Aim Intensity modulated proton therapy (IMPT) in breath-hold (BH) could reduce the mean heart dose (MHD) compared to IMPT in free breathing (FB) in a subgroup of breast cancer (BC) patients. The aim of this study is to identify subgroups of BC patients who benefit the most from IMPT in BH. Methods We conducted an in-silico study involving fifteen left-sided BC patients treated with regional nodal irradiation, including the internal mammary lymph nodes. IMPT plans were created on FB and BH-CT planning scans. Based on the MHD and mean lung dose (MLD), the difference in risk (ΔNTCP) of acute coronary events (ACE) and secondary lung cancer (SLC) between IMPT BH and FB-plans was calculated for subgroups based on the Dutch national indication protocol for IMPT. A Wilcoxon signed-rank test (p = 0.05) identified subgroups for whom the absolute ACE-risk with IMPT BH was ≥1% lower than with IMPT FB. Results All ACE ΔNTCP values favoured IMPT in BH over FB (p ≤ 0.002). Age- and risk-stratified analysis showed that in patients ≤ 60 years and with cardiac risk factors, the difference in NTCP between proton-BH and FB was ≥1%. In 14 of 15 plans, BH increased MLD (p < 0.05), yielding higher SLC risks in smokers ≤ 50 years. Median (25th–75th interquartile range) MLD was 6.7 (5.4–7.5) Gy for BH vs 5.4 (4.1–6.6) Gy for FB. Conclusions Female patients ≤60 years, with left-sided BC, IMN indication and cardiac risk factors benefit most from IMPT in BH. For smokers ≤ 50 years, an individualized FB versus BH comparison is required due to the potential increase in secondary lung cancer risk associated with higher MLD.
Background Deep inspiration breath-hold (DIBH) reduces cardiac and lung dose in breast radiotherapy but relies on patients achieving reproducible breath-holds. We evaluated whether a take-home wireless respiration-belt coaching system (RBC) used before simulation improves CT efficiency, treatment times and dosimetry versus standard-of-care (SOC). Methods This mixed methods pilot study compared a prospective RBC cohort (n = 20) with a matched SOC cohort (n = 21). RBC participants practised DIBH at home for 1–2 weeks using a Vernier respiration belt with tablet-based real time visual feedback; SOC received routine verbal coaching at CT simulation. Primary outcome was CT simulation set-up duration. Secondary outcomes were treatment times (total, set-up, field) for fractions 1–5 (grouped by imaging modality) and patient feedback. Dosimetry (left lung mean dose, heart mean dose, heart V10Gy) was assessed in a homogeneous subgroup of left-breast DIBH plans (no nodal irradiation). Results CT set-up duration was shorter with RBC (30.9 ± 11.5 vs 58.3 ± 13.6 min; mean difference − 27.4 min; p < 0.001). Treatment delivery times did not differ significantly between coaching groups for kV-guided fractions. Dosimetry analyses included 34 plans (RBC n = 15; SOC n = 19) and favoured RBC: heart V10Gy 0.4 ± 0.4 vs 1.2 ± 1.72% (p = 0.041), heart mean dose 0.9 ± 0.4 vs 1.1 ± 0.6 Gy (p = 0.077) and left lung mean dose 5.2 ± 1.3 vs 5.7 ± 0.9 Gy (p = 0.096). Patient feedback was positive; all 19 respondents to this item would recommend the belt. Conclusions Take-home respiration-belt coaching halved CT simulation set-up duration and was associated with lower cardiac dose metrics, treatment delivery times did not differ significantly between groups.
Purpose Bowel and bladder preparation for radiation treatment (RT) can be problematic for men with prostate cancer and can delay treatment delivery. This study aimed to describe the rate of successful treatment delivery on first attempt (no corrective interventions required) for the first 5 radiation fractions, as well as describe clinic efficiency and patient experience. Methods This study followed a cohort of patients previously recruited at their CT simulation and followed up with during their first week of RT. Data collected included successful RT delivery on first attempt for the first 5 fractions, reasons for unsuccessful treatment attempts and appointment timestamps. Patients completed a survey regarding their preparation experiences at their fifth treatment. Descriptive analysis was completed. Poisson modelling estimated factors predicting the total number of first-attempt successes. A generalized estimating equation model evaluated fraction number on success. Content analysis was completed on open-text patient feedback. Results This study included 240 patients, with 42% (101) achieving first attempt success for 5 out of 5 fractions. Bowel preparation issues were the most common reason for unsuccessful treatment delivery. Poisson modelling found no significant predictors of success. The highest odds of success were at fraction 4 (OR = 2.35, p < 0.001) and 5 (OR = 2.34, p < 0.001). Patients found radiation therapists to be a major source of support during RT, although timing and scheduling were problematic to treatment preparation. Conclusion Bowel and bladder preparation is a complex issue for men with prostate cancer. First-attempt treatment success improved over fractions. Redefining preparation as a skill to be developed may help to improve patient experience.
