PIVOTALboost Trial

I took part in a Phase 1/2 trial which was a pilot for the PIVOTALboost trial. I was diagnosed as T3b N0 M0 Gleason 4+3 in 2009. I had hormone therapy for about 12 months before starting RT in 2010. I had RT to the prostate 60Gy in 20 fractions and 47Gy to the lymph nodes also in 20 fractions i.e. the same as one of the treatments in the PIVOTALboost trial. I continued on hormone therapy for another two years making it a total of 3 years hormone therapy.

Unfortunately I now have biochemical recurrence but have not yet started any further treatment as my PSA doubling time is still about 3 years. I will have a PSMA PET/CT scan in May.

There is a summary of the results of the trial reported here. The full study publication concluded that "the safety data of hypofractionated schedules in the present study is encouraging, and the use of hypofractionated radiotherapy in a new trial, PIVOTALboost, is planned."

I enrolled in the study because I thought that IMRT which was not widely used at that time was better than standard external beam radiotherapy.  Everyone taking part had IMRT, but the number of treatments and the dose per treatment varied a bit between the groups.

Those of us in the trial who had 20 fractions rather than the standard 35-37 seemed to fare better in terms of lack of recurrence after 5 years.

I seem to remember I had some minor bowel and bladder problems but none that seriously inconvenienced me. I certainly have no regrets in taking part in the trial.

I was treated according to one of the PIVOTALboost trial arms because my onco thought it was my best option, but I wasn't treated on the trial.

Brachytherapy boost is where radiotherapy is provided as external beam, but boosted in the prostate (and seminal vesicles if appropriate) using brachytherapy.

PIVOTALboost is about providing evidence to show that HDR boost is (or isn't) a beneficial treatment over plain EBRT in high risk patients with no known lymph node spread. It's widely thought that it is beneficial, but there's no proper proof at the moment, and this is a randomised trial to provide this. The trial has many arms, because there are many variable parameters, including using classic EBRT.

The arm I was treated according to was tri-modal:

Hormone therapy, 18-36 months in total.

EBRT: 23 fractions of 2Gy (46Gy) to prostate, seminal vesicles, and pelvic lymph nodes (often incorrectly called whole pelvis or wide beam - it's not, it's accurately aimed at organs and pelvic lymph nodes).

HDR Brachytherapy 1 fraction of 15Gy to prostate only.

In spite of the differences in Gy, these two treatments are both half the dose they would be if done as monotherapies, so it's a half dose EBRT plus a half dose HDR Brachytherapy. Some of the trial arms adjust this ratio a bit.

I was told the half dose EBRT doesn't generally give any side effects, but bear in mind your rectum does get spill from both doses. I do have some minor rectal bleeding as a result, but in my case is painless and it has no impact on quality of life, and I don't regret my decision.

I was offered SpaceOAR on the NHS as part of the original NHS trial, but in discussion with my onco, we decided not to. As a high risk patient, there's a theoretical chance the spacer could push micromets out of the radiation field, allowing them to survive and cause recurrence. (The ICEMAN trial at UCLH is looking to get evidence on this, but it's closed now.)

You could ask to be treated according to one of the trial arms instead of on the trial. I was offered PIVOTALboost or this trial arm off-trial. My onco thought I might not get accepted on to PIVOTALboost because my hormone therapy had been messed up for 6 months, and in my case, also thought I should be doing one particular arm, not something you can control on the randomised trial.

Edited by member 23 Feb 2021 at 09:04  | Reason: Not specified