Proton Therapy Study Results for Localized Cancer
Since I plan to pursue radiotherapy if & when I have to step off of the AS track, I keep up with the research on efficacy of different methods. Here's the results of a recent randomized study comparing Proton Beam Therapy (PBT) and Intensity Modulated Ration Therapy (IMRT) which uses photons, for localized cancer.
https://www.redjournal.org/article/S0360-3016(24)03237-1/fulltext
News release
The key statements are my bold, surprising to me:
Results
Between 06/2012-11/2021, 450 patients from 30 recruiting centers were randomized: PBT (N=226) and IMRT (N=224), of whom 221 and 216 were eligible and started radiation on the respective arms. Median follow-up was 60.3 mo among 424 patients still alive. Median age was 68 yrs (range 46-89), 59% had intermediate-risk disease, 51% received hypofractionation, 48% used a rectal spacer, and 49% of PBT patients were treated with pencil beam scanning. There was no difference between PBT or IMRT in mean change of health care software bowel score at 24 mo (p=0.836), with both arms showing only small, clinically non-meaningful decline from baseline (see Table). Similarly, there was no difference in bowel function at earlier timepoints (3, 6, 9, 12, 18 mo) or later timepoints (36, 48, 60 mo). No differences were observed in other domains (urinary, sexual, hormonal) at any timepoint. There was no difference in progression-free survival (PFS) (93.4% vs 93.7% at 60 mo, HR 1.16 [0.53, 2.57], p=0.706). There was no sustained difference in any QOL domain or PFS between arms in subgroups defined by stratification variables.
Conclusion
This prospective randomized clinical trial shows that patients treated with contemporary radiotherapy for localized prostate cancer achieve excellent QOL with highly effective tumor control, without measurable differences between PBT and IMRT. We continue to monitor participants for longer follow-up and secondary endpoints.
******
If the cancer has escaped the prostate ( @swl1956 ) , that's a different problem.
Comments
-
Lucky Metastatic Me! Lols! From my research and conversations with professionals I've come to an anecdotal conclusion agreeing with as stated above. Proton vs. Photon is likely a wash. Both are equally effective and relatively safe. There is much marketing going on within the cancer industry to convince us that one technology is better than the other. In my unprofessional opinion the case of PBT vs. IMRT the real issue is how good and experienced the individuals are running the equipment. A difficult task to qualify.
0 -
Hi,
The one advantage with Proton therapy is that the beam is fixed focal length which means the beam does not impact other organ's or tissue past the cancer. No need for protective gel, which is another thing that could go wrong.
Dave 3+4
0 -
I agree with your assessment. It may offer some benefit with preventing toxicity of the rectum. The Fox Chase facility that I'm dealing with does not offer Proton. To search out a new doctor at another institution that does offer Proton would require more time and stress me out more than I already am. Also one of Fox Chase's radiation facilities is very convenient for me to get to. I'd have to get to Penn Medicine in downtown Philly or MSK in New York for Proton. If I get any more stressed, I'll be dead of a heart attack before the Pca gets me. Lols!
0 -
They have to deal with setting the power so the beam stops exactly where they want it to, which is pretty much impossible since the innards aren’t fixed in space and their model of the tissue’s absorbency is not exact. They end up extending their target zone to make sure they get the target, leading to some healthy tissue getting zapped too.
It’s still good stuff, but there are challenges.
0 -
Hi,
If they can gain sub mmm accuracy with other forms of external beam radiation they can do the same for Proton if the technicians are trained properly. It just makes sense there will be less tissue damage with a fixed beam length not penetrating past the tumor into other tissues. John Hopkins Medicine states it is very accurate process with less surrounding tissue damage due to the nature of the process. If you have a superbly trained staff and great facilities I feel it would be my choice.
Dave 3+4
0 -
They can for sure get sub-millimeter on the direction just like photon beam methods, there are fundamental physics hindering sub-millimeter accuracy on the range. Cool explanation on some reasons.
Because the prostate is a floating blob in a moving body, they design in a 2-8 millimeter margin to their planning volume.And an excellent thorough discussion on its use for prostate cancer. A 2021 paper that notes the importance of the clinical trial I cited in my first post. The hypothesis was they’d see less bowel issues with proton beam. They didn’t. I’m sure it has them scratching their heads.
0 -
Hi,
From one of the 1st papers you referenced: “ Another external-beam option — proton therapy — uses protons rather than photon beams. These charged particles kill cancer by producing a sudden burst of energy once they stop inside a tumor. Because this release happens directly at the tumor site, protons deliver less radiation along their path and are potentially less likely to harm surrounding healthy tissue.” I like that a lot👍……
Dave 3+4
0
Discussion Boards
- All Discussion Boards
- 6 CSN Information
- 6 Welcome to CSN
- 122.1K Cancer specific
- 2.8K Anal Cancer
- 448 Bladder Cancer
- 309 Bone Cancers
- 1.6K Brain Cancer
- 28.5K Breast Cancer
- 398 Childhood Cancers
- 27.9K Colorectal Cancer
- 4.6K Esophageal Cancer
- 1.2K Gynecological Cancers (other than ovarian and uterine)
- 13K Head and Neck Cancer
- 6.4K Kidney Cancer
- 673 Leukemia
- 795 Liver Cancer
- 4.1K Lung Cancer
- 5.1K Lymphoma (Hodgkin and Non-Hodgkin)
- 239 Multiple Myeloma
- 7.2K Ovarian Cancer
- 65 Pancreatic Cancer
- 490 Peritoneal Cancer
- 5.5K Prostate Cancer
- 1.2K Rare and Other Cancers
- 543 Sarcoma
- 737 Skin Cancer
- 658 Stomach Cancer
- 192 Testicular Cancer
- 1.5K Thyroid Cancer
- 5.9K Uterine/Endometrial Cancer
- 6.3K Lifestyle Discussion Boards