Proton Pencil Beam Scanning GRID for Treatment of Bulky Tumors

A Phase 1 Study of Proton Pencil Beam Scanning GRID for Treatment of Bulky Tumors (ProGRID)

This is a single arm, phase I study, evaluating the feasibility, toxicity, and degree of tumor response after novel proton pencil beam scanning (PBS GRID) treatment in patients with bulky tumors that are difficult to manage.

The proton group at Sibley Memorial Hospital has developed a new method for multi-beam proton delivery making it possible to arrange and optimize GRID dosimetry and normal tissue sparing compared to other similar techniques.

In this phase I pilot study, patients with bulky tumors will receive this novel method of GRID-therapy also called spatially-fractionated radiotherapy which involves delivering high dose radiation to small amounts of tumor in a manner that creates alternating regions of high and low dose radiation within the tumor and is often aligned in a grid pattern.

In so doing, this study will ascertain the feasibility, safety and tumor response i.e. shrinkage and resectability of this treatment. Ultimately, the goal is to improve local outcomes of patients with bulky tumors and to offer new treatment options for patients with difficult-to-manage bulky tumors.

Inclusion Criteria:

• Age > 18
• Histologically or cytologically confirmed invasive cancer
• Bulky tumor > 7 cm, determined clinically and/or radiographically, at the time of evaluation prior to enrollment
• Treated indicated for palliative intent
• Eastern Cooperative Oncology Group (ECOG) performance status < 2
• Anticipated treatment deemed safe on pre-review by PI
• For patients with prior Radiation Therapy (RT): Dicoms must be available for dose fusion if overlap anticipated with GRID
• Willing and able to provide informed consent
• Discussion with medical oncology or surgical specialty

Exclusion Criteria:

• Age < 18
• ECOG performance status 3-4
• Planned for definitive, curative management
• For patients with prior RT that overlaps with Pro-GRID: Dicoms not available Pregnant women
• Tumor encasing critical structure, as defined by the treating MD.