pituitary gland (best seen in the 2nd pic if you know where to look) doesn't receive radiation so the effects of all the consequences of pituary damage are going to be escaped, hopefully. For more specific info ... http://www.patient.co.uk/health/the-pituitary-gland

Similarly, Sam's ears are not affeted by any radiation so his hearing should remain unaffected.

The concerns are asociated with the general concerns for all patients in receipt of radiation to the head in that ...

There is an increased risk of stroke due to unavoidable damage to blood vessels. This will remain through Sam's life & he is encouraged to maintain as healthy a lifestyle as possible.

Seizures. An increased rick of seizures is present for any patient.

Re-occurrence of brain tumours anywhere along the path of the radiation treatment.

There are other, more specific & personal, short & long term effects of Sam's specific treatment that it would be insensitive to print here, but suffice to say, we will have to keep a close eye on his health.

Sam's Tumour