Pancreatic Cancer Radiotherapy

Radiotherapy is the use of ionising radiation (high energy X-rays) to destroy cancer cells.

Unlike systemic treatments, such as chemotherapy and biological therapies, which can act on cancer cells in any part of the body, radiotherapy, a little like surgery, is a localised therapy. Therefore, generally, radiotherapy only tends to affect a person in the part of the body where the radiation is targeted.

Radiotherapy with or without chemotherapy may be used to control localized disease ie shrink the cancer and keep it under control for as long as possible. Research has shown that this should normally given after a course of chemotherapy.

Once full dose radiotherapy has been given that part of the body can not receive any more radiotherapy in the future though other treatment such as chemotherapy may be considered.

This is where a cancer is advanced (ie not possible to be removed by surgery due to involvement of veins or arteries) but has not spread to other parts of the body i.e. there is no evidence of secondary or metastatic disease.

If following discussion at a specialist pancreatic cacner multi-disiplinary team meeting a specialist surgeon feels the tumour is not operable, locally advanced disease may be treated by chemotherapy alone, as in advanced/metastatic cancer, or, less commonly, with the combination of chemotherapy and radiation treatment (Chemo-radiation or CRT). Very rarely following chemotherapy or chemo-radiation the tumour may shrink so that it is possible to undergo surgical resection.

It is not certain whether chemo-radiation is superior or less effective than chemotherapy alone and trials are being undertaken in the USA to investigate this.

There is little evidence to support routinely using chemo-radiotherapy after surgery. The UK trial ESPAC-1 showed that there was no benefit from the addition of chemo-radiotherapy after surgery whereas there was benefit seen with adjuvant chemotherapy (adjuvant means following surgery).

Chemo-radiotherapy is used more widely pre and post operatively in the United States of America and some parts of Europe. Although there is little evidence to support this approach.

Radiotherapy designed to change the course of pancreatic cancer is called radical radiotherapy. Radiotherapy in either radical mode or reduced intensity or over a reduced period of time may be used to try to reduce pain from pancreatic cancer.

Radiotherapy is given in small daily treatments called fractions, given Monday to Friday. You cannot see or feel radiation therapy. You cannot see or feel radiation therapy. The radiotherapy is carefully planned, usually with the help of a CT Scan to accurately define the area that needs to be treated, and likewise avoid normal tissue organs away from the tumour. It is usual to require approximately 4-6 weeks or 20-30 fractions of treatment.

You will feel some tiredness during radiotherapy though this is not usually as severe as with chemotherapy. Other side affects include nausea, abdominal discomfort and cramping and diarrhoea. Because of careful radiotherapy planning the risk to surrounding organs such as the liver, kidneys and bowel is kept to a very low level. You will be reviewed regularly throughout your treatment. There are long term risks from the radiotherapy in particular to the small bowel where we absorb our food. The risk is related to the amount of radiotherapy given. You should discuss with your oncologist the potential advantages and disadvantages of treatment

If you are also to receive chemotherapy this is given as per usual with radiotherapy. It is now recommended that you start for some weeks with chemotherapy alone prior to receiving both treatments together.

A patient generally waits about six to eight weeks before having a follow-up magnetic resonance image or computed tomography scan, to measure the tumour's response to treatment. The wait is necessary to allow possible internal swelling to subside.

There are various novel forms of radiotherapy now available that are used to treat other types of cancer (such as small brain tumours and arterial aneurysms) but it is too early to say whether they are of benefit in pancreatic cancer. These include treatments known as IMRT (intensity modulated radiotherapy), SBRT (stereotactic body radiotherapy) and cyberknife (a misnomer as it isn't a knife at all or a form of surgery just intense beams of radiation). Some of these have been used in trials but no major trials for advanced cancer comparing cyberknife with other types of treatment including other methods of giving radiotherapy have been performed. Thus it is not known what impact they have on survival or quality of life compared to other treatments, and also importantly what the difference in side effects is. They can at best provide local control but as common pancreatic cancer, ie adenocarcinoma, is usually a systemic disease other treatments such as chemotherapy are likely to be needed to try to limit or control spread to other organs such as the liver. Due to the proximity of so many other organs care has to be taken to try to treat just the tumour itself and not damage other parts of the body or digestive system. A recent trial of stereotactic body radiotherapy/cyberknife with chemotherapy for locally advanced (as opposed to metastatic ie it hasn't spread to other parts of the body) pancreatic cancer showed similar survival rates to conventional chemoradiotherapy (locally advanced pancreatic cancer has median survival of around 9-12months with treatment by chemotherapy or chemoradiotherapy) but a significant rate of duodenal ulcer development.

radiotherapy for pancreatic cancer from CancerHelp UK
radiotherapy for pancreatic cancer from Macmillan
Stereotactic Radiation Therapy and CyberKnife: Fact or Fiction? blog from Johns Hopkins Medicine
stereotactic radiotherapy from Macmillan
novel forms of radiotherapy from CancerHelp UK
Treatment with cyberknife from CancerHelp UK