What Data Should Radiation Oncologists Know From ASTRO 2026?

In the newest episode of RadOnc on the Run, host Brandon Mancini, MD, MBA, FACRO, highlighted the key presentations and themes that emerged from the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting. Across several oral abstracts and sessions, he discussed how new data affirm that precision targeting is increasingly replacing volumetric approaches and that MRI surveillance is challenging prophylactic cranial irradiation, along with other key shifts in the field.

According to Mancini, key data and presentations included the following:

• PACE-A
  • Long-term follow-up from the phase 3 PACE-A trial (NCT01584258) showed excellent biochemical control with prostatectomy and stereotactic body radiotherapy (SBRT) in patients with localized prostate cancer.¹
  • The trial strengthens the argument that every patient with localized prostate cancer who is considering prostatectomy deserves a meaningful discussion about modern radiation therapy, particularly SBRT, before making a treatment decision.
• SWOG S1827/MAVERICK
  • In a phase 3 trial (NCT04155034) that enrolled patients with limited- and extensive-stage small cell lung cancer, MRI alone was associated with improved cognitive failure-free survival vs MRI plus prophylactic cranial irradiation.²
  • The results may fundamentally change the conversation for patients who can reliably undergo MRI surveillance, as routine prophylactic irradiation of a brain without visible disease may no longer be necessary.
• Alliance A071801
  • The phase 3 Alliance A071801 study (NCT04114981) showed that among patients who underwent resection for large brain metastases, fractionated stereotactic radiosurgery (SRS) yielded superior surgical bed control over standard SRS.³
  • When treating a patient with a larger postoperative brain metastasis cavity with external beam stereotactic radiation, fractionated SRS should be strongly favored over single-fraction treatment.

Mancini is the medical director at Bold Advanced Medical Future Health, a clinical associate professor in the Department of Radiology at Michigan State University College of Human Medicine, and the editor at large for RadOnc Review, a supplement of the journal ONCOLOGY®.

References

1. van As N, Patel J, Tree A, et al. Efficacy of radical prostatectomy versus stereotactic body radiotherapy (SBRT) for localised prostate cancer: results from an international phase III randomised controlled trial (PACE-A). Presented at: 2026 ASTRO Annual Meeting; September 26-30, 2026; Boston, MA. Abstract LBA 32.
2. Rusthoven CG, Redman M, Brown PD, et al. SWOG S1827/MAVERICK: a randomized phase III trial of brain MRI surveillance with and without prophylactic cranial irradiation (PCI) for small-cell lung cancer (SCLC). Presented at: 2026 ASTRO Annual Meeting; September 26-30, 2026; Boston, MA. Abstract LBA 03.
3. Aizer AA, Brown PD, Ballman KV, et al. Alliance A071801 phase III trial: Postoperative single fraction SRS vs. fractionated SRS (fSRS) for resected brain metastases: results from the phase III Alliance A071801 randomized trial. Presented at: 2026 ASTRO Annual Meeting; September 26-30, 2026; Boston, MA. Abstract LBA 01.