Amount of radiotherapy sessions

User

Posted 17 Oct 2019 at 12:29

Hi again , another query . My partner is in the process of receiving 33 sessions yet most of the other men he meets there are only getting around 20 sessions ! What could be the reason for this?Thanks for any suggestions.

User

Posted 17 Oct 2019 at 13:55

The dose is given by the dose per session x number of sessions.

A dose of 60-72 Gy (Gy is the radiotherapy dose unit) is quite normal, at 2Gy per session, which is what your husband is having. This is known as hyperfractionated dosing.

There are some reasons for fewer sessions.

Some places do 3Gy per session, which is known as a hypofractionated dose. Then you need 1/3rd fewer sessions because each one is delivering a higher dose. The higher per session dose can be useful if the patient can withstand it (age may be a factor, not sure). It can result in fewer side effects for some patients and there's some theory suggesting it might work very slightly better on the cancer, but no long term data yet, and fewer trips to hospital may be more convenient to the patient.

Another possibility is that not all the dose is given by external beam radiotherapy. I had 23 sessions of 2Gy to prostate, seminal vesicles, and pelvic lymph nodes making 46Gy, topped up to 61Gy in the prostate only with 15Gy HDR brachytherapy. The lower dose to seminal vesicles and pelvic lymph nodes was prophylactic just in case they contain any micro-mets, but no cancer had been found in them. This combination is known as HDR-boost and has been shown to work well for high risk T3a patients.

Edited by member 17 Oct 2019 at 13:56 | Reason: Not specified

User

Posted 17 Oct 2019 at 15:54

Please advise your partner that it's not a good idea to compare his own treatment to that of other people. Everyone's RT is tailored to their individual needs, and every case is different. Your partner's oncologist will have designed his treatment programme to give the optimal results for his specific circumstances.

Best wishes,

Chris

User

Posted 18 Oct 2019 at 15:05

I didn't have gold markers, so I had a CT scan (or more strictly, a CBCT scan) every day on the treatment machine immediately before treatment, to do the positioning.
With the gold markers, the positioning is done with 2 X-rays at right-angles instead (which is a lower X-ray dose than the CBCT scan, and takes up less time on the machine).

These are referred to as Image Guided Radiotherapy (IGRT). The external beam radiotherapy is usually Intensity Modulated nowadays too, so you get IG-IMRT.

I couldn't have the gold markers because I was having brachytherapy afterwards, and the markers could get in the way. At my place, if you are having gold markers (which you do if you aren't having brachytherapy afterwards), the gold markers are inserted through perineum, rather than through the bowel wall nowadays (just like the biopsies have changed to be through perineum rather than TRUS).

So yes, variations in just about every aspect of the treatment.

Edited by member 18 Oct 2019 at 18:31 | Reason: Not specified

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User

Posted 17 Oct 2019 at 12:32

Did he have lymph node involvement ?? Need more stats off you

User

Posted 17 Oct 2019 at 12:35

Hi, no lymph node involvement, but the Consultant did note the type of cancer was aggressive

User

Posted 17 Oct 2019 at 13:36

I’m sure an expert will be along. My cancer is aggressive G9T4N1. I’ve been offered RT about 6 times since my surgery to to remove my prostate but they have always said it’s unlikely to be curative so I have refused. They only ever offered me the 33 or 35 sessions here in Southampton , yet I know of men who had 20 sessions here. I guess if they think there is likelihood of spread then they zap wider for longer. For men with obvious local recurrence and small psa they may do the 20.

User

Posted 17 Oct 2019 at 13:55

The dose is given by the dose per session x number of sessions.

A dose of 60-72 Gy (Gy is the radiotherapy dose unit) is quite normal, at 2Gy per session, which is what your husband is having. This is known as hyperfractionated dosing.

There are some reasons for fewer sessions.

Edited by member 17 Oct 2019 at 13:56 | Reason: Not specified

User

Posted 17 Oct 2019 at 15:54

Best wishes,

Chris

User

Posted 17 Oct 2019 at 16:31

Thank you for your comments .We accept everyone’s treatment is different but it doesn’t stop us from wanting to find out as much as possible or are you saying mistakes are never made . If people never asked questions we would never make progress .

User

Posted 17 Oct 2019 at 18:09

It’s not just ‘ mistakes ‘ — it’s postcode lottery as well. You will find that Oncologists all over the country have their own little ideas based around the ‘ model ‘ that has worked for them. Yes you are wise to stay informed and you don’t have to do as they say. They are not gods and are rarely as empathetic as GP’s. They don’t always take into account a patients wants and needs whereas a GP might. Yes they are doing their best but just throwing treatment at you. I swapped Oncologists as my original simply wasn’t listening to me at all. It’s VERY important when you have meetings to pre-plan questions and bullet points etc and to take notes. Also , please use the phone line on this website. The nurses are specialists in their field.

User

Posted 17 Oct 2019 at 21:56

From my own experience (Gleason 7 - 4+3 T2b) the 20 session idea came out of clinical trials. The view was that more intense, but shorter courses, might be better from a number of perspectives. Mine was also called "dose painting" which I understood to mean a more intense treatment to the tumour but less to healthy prostate tissue.

My treatment was in 2016 at the Clatterbridge Cancer Centre on the Wirral. I was aware of the trials and asked my oncologist if I could go on it. She said that the trials had actually finished and would shortly be rolled out more widely. She sought, and got, permission for me to have the 20 session treatment. I know for a fact that the more normal 35 session treatment was being delivered to other patients at the same time.

What I don't know, and this is why I can't fully help with your question, is whether oncologists now decide one protocol is more suitable to one patient and another one to another patient.

Finally all the best to you and your partner. Let's hope he does well.

User

Posted 17 Oct 2019 at 22:21

The outcome of the trial was that for a fit man, the 20 fractions at a higher dose has better outcomes with fewer side effects. However, older men, men who are less fit, men with very pale skin, men with existing urinary retention problems, etc can find the higher dose too difficult. My guess is that there will also be personal preferences at play ... perhaps the other men in the waiting room are under a different oncologist or are being treated on a different machine? Or men that are still working get fewer sessions than men who are not working?

37 fractions is the standard - you could ask the onco at next review why it was decided that your OH was best having the 33 sessions and what dose it was.

37 fractions at 2Gy = 74Gy

33 fractions at 2.2Gy is almost 73Gy

20 fractions at 3.2Gy (generally thought to be at the top end of the optimum range) = 64Gy

In the end, however many sessions he has, the amount of radiation delivered to the cancer cells is broadly similar.

"Life can only be understood backwards; but it must be lived forwards." Soren Kierkegaard

User

Posted 17 Oct 2019 at 23:13

For radical treatment by EBRT, the most usual dose has been 37 fractions each of 2gy. However, following successful trials it was found that 20 fractions of 3gy achieved results that were just as good. This has saved a lot of setting up time and patients making fewer attendances. The fewer doses at higher gy is being increasingly adopted. In fact even fewer fractions at yet higher doses is being considered having been used in some countries. As has been said, there are several reasons why it may be decided that the way the RT may be delivered may be tailored to suit an individual as well as the type of linac being used.

The idea is to give sufficient radiation to do the job but not so much that the risk of side effects becomes unacceptable.

Like Andy, I had a regime using mixed ways of delivering RT. I had 30 fractions each of 2gy plus 6 fractions of very precisely delivered Carbon Ions each at 3gy (the latter being similar to Protons but are more damaging) but within a study. So there are a number of ways that RT can be delivered. Generally, a patient relies on the experience and expertise of the radio oncologist who has to work with the equipment available to her/him in a way most appropriate for the patient or if more than one option is appropriate the one the patient would prefer.

Barry

User

Posted 18 Oct 2019 at 14:47

The other slight variation of my treatment was the use of gold markers, injected into the prostate through the bowel wall (actually not as painful as it sounds!). This enables them to aim the dose more accurately as the prostate tends to change position. A former colleague of mine had the 20 session treatment as well but at the Christie in Manchester. He didn't have the gold markers.

So lots of variations around the treatment. From what I have read and in discussion with other patients in a similar position, there is no firm evidence that one treatment protocol is any better than another. Certainly the 20 session idea was useful for me as I had a 70 mile round trip to the treatment centre.

User

Posted 18 Oct 2019 at 15:05

So yes, variations in just about every aspect of the treatment.

Edited by member 18 Oct 2019 at 18:31 | Reason: Not specified

User

Posted 18 Oct 2019 at 15:18

Interesting Andy. My gut (pardon the pun) reaction is that the perineum would be preferable as a route in.

User

Posted 18 Oct 2019 at 17:10

Your gut reaction is spot-on.

About 3% of TRUS procedures result in infections.
About 0.1% of the newer transperineal equivalent procedure result in infections, i.e. 30x safer.

I would guess the same difference might apply with gold marker insertion.

I have heard that the transperineal procedures generate more of a dent on the dignity for anyone worried about that. You end up in the lithotomy position, rather than on your side facing away from the urologist with your knees drawn up to your chest which is more common with TRUS.

Edited by member 18 Oct 2019 at 17:26 | Reason: Not specified

User

Posted 18 Oct 2019 at 18:05

Originally Posted by: Online Community Member

Very true, some hospitals believe in space oar more than others and similarly not all require you to drink copious amounts of water before each fraction. In my case extra care was exercised in establishing position of the Prostate prior to treatment with 5 CT scans given in a week (plus an MRI for good measure as part of the setting up process). The study protocol stated that there would also be a CT scan done each week but in the event this did not happen every week. When I questioned this I was told that they found my positioning was very good and that they wished to avoid any further scan radiation that was not necessary. (I had more radiation than I would have been given in the UK anyway).

Even with regard to scans, there can be differences between hospitals, for example the Royal Marsden gave me an endorerectal coil MRI but when they transferred me to UCLH they told me they didn't believe in the endorectal coil MRI so repeated the scan without it. So there are different approaches and innovations in a number of ways, some tried on a small number of patients before results are assessed and where shown to be beneficial being gradually rolled out more widely. NICE guide lines generally cover the norm but small differences will apply, particularly where some patients are being treated within a trial. These are some other reasons why men have different treatment at different hospitals and sometimes within the same hospital quite apart from considering individual circumstances which can determine suitability.

Barry

User

Posted 19 Oct 2019 at 08:03

Hi, we thank you to everyone for all for your help, it is obvious how many different approaches there are to delivering radiotherapy. Would the fact that he has had a radical prostatectomy affect radiotherapy treatment ? Any thoughts ?

User

Posted 19 Oct 2019 at 09:11

It might affect what they target, since there's no prostate there. It depends where they think the active cells are. Typically the prostate bed would be targeted, but maybe all the pelvic lymph nodes and area of seminal vesicles too, in part because they can't go back and do those afterwards.

User

Posted 19 Oct 2019 at 11:21

Originally Posted by: Online Community Member

No, I'm certainly not saying "don't ask questions". Ask as many questions as you like. All I was meaning is that worrying because your own treatment differs from that of another patient is an unnecessary cause of anxiety. Everyone's treatment is tailored to their specific situation.

Best wishes,

Chris

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