Deep inspiration breath-hold intensity modulated radiation therapy in a large clinical series of 239 left-sided breast cancer patients: a dosimetric analysis of organs at risk doses and clinical feasibility from a single center experience

Abstract

Objective: To evaluate dose to organs at risk, target coverage and treatment compliance in left-sided breast cancer patients (LSBCP) treated with deep inspiration breath-hold (DIBH) and intensity modulated radiation therapy (IMRT) technique in a contest of daily clinical practice. Methods: A total of 280 consecutive LSBCP referred for adjuvant radiotherapy were systematically screened for suitability of DIBH technique. 239 were able to comply with the requirement for DIBH. Whole breast or chest wall were irradiated in DIBH, monitored by Varian RPM™ Respiratory Gating System, and two tangential inverse-planned beams with dynamic dose delivery. Dose prescription was 42.4 Gy/16 fractions in 205 patients and 50 Gy/25 fractions in 34. 23 patients received local and nodal treatment. Boost to tumor bed, of 10 Gy/5 fractions was used in 135 patients. Relevant dose metrics for heart, left anterior descending (LAD) coronary artery, lungs, contralateral breast and planning target volume were retrospectively analyzed. Results: The average mean heart dose (MHD) for all patients was 0.94 Gy and mean maximum LAD dose was 13.82 Gy. MHD and LAD maximum dose were significantly higher in patients treated with conventional fractionation whether expressed in absolute dose (1.44 vs 0.85 Gy, p < 0.0005 and 20.78 vs 12.45 Gy, p < 0.0005 respectively) or in equivalent doses of 2 Gy fractionation (0.88 vs 0.52 Gy, p =< 0.0005 and 17.68 vs 10.63 Gy, p = 0.0002 respectively). In 57 patients (23.8%) the maximum LAD dose was >20 Gy. Mean V20 ipsilateral lung dose was 8.5%. Mean doses of contralateral breast and lung were 0.13 Gy and 0.09 Gy respectively. Mean planning target volume V95% coverage was 96.1%. Compliance rate of DIBH technique was 84.5% (239/280). Conclusion: DIBH and IMRT in daily clinical practice are feasible in high percentage of unselected patients and allows low levels of irradiation of organs at risk without compromising target coverage. However, despite low MHD a significant proportion of patients receives a maximum LAD dose superior to 20 Gy. Advances in knowledge: The value of MHD used exclusively is not able to describe entirely the risk of late heart toxicity, which can be better evaluated with the joint analysis of the maximum dose to LAD region. The vast majority of LSBCP referred to adjuvant radiotherapy in the setting of routine practice are able to comply with the requirement of DIBH.

The Advantages of Active Breathing Coordinator Device During Left-Sided Breast Cancer Radiation Therapy: A Dosimetric Comparison Study

“…Besides heart radiation exposure, lungs dose represents another relevant endpoint when considering acute and late toxicities (like radiation pneumonitis and brosis) during and after breast cancer irradiation. In agreement with previous studies [24][25][26], we also showed that the mDIBH technique signi cantly reduced left lung dose. This might seem counterintuitive at rst, since more lung volume is within the tangential beam when the heart moves out of the treatment eld during mDIBH, but through in ation, only low density lung tissue remains within the tangential eld, thus avoiding its deterioration.…”

Design of a new breast vacuum bag to reduce the global and local setup errors and to reduce PTV margin in post-mastectomy radiation therapy

“…To ensure the accuracy of radiation therapy and reduce the patient’s additional radiation dose, optical surface imaging (OSI) systems [ 17 , 18 ] play an increasingly important role in breast radiation therapy. Furthermore, to reduce the radiation dose to the lung and the heart, changing the patient’s position [ 13 , 19 , 20 ] and using deep inspiration breath-hold (DIBH) [ 21 , 22 ] technology were studied. Based on these studies, we will combine OSI and DIBH technology with the new vacuum bag in a further study.…”

The effect of deep inspiration breath-hold technique on left anterior descending coronary artery and heart dose in left breast irradiation

“…Effects of the DIBH technique in reducing the radiation dose to the LAD have recently been reported [10][11][12][13]; however, delineation of the LAD requires an injection of a contrast agent, which is not usually performed in our clinical practice. We contoured the anterior interventricular groove from its origin down to the apex of the heart as the LAD region.…”