Risk of Ischemic Heart Disease in Women after Radiotherapy for Breast Cancer

Deep inspiration breath hold (DIBH) in left‐sided breast cancer radiotherapy is a technique to reduce cardiac and pulmonary doses while maintaining target coverage. This study aims at evaluating an in‐house developed DIBH system. Free‐breathing (FB) and DIBH plans were generated for 22 left‐sided localized breast cancer patients who had radiation therapy (RT) after breast‐conserving surgery. All patients were treated utilizing an in‐house laser distance measuring system. 50 Gy was prescribed, and parameters of interest were target coverage, left anterior descending coronary artery, (LAD) and heart doses. Portal images were acquired and the reproducibility and stability of DIBH treatment were compared to FB. The comparing result shows there is a significant reduction in all LAD and heart dose statistics for DIBH compared to FB plans without compromising the target coverage. The maximum LAD dose was reduced from 43.7 Gy to 29.0 Gy and the volume of the heart receiving >25 Gy was reduced from 3.3% to 1.0% using the in‐house system, both statistically significant. The in‐house system gave a reproducible and stable DIBH treatment where the systematic error ∑, and random error σ, were less than 2.2 mm in all directions, but were not significantly better than at FB. The system was well tolerated and all patients completed their treatment sessions with DIBH.

Section: Discussionmentioning

confidence: 99%

Monitoring deep inspiration breath hold for left‐sided localized breast cancer radiotherapy with an in‐house developed laser distance meter system

Jensen

Абрамова

Frengen

et al. 2017

“…However, long‐term follow‐up from multiple trials has found that patients receiving whole‐breast radiotherapy also have an increased risk of cardiac disease 2 , 3 . Given the potential for radiation‐induced cardiac toxicity, it is recommended that the irradiated heart volume be minimized to the greatest possible degree without compromising the tumor coverage (4) …”

Section: Introductionmentioning

confidence: 99%

Clinical experience using a video‐guided spirometry system for deep inhalation breath‐hold radiotherapy of left‐sided breast cancer

Yang

McKenzie

Burnison

et al. 2015

The purpose was to report clinical experience of a video‐guided spirometry system in applying deep inhalation breath‐hold (DIBH) radiotherapy for left‐sided breast cancer, and to study the systematic and random uncertainties, intra‐ and interfraction motion and impact on cardiac dose associated with DIBH. The data from 28 left‐sided breast cancer patients treated with spirometer‐guided DIBH radiation were studied. Dosimetric comparisons between free‐breathing (FB) and DIBH plans were performed. The distance between the heart and chest wall measured on the digitally reconstructed radiographs (DRR) and MV portal images, dDRR(DIBH) and dport(DIBH), respectively, was compared as a measure of DIBH setup uncertainty. The difference (Δd) between dDRR(DIBH) and dport(DIBH) was defined as the systematic uncertainty. The standard deviation of Δd for each patient was defined as the random uncertainty. MV cine images during radiation were acquired. Affine registrations of the cine images acquired during one fraction and multiple fractions were performed to study the intra‐ and interfraction motion of the chest wall. The median chest wall motion was used as the metric for intra‐ and interfraction analysis. Breast motions in superior–inferior (SI) direction and “AP” (defined on the DRR or MV portal image as the direction perpendicular to the SI direction) are reported. Systematic and random uncertainties of 3.8 mm and 2 mm, respectively, were found for this spirometer‐guided DIBH treatment. MV cine analysis showed that intrafraction chest wall motions during DIBH were 0.3 mm in “AP” and 0.6 mm in SI. The interfraction chest wall motions were 3.6 mm in “AP” and 3.4 mm in SI. Utilization of DIBH with this spirometry system led to a statistically significant reduction of cardiac dose relative to FB treatment. The DIBH using video‐guided spirometry provided reproducible cardiac sparing with minimal intra‐ and interfraction chest wall motion, and thus is a valuable adjunct to modern breast treatment techniques.PACS number: 87.55.kh, 87.55.ne, 87.55.tg

“…Research has shown a dose–effect relationship between occurrence of radiotherapy‐induced heart diseases and irradiation dose and volume in the heart 27. When irradiation dose in the heart is smaller than 3000 cGy, occurrence rate of radiotherapy‐induced heart diseases reduces significantly, whereas that of coronary ischemia caused by IMRT is low, and this result is related to the small V 30 28.…”

Section: Discussionmentioning

confidence: 99%

Dosimetric comparison of three intensity‐modulated radiation therapies for left breast cancer after breast‐conserving surgery

Zhang

Xie

et al. 2018

PurposeThis study aimed to evaluate dosimetric differences of intensity‐modulated radiation therapy (IMRT) in target and normal tissues after breast‐conserving surgery.MethodsIMRT five‐field plan I, IMRT six‐field plan II, and field‐in‐field–direct machine parameter optimization–IMRT plan III were designed for each of the 50 patients. One‐way analysis of variance was performed to compare differences, and P < 0.05 was considered statistically significant.ResultsHomogeneity index of plan III is lower than those of plans I and II. No difference was identified in conformity index of targets. Plan I exhibited difference in mean dose (D mean) for the heart (P < 0.05). Plan I featured smaller irradiation dose volumes in V 5, V 20 (P < 0.05) of the left lung than II. Plan I exhibited significantly higher V 5 in the right lung than plans II and III (P < 0.05). Under plan I, irradiation dose at V 5 in the right breast is higher than that in plans II and III. Patients in plan III presented less total monitor unit and total treatment time than those in plans I and II (P < 0.05).ConclusionIMRT six‐field plans II, and field‐in‐field–direct machine parameter optimization–IMRT plans III can reduce doses and volumes to the lungs and heart better while maintaining satisfying conformity index and homogeneity index of target. Nevertheless, plan II neglects target movements caused by respiration. In the same manner, plan III can substantially reduce MU and shorten patient treatment time. Therefore, plan III, which considers target movement caused by respiration, is a more practical radiation mode.