Proton pulsed reduced-dose-rate radiotherapy for recurrent high-grade glioma

PrOton Pulsed reduCed dOse Rate Radiotherapy for Recurrent CNS maligNancies (POPCORN) Trial

Not applicable Interventional Baptist Health South Florida · NCT06397560

This trial tests whether a special proton radiation method called PRDR helps people whose fast-growing glioma has come back after prior radiation.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment28 (estimated)
Ages18 Years and up
SexAll
SponsorBaptist Health South Florida Academic / other
Drugs / interventionsChemotherapy, radiation
Locations2 sites (Boca Raton, Florida and 1 other locations)
Trial IDNCT06397560 on ClinicalTrials.gov

What this trial studies

This interventional trial delivers proton pulsed reduced-dose-rate (PRDR) radiotherapy to people with recurrent high-grade glioma who previously received at least 45 Gy of radiation. Participants must have clinical, imaging, or histologic evidence of tumor progression and a Karnofsky performance status of 50 or higher, with specific timing rules about the interval since prior radiotherapy and exceptions for biopsy-proven or out-of-field recurrences. The protocol uses dose levels and fractionation schemes considered acceptable from earlier work to document both beneficial effects and toxicities of PRDR re-irradiation. Treatments are performed at Baptist Health South Florida locations in Boca Raton and Miami and outcomes will include treatment-related side effects and measures of tumor control.

Who should consider this trial

Good fit: Ideal candidates are adults with histologically confirmed or radiographically proven recurrent high-grade glioma, prior radiotherapy of at least 45 Gy, a Karnofsky performance status ≥50, and who meet the study's timing or exception criteria for prior radiation.

Not a fit: Patients with very poor performance status (KPS <50), widespread systemic disease, diffuse multifocal intracranial disease not amenable to focal re-irradiation, or those whose imaging indicates pure radiation necrosis rather than tumor recurrence are unlikely to benefit.

Why it matters

Potential benefit: If successful, PRDR with protons could allow safer re-irradiation that reduces harm to normal brain tissue while improving local tumor control.

How similar studies have performed: Small and mostly retrospective series of PRDR (primarily with photons) have suggested reduced toxicity in some re-irradiation settings, but proton PRDR is a newer application with limited prospective data.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Karnofsky performance status ≥ 50
* Histologically-confirmed or radiographic evidence of recurrent / progressive glioma
* Prior treatment with radiotherapy to a minimum dose of 45 Gy
* At least 6 months or greater between completion of prior radiotherapy and enrollment in this study. If prospective participants have not passed an interval of at least 6 months, they may still be eligible if they meet one or more of the following criteria:

  1. New areas of tumor outside the original radiotherapy fields as determined by the investigator.
  2. Histologic confirmation of tumor through biopsy or resection AND an interval of at least 90 days between completion of radiotherapy and enrollment.
  3. Nuclear medicine imaging, magnetic resonance (MR) spectroscopy, or MR perfusion imaging consistent with true progressive disease, rather than radiation necrosis obtained within 28 days of enrollment AND an interval of at least 90 days between completion of radiotherapy and enrollment.
* Must have recovered from grade 3+ toxicities of prior therapy and there must be a minimum time of 28 days prior to enrollment from the administration of any investigational agent or prior cytotoxic therapy
* Must not be pregnant (positive pregnancy test) or breastfeeding. Must agree to use of highly effective contraception during radiotherapy treatment and for an additional 6 months. Should a participant become pregnant or suspect that they are pregnant while participating in this study, they should notify the treating physician immediately.

Highly effective and acceptable forms of contraception are:

* Male condom plus spermicide
* Cap plus spermicide
* Diaphragm plus spermicide
* Copper T
* Progesterone T
* Levonorgestrel-releasing intrauterine system (e.g., Mirena®)
* Implants
* Hormone shot or injection
* Combined pill
* Mini-pill
* Patch

Individuals who meet any of the following criteria will not need contraception:

* Individuals assigned male at birth
* Amenorrhoeic for 1 year or more following cessation of exogenous hormonal treatments
* Luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in the postmenopausal range for individuals under 50
* Radiation-induced oophorectomy with last menses \> 1 year ago
* Chemotherapy-induced menopause with \>1 year interval since last menses
* Surgical sterilization (bilateral oophorectomy or hysterectomy)

Exclusion Criteria:

* Two or more courses of prior radiotherapy
* Inability to undergo an MRI with contrast
* Leptomeningeal evidence of recurrent disease
* Multi-focal disease
* Any other condition that may put a participant at higher risk, at the discretion of the investigator.

Where this trial is running

Boca Raton, Florida and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions GliomaGlioma, MalignantRecurrent Glioma
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.