Radiotherapy Treatment Planning Comparison Using SBRT-PATHY (Photons) Versus CARBON-PATHY for Unresectable Bulky Tumors

NCT06390657 | Withdrawn

• 1 other identifier: S-C-PATHY-MA-122022
• Study Type: observational
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

This study uses a novel unconventional radiotherapy technique, consisting of high dose PArtial Tumor irradiation targeting exclusively the HYpoxic segment of unresectable bulky tumors delivered either with photons (SBRT-PATHY) or with carbon-ions (CARBON-PATHY) while sparing the peritumoral immune microenvironment (PIM).

Conditions

Cancer

Keywords

Particle Radiotherapy; Partial Tumor Irradiation

Outcome Measures

Primary Outcomes (2)

• Phase A: optimization of contouring and planning using PATHY strategy

  The objective of phase A is to optimize the target delineation, planning strategy and techniques for SBRT-PATHY at Princess Margaret and CARBON-PATHY at MedAustron.

  18 months (phase A and B combined)

• Phase B: optimal coverage of Bystander tumor volume (BTV) while allowing the maximal radiation-sparing of PIM and regional lymph nodes

  a prospective identification of 10 patients who are recommended to receive radiotherapy fulfilling the inclusion criteria. SBRT-PATHY and CARBON-PATHY planning is perfomed for study purposes only. A planning comparison between SBRT-PATHY (using photons) and CARBON-PATHY (using carbon-ions) based on dosimetric consideration achieved for the targeted BTV, non-targeted surrounding NTV (normoxic tumor segment), PIM, regional metastases (i.e. local regional involved nodes and distant metastases located within 15 cm cranial caudal to GTV), regional uninvolved lymph nodes and surrounding organs at risk (OAR) will be performed.

  18 months (phase A and B combined)

Secondary Outcomes (3)

• Phase B: Dosimetric-sparing of normoxic tumor volume (NTV)

  18 months (phase A and B combined)

• Phase B: Dosimetric-sparing of Organs at risk (OAR) and regional nodes

  18 months (phase A and B combined)

• Phase B: Feasibility for dosimetric-sparing of regional/distant metastases as abscopal tumor sites (if present)

  18 months (phase A and B combined)

Study Arms (2)

Phase A: retrospective planning study

Simulation CTs of up to ten patients with bulky (\>6cm) tumors will be selected. This will be used for optimization of contouring and planning strategy.

Other: Planning CT, MRI

Phase B: prospective planning study

Ten patients with bulky tumors (\>6cm) recommended to receive RT with CT and MRI planning will be accrued. MRI DCE sequence (20-30mins) will be added if not requested for clinical use. They will be treated with standard clinical plans. Every effort will be made to include equal numbers of patients (2-3) from head and neck, thorax, abdomen and pelvis. Planning images will be used for the purpose of dosimetric comparison between SBRT-PATHY and CARBON-PATHY radiation plans.

Other: Planning CT, MRI

Interventions

Planning CT, MRI OTHER

SBRT-PATHY and CARBON-PATHY planning is performed for study purposes only. Patients will be treated according to standard radiotherapy as per institutional policies. The planning images (CT, MRI) will be anonymized and used for planning purposes only.

Phase A: retrospective planning study; Phase B: prospective planning study

Eligibility Criteria

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

Study Population

Patients with unresectable bulky tumors (primary or metastatic) recommended to receive external beam radiotherapy, will be recruited from Princess Margaret Cancer Center and Medaustron. Every effort will be made to equal numbers (i.e. 2-3) from head and neck, thorax, abdomen, pelvis.

You may qualify if:

• Written informed consent (for use their planning CT and MR data for study specific planning)
• Malignant solid bulky primary or recurrent tumor with diameter of ≥6 cm
• Age \> 18 years
• Radiation planning CT (with IV contrast) and MRI (with or without IV contrast) is planned

You may not qualify if:

• Patients without bulky lesions,
• Contraindication to i.v. CT and MRT contrast medium administration, particularly estimated glomerular filtration rate (GFR) less than 45 mL/min/1.73 m².
• Female patients who are pregnant, breast-feeding or male or female patients of reproductive potential who are not employing an effective method of birth control,
• Any condition that, in the opinion of the investigators, would interfere with treatment planning or interpretation of study results
• Note (1): criterion n°4 will be evaluated on the four eyes principle, evaluated by both Principle Investigator and Sub-Investigators.

Sponsors & Collaborators

• EBG MedAustron GmbH: lead
• The Princess Margaret Cancer Foundation: collaborator

Study Sites (1)

EBG MedAustron GmbH

Wiener Neustadt, Lower Austria, 2700, Austria

Location

MeSH Terms

Conditions

Neoplasms

Interventions

Magnetic Resonance Spectroscopy

Intervention Hierarchy (Ancestors)

Spectrum Analysis; Chemistry Techniques, Analytical; Investigative Techniques

Study Officials

• Slavisa Tubin, M.D.

  EBG MedAustron

  PRINCIPAL INVESTIGATOR

• Rebecca Wong, MBChB, FRCPC, MSc, Prof.

  Princess Margaret Cancer Centre

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: OTHER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 29, 2024
• First Posted: April 30, 2024
• Study Start: June 1, 2024
• Primary Completion: December 1, 2025
• Study Completion: December 1, 2025
• Last Updated: May 11, 2025

Record last verified: 2025-05

Locations

AU (1)