November 12 2024
Written by Bridget Koontz, MD FASTRO,AdventHealth Cancer Institute, National PI for NRG-GU011
PSMA PET imaging can detect sites of prostate cancer recurrence in 60-90% of patients with biochemical recurrence. But do PET-staged metastases, now detected earlier in the natural course of disease, have the same prognosis or need the same treatment as conventionally-detected metastases? That is the question asked by NRG-GU011: can men with a limited number of PET-detected metastases and a PSA less than 10 ng/ml be treated with SBRT alone, or does adding short course ADT improve progression free survival?
This study, open since December 2022, has undergone several important eligibility changes to match current clinical practice: initial diagnosis of recurrence can be made by PSMA or fluciclovine PET alone and does not require CT or bone scan; and PSA after definitive radiotherapy must rise from nadir, but does not have to reach Phoenix definition of failure.
Patients and clinicians alike often have strong feelings about the use of ADT in the setting of PET-metastatic recurrent prostate cancer. Whether it’s favoring a “kitchen sink” maximal therapy approach, or wanting to avoid ADT as long as possible, patients and our colleagues often have questions about the study design.
What do I say in tumor board when eligible patients are discussed? I remind my colleagues of the trial - highlighting that before PET these patients were PSA recurrences and we were comfortable letting PSA rise (in many cases. I request that before starting on systemic therapy, we have a chance to discuss the trial with the patient.
What about the patient who doesn’t want the chance of being randomized to the ADT arm? I explain that this trial was written with quality of life in mind, and both the choice of ADT treatment length (just 6 months) and the drug itself (relugolix) was intentional because of its favorable testosterone recovery profile. Of course side effects vary, but in my experience relugolix is very well tolerated – part of it may be the control men feel when taking ADT as a pill knowing they can stop at any time!
We have a new educational slide deck on the CTSU trial website, which includes discussion of literature supporting both study arms. We hope this will be useful in discussing with peers! Today’s “Take Home Message”: Both treatment arms are justified by current evidence, which is why enrolling on NRG-GU011 is so important. Study results will provide key insights to understand the impact of SBRT alone or with ADT on patient outcomes, cancer control and quality of life. Consider offering this trial to your patients to provide current best practice options and contribute to optimized treatment in the future.
NRG-GU011 key eligibility:
- Castration sensitive biochemically recurrent prostate cancer with PSA up to 10 ng/ml
- Prior curative intent treatment to prostate with no evidence of local recurrence
- Positive fluciclovine or PSMA PET with up to 5 lesions in bone and/or nodal/soft tissue sites
- Not actively on ADT with testosterone >/= 100 ng/dl within last 120 d
For more information and materials please visit the ClinicalTrials.gov study page.