The PET- Retroperitoneal Sarcoma Study

NCT04224948 | Completed

• 1 other identifier: 19-5429
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

Retroperitoneal sarcoma(RPS) is a rare cancer that is difficult to cure as it typically presents as a very large abdominal mass, and complete removal with clear margins is challenging . This study will focus on improving the outcomes of surgery by treating RPS before surgery, to make resection more effective. The role of chemotherapy as a preoperative treatment for RPS is highly controversial. Response to chemotherapy is unpredictable and if the patient's tumour progresses instead of responding, the window of opportunity for resection will be lost. Conventional cross sectional imaging (CT scan) is inadequate to measure response to chemotherapy until 5-6 cycles have been given, possibly with no improvement. Thus it is critical to develop an earlier and reliable way to assess response. Functional imaging by PET scan is used in other tumour types to identify early response to treatment. PET imaging may provide a more meaningful assessment of RPS response to systemic therapy much earlier in the course of treatment than conventional imaging, allowing timely modification of the treatment plan. This study will define the role of PET imaging in evaluating early response to systemic therapy in high grade RPS, improving patient treatment.

Conditions

Retroperitoneal Sarcoma

Keywords

Retroperitoneal Sarcoma; Retroperitoneal; Sarcoma; Neoadjuvant Chemotherapy; preoperative Chemotherapy

Outcome Measures

Primary Outcomes (1)

• Correlation of PET imaging with histologic response following preoperative chemotherapy.

  Pathology of RPS specimens, resected following standard ifosfamide/doxorubicin chemotherapy every 3 weeks for 5-6 cycles, will be compared with PET response (FDG uptake) after cycle 1 of chemotherapy.

  3 years

Secondary Outcomes (1)

• Correlation of CT imaging with histologic response, and comparing prognostic accuracy of PET-MR vs.CT imaging for histologic response, recurrence status, and survival.

  3 years

Study Arms (1)

PET-MR arm

EXPERIMENTAL

Every eligible patient will be scanned by PET-MR at baseline and following 1 cycle of chemotherapy. PET-CT at baseline will also be obtained as it is the current standard of care and will be used to determine trial eligibility (no evidence metastasis at baseline).

Device: PET MRI scan

Interventions

PET MRI scan DEVICE

Standard of care includes a baseline PET-CT and conventional CT after 2 cycles of neoadjuvant chemotherapy, and after 5-6 cycles, of neoadjuvant chemotherapy, as per current practice/ standard of care. Patients that enroll in the trial will receive two additional PET MRI scans- one at baseline and one after 1 cycle of chemotherapy

PET-MR arm

Eligibility Criteria

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

You may qualify if:

• Tumour-related criteria
• Primary soft tissue sarcoma of retroperitoneal space or infra-peritoneal spaces of pelvis
• Sarcoma not originated from bone structure, abdominal or gynecological viscera
• Unifocal tumour (not multifocal disease)
• Absence of extension through the sciatic notch or across the diaphragm
• Histologically-proven RPS (local pathologist/ imaging-guided or surgical biopsy), only including the following histological sub-types:
• High grade Leiomyosarcoma
• High grade Dedifferentiated Liposarcoma
• Tumour not previously treated (no previous surgery -excluding diagnosis biopsy-, radiotherapy or systemic therapy)
• Tumour both operable and suitable for chemotherapy (This will be based on pretreatment CT scan/MRI and multidisciplinary consultation with surgeon medical oncologist and radiologist (anticipated macroscopically complete resection, R0/R1resection)
• Patients for whom surgery is expected to be R2 on the CT-scan before randomization are not eligible
• Patients must have American Society of Anesthesiologist (ASA) score ≤ 2 (see Appendix G)
• The criteria for non-resectability are:
• (i) involvement of superior mesenteric artery
• (ii) involvement of aorta

You may not qualify if:

• Age\< 18 years
• Recurrent tumour
• Benign retroperitoneal tumours
• Presence of second active cancer
• Serious psychiatric disease that precludes informed consent or limits compliance
• impossible to ensure adequate follow up

Sponsors & Collaborators

• University Health Network, Toronto: lead

Study Sites (1)

University Health Network and The Sinai Health System

Toronto, Ontario, M5G 1X5, Canada

Location

MeSH Terms

Conditions

Sarcoma

Condition Hierarchy (Ancestors)

Neoplasms, Connective and Soft Tissue; Neoplasms by Histologic Type; Neoplasms

Study Officials

• Carol Swallow, MD, PhD

  Sinai Health System

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: SCREENING
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 4, 2019
• First Posted: January 13, 2020
• Study Start: January 3, 2020
• Primary Completion: December 31, 2024
• Study Completion: December 31, 2024
• Last Updated: December 3, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)