what is the “real difference” between a proton and a photon as it relates to the treatment of prostate cancer?

Proton-photon…it’s all the same to me…. Comparing the two as it relates to the treatment of prostate cancer.

Iceberg-Feinberg it’s all the same to me.

Commentary on Proton therapy-Cost and “bang for the buck” concerns.

Did you know that for some prostate cancers a photon is better than a proton?

I have asked a physicist, who I have worked with on patients having radioactive seeds, to tell this blog his perspective of the two. Following this I will ask a Radiation Therapist to do the same from the clinical aspect.

Hint: If a prostate cancer involves the capsule, a photon (EBRT) is better than a proton.

Comments anyone?

Your book is of great help in understanding prostate cancer and in making a decision as to treatment. Why do you not cover Proton Therapy? I know that most urologists don’t even discuss it and my experience is that they don’t know a lot about it. But in a book that covers the options of treatments I cannot understand why it was not included in your book. My research shows that proton therapy is very effective with few if any side effects. I personally plan to have this treatment. I am interested in your feedback.

Thank you.

Jim

Reply by John McHugh M.D.

You are right, I don’t think most urologists understand the pros and cons of proton therapy, I certainly don’t. I had an extended discussion with a physicist and a radiation therapist this past Friday. Their contention is that patients are the ones (particularly the ones that opt for proton therapy without taking into account the specifics of “their” disease) who don’t understand the difference between a photon and a proton and its clinical usefulness. For instance, they told me that if there is a concern of capsular penetration by the cancer (higher Gleason, higher PSA, and the positive cores are lateral) then photon therapy is better than proton. Now, as to why I don’t discuss proton therapy in the book is that I , rightfully or wrongly, considered proton a form of radiation therapy and that if a patient chose that option then the radiation therapist would discuss the pros and cons of each. A point you have not made but is relevant is that will a radiation therapist or hospital that doesn’t have the proton machine be biased against recommending it. (Or, an institution that has the machine having a bias toward  recommending it too often.) For a patient to be a candidate in most cases he would have to be willing to travel and possibly pay more.(See the link on this post.) So…in your case (although I am sure you have vetted this) the specifics of your cancer may be better suited to the photon and not the proton. If you’d like, if you’ll give your stats I’ll ask our guy here and see what his thoughts are. We might all learn from this. Thanks so much for your input and I sincerely wish you well. JM Ps…put you stats up against the Partin Table and determine the likelihood of capsular extension. If the percentage is on the high side i.e. 20%, you may be better served with EBRT. I of course defer to your radiation therapist. Something to consider…do you know the distribution curve of energy released as it relates to the photon and the proton and then how that relates to the treatment of prostate cancer? If you do you are ahead of the curve. I did not, but the radiation therapist made a big deal about it. It has to do with whether a particle loses energy throughout its journey to the cancer or whether it gets to the determined point and dumps all the energy all at once. The latter characteristic is not ideally suited to capsular extension. I’d love for you to have your “proton guy” to opine in terms of your specific prostate cancer.  Again…thanks so much for your input…it will ultimately help another fellow prostate cancer patient.