Cardiac dose reduction with breathing adapted radiotherapy using self respiration monitoring system for left-sided breast cancer

Abstract

PurposeTo quantify the cardiac dose reduction during breathing adapted radiotherapy using Real-time Position Management (RPM) system in the treatment of left-sided breast cancer.Materials and MethodsTwenty-two patients with left-sided breast cancer underwent CT scans during breathing maneuvers including free breathing (FB), deep inspiration breath-hold (DIBH), and end inspiration breath-hold (EIBH). The RPM system was used to monitor respiratory motion, and the in-house self respiration monitoring (SRM) system was used for visual feedback. For each scan, treatment plans were generated and dosimetric parameters from DIBH and EIBH plans were compared to those of FB plans.ResultsAll patients completed CT scans with different breathing maneuvers. When compared with FB plans, DIBH plans demonstrated significant reductions in irradiated heart volume and the heart V25, with the relative reduction of 71% and 70%, respectively (p < 0.001). EIBH plans also resulted in significantly smaller irradiated heart volume and lower heart V25 than FB plans, with the relative reduction of 39% and 37%, respectively (p = 0.002). Despite of significant expansion of lung volume using inspiration breath-hold, there were no significant differences in left lung V25 among the three plans.ConclusionIn comparison with FB, both DIBH and EIBH plans demonstrated a significant reduction of radiation dose to the heart. In the training course, SRM system was useful and effective in terms of positional reproducibility and patient compliance.

Feasibility evaluation of prone breast irradiation with the Sagittilt© system including residual-intrafractional error assessment

“…However, cardiac protection is still a debatable question due to gravityinduced anterior heart displacement toward the irradiated region [13,30,31]. Dosimetric data showed that whole-breast irradiation is superior in prone position over supine position for heartsparing, especially in patients with large breast volumes [18,19,32]. On the other hand, comparative dosimetric data are available, supine deep inspiration breath-hold treatment is better at heartsparing than treatment using a free-breathing prone technique [13,30].…”

Palliative radiotherapy for thoracic spine metastases: Dosimetric advantage of three-dimensional conformal plans

“…Calculated doses to the PTV and organs at risk according to three radiotherapy plans. from RT-associated heart disease was reported to offset the improvement of cancer-specific survival due to adjuvant RT (11,12). A clear quantitative dose-volume dependence for the majority of cardiac toxicities remains to be determined (10).…”

“…A recent study, however, suggested that the rates of major coronary events increase linearly with the mean heart dose by 7.4% per Gy, with no apparent threshold (13). In addition, it has been established that various clinical parameters may aggravate the risk of radiation-induced heart injury; these include age, diabetes mellitus, smoking, hypertension and the use of cardiotoxic anthracycline-containing chemotherapy (10,12). Re-irradiation for painful spine metastases may be required in patients who achieve no pain relief following initial RT or those who outlive the duration of the first RT response.…”

Hybrid intensity-modulated radiation therapy (IMRT) simultaneous integrated boost (SIB) technique versus three-dimensional (3D) conformal radiotherapy with SIB for breast radiotherapy: a planning comparison

“…Other than optimisation of beams and shielding, the utilisation of breath-hold techniques is another technique to reduce the dose to the heart in the tangential beam path. [38][39][40] The use of physical wedges used on the lateral tangent in conventional planning, is associated with a three-fold increase in scattered dose compared with virtual wedges or hybrid IMRT. 41,42 This is observed in the contralateral breast parameters with the mean, V5 and V1 doses showing a decrease in the hybrid arms.…”