By Dr Mihir Shanker, Radiation Oncologist, Icon Cancer Centre
For many men, a prostate cancer diagnosis raises understandable questions about what comes next.
Depending on the stage of cancer, there are several effective treatments including active surveillance, surgery, radiation therapy, focal therapies, hormone therapy, chemotherapy, or newer targeted or immunotherapy options.
Radiation therapy or radiotherapy plays a central role in prostate cancer treatment and preserving quality of life.
In this article, I'll explain how it works, the types available, what to expect during treatment, and how advances in stereotactic techniques are improving precision, convenience and outcomes for patients.
Our goal is to help men and their families better understand radiation therapy so they can make informed decisions with confidence.
Radiation therapy and how it is used to treat prostate cancer
As a radiation oncologist, I often describe radiation therapy as one of two main treatments for prostate cancer which are widely accessible to the Australian population, alongside surgery.
Radiation therapy destroys cancer cells while protecting nearby healthy organs such as the bladder and bowel. Radiation therapy is painless, and with today's technology can be accurate to less than a millimetre.
The most common form, external beam radiation therapy (EBRT), treats the prostate from outside the body. Every treatment plan is personalised using a detailed combination of scans from CT, MRI, and PSMA PET, to create a detailed 3D map of each man's anatomy.
Stereotactic radiation therapy
Stereotactic radiotherapy is an advancement in EBRT, where radiation is delivered with very high precision and high dose, often over just a few sessions.
As part of your treatment, you will have fiducial markers (gold seeds) placed in the prostate gland that act as guides. During treatment, low-dose x-ray imaging monitors the position of these markers, and if the system detects movement beyond a preset limit, from breathing or small twitches, active beam hold technology automatically pauses the radiation beam.
This high level of monitoring and maximum precision helps keep patients safe, provides a consistent quality of treatment, with as little radiation as possible delivered to the surrounding healthy tissues and organs.
At Icon Cancer Centre, our fleet of over 50 radiation therapy machines all have stereotactic capability.
Brachytherapy
Another well-established option is brachytherapy, sometimes called internal radiation. In this approach, the radioactive source is placed inside the prostate gland itself. There are two main types:
- Low-dose-rate (LDR) brachytherapy, where tiny radioactive seeds are permanently implanted and release radiation slowly over time.
- High-dose-rate (HDR) brachytherapy, where temporary catheters deliver a stronger dose over a short period, usually during a brief hospital stay.
Deciding on treatment
For men with more advanced or metastatic prostate cancer, radioligand (radionuclide) therapy has emerged as another development. This involves injecting a radioactive molecule that seeks out prostate cancer cells wherever they are in the body and delivers radiation directly to them. It's currently used mainly for advanced disease, with promising results.
When deciding on the best treatment, we work as a multidisciplinary team, bringing together radiation oncologists, urologists, medical oncologists, nuclear medicine specialists, radiologists and specialist prostate nurses.
Each man's treatment plan is guided by factors such as PSA level, tumour grade, scans, urinary function, prostate size, personal preferences, and practical considerations such as travel or treatment access.
Radiation therapy is not a one-size-fits-all approach, it is about finding the right balance between effectiveness, side effects and quality of life, ensuring every patient receives care that fits his needs.
What to expect
Before treatment, a planning or 'mapping' session uses detailed scans to create a 3D model of the prostate and surrounding anatomy. Some men will have small gold seeds inserted, and some have a rectal spacer gel. This gel is a soft, synthetic material that mostly consists of water and can be safely used in the body, it is implanted between the prostate and rectum. As the rectum and prostate are very close and separated by only a small space, the rectum can be affected by radiation to the prostate. The gel gently moves the rectal wall away from the prostate, reducing radiation exposure and protecting healthy tissue. Over time, the gel dissolves and the organ position returns to normal.
Treatment usually begins one to two weeks later and is delivered once per day, 2-5 treatments per week, in sessions that last 10 to 15 minutes. Most men continue normal daily activities throughout their treatment.
Radiation therapy advancement
Radiation therapy has advanced significantly over the past decade. Once a broad, two-dimensional treatment, it is now a millimetre-accurate therapy precisely shaped to each patient's anatomy.
Modern technology allows us to sculpt the radiation dose around the prostate while protecting surrounding organs such as the bladder and bowel. This precision means we can safely deliver higher doses to the cancer, improving long-term control and survival rates while reducing side effects.
Combining radiation with other therapies
For many men, combining hormone therapy (also known as androgen deprivation therapy) with radiation therapy remains a proven and well-established treatment. It's the current standard of care for higher-risk prostate cancers and for relapsed or advanced cases in conjunction with newer hormone treatments such as androgen receptor pathway inhibitors.
The duration of hormone therapy varies and is always tailored to the individual based on disease and patient factors.
We're also exploring how radiation can work together with new systemic treatments, including immunotherapy and targeted therapies. Clinical trials are focusing on men with oligometastatic disease, cases where prostate cancer has spread but only to a few sites.
Further guidance or support
Australia has a strong network of specialists, treatment centres and support organisations offering world-class care. Your treating team is your first point of contact. Ask them questions and seek clarification at any time. Understanding your options helps you feel informed and in control.
