Non-Invasive ProstateCancer Treatment

• It is effective – long term outcomes show very low recurrence rates for low and intermediate risk prostate cancers.
• It is safe – serious urinary (2.4%) and gastrointestinal (0.4%) side effect rates are low and comparable to the already historically low rates for IMRT and brachytherapy.
• It is non-invasive – no cutting, no poking of needles, no insertion of catheters, no anaesthesia required.
• It is convenient – 5 outpatient treatments each taking up to half an hour, done over one and a half weeks. Normal life can continue before, during and after.
• It is economical even for those without private insurance coverage – Medisave and MediShield can be used for most of the treatment cost, with less cash outlay compared to IMRT.

International guidelines state Prostate Radiosurgery is suitable for low and intermediate risk prostate cancers. It is also a possible option for high risk prostate cancer in patients who are unable to undertake a prolonged course of IMRT or brachytherapy for medical or social reasons.

In navigating this choice, it is important to consult a prostate oncologist well trained in all treatment options, especially radiosurgery, to provide a balanced view before settling on radiosurgery.

Being an outpatient treatment, Prostate Radiosurgery does not involve hospital stays unlike Robotic Prostatectomy and, in most cases, Prostate Brachytherapy. Hence, the cost of Prostate Radiosurgery generally is half or less of the above procedures.

Furthermore, Medisave and MediShield can be used to cover the majority (80–90%) of treatment cost, with significantly less cash outlay compared to that of IMRT.

Hormone therapy can control prostate cancer and is used together with IMRT in intermediate and high-risk cancers. Because of the high doses used in Prostate Radiosurgery, in some intermediate risk cases, hormone therapy is not needed at all. Radiosurgery can be combined with high risk cases to improve outcomes.

Highly focussed ultrasound (HIFU) or cryosurgery are not recommended in guidelines as the main treatment for localised prostate cancer, due to the lack of long term data compared to surgery or radiotherapy.

Proton therapy potentially spares more normal tissue from radiation compared to photon therapy (IMRT or SBRT), but this is more in the low to moderate dose range. The rectum and bladder adjacent to the prostate can still receive high doses of radiation with proton therapy. There is still a lack of direct comparative studies showing that proton therapy is better than IMRT or Radiosurgery for prostate cancer.

Radiosurgery involves delivering extremely high doses of radiation to a focused area. Thus the margin for error is very small and radiation once released cannot be reversed.

Hence not only must the radiosurgeon in charge be well trained in radiation medicine, they must also have the necessary training in handling the navigational software and radiation delivery equipment, as well as sufficient clinical experience in giving high radiation doses to different areas of the body.

In addition, they need to ensure that the entire radiation team is well coordinated and familiar with radiosurgery treatment protocols and quality assurance procedures so that the final result is safe and effective. As the saying goes, we are only as strong as our weakest link.

Prostate SBRT was first performed using the CyberKnife, but since then the proportion of Prostate SBRT treated with Linac has increased rapidly, with similar results in terms of effectiveness and long term side effects.

The main difference is that CyberKnife requires an extra procedure of implantation of gold markers into the prostate, and requires the patient to keep still for longer.