Austin Kirschner, MD, on integrating PROSTOX Standard into prostate radiation planning

In the following video, Austin Kirschner, MD, PhD, discusses the recent US commercial launch of the PROSTOX Standard test¹ and its potential to inform radiation treatment decisions for patients with prostate cancer. Kirschner is a radiation oncologist at Vanderbilt University Medical Center in Nashville, Tennessee.

PROSTOX is a microRNA-based germline assay that estimates an individual patient’s risk of developing late genitourinary (GU) toxicity following conventionally fractionated or moderately hypofractionated radiation therapy (CFRT or MHFRT). Drawing on genetic signatures identified through retrospective analyses of clinical trial datasets, the test generates a personalized risk profile that may help clinicians anticipate which patients are more likely to experience long-term treatment-related urinary complications.

Kirschner emphasized that this form of toxicity risk stratification introduces a new dimension to shared decision-making conversations, which have historically relied on institutional practice patterns, provider experience, and patient preferences, particularly regarding treatment logistics such as duration and visit frequency. By incorporating germline susceptibility to late GU toxicity into the discussion, clinicians may now be better positioned to individualize radiation treatment schedules among multiple guideline-supported options. This approach is particularly relevant given the close anatomic relationship between the prostate and bladder, which can make dose separation challenging and elevate the risk of bladder-related toxicity.

Kirschner noted that PROSTOX is already being used routinely in his clinical practice to help guide treatment recommendations. By identifying patients who may be better suited to one course of therapy over another based on predicted toxicity risk, the test has the potential to support more favorable long-term outcomes and may represent a meaningful step toward more personalized radiation planning in localized prostate cancer.

REFERENCE

1. MiraDx launches new genetic test expanding radiation therapy risk assessment for prostate cancer patients. News release. MiraDx. February 24, 2026. Accessed February 25, 2026. https://miradx.com/new-genetic-test-radiation-risk-assessment-prostate-cancer/