Neoadjuvant Short-course Hypofractionated PBT for Non-metastatic RPS (PROTONS-RPS)

Johns Hopkins Medicine

Status and phase: Withdrawn; Phase 2

Conditions: Retroperitoneal Sarcoma

Treatments: Radiation: Hypofractionated Proton Beam Therapy

Study type: Interventional

Funder types: Other

Identifiers

NCT05302570

IRB00315399

Details and patient eligibility

About

The investigators' study titled "PROTONS-RPS: a Phase II non-Randomized Open-label single-arm Trial Of Neoadjuvant Short-course hypofractionated proton beam therapy for non-metastatic RetroPeritoneal Sarcoma" is a phase II trial evaluating the safety and efficacy of hypofractionated proton beam therapy (H-PBT) in the neoadjuvant (NA) setting for patients with non-metastatic retroperitoneal sarcoma (RPS) planned for surgical resection. This trial will include adult patients with resectable RPS.

Full description

The investigators' primary outcome is overall complication rate after treatment with NA H-PBT and surgical resection based on National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.2 Secondary objectives include evaluating the acute toxicity of H-PBT prior to surgical resection, rate of progression between diagnosis and definitive resection, early post-operative complication rate after resection of RPS in patients who received NA H-PBT, and local recurrence-free survival at 1 and 2 years. A priori subset analyses will be conducted for patients with well-differentiated and dedifferentiated liposarcoma.

The investigators plan to accrue a minimum of 44 patients to evaluate the investigators' primary outcome. Treatment will be 5 doses of H-PBT including a simultaneous integrated boost to at-risk margins followed by surgical resection after 4-6 weeks. Patients will be followed in the post-operative setting according to standard of care surveillance for RPS.

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult patients (≥18 years of age)
• Patients with primary non-recurrent retroperitoneal sarcoma
• Calculated creatinine clearance ≥50 mL/min and functional contralateral kidney based on nuclear medicine renal scan
• Normal bone marrow function (WBC ≥ 4 x109 /L)
• Eastern Cooperative Oncology Group status ≤ 2
• Cardiac function ≤ New York Heart Association class II
• Proton beam therapy approved by insurance (including Medicare/Medicaid)

Exclusion criteria

• Evidence of metastatic disease on staging CT of chest/abdomen/pelvis
• History of abdominal or pelvic radiation therapy
• Inability to tolerate supine position for duration of PBT simulation or treatment
• Tumor originating from gastrointestinal or gynecologic organs
• Specific sarcoma histologies including osteosarcoma, desmoid tumors, chondrosarcoma arising from vertebrae or pelvic bones, embryonal rhabdomyosarcoma
• Tumor extending into femoral or obturator canal
• History of systemic lupus erythematosus or ulcerative colitis
• Genetic syndrome with radiation-associated tumorigenicity (i.e.: Li-Fraumeni)
• Presence of clinically significant ascites
• Co-existing malignancy or treated malignancy in the last 2 years expected to limit life expectancy; does not include completely resected cutaneous basal cell carcinoma, squamous cell carcinoma, in situ breast or cervical malignancies, or other pathologies at the discretion of the investigators.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

---

0 participants in 1 patient group

Hypofractionated Proton Beam Therapy

Experimental group

Description:

5 fractions of 5 Gy of PBT to clinical tumor volume +/- an additional simultaneous 1 Gy per fraction to any pre-determined at-risk margin (for a total of 6 Gy per fraction x 5 fractions for at-risk margins as a simultaneous integrated boost (SIB)).

Treatment:

Radiation: Hypofractionated Proton Beam Therapy