Updated May 2026 · ClinicalTrials.gov
Proton or Photon RT for Retroperitoneal Sarcomas
Phase I/II Trial of Pre-Operative Image Guided Intensity Modulated Proton Radiation Therapy (IMPT) or Photon (IMRT) With Simultaneously Integrated Boost to the High Risk Margin for Retroperitoneal Sarcomas
Proton or Photon RT for Retroperitoneal Sarcomas (NCT01659203) is a Phase 1 / Phase 2 interventional studying Retroperitoneal Sarcoma, sponsored by Massachusetts General Hospital. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.
About This Trial
This research study is a Phase I clinical trial. Phase I clinical trials test the safety of an investigational intervention. Phase I studies also try to define the appropriate dose of the investigational therapy to use for further studies. "Investigational" means that the intervention is still being studied and that research doctors are trying to find out more about it. Retroperitoneal sarcomas are soft tissue tumors located at the far back of the abdomen. Typically, patients with retroperitoneal sarcomas either have surgery for the removal of their tumors alone, or have their tumors removed, followed by standard radiation therapy, or have pre-operative radiation followed by surgery. When conventional radiation therapy is delivered after surgery, it can damage normal tissue. In this study, you will undergo proton beam radiation therapy or IMRT before undergoing surgery for the removal of your tumor. Proton radiation and IMRT are FDA approved radiation delivery systems. Protons are tiny particles with positive charge that can be controlled to travel a certain distance and stop inside the body. In theory, this allows better control of where the radiation dose is delivered as compared to photons. Since proton radiation is more targeted, it may help to reduce unwanted side effects from radiation. In this study, a standard dose of radiation will be given to the majority of the tumor, while a simultaneously integrated boost of additional radiation will be given to certain areas of the tumor identified as higher risk. This means that a higher radiation dose will be given to the higher risk areas of the tumor. The purpose of this study is to determine the highest dose of radiation therapy with protons or IMRT that can be delivered safely in patients with retroperitoneal sarcomas and the effectiveness of proton beam radiation therapy as an intervention for patients with retroperitoneal sarcomas.
What Stage of Research Is This?
Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Retroperitoneal Sarcoma, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.
This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.
Target enrollment of 80 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Retroperitoneal Sarcoma subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.
Who May Be Eligible (Plain English)
These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.
Original Eligibility Criteria
View original clinical language
Treatments Being Tested
IG-IMPT
Daily, Monday-Friday for about 6 weeks
IG IMRT
Daily, Monday-Friday for about 6 weeks
Locations (10)
Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.
How to Talk to Your Doctor About This Trial
Bring the printable summary of this trial — including the NCT ID (NCT01659203), the sponsor (Massachusetts General Hospital), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.
Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.
Authoritative Sources
The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.
Frequently Asked Questions
What is the NCT01659203 clinical trial studying?
This research study is a Phase I clinical trial. Phase I clinical trials test the safety of an investigational intervention. Phase I studies also try to define the appropriate dose of the investigational therapy to use for further studies. "Investigational" means that the intervention is still being studied and that research doctors are trying to find out more about it. Retroperitoneal sarcomas are soft tissue tumors located at the far back of the abdomen. Typically, patients with retroperitoneal sarcomas either have surgery for the removal of their tumors alone, or have their tumors removed,… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.
Who can participate in NCT01659203?
Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.
How do I contact the trial site for NCT01659203?
Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.
Is participating in a clinical trial safe?
Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.
Where can I verify the data on this page?
Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.
How This Page Is Built
Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.
Source: ClinicalTrials.gov API v2 record for NCT01659203. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT01659203. Data: ClinicalTrials.gov."
Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.
Last updated 2026-05-08 · Data from ClinicalTrials.gov.