Difference between 3T MRI and mpMRI

I recently had 3t MRI with dye done to me few days ago, but I also heard that the best imaging to identify areas of concern is mpMRI. The question I have is What kind of imaging testing is the best for PC, or 3t MRI and mpMRI are equivalent in terms of results?

A 3T MRI is a type of Magnetic Resonance Imaging scanner that operates using a high (strong) magnetic field. As TA indicated above, it uses a 3 Tesla field and is the most common high field scanner used today. More commonly, MRI scanners use 1.5 T magnet. Multiparametric MRI or mpMRI is an imaging procedure performed using an MRI scanner, most commonly a 3T scanner. mpMRI uses multiple imaging sequences (typically 3) to generate and compare high resolution images of the prostate. It is possible to use a lower field MRI (such as a 1.5T) to perform mpMRI, but an appropriate extra coil (sometimes called a diaper coil) needs to be used. Most commonly, a 3T unit is used for prostate imaging. More importantly, the radiologist performing the read needs additional training and experience. Prostate imaging is notoriously difficult and even experienced radiologists may disagree on a read. I would want my mpMRI read by a radiologist who is a sub specialist in body radiology and who also reads a high volume of prostate images.

As TA said, I had the MP MRI to first identify the lesion and then to plan the HDRBT. Denis

If you post your MRI results, we can tell if it was a MP MRI

Sorry about your lesion. You will need a biopsy to find out its real significancy.
about your question, I can only answer in part. Not idea what the blood mass can mean. But PIRADS 4 is only given if the lesion is not larger than 1.5 cm. and, more important for your case, these is not evidence of an extraprostatic invasion, such as SVI. Otherwise, it would be a PIRADS 5.

If they do a MRI fusion biopsy next, they will be able to sink 4 or so needles through the lesion from multiple angles and get a very good sampling of the lesion. Hopefully, it will continue to be G6. I do note that given you have a relatively small 26cc prostate, a 1.4cm lesion (were there other dimensions?) seems quite large straddling two quadrants from middle to apex. One question to ask the doctor is how close the lesion is to the apex where there is no prostatic capsule. The next biopsy is crucial and will determine your actions, but if it were me, I would start to explore the treatment options at this point, just from the size of the lesion.

I would think that either HDR brachy or SBRT would be great choices for you.

Do keep us updated on your research progress.

Andrew

SergeFL said...
After receiving MRI results he mentioned that AS is no longer an option regardless G 6 tumor. I agree with him I did lot of research about treatment option.

AS certainly is an option for you. An MRI finding of PIRADS 4 does NOT change anything - it only shows a lesion suspicious for cancer. That suspicion is either confirmed or denied by a biopsy. You are a great candidate for AS, or you can opt for either kind of brachytherapy or SBRT.

Hello Tall Allen,

He mentioned that he would not recommend treatment if my MRI report comes in negative, but once lesion is formed it will require treatment in near future anyway. I think he recommends treatment based on the size of tumor and my very small prostate gland. He mentioned that I may not need treatment right away but I should not put it aside for long.

SergeFL said...
I was thinking about SBRT, but it requires placement of 4 markers which is similar to biopsy procedure just with less shots plus 5 treatments. While HDR is also similar to biopsy but all things are done under general anesthesia in 2 treatments. All radiation temporarily delivered directly to gland and all other organs are spared from direct impact.

The fiducial markers are placed for both HDR brachy and SBRT (I had 3). With SBRT, they can be placed transperineally to lessen chance of infection (with HDR brachy they are always placed transperineally). They numb the area with a pelvic nerve block, so you don't feel them.

HDR brachy is MUCH more involved than a biopsy - it requires one or two hospital stays.

It is not true that "all other organs are spared direct impact." The fact that the doctor has to be another room should tell you something - this is why it's called "high dose rate."The Ir 192 implants are highly radioactive and shoot out penetrating X-rays in all directions. The only difference between SBRT and HDR-BT is that with SBRT, the X-rays shoot out from widely spread positions and converge in the prostate, while with HDR-BT the X-rays originate in the prostate and shoot out in widely divergent directions. The doses received by the organs at risk are very much the same. They were designed to have equivalent dosimetry.

Thank you for all valuable information inputs I need to think about. Still learning.

The fiducial markers are required for placement of the catheters in HDR-BT. They are also necessary to generate the plan (i.e., what the doses within the prostate and to organs at risk will be). Without them, they cannot tailor the plan to your individual anatomy. The plan dictates the dwell time of each needle inserted into all the catheters. Your provider may not use them - I know that Jeff Demanes did.

"Also, highest radiation dose gets delivered preciously at tumor location while external radiation highest dose is on body entrance rather then on organ itself. "

Not so. It is true for both external beam and brachytherapy that the highest radiation dose is within the prostate. With external beam, hundreds of beams are aimed from different locations outside of the prostate and converge in the prostate. Plus, beam energies (typically 6 MV) are set so that the X-rays only deposit their energy when inside the prostate, not at the surface (or you would get skin burns). And the beams are highly conformed to the shape of the prostate.

The quote you presented gets it wrong when they say, "The treatment significantly limits radiation to the bladder or rectum beyond what is achievable with other external radiation treatments." It depends on which "external beam radiation treatments" they are referring to. Certainly that is true if they are talking about 3D-CRT or older technologies. In fact, the doses delivered to organs at risk by SBRT and HDR-BT are identical (with somewhat higher urethral dose with HDR-BT). I have seen dose-volume histograms for both and can personally attest to that - I looked at this very closely when I was making my treatment decision.

The fiducials are what shows up on the CT. How do they align the first set of 15 or so catheters placed with the second set (and the third or the forth- depending upon the protocol)? Without fiducials, they can only guess at placement, which isn't good enough - they have to follow a plan. you won't know they're in there - they doit while you're out. They don't interfere with MRIs- they're made of gold or platinum. In fact they often do an MRI fused on top of the CT scan to get a more detailed image.

I don't recommend books- they're out of date by the time they're printed. I rely only on articles published in peer-reviewed journals. Click on the links in my signature for detailed papers on SBRT.