Originally published May 29, 2024
A new paper reports, “Up to 50% of clinical recurrences after curative-intent prostate cancer radiation are intraprostatic radiorecurrences (IPRRs).”[i]
This means that nearly half of PCa patients who have radiation for localized disease may have a return of their cancer that is still contained in the gland.
Since the first treatment failed, a second effort to destroy all the cancer is called salvage therapy.
Salvage therapies typically have higher risks of side effects due to post-radiation scar tissue. Thus, the idea of a focal salvage treatment is appealing as a way to lower those risks.
However, radiation recurrence may be difficult to identify. The original blog below concludes that MRI may not pick up all the sites of recurrence. Now, a new paper offers the same results.
The authors tested the accuracy of MRI, PET/CT and biopsy for picking up radiation recurrence in 62 patients. Under consideration was a focal salvage treatment using high dose brachytherapy.
While MRI outperformed PET/CT (91.8% vs. 85.5% sensitivity, respectively), both types missed the full extent of recurrence in 63.9% of cases.
The authors write, “Although MRI and PET/CT are valuable, a thorough biopsy is a mandatory tool to avoid missing areas of imaging-occult prostatic involvement when delivering focal [salvage local therapy.]”[ii]
How do you feel about the number 13? For some, Friday the 13th is considered unlucky. The number 13 may not have been the luckiest number for the 1970 Apollo 13 lunar landing mission. In fact, while circling the moon, Monday April 13 nearly became very unlucky indeed. The No. 2 oxygen tank in the service module ruptured, causing the No. 1 tank to fail. The lives of all three crew members were on the line. As NASA details the situation, “The command module’s normal supply of electricity, light and water was lost, and they were about 200,000 miles from Earth.” John Swigert Jr., pilot of the command module, issued his famous (but thankfully not his last!) words: Houston, we’ve had a problem here.
NASA’s mission controllers in Houston brainstormed a solution. With their intervention, the command module splashed down in the Pacific Ocean four days later. The crew members were saved! On the 50th anniversary of that rescue, aerospace authority Paul Ceruzzi reflected, “Were the astronauts just lucky? Or was their safe return the result of careful attention to detail by NASA engineers? There was luck involved in many aspects of the mission. In this case, I would say it was a combination of both.”
It’s hard to imagine a more harrowing crisis, but let’s face it. Any unexpected situation suggesting your life may be in danger triggers immediate alarm. In fact, high anxiety may befall 20-30% of prostate cancer (PCa) patients treated with radiation, and who subsequently have a rise in PSA.[iii] The immediate suspicion is that they have radiorecurrent PCa, meaning their disease is back.
If they had high risk PCa at the time of diagnosis, it may now be an even more aggressive cancer that can spread to other parts of the body (metastasis). According to a 2021 paper on the course of high risk radiorecurrence, “Some 60% of metastases occur within 1 yr. Approximately 30% of these patients die from their prostate cancer.”[iv] Yet the situation may not be so bleak. With luck, their disease is still intraprostatic (that is, contained in the gland). If so, a salvage treatment is potentially curative. In some cases, they may even be qualified for focal therapy using ablation. “Thus, it is imperative to be able to detect and quantify intraprostatic radiorecurrent disease effectively,” write Kishan, et al. (2024).[v]
Just as NASA’s mission control in Houston had the astronauts’ backs, a team of British experts have put their heads together to solve the problem of how to know which patients have treatable intraprostatic radiorecurrence. They published a report of results from the Focal RECurrent Assessment and Salvage Treatment (FORECAST) trial. The purpose of the trial was to evaluate MRI and MRI-targeted biopsies for detecting intraprostatic cancer recurrence and planning for salvage focal ablation.[vi]
Their analysis included 144 patients with suspected radiorecurrent PCa who were enrolled between 2014-2018. All patients had prostate MRI plus transperineal mapping biopsies, while 84 also had MRI-targeted biopsies. The researchers then conducted several steps to analyze and compare the most accurate ways to identify the location and extent of recurrence, and to determine which patients might be candidates for focal salvage ablative therapy. They considered MRI combined with targeted biopsy, or with mapping biopsy, or with systematic sampling of one or two additional prostate quadrants.
Thus, the authors generated a thorough analysis of diagnostic options to determine if and how much radiorecurrent PCa a patient has, and how to qualify patients for focal treatment:
After radiotherapy, magnetic resonance imaging (MRI) is accurate for detecting recurrent prostate cancer, with missed cancer being smaller and of lower grade. Targeting a biopsy to suspicious areas on MRI results in a diagnosis of cancer in most patients. However, for every five men who have recurrent cancer, this targeted approach would miss cancers elsewhere in the prostate in three of these men. If further focal treatment of the prostate is planned, random biopsies covering the whole prostate in addition to targeted biopsies should be considered so that tumours are not missed.[vii]
It is perfectly understandable that a post-radiation PCa patient whose PSA begins to rise will have an immediate “Uh oh” response similar to Swiger’s “Houston, we’ve had a problem here.” While he may feel like he’s doomed in outer space, he needs to know that there is a global “mission control” in the form of researchers working to resolve the radiation recurrence crisis. Thanks to the FORECAST study, we know that MRI is a key player in diagnosis, but due to the tricky and aggressive nature of radiation recurrence, a biopsy more thorough than MRI-targeted biopsy alone may be required. Then, with a combination of attention to detail and a little luck, rescue may be his in the form of focal salvage therapy.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
References
[i] Venkatesulu B, Adams W, Joel R, Ross D et al. The Importance of Multiparametric Magnetic Resonance Imaging, Positron Emission Tomography/Computed Tomography, and Biopsy for Identifying and Delineating the Extent of Intraprostatic Radiorecurrent Prostate Cancer: A Secondary Analysis of the F-SHARP Clinical Trial. Int J Radiat Oncol Biol Phys. 2025 Aug 1;122(5):1186-1191.
[ii] Ibid.
[iii] Kishan AU, Valle LF, Marks LS. Bullseye or Tip of the Iceberg: Magnetic Resonance Imaging-visible Disease in Radiorecurrent Prostate Cancer. Eur Urol. 2024 Jan;85(1):47-48.
[iv] Philipson RG, Romero T, Wong JK, Stish BJ et al. Patterns of Clinical Progression in Radiorecurrent High-risk Prostate Cancer. Eur Urol. 2021 Aug;80(2):142-146.
[v] Kishan, Ibid.
[vi] Light A, Kanthabalan A, Otieno M, Pavlou M et al. The Role of Multiparametric MRI and MRI-targeted Biopsy in the Diagnosis of Radiorecurrent Prostate Cancer: An Analysis from the FORECAST Trial. Eur Urol. 2024 Jan;85(1):35-46.
[vii] Ibid.
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
