Radiation therapy for pancreatic cancer
What is radiotherapy?
Radiation therapy, or radiotherapy, is the use of high-energy x-rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist.
How does radiotherapy work?
The radiation therapy is usually generated electrically by a machine called a linear accelerator. This creates very high energy X-rays which are focused at the cancer. The X-rays can kill the cancer cells by damaging the DNA of the cancer cells.
How long does it take for radiotherapy to work?
The radiotherapy has some effect immediately on the cancer, but continues to damage it for up to 6 weeks after the treatment is completed.
What are the different types of radiotherapy?
The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body.
This is the type of radiation therapy used most often for pancreatic cancer. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. There are different ways that radiation therapy can be given:
- Traditional radiation therapy is also called conventional or standard fraction radiation therapy. It is made up of daily treatments of lower doses of radiation per fraction or day. It is given over 5 to 6 weeks in total.
- Shorter treatments of higher doses of radiation therapy given over as few as 5 days is called stereotactic body radiation therapy (SBRT) stereotactic ablative radiation therapy (SABR). This is a newer type of radiation therapy that can provide more localized treatment in fewer treatment sessions. SRBT should only be given in specialized centers with experience and expertise in using this technology for pancreatic cancer and identifying who it will work best for.
- Proton beam therapy is a type of external-beam radiation therapy that uses protons rather than x-rays. At high energy, protons can destroy cancer cells. It also lessens the amount of healthy tissue that receives radiation. Proton beam therapy may be given for a standard amount of time or for a shorter time like SBRT. It is not yet known whether it works better than standard radiation therapy, and is not available in Australia.
What is chemoradiotherapy or chemoradiation?
Chemotherapy can be given at the same time as radiation therapy because it can enhance the effects of the radiation therapy, which is called radio-sensitisation. However, chemotherapy given at the same time as radiation therapy often has to be given at lower doses than when given alone as the side effects may be greater.
Is radiotherapy given before or after surgery?
Radiotherapy may be given before surgery. This is called neoadjuvant treatment. It is usually prescribed with chemotherapy, to help shrink the cancer down and to minimise the chance of the cancer coming back in the abdomen after the operation. It can also be given after surgery, in which case it is called adjuvant treatment, and is also usually prescribed with chemotherapy, to minimise the chance of the cancer coming back in the abdomen after the operation.
Radiation therapy may be helpful for decreasing the likelihood of a pancreatic cancer returning or re-growing in the original location, but there remains much uncertainty as to how much, if at all, it lengthens a person’s life.
Does radiotherapy hurt? Is radiotherapy painful?
The radiotherapy uses invisible X-rays that do not hurt or burn.
What does it feel like when radiotherapy is given?
Most patients do not feel anything when they have radiotherapy.
Do I need to stay in hospital for radiotherapy?
No. Almost all patients come in every day from home for their radiotherapy treatments.
How many times will I need radiotherapy?
You will need to visit the radiation oncology doctor at least once for a consultation. After this there is a planning or simulation session, which involves having a CT scan in the radiotherapy department to help plan the treatment, and then you will need to attend for daily treatment visits.
Most patients will need five to six weeks of daily (Monday-Friday) radiotherapy treatments. Sometimes only one or a few treatments are needed. Treatments usually take only a few minutes, but you will be lying on the couch of the treatment machine for 10-15 minutes and be in the radiation oncology department for half – one hour.
What are the side effects of radiotherapy?
Side effects from radiation therapy may include fatigue, mild skin reactions, nausea, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished. You will see the radiation oncology doctors during treatment to manage any side effects. There can be long term side effects from radiotherapy, but these are uncommon and usually mild. Talk with your health care team about what you can expect and how side effects will be managed.
Are there any new radiotherapy treatments available?
In recent years there have been exciting advances in radiotherapy technology, with techniques such as Intensity Modulated Radiotherapy (IMRT), Volumetric Arc Therapy (VMAT), Image Guided Radiotherapy (IGRT), Deep Inspiration Breath Hold (DIBH), Simultaneous Integrated Boost (SIB), and Stereotactic Body Radiotherapy (SRBT). These enable higher doses of radiotherapy to be delivered more safely. Prince of Wales has been in the vanguard of the adoption of these techniques in Australia.