Dose-escalated, Hypofractionated, Definitive Proton Radiotherapy for Patients With Inoperable Soft Tissue Sarcoma.

NCT07173972 | Recruiting Phase 2 DMC

• 1 other identifier: 916024
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 2

Brief Summary

The purpose of the study is to study if dose escalated proton radiotherapy can improve local controll for patients with inoperable soft tissue sarcomas. The standard treatment is photon-based radiation. By using proton radiotherapy instead, the hypothesis is that the dose can be increased to enhance treatment effectiveness without increasing side effects. The planned radiation dose is 56 Gy in 16 fractions (treatments) over 4 weeks (4 fractions per week), with a maximum dose escalation centrally in the tumor up to 80 Gy (5 Gy per fraction). At the same time, the study will investigate biomarkers that can predict treatment response, including changes in the tumor's genetic material (DNA), measurements of various molecules in the bloodstream, and the tumor's appearance on MRI scans. The primary endpoint is local control after 2 years, meaning that the treated tumor has not grown during this period. Secondary endpoints include overall survival, progression-free survival, radiological response rates, side effects, and quality of life. The study will be conducted in Norway, with a planned inclusion of 40 patients.

Conditions

Soft Tissue Sarcoma (STS); Soft Tissue Sarcoma Adult; Soft Tissue Sarcoma of the Trunk and Extremities; Synovial Sarcomas; Undifferentiated Pleomorphic Sarcoma (UPS); Myxofibrosarcoma; Leiomyosarcoma (LMS); Pleomorphic Liposarcoma; Pleomorphic Rhabdomyosarcoma; Liposarcoma

Keywords

soft tissue sarcoma; proton radiotherapy; inoperable soft tissue sarcoma

Outcome Measures

Primary Outcomes (1)

• Local progression-free survival

  Local progression-free survival is measured from the date of start of study treatment until date of local progression of the tumor that has undergone proton beam radiotherapy evaluated using RECIST v1.1 or date of death of any cause, whichever occurs first.

  2 Year

Secondary Outcomes (5)

• Progression-free survival

  Up to five years after radiation therapy

• Overall survival

  Up to five years after radiation therapy.

• Overall response rate, defined as partial or complete response using RECIST v1.1

  Up to five years after radiation therapy.

• Health-related quality of life

  Up to five years after radiation therapy.

• To assess acute and late toxicity

  Up to five years after radiation therapy.

Study Arms (1)

Inoperable soft tissue sarcoma

EXPERIMENTAL

Radiation: Definitive radiotherapy

Interventions

Definitive radiotherapy RADIATION

The prescribed dose is 56 Gray (Gy) in 16 fractions over 4 weeks (14 Gy per week) with a maximum dose-escalation to the tumor core of 80 Gy (5 Gy per fraction).

Inoperable soft tissue sarcoma

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• ≥ 18 years of age at the time of informed consent.
• Histological diagnosis of soft tissue sarcoma including gastrointestinal stromal tumor (GIST).
• Measurable disease according to RECIST v1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2
• For patients with metastatic disease a life-expectancy greater than 2 years should be expected.
• Before patient registration, written informed consent must be given according to national and local regulations.
• Ability to fill in patient questionnaires and comply with study procedures, including travelling to Bergen or Oslo for Proton Beam radiotherapy.

You may not qualify if:

• Patients with a prior or concurrent malignant disease whose natural history or treatment have the potential to interfere with the safety or efficacy assessment of this clinical trial are not eligible. Patients with a history of breast cancer, requiring continued hormonal treatment (e.g. anti-estrogen or an aromatase inhibitor) may be included. Patients with a history of prostate cancer, requiring continued support with luteinizing hormone releasing hormone (LHRH) agonists, with or without androgens, may be included.
• Previous radiotherapy to the tumor site.
• Patients with pacemakers and/or implanted defibrillators.
• Patients not able to give an informed consent or comply with study regulations as deemed by study investigator.
• Administration of systemic cancer therapy (i.e. chemotherapy, targeted therapy or immune therapy) within 14 days prior to the first fraction of radiotherapy.

Sponsors & Collaborators

• Oslo University Hospital: lead
• Haukeland University Hospital: collaborator
• St. Olavs Hospital: collaborator
• University Hospital of North Norway: collaborator

Study Sites (2)

Haukeland University Hospital

Bergen, Norway

NOT YET RECRUITING

Oslo University Hospital

Oslo, Norway

RECRUITING

MeSH Terms

Conditions

Sarcoma; Sarcoma, Synovial; Histiocytoma, Malignant Fibrous; Dermatofibrosarcoma; Leiomyosarcoma; Liposarcoma

Condition Hierarchy (Ancestors)

Neoplasms, Connective and Soft Tissue; Neoplasms by Histologic Type; Neoplasms; Neoplasms, Connective Tissue; Histiocytoma; Neoplasms, Fibrous Tissue; Fibrosarcoma; Neoplasms, Muscle Tissue; Neoplasms, Adipose Tissue

Study Officials

• Ivar Hompland, MD, PhD

  Oslo University Hospital

  PRINCIPAL INVESTIGATOR

• Kjetil Boye, MD, PhD

  Oslo University Hospital

  STUDY DIRECTOR

Central Study Contacts

Martine Karlsen Karlsen Ødegaard, Cancer Nurse

CONTACT

+47 99562019; martineko@ous-hf.no

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Consultant, MD, PhD

Study Record Dates

• First Submitted: September 8, 2025
• First Posted: September 15, 2025
• Study Start: January 26, 2026
• Primary Completion (Estimated): January 26, 2029
• Study Completion (Estimated): November 1, 2035
• Last Updated: January 28, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR

Locations

NO (2)