Lattice radiation versus conventional radiation to relieve symptoms from large solid tumors.

Lattice Radiation Therapy Versus Conventional Radiation Therapy for the Palliation of Large Tumors

Phase 3 Interventional University Health Network, Toronto · NCT07444775

This trial tests whether lattice (spatially fractionated) radiotherapy gives better pain relief than conventional radiotherapy for people with solid tumors at least 5 cm who need palliative radiation.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment148 (estimated)
Ages18 Years to 99 Years
SexAll
SponsorUniversity Health Network, Toronto Academic / other
Drugs / interventionsradiation
Locations1 site (Toronto, Ontario)
Trial IDNCT07444775 on ClinicalTrials.gov

What this trial studies

This randomized phase III trial compares spatially fractionated lattice radiotherapy (SFRT or LATTICE) to conventional palliative radiation in patients with solid tumors at least 5 cm. Participants are randomized to receive either lattice treatment, which delivers very high doses to discrete spots within the tumor while lowering dose at the tumor edges, or standard radiation planning, with treatment guided by CT simulation. The primary outcome is pain improvement at 30 ±7 days measured by the International Consensus Pain Response using the Brief Pain Inventory and changes in opioid or co-analgesic use. Eligible patients must have pathologically or radiographically confirmed solid tumors ≥5 cm that are unsuitable for surgery or definitive RT and be able to undergo planning and treatment at the trial center.

Who should consider this trial

Good fit: Ideal candidates are adults with pathologically confirmed solid tumors 5 cm or larger who need palliative radiation, are unsuitable for surgery or definitive RT, and can undergo CT simulation and treatment at the trial center.

Not a fit: Patients with tumors smaller than 5 cm, those eligible for curative SBRT or surgery, or tumors not suitable for a lattice dose pattern are unlikely to benefit from this approach.

Why it matters

Potential benefit: If successful, lattice RT could provide faster and greater pain relief for patients with large tumors while limiting dose to nearby healthy tissue.

How similar studies have performed: Early-phase and single-center reports have shown rapid and substantial pain and tumor responses with SFRT in bulky tumors of the lung, head and neck, and cervix, but randomized phase III data are not yet established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Diagnosis of solid tumor by at least one criterion below:

  a. Pathologically or cytologically proven solid tumor greater than 5 cm (largest dimension) from a primary site or site of metastasis and unsuitable for surgical resection or definitive RT. b. HCC diagnosed by standard imaging criteria permitted: arterial enhancement and delayed washout on multiphasic computerized tomography (CT) or magnetic resonance imaging (MRI) in the setting of cirrhosis or chronic hepatitis B or C without cirrhosis
* Eastern Cooperative Oncology Group (ECOG) Status: 0-4 within 14 days of randomization
* In the investigator's opinion, patient requires palliative radiation therapy to a lesion \>5 cm measured in one of the following ways:
* Imaging performed within 90 days prior to randomization per Response Evaluation Criteria in Solid Tumors (RECIST)
* CT simulation performed for radiation planning
* Able to understand and provide written consent
* Willing and have the ability to complete the baseline and post-treatment questionnaires (short form brief-pain inventory) and to maintain a pain diary
* Patient is not pregnant, planning on becoming pregnant or planning on fathering a child in the next 90 days
* Patient must be accessible for treatment and follow-up. Investigators must ensure the patients randomized on this trial will be available for complete documentation of the treatment, adverse events, and follow-up

Exclusion Criteria:

* Prior radiotherapy that would result in substantial overlap of the irradiated volume thus precluding per protocol treatment
* Requirement for urgent surgical intervention prior to radiation treatment
* Confirmed pregnancy
* Hematologic primary malignancy
* Medical condition precluding the delivery of per protocol treatment (e.g. connective tissue disorder)
* Tumors overlying critical CNS, heart or spinal cord compression

Where this trial is running

Toronto, Ontario

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 Histopathologically or Cytologically Confirmed Solid Tumor Who Require Palliation Radiation Therapy to a Lesion ≥5cmLattice Radiation TherapyConventional Radiation TherapySpatially fractionated radiation therapySFRT
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.