New frontiers in proton therapy: applications in cancers

Abstract

Proton therapy offers dominant advantages over photon therapy due to the unique depth-dose characteristics of proton, which can cause a dramatic reduction in normal tissue doses both distal and proximal to the tumor target volume. In turn, this feature may allow dose escalation to the tumor target volume while sparing the tumor-neighboring susceptible organs at risk, which has the potential to reduce treatment toxicity and improve local control rate, quality of life and survival. Some dosimetric studies in various cancers have demonstrated the advantages over photon therapy in dose distributions. Further, it has been observed that proton therapy confers to substantial clinical advantage over photon therapy in head and neck, breast, hepatocellular, and non-small cell lung cancers. As such, proton therapy is regarded as the standard modality of radiotherapy in many pediatric cancers from the technical point of view. However, due to the limited clinical evidence, there have been concerns about the high cost of proton therapy from an economic point of view. Considering the treatment expenses for late radiation-induced toxicities, cost-effective analysis in many studies have shown that proton therapy is the most cost-effective option for brain, head and neck and selected breast cancers. Additional studies are warranted to better unveil the cost-effective values of proton therapy and to develop newer ways for better protection of normal tissues. This review aims at reviewing the recent studies on proton therapy to explore its benefits and cost-effectiveness in cancers. We strongly believe that proton therapy will be a common radiotherapy modality for most types of solid cancers in the future.

Particle therapy toxicity outcomes: A systematic review

“…3 These dosimetry considerations, supported by specific clinical predictions from comparative dosimetric modelling and in silico studies, have been the main rationale for accepting PBT as the optimal radiotherapy for paediatric patients in many jurisdictions, 4 and the reason PT is being actively studied for various adult tumour types. 5 This study extends the findings from a recent systematic review by the current authors which concentrated on tumour outcomes for PT, 6 to now examine toxicity as a separate focused outcome. Together, these reviews present a comprehensive review of the current evidence relating to the outcomes of PBT and CIT in clinical practice.…”

“…This should translate to reduced acute and long‐term toxicity 2 and improved post‐therapy quality of life 3 . These dosimetry considerations, supported by specific clinical predictions from comparative dosimetric modelling and in silico studies, have been the main rationale for accepting PBT as the optimal radiotherapy for paediatric patients in many jurisdictions, 4 and the reason PT is being actively studied for various adult tumour types 5 …”

Addressing the Biochemical Foundations of a Glucose-Based “Trojan Horse”-Strategy to Boron Neutron Capture Therapy: From Chemical Synthesis to In Vitro Assessment

“… 3 A number of novel treatment strategies have recently gained ground. These include antibody–drug conjugates, 4 proton therapy, 5 , 6 and, especially, boron neutron capture therapy (BNCT). 7 BNCT represents one of the most promising noninvasive binary treatment modalities for head and neck cancers since it can eradicate cancer cells while simultaneously sparing healthy cells (the basis of our approach is displayed in Figure 1 ).…”

Dictionary-based protoacoustic dose map imaging for proton range verification

“…Besides, protons have a limited range and therefore no dose is deposited beyond the Bragg peak [ 1 ]. The depth reached by proton beams is determined by their energy [ 2 ], which varies from 50 to 250 MeV in therapeutic situations [ 3 ]. These energies give proton ranges in water between 22 and 380 mm according to the NIST PSTAR database [ 4 ].…”

“…In this technique, thousands of narrow and quasi-monoenergetic proton ‘pencil’ beams are magnetically scanned to cover voxel by voxel each of the energy layers in which the tumor is divided [ 6 , 7 ]. All these characteristics make proton therapy especially suitable for the treatment of pediatric, head and neck, liver, pancreatic and prostate cancers [ 2 ].…”