Proton therapy in paediatric oncology: an Irish perspective

Recent Updates on Radiation Therapy for Pediatric Optic Pathway Glioma

Optic pathway glioma (OPG) is a rare tumor located in optic nerve, optic tract, or optic chiasm. Treatment options for OPG include surgery, radiation therapy (RT), and chemotherapy. Although RT may provide favorable long-term outcomes in manner of either adjuvant or salvage aim, chemotherapy-first approach is increasingly performed due to possible late effects of RT. Proton beam RT may allow normal tissue sparing of radiation exposure compared to conventional X-ray treatment. Therefore, proton beam RT is expected to reduce complications from RT. This review discusses the recent updates on oncologic outcomes of OPG, late toxicities following RT, and compares the outcomes between X-ray treatment and proton beam RT.

Scoping the literature on patient travel abroad for cancer screening, diagnosis and treatment

The incidence of cancer is on the rise globally. Under particular circumstances, patients are willing to travel abroad for healthcare treatments. We know relatively little however about patients travelling overseas for cancer-related screening, diagnosis and treatment. Where do patients go, for what treatments, what are their motivations, decision-making processes and treatment experiences? What do we know about patient safety and risk, and outcomes? More broadly, what are the ethical and legal implications? This review presents the first published assessment of what we term 'transnational oncology treatment', defined as patients travelling overseas or across borders for cancer screening, diagnosis and treatment. The review undertakes detailed search and retrieval of the literature, using an accepted scoping review method. We present a narrative review of existing knowledge and themes, identifying coverage and gaps. There is a five-fold agenda for future investigation: trajectories and itineraries; in depth focus on treatment decisions, experiences and outcomes; locating patient travel within wider health system analysis; exploration of professional perspectives and coordination; and situating travel within the context of health trade. Such an agenda is multidisciplinary and wide-ranging, encompassing epidemiology, health economics, health policy ethics, health politics, health management, and health policy.

Systematic review of the incidence and risk factors for cerebral vasculopathy and stroke after cranial proton and photon radiation for childhood brain tumors

Background

The aim of our study is to determine the incidence, timing, and risk factors for cerebral vasculopathy after cranial proton and photon radiation for pediatric brain tumors.

Methods

We performed a single-institution retrospective review of a cohort of children treated with proton radiation for brain tumors. MRA and/or MRI were reviewed for evidence of cerebral vascular stenosis and infarcts. Twenty-one similar studies (17 photon, 4 proton) were identified by systematic literature review.

Results

For 81 patients with median follow-up of 3 years, the rates of overall and severe vasculopathy were 9.9% and 6.2% respectively, occurring a median of 2 years post radiation. Dose to optic chiasm greater than 45 Gy and suprasellar location were significant risk factors. Results were consistent with 4 prior proton studies (752 patients) that reported incidence of 5% to 6.7%, 1.5 to 3 years post radiation. With significantly longer follow-up (3.7-19 years), 9 studies (1108 patients) with traditional photon radiation reported a higher rate (6.3%-20%) and longer time to vasculopathy (2-28 years). Significant risk factors were neurofibromatosis type 1 (NF-1; rate 7.6%-60%) and suprasellar tumors (9%-20%). In 10 studies with photon radiation (1708 patients), the stroke rate was 2% to 18.8% (2.3-24 years post radiation).

Conclusions

Childhood brain tumor survivors need screening for vasculopathy after cranial radiation, especially with higher dose to optic chiasm, NF-1, and suprasellar tumors. Prospective studies are needed to identify risk groups, and ideal modality and timing, for screening of this toxicity.