AI Article Synopsis

  • The study investigates how proton linear energy transfer (LET) affects rib fractures in breast cancer patients treated with pencil-beam scanning proton therapy (PBS).
  • Researchers analyzed data from a registry of patients and matched rib fracture cases with control patients to assess differences in dose-LET using a tool called dose-LET volume histogram (DLVH).
  • The results suggest that higher volumes of chest wall receiving moderate dose and high LET contribute to a higher risk of rib fractures, with the relationship quantified through a statistical model.

Article Abstract

Purpose: To study the effect of proton linear energy transfer (LET) on rib fracture in breast cancer patients treated with pencil-beam scanning proton therapy (PBS) using a novel tool of dose-LET volume histogram (DLVH).

Methods: From a prospective registry of patients treated with post-mastectomy proton therapy to the chest wall and regional lymph nodes for breast cancer between 2015 and 2020, we retrospectively identified rib fracture cases detected after completing treatment. Contemporaneously treated control patients that did not develop rib fracture were matched to patients 2:1 considering prescription dose, boost location, reconstruction status, laterality, chest wall thickness, and treatment year.The DLVH index, (, ), defined as volume() of the structure with at least dose and LET(, was calculated. DLVH plots between the fracture and control group were compared. Conditional logistic regression (CLR) model was used to establish the relation of (, ) and the observed fracture at each combination of and . The -value derived from CLR model shows the statistical difference between fracture patients and the matched control group. Using the 2D -value map derived from CLR model, the DLVH features associated with the patient outcomes were extracted.

Results: Seven rib fracture patients were identified, and fourteen matched patients were selected for the control group. The median time from the completion of proton therapy to rib fracture diagnosis was 12 months (range 5 to 14 months). Two patients had grade 2 symptomatic rib fracture while the remaining 5 were grade 1 incidentally detected on imaging. The derived -value map demonstrated larger (0-36Gy[RBE], 4.0-5.0 keV/μm) in patients experiencing fracture (<0.1). For example, the value for V(30 Gy[RBE], 4.0 keV/um) was 0.069.

Conclusions: In breast cancer patients receiving PBS, a larger volume of chest wall receiving moderate dose and high LET may result in increased risk of rib fracture.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10635309PMC

Publication Analysis

Top Keywords

rib fracture
28
proton therapy
16
control group
12
clr model
12
fracture
11
patients
10
linear energy
8
energy transfer
8
transfer rib
8
fracture breast
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!