NCT06397560 · Baptist Health South Florida
PrOton Pulsed reduCed dOse Rate Radiotherapy for Recurrent CNS maligNancies Trial
(POPCORN)
What this study is about
The purpose of this research study is to see if a specific type of radiation therapy, called "proton pulsed reduced dose rate" or "PRDR radiotherapy" has any benefits at dose levels and number of fractions thought to be acceptable in earlier research studies.
View original scientific description
The purpose of this research study is to see if a specific type of radiation therapy, called "proton pulsed reduced dose rate" or "PRDR radiotherapy" has any benefits at dose levels and number of fractions thought to be acceptable in earlier research studies. The researchers want to find out what effects (good and bad) PRDR has on people with cancer in the brain called a "recurrent high-grade glioma" meaning that it grows fast, can spread quickly, and it has come back or gotten worse after being treated previously.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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:
- New areas of tumor outside the original radiotherapy fields as determined by the investigator.
- Histologic confirmation of tumor through biopsy or resection AND an interval of at least 90 days between completion of radiotherapy and enrollment.
- 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
- Progesterone T
- Levonorgestrel-releasing intrauterine system (e.g., Mirena®)
- Hormone shot or injection
- Combined 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
- Boca Raton, Florida
- Miami, Florida
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 1, 2026 · Source of record for eligibility and locations