NCT06327477

Proton-Spatially Fractionated Radiotherapy and Standard Radiation Therapy for the Treatment of Newly Diagnosed Retroperitoneal Soft Tissue Sarcoma

Recruiting now Phase 1, PHASE2 Last updated 20 October 2025

What this trial tests

Phase 1, PHASE2 trial testing Biopsy in Retroperitoneal Sarcoma in 28 participants. Currently enrolling.

Timeline

2 April 2024

Primary endpoint
1 July 2027

1 July 2028

Quick facts

Lead sponsor	Northwestern University
Phase	Phase 1, PHASE2
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	na
Design	sequential
Masking	none
Primary purpose	treatment
Enrollment	28
Start date	2 April 2024
Primary completion	1 July 2027
Estimated completion	1 July 2028
Sites	1 location across United States

Drugs / interventions tested

• Biopsy — full drug profile →
• Biospecimen Collection — full drug profile →
• Computed Tomography
• Intensity-Modulated Radiation Therapy
• Resection
• Spatially-fractionated Radiation Therapy

Conditions studied

• Retroperitoneal Sarcoma — all drugs for Retroperitoneal Sarcoma →

Sponsor

Northwestern University

Who can join

18 and older, any sex, with Retroperitoneal Sarcoma. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This phase I/II trial studies the side effects and best dose of proton-spatially fractionated radiotherapy (P-SFRT) and to see how well it works with standard radiation therapy in treating patients with newly diagnosed retroperitoneal soft tissue sarcoma. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Standard spatially fractionated radiotherapy (SFRT) refers to how the radiation is delivered to the tumor. SFRT means that different parts of the tumor are receiving different doses of radiation (fractionation) through beams that allow areas of higher and lower (peaks and valleys) of doses of the radiation. This spatial fractionation allows an overall high-dose radiation to be given in the peaks and those areas of the tumor may release cells and substances that may help with killing tumor cells, reducing tumor symptoms and shrinking tumors. Proton therapy is a type of radiation therapy that can overcome some of the barriers of standard SFRT. Protons are tiny radioactive particles that can be controlled in a beam to travel up to the tumor and, compared to the particles used in standard radiotherapy, proton therapy can deliver higher doses to the tumor because smaller doses of radiation are delivered to tissues away from the tumor. This allows radiation therapy dose-escalated (continuously increasing the dose of radiation) treatment to tumors even though the tumor is near radiation sensitive organs like the colon. Giving P-SFRT with standard radiation therapy may work better in treating patients with newly diagnosed retroperitoneal soft tissue sarcoma.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. New Approaches in Radiotherapy.
   Webster M, Podgorsak A, Li F, Zhou Y, et al · · 2025 · cited 9× · PMID 40563630 · DOI 10.3390/cancers17121980