Proton Whole Lung Irradiation: Initial Report of Outcomes
Menée sur la période 2018-2022 auprès de 12 patients atteints d'un cancer pédiatrique (âge médian : 15 ans ; durée médiane de suivi : 16.5 mois), cette étude analyse la faisabilité et la toxicité d'une protonthérapie du poumon entier
Résumé en anglais
Background: Whole lung irradiation is typically utilized in pediatric patients to decrease the risk of future lung metastases, but radiation dose to normal tissue is associated with long-term risks. Proton whole lung irradiation (PWLI) provides an opportunity to decrease radiation dose to normal tissue and potentially decrease late toxicity.
Methods: This retrospective study included patients treated with spot-scanning PWLI at a single institution. Toxicity and oncologic outcomes were reviewed. IMRT plans were created prospectively or retrospectively for dosimetric comparisons. Simple paired t-tests were performed to assess differences between IMRT and PWLI dosimetric parameters.
Results: Twelve patients were treated with PWLI and included in this study. Median age was 15 years (range 3-34). Most (75%) had Ewing sarcoma. Most (92%) received 15 Gy in 10 fractions PWLI, and three (25%) received a focal pulmonary boost. Median follow-up was 16.5 months (range 0-40.4 months). At last follow-up, one patient had died of disease, while eleven were still alive (7 without disease, 4 with ongoing disease). During and immediately after treatment, five patients developed fatigue, two patients developed cough, and one patient developed nausea. Each treatment-related adverse event was CTCAE v5.0 grade 1 and resolved within 3 weeks of treatment completion. No patients have experienced clinical or radiographic pneumonitis or evidence of clinically apparent cardiac toxicity. Compared to IMRT plans, PWLI decreased mean dose to the heart, coronary artery, cardiac valve, left ventricle, aorta, breast, esophagus, kidney, liver, pancreas, thyroid, stomach, and spleen (all p<0.001), without sacrificing target coverage.
Conclusions: PWLI is feasible to deliver, decreases dose to normal tissue compared to IMRT, and appears to be well-tolerated. PWLI provides potential for decreased late toxicity and merits further investigation.
