The Treatment

Stage 1

Fiducial Placement

For tumours affected by respiratory movement, the insertion of internal fiducial markers into or near to the tumour will be necessary. Fiducial markers are tiny gold ‘seeds’ (about the size of sugar strands that you use to decorate cakes with) and they allow the Cyberknife system to continually track the position of the tumour. The fiducial markers can be inserted into the tumour either through the skin (using the same procedure as when having a fine needle biopsy) or endoscopically (camera inserted down into the stomach). Once the markers are in place, they do not require removal following your Cyberknife treatment.

Stage 2

CT Imaging

About 1 week after the placement of the fiducial markers, a CT scan will be performed. Once the markers are inserted into the tumour, they will often ‘shift’ about a little before settling into place, hence the reason for the wait period of about a week between fiducial placement and the CT scan. Even though you may have recently had a CT scan, it will still be necessary to perform another one prior to your Cyberknife treatment. This is because Cyberknife requires specific protocols that are not normally used in standard CT imaging.

Some Cyberknife centres may require an immobilisation device to be made for you prior to your treatment. They are made to ensure you stay in the same position for each of your treatments. This will be either be a body mould (for tumours below the neck) or a treatment mask (for tumours of the head or neck). The making of the mould is a completely painless procedure. Your planning CT scan will be performed with the mould in place. Not all Cyberknife centres will require the use of an immobilisation device, many centres are happy to perform the treatments without one.

Stage 3

The Planning Process

This part is all down to the doctors and you will not need to be present. The CT images are downloaded onto the Cyberknife treatment planning computer and using advanced computer software the doctors will work out a customized treatment plan in accordance with your anatomy and the shape and size of your tumour. The waiting period between your planning CT scan and your first treatment is normally 1-2 weeks.

In our experience, as we were in Georgetown for a relatively short time, Alan only had to wait 5 days between his scan and first Cyberknife session.

Stage 4

The Cyberknife treatment is performed as an Outpatient procedure and no overnight stay is normally necessary. The number of Cyberknife treatments that you have will be determined by the doctor treating you. The average number of sessions is between 3 and 5. The sessions are normally arranged with short intervals in between.

In our experience, Alan had 3 sessions of Cyberknife, arranged over 3 consecutive days.

The treatment sessions normally last between 60-90 minutes, depending on the site and nature of the tumour being treated. On the day of your treatment, you will be able to eat normally and take your regular prescribed medication. Some centres will offer you the option of having a mild sedative prior to the treatment. Although the treatment is painless, you are naturally quite anxious prior to it and the sedative will help you to relax.

You will be asked to lie on the treatment table and if being used, the immobilisation device will be fitted. You will be asked to keep as still as possible during the Cyberknife treatment. Throughout your treatment session, you will be able to communicate with the treatment therapist, so if you do feel the need to move, i.e. to sneeze or scratch yourself, the therapist will advise you how to attract his attention and he will then temporarily stop the robot.

Once the session has finished, you can normally leave the centre once you have been seen by the doctor treating you.

Following the treatment, the majority of people experience no side effects and resume normal activities. Some people may experience tiredness, mild nausea and a slight increase in their normal pain. All of these symptoms are usually short lasting and can be treated easily with medications.

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Alan’s Experience Of The Treatment

Prior to Alan’s treatment, he was in an enormous amount of pain. Due to the type of Alan’s tumour (a nerve sheath tumour) and where it was located in his abdomen he experienced constant intense pain. He was taking high doses of morphine to control his pain and his days were consumed with when he could take his next dose of painkiller. Following his 1st and 2nd Cyberknife treatment, Alan did experience a considerable increase in his usual pain. The doctors treating Alan at Georgetown had said this was unusual and such an increase in pain was very uncommon. Thankfully, the doctors were able to control his pain but it was decided Alan’s 3rd Cyberknife session would be postponed for a couple of days until his pain had eased.

However, quite an incredible thing happened to Alan 12 hours after the 2nd treatment. He woke up from his morphine-induced sleep, having gone to sleep in intense pain, to wake up completely pain free. We couldn’t believe the sudden change in his pain level. The change in him was quite astounding. Alan continued to be pain free for the following few days. Even after his 3rd Cyberknife treatment he remained pain free.

As far as the actual treatment went, Alan found it a comfortable procedure and was able to relax on the treatment table while the robot did its ‘magic’. He says he was aware of the robot moving around him throughout the hour long procedure but it didn’t alarm him. He was advised by the treatment therapist to wear warm clothes, as lying still for an hour or so he could possible feel the cold. Being only 9 stone Alan did not have much body fat to keep him warm anyway!

Stage 5

Follow-Up Care

Most people who have Cyberknife treatment continue with normal life without any interruptions. Any side effects experienced after the Cyberknife tend to be short lived.

The doctor treating you will normally suggest that you have a follow-up CT/PET scan 3-6months after completion of your Cyberknife treatment. Following that, your doctor will recommend periodic scans to assess the progress of your tumour.

It is important to understand that the actual size of your tumour or lesion may not have changed on follow-up scans but this does not mean your treatment has not been effective or successful. Radiosurgery works by destroying the abnormal cells. This process leaves behind scar tissue that looks visually similar to the original tumour on CT scans. Therefore, even though the abnormal cells are dying or “dead”, the mass may not look any smaller. It may gradually shrink over time; however it is not uncommon for the size of successfully treated tumours to remain unchanged, even after several years. The tumour or lesion will not suddenly disappear after the treatment.

Another important factor to remember is that at your follow-up scans, the volume/dimensions of your tumour or lesion are measured. As CT scans take many pictures or ‘slices’, when your follow-up scan is reviewed by your doctor, there may be some variability of the measurement depending on which picture he looks at. A change of 1-2mm, smaller or larger, is considered insignificant and is commonly known as routine variation measurement. Thus if the measured tumour size has increased by 1mm, for example, this would not necessarily mean your tumour has grown by 1mm but may be remarked as ‘unchanged’.

Success of your Cyberknife treatment may be seen as alleviation of symptoms, shrinking or halting the growth of your tumour. Through assessment of your symptoms and periodic CT/PET scans your doctor will be able to determine your progress.