OUR TURN FOR THE PROTON BEAM TOUR (WARNING: LONG POST)

First, the update on Odel: He has now had 18 proton beam treatments out of the 45 total required. So far, very minor side effects, treatable with Advil and Flomax. He spends two hours working out in the gym 5 days a week, plays golf every Wednesday, eats with gusto, and awakens in good spirits every morning.

One Sunday per month, proton beam patients and a guest can take a tour of the proton beam facility to learn what goes on behind the scenes. It is a popular tour - advance signups are required and woe to those who aren't there on the day signups open (two weeks before the tour). Yesterday was our tour day.

All the proton beam equipment is in the basement of the hospital. In the ground floor lobby near the Proton Beam elevator, a model of the proton beam complex (top photo) gives visitors and new patients an overview of the mechanics of the process. The tour brings it all to life.

The tour is led by the LLUMC Historian, who has been involved with the program and the building of the complex from the beginning, 18 years ago. The engineers in the group were in Physics Heaven, bathed in big, bigger and biggest words and concepts: 250-million-electron-volt accelerator, variable-energy proton synchrotron, cyclotron, exponentially, ionization events, dose-distribution characteristics, 411 million miles per hour...

I mostly heard "blah, blah, blah, kill cancer cells, blah, blah, healthy cells, blah, blah, rotating gantry, blah, photographs, blah, single-file, blah, blah, modulator wheel, Bragg Peak." A-HA! Modulator wheel and Bragg Peak - those were the Two Important Concepts that I understood and retained, and that is what I can explain to you. Engineers, google it.

Here are the basics: LLUMC has an accelerator that makes really, really, REALLY fast protons zoom around and around all day long. Very large numbers were discussed here - speeds, watts, etc. This is where "411 million miles per hour" came in.

Two things can happen to these speeding protons. They either can be "called to the treatment room" (and beamed into the patient), or discarded, sent into a carbon dump where they are absorbed.

We were not allowed to take photos in that area, so picture a large-ish room PACKED with heavy-duty metal structures, a circular accelerator, wires, dials - the mad scientist's hide-away times ten.

Next, check out the treatment gantry, the second photo. LLUMC has 3 gantries (one of which is closed, being rebuilt) and one Horizontal Beam Treatment room. Odel is being treated in the HBT room, so neither of us had seen a gantry.

In the gantry, the patient always faces the same direction (in the HBT, the patient's position alternates each day) and the huge gantry wheel (3 stories tall, 90 tons, so perfectly balanced that it is turned by a one-half horsepower engine) turns around the patient. Check out the lighting - wouldn't you expect music provided by a celestial choir? Hallelujah!

When the patient is properly positioned in either the gantry or the HBL, the tech team "calls the beam". From the accelerator, the super-speedy protons rush to the treatment room, guided and turned by focusing magnets. The Modulator Wheel spins (an incredibly fast number was mentioned here - imagine any number too high to grasp), the protons beam, and the cancer pays the ultimate price.

Each patient has several customized Important Parts (photo on left): the pod (expansion foam in the lengthwise half of a PVC pipe, the hilariously low-tech component); the blue wax Bolus and two metal apertures involved in shaping the beam, and the Modulator Wheel - the item of most interest to me.

Here is the difference, in simplistic and probably not totally accurate laywoman's terms, between pHoton and pRoton therapy (besides the second letter in their names): Photon beams, the standard radiation therapy, are kind of a "straight line" energy. They enter the body at 100% strength, and begin degrading as they go. At tumor depth, perhaps they are at 60% strength. They continue on past the tumor and exit the body at, say 40% energy. At all times, the photons are destroying tissue, whether healthy or cancerous, from entrance to exit.

Protons act differently, and the key is the Bragg Peak. Protons enter the body at a lower energy, travel a measurable distance, then begin to release energy, which peaks - BANG - at the Bragg Peak. After that, the energy dies - end of beam. So the key to PBT is the placement of the Bragg Peak. Shoot the protons in through the hip, arranged to peak in the prostate, and that's it - peak radiation where the cancer cells reside, and no radiation coming out the other side.

The Bragg Peak itself - the area of maximum energy release - is narrow, one millimeter or so. Of course, the prostate is much wider than that - so how do you position the Bragg Peak to cover the entire prostate?

Enter the Modulator Wheel, spinning at 300 revolutions per minute (Odel looked that up for me). Each "spoke" on the wheel consists of "stepped" thicknesses of material that deflects/absorbs/weakens (yeah, I didn't quite "get" that part) the protons before they enter the body, which means that the protons' "peak" is "spread" through the prostate. Protons that are not weakened by a spoke peak at the far side of the prostate, protons that pass through a thin part of a spoke peak in the middle of the prostate, protons that pass through the thickest part of the spoke peak on the near side of the prostate.

So, picture the beam coming from the accelerator, though the modulator wheel, and into Odel, with the Bragg Peak moving quickly back and forth throughout his prostate for a couple of minutes. That is one treatment. His next treatment is identical, except it is shot through the other hip, alternating each day.

While this is going on, the 3-4 person team of technicians retire to the control room. Computer monitors, keyboards - all the high-tech gadgetry you would expect. Very comforting to us "tourists".

Here is the other thing I learned on the tour that is a great interest to me: what's really going on in the prostate when it gets beamed?

All the cells are being damaged, both healthy prostate cells and cancer cells. The healthy cells, thanks to the miracle of your body's ability to heal, begin their recovery and healing as quickly as 5-7 hours post-proton treatment. The cancer cells can't do that. With each treatment, the cancer cells become weaker and weaker. By the 45th treatment, the cancer cells are either 1) DEAD or 2) STERILE and unable to reproduce. Your healthy cells, on the other hand, have worked to repair and recover each day. Once the 45 treatments are completed, the healthy cells continue to recover and reproduce. Result? A healthy, living prostate - and life goes on.

If you are a PBT patient: TAKE THE TOUR. It was totally fascinating, filled with history and anecdotes of early patients and treatment. We left feeling even more confident that Odel had made the right decision and, once again, grateful that PBT is available to us.