US-UK collaboration in Proton therapy: The Proton Overseas Program

Abstract

In 2008 the National Health Service (NHS) in the United Kingdom (UK) started the Proton Overseas Program (POP). This enabled and still enables eligible UK patients to access high energy Proton Beam Therapy (PBT) overseas, a large majority of which were sent to the United States (US), preceding the opening of the first NHS England PBT center in late 2018. More than 10 years since its inception, we report the long-term outcomes on patient groups who have accessed this program and were treated in the US proton centers. Between 2008 and 2018, 1102 patients with indications eligible for PBT (adhering to approved criteria) were treated in the US. The majority of these were managed at the University of Florida Proton Therapy Institute, Jacksonville, although significant numbers have also been treated at Procure Oklahoma. All cases were of sufficient performance status to travel and were appropriately staged. Patient, tumor, treatment and follow-up data were collated in a centralized database. In light of the establishment of the NHS England PBT centers, the Proton Clinical Outcomes Unit (PCOU) has been simultaneously initiated and developed to systematically monitor this patient cohort as well as standardize and improve prospective outcome data collection for UK PBT patients going forward. Systematic follow-up data was available for 878 patients (79.7% of those treated in the US). Analysis has been conducted on the subgroups <25 vs ≥25 years old (y). After a median follow-up of 34 months (range 6-105), the Local Control (LC) rate for the entire cohort was 81%; by age (<25 y vs ≥ 25 y) LC rates were 82.1% for the younger group vs 74.8% for the older group. For tumors of the central nervous system (CNS), the LC rate was 80% (81.6% < 25 y vs 74.4% ≥25 y). For tumors outside the CNS (referred to as ‘body’ tumors), the LC rate was 82.6% (82.8% in <25 y vs 78.6% in ≥25 y). The data show that LC was highest for craniopharyngioma (90.3%) in the CNS subgroup and for Adult type Sarcomas (85.7%) in the body subgroup. Table 1 illustrates the 1- and 5-years survival estimates (95% Confidence Intervals) for the main subgroups. The outcome of patients treated through the POP compares favorably with that reported in the literature (1). The POP has been successful in facilitating equitable access to PBT abroad for patients with complex needs from across the UK without disadvantaging patient outcomes. It is arguably the largest national PBT access program, drawing equitably from a whole population, with treatment, transport abroad and accommodation funded by the NHS, and has enabled collaborative ties and a strengthening of network between the UK and the US.Tabled 1Abstract 2914; TableTimepointAll< 25, Body≥ 25, Body*< 25, CNS≥ 25, CNS1 year99.2% (98.6-99.8%)98.1% (96.6-99.6%)100% (-)100% (-)99.2% (97.5-100%)5 year88.4% (85.5-91.5%)87.3% (82.7-92.2%)80.0% (51.6-100%)91.4% (87.6-95.3%)81.8% (71.9-93.0%) Open table in a new tab