Exploring Helium Ions’ Potential for Post-Mastectomy Left-Sided Breast Cancer Radiotherapy

Abstract

Proton therapy presents a promising modality for treating left-sided breast cancer due to its unique dose distribution. Helium ions provide increased conformality thanks to a reduced lateral scattering. Consequently, the potential clinical benefit of both techniques was explored. An explorative treatment planning study involving ten patients, previously treated with VMAT (Volumetric Modulated Arc Therapy) for 50 Gy in 25 fractions for locally advanced, node-positive breast cancer, was carried out using proton pencil beam therapy with a fixed relative biological effectiveness (RBE) of 1.1 and helium therapy with a variable RBE described by the mMKM (modified microdosimetric kinetic model). Results indicated that target coverage was improved with particle therapy for both the clinical target volume and especially the internal mammary lymph nodes compared to VMAT. Median dose value analysis revealed that proton and helium plans provided lower dose on the left anterior descending artery (LAD), heart, lungs and right breast than VMAT. Notably, helium therapy exhibited improved ipsilateral lung sparing over protons. Employing NTCP models as available in the literature, helium therapy showed a lower probability of grade ≤ 2 radiation pneumonitis (22% for photons, 5% for protons and 2% for helium ions), while both proton and helium ions reduce the probability of major coronary events with respect to VMAT.

Helium Ion Therapy for Advanced Juvenile Nasopharyngeal Angiofibroma

“…Yet, helium ions are currently being considered for reintroduction into clinical practice, recognizing their potential benefits over protons and carbon ions [ 11 ]. Indeed, they hold promise in potentially enhancing treatment effectiveness and sparing healthy tissue across diverse tumor sites [ 10 , 12 , 13 , 14 ], potentially further reducing radiation-induced long-term complications. This holds particular significance in the treatment of advanced JNA which are typically localized close to critical structures essential for patients’ quality of life, not least considering the generally young age of the affected patients and their considerable life expectancy.…”

Evaluation of Helium Ion Radiotherapy in Combination with Gemcitabine in Pancreatic Cancer In Vitro

“…To date, helium ions are rarely used in clinical settings. Initial studies at the Heidelberg Ion Beam Therapy Center (HIT) showed that helium ion therapy could offer better organs-at-risk sparing compared to protons or conventional photon radiotherapy [17] for head and left-sided breast cancers.…”

Irradiation and Alterations in Hippocampal DNA Methylation

“…Carbon therapy is also being considered for rare and hard-to-treat tumors [ 4 ]. Compared to protons and carbon ions, helium ions offer intermediate physical and biological properties [ 6 ], higher relative biological effectiveness and dose-weighted linear energy transfer (LET d ) [ 7 ], and improved lung sparing compared to proton therapy in patients with left-sided breast cancer therapy [ 8 ]. However, while these newer radiation therapies might be better with regard to tumor control, that does not mean that they are necessarily associated with less detrimental effects on the brain or outside the brain.…”