Clinical trial · Interventional
Reduced Dose Radiotherapy for the Treatment of Indolent Non-Hodgkin Lymphoma
MC230808 Reduced Dose Hypofractionated Radiotherapy (3Gy x 3 Fractions) for Indolent Non-Hodgkin Lymphoma (POSEIDON): A Multisite Phase 2 Randomized Trial
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
This phase II trial compares the safety, side effects and effectiveness of reduced dose radiation therapy to standard of care dose radiation in treating patients with indolent non-Hodgkin lymphoma. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Standard of care radiation treatment for indolent non-Hodgkin lymphoma is usually delivered in 12 treatments. Studies have shown indolent lymphoma to be sensitive to radiation treatment, however, larger doses have higher rates of toxicities. A reduced radiation dose may be safe, tolerable and/or effective compared to standard of care radiation dose in treating patients with indolent non-Hodgkin lymphoma.
Conditions
Conditions (5)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Indolent B-Cell Non-Hodgkin Lymphoma | Indolent B-Cell Non-Hodgkin Lymphoma | ONTOLOGY_EXACT | 0.98 |
| Recurrent Indolent B-Cell Non-Hodgkin Lymphoma | Indolent B-Cell Non-Hodgkin Lymphoma | CURATED_BROADER | 0.78 |
| Recurrent Indolent Non-Hodgkin Lymphoma | Indolent Non-Hodgkin Lymphoma | CURATED_BROADER | 0.78 |
| Refractory Indolent B-Cell Non-Hodgkin Lymphoma | Indolent B-Cell Non-Hodgkin Lymphoma | CURATED_BROADER | 0.78 |
| Refractory Indolent Non-Hodgkin Lymphoma | Indolent Non-Hodgkin Lymphoma | CURATED_BROADER | 0.78 |
Interventions
Interventions (6)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Computed Tomography | Procedure | — | UNRESOLVED |
| Endoscopic Procedure | Procedure | — | UNRESOLVED |
| Involved-site Radiation Therapy (12 Fractions) | Radiation | — | UNRESOLVED |
| Involved-site Radiation Therapy (3 Fractions) | Radiation | — | UNRESOLVED |
| Positron Emission Tomography | Procedure | — | UNRESOLVED |
| Questionnaire Administration | Other | — | UNRESOLVED |
Design
Arms and outcomes
Arms (2)
- type
- EXPERIMENTAL
- label
- ARM 1 (reduced dose ISRT)
- description
- Patients undergo reduced dose ISRT once daily (excluding weekends): 9 Gy delivered in 3 treatment fractions or 8 Gy in 2 fractions. At physician discretion, patients may receive 10 Gy in 5 fractions. Patients also undergo CT or PET/CT throughout the study. Patients may additionally undergo endoscopy during screening and during follow up.
- interventionNames
- Procedure: Computed Tomography
- Procedure: Endoscopic Procedure
- Radiation: Involved-site Radiation Therapy (3 Fractions)
- Procedure: Positron Emission Tomography
- Other: Questionnaire Administration
- type
- ACTIVE_COMPARATOR
- label
- ARM 2 (SOC ISRT)
- description
- Patients undergo standard of care (SOC) radiation therapy once daily (excluding weekends): 24 Gy in 12 treatment fractions. Patients also undergo CT or PET/CT throughout the study. Patients may additionally undergo endoscopy during screening and during follow up.
- interventionNames
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: * Age ≥ 18 years * Histological confirmation of indolent B-cell lymphoma that can include any of the following: * Follicular lymphoma (grade 1 or 2 or 3A) * Marginal zone lymphoma (nodal or extranodal) * Follicle center lymphoma * Any stage disease * Initial, refractory, or relapsed disease. If relapse involves the site to be treated there must be evidence of disease progression * Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 3 * Negative pregnancy test done ≤ 7 days prior to registration, for persons of childbearing potential only * Provide written informed consent * Ability to complete questionnaire(s) by themselves or with assistance * Willing to return to enrolling institution for follow-up visits (during the active monitoring phase of the study). Virtual visits can also be considered as an option for applicable items * Confirmation from radiation oncologist of suitability to participate in study Exclusion Criteria: * Any of the following: * Pregnant women * Nursing women * Women of childbearing potential who are unwilling to employ adequate contraception * T-cell lymphoma * Receiving treatment for small and chronic lymphocytic lymphoma * Grade 3B follicular lymphoma
References
Publications (0)
Data not yet available