Anyone had experience of VMAT (RapidArc) treatment?

[StuartS]

Situation age 71 Based in UK (Scotland): Gleason score 3+4 - 7. Biopsy was 12 core with 8 targeted. Results were targeted 8 = 4 positive - General 4 = Nil positive. Noted as Stage T3a. PSA 33.2 but no mets and MRI/Bone Scan and x-ray all show no indication that PC has spread other than bulging of the capsule.

Started formal treatment in December 18 – advised that cancer was Locally Advanced - Treatment started with 3 weeks of Bicalutamide then overlapped with Lupron with a one month injection late December and a 3 month injection in late January. Mid-term bloods in late Feb showed PSA dropped from 33.2 to 3.1, so appears Lupron is working. Latest bloods in mid Mar showed that PSA had risen slightly to 3.7, but Consultant Radiologist(CR) not too worried (dead cat bounce!) and recommended that we continue with next stage of treatment. They have taken another blood sample (last week) to check current testosterone levels.

Treatment initially mapped out as IMRT, but when discussing an additional round of brachy treatment, given issues relating to the broached capsule, was advised by CR that this is not part of the current treatment protocol. Appears that the IMRT will in fact be VMAT (RapidArc) which appears to be more focused than standard IMRT and therefore, a reduced number of sessions (20 have been quoted Vs 40+ for standard IMRT). However, the dose increases to 74gy rather than the usual 62gy as delivered by the current IMRT treatment. The more focused and directed RT appears to be the reason that brachy treatment is deemed unnecessary.

I do not know that much about VMAT, and would be interested if anyone could advise of their experience in this respect. I am guessing that having the 40+ sessions reduced to 20 will be beneficial, but not too sure about the dosage, and having no brachy follow-up! Also broached the topic of taking Metformin to reduce the amount of glucose in the system in a bid to reduce the amount getting to the tumour, but again, was shot down by the CR as it is not treatment protocol, and any suggestion of ‘self-medication’ in this respect was deemed sacrilegious!

[Tall_Allen]

I had VMAT (Truebeam with RapidArc). In my case, I only had 5 treatments, called extreme hypofractionation or SBRT. It is being tried experimentally in high risk cases like yours.

You are correct that that the biologically effective dose of 72 Gy in 20 sessions is nearly as high as the biologically effective dose usually given with brachytherapy boost, and it may be less toxic.

I wouldn't worry too much about metformin or any other supplement for now. I agree that there is some evidence that it increases the radiosensitivity of cancer cells, but there are no data from clinical studies yet. It seems to do this by increasing cell oxygenation. A better way of doing this is by increasing your exercise regime throughout your course of treatment. I did very vigorous workouts at the gym before each radiation session. If you can afford it, get a personal trainer to push you. It will probably have a much greater effect than metformin, and it will prevent fatigue too.

[Don_1213 in reply to Tall_Allen]

I have to agree with Allen.. My treatment was Image-Guided-IMRT/VMAT treatment with RapidArc/Truebeam (done on a new Varian EDGE.) Treatment was 81Gy, done in 45 sessions. The first 25 were to the general prostate floor and the gland, the final 20 were directed just at the prostate (aka - "Boost" phase, designed as an alternative to brachy I understand.) This was done as I was on Lupron, and I've been taking Metformin (2x 500mg/daily) all along (dunno if it did any good, but it likely did no harm.) I'm G9 and classified as T2B N0, M0. Mine was 1.8 GY/treatment - so it was standard fractionation which is the standard for G9.

The side-effects were/are minimal. Some urinary urgency (getting better now 3 weeks after radiation was completed) and a bit of gastro (loose stool occasionally, also getting better.) Tiredness can be from the radiation or Lupron. I did continue my 3x weekly gym workouts throughout the treatment, although I've had to back off about 10% on weight, hopefully only temporarily (my radiation-oncologist said the side-effects generally are cleared by 3 months after treatment.) I'll have my first PSA read toward the end of April, hoping for good results (Oncologist was very happy with what he saw in the ConeXRay taken before every treatment starts..)

[StuartS in reply to Don_1213]

Hi Don...., thanks for your input. Very interested in your comments covering side effects of the treatment. Was not sure if VMAT would have similar effects as IMRT. A bit more relaxed now knowing that (hopefully) I wont have too much in the way of major issues post treatment. The consultant radiologist covered those areas you have mentioned but it is always reassuring to get first-hand input from someone who has already completed that treatment. Also glad that the original treatment envisaged in September last year after my biopsy, which was looking at 40+ IMRT treatments is now reduced to 20 VMAT sessions.

I wish you well on your journey....

[StuartS in reply to Tall_Allen]

Hi Tall_Allen.., many thanks for your input. Your comments echo the consultant who considers VMAT for my specific PC issues as the best available on the NHS at this time. I expect to commence treatment in mid-March. Regarding keeping fit..., I currently have two personal trainers..., my wife, who drags me out seven days a week on a two hour fast walk/jog around a woodland/river pathway walk which includes some pretty steep climbs..., and my border collie who expects me to keep up with her on an additional two daily walks! Upper body sorted with garden maintenance and dry-stone wall building!

[Handdrummer777]

I had a PSA of 18 and Gleason 4+3. That's high intermediate risk/unfavorable, Stage 3. Upon hearing my strong desire to avoid the immediate ED and incontinence post-surgery, the oncologist recommended the VMAT treatments.

In retrospect, I just hope that the sharper focussing will be beneficial -- will avoid at least some of the downstream ED effects associated with IMRT. Originally the doctor wanted 25 treatments, because brachytherapy was to be included, along with a "minimum of" 6 months ADT. However, my urine flow was not sufficient to qualify for brachytherapy. The new program: 43 radiation treatments and 18 months ADT. Going in for treatments 5 days a week was easy because of my fortunate proximity to the hospital.

I did develop a nasty UTI a week into treatments; the following week I severed my right patella tendon getting knocked over on the beach, which required a cumbersome leg brace and 3 months PT. Two treatment streams!

Because I'm utilizing the JoyLoop (link available from a member who reposted it in a reply to my initial post) I'm maintaining libido and erectile functioning while going through ADT. Without that almost magical tool, I would be in a depressed state.

[Handdrummer777 in reply to Handdrummer777]

Also the bowel side effects have been minimal, and the ADT has so far been essentially without hot flashes or much fatigue. Even though the gym is my new friend, I still have to push myself to do enough. Fun fact: undergoing ADT, you have to burn 4500 instead of 3500 calories to lose a pound.

[StuartS in reply to Handdrummer777]

Hi H777..., Thanks for the feedback, and hoping my post treatment side effects are minimal as yours have been. Time will tell as I start my

VMAT in 3 weeks.

Good luck on your journey...

[Handdrummer777 in reply to StuartS]

Thx -- U too! Try the Loop, see what you think.