Single dose partial breast irradiation using an MRI linear accelerator in the supine and prone treatment position

Charaghvandi, K.R.; Westeinde, T. van't; Yoo, Sua; Houweling, Antonetta C.; Rodrigues, Anna; Verkooijen, Helena M.; Philippens, M.E.P.; Asselen, Bram van; Horton, Janet K.; Bongard, H. J. G. D. van den

doi:10.1016/j.ctro.2018.09.001

Cited by 19 publications

(48 citation statements)

References 30 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the ERE effect is also present at the lung-tissue interface, it is also important to check the maximum lung and chest wall dose (57,62). Previous planning studies concluded that the effects of the magnetic field on OARs, other than the skin, are generally negligible, and doses were within clinical constraints (60,62,63).…”

Section: Electron Return Effectmentioning

confidence: 99%

“…Because of the design of the hybrid machines, rotations of the table with respect to the gantry angle and therefore irradiation with non-coplanar beams are not possible. No problems are expected because of this because good plan quality for PBI can be achieved with coplanar IMRT (26,63,68). With respect to the methods currently used for dose calculation, co-registration of the planning CT to the pretreatment and/or online MR images or bulk density assignment are currently used for electron density information for both the ViewRay and Elekta hybrid machines (15,67,69).…”

Section: Planning Restrictionsmentioning

confidence: 99%

“…However, no patients have yet been treated with neoadjuvant PBI on a hybrid machine. A planning study has shown that neoadjuvant PBI in a single fraction in prone or supine position on the 1.5-T Elekta MR-linac would be dosimetrically feasible with adequate target coverage and within predefined constraints for OAR (63).…”

Section: First Clinical Experiencesmentioning

confidence: 99%

See 2 more Smart Citations

Optimizing MR-Guided Radiotherapy for Breast Cancer Patients

et al. 2020

View full text Add to dashboard Cite

Current research in radiotherapy (RT) for breast cancer is evaluating neoadjuvant as opposed to adjuvant partial breast irradiation (PBI) with the aim of reducing the volume of breast tissue irradiated and therefore the risk of late treatment-related toxicity. The development of magnetic resonance (MR)-guided RT, including dedicated MR-guided RT systems [hybrid machines combining an MR scanner with a linear accelerator (MR-linac) or 60 Co sources], could potentially reduce the irradiated volume even further by improving tumour visibility before and during each RT treatment. In this position paper, we discuss MR guidance in relation to each step of the breast RT planning and treatment pathway, focusing on the application of MR-guided RT to neoadjuvant PBI.

show abstract

Section: Electron Return Effectmentioning

confidence: 99%

Section: Planning Restrictionsmentioning

confidence: 99%

See 1 more Smart Citation

Optimizing MR-Guided Radiotherapy for Breast Cancer Patients

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Particularly for largebreasted patients, the face-down orientation enables superior lung and chest wall dose sparing. [10][11][12][13][14][15][16][17][18][19][20][21][22][23] Cosmetic outcomes have also been reported to improve with the prone position compared with patients treated supine. 16,24,25 Some investigations have demonstrated reduced skin toxicity, 24,26 whereas others have reported opposite effects.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Respiration-Induced Motion in Prone Versus Supine Patient Positioning for Thoracic Radiation Therapy

Guy

Weiss

Rosu‐Bubulac

2020

Advances in Radiation Oncology

View full text Add to dashboard Cite

Variations in the breathing characteristics, both on short term (intrafraction) and long term (interfraction) time scales, may adversely affect the radiation therapy process at all stages when treating lung tumors. Prone position has been shown to improve consistency (ie, reduced intrafraction variability) and reproducibility (ie, reduced interfraction variability) of the respiratory pattern with respect to breathing amplitude and period as a result of natural abdominal compression, with no active involvement required from the patient. The next natural step in investigating breathing-induced changes is to evaluate motion amplitude changes between prone and supine targets or organs at risk, which is the purpose of the present study. Methods and Materials: Patients with lung cancer received repeat helical 4-dimensional computed tomography scans, one prone and one supine, during the same radiation therapy simulation session. In the maximum-inhale and maximum-exhale phases, all thoracic structures were delineated by an expert radiation oncologist. Geometric centroid trajectories of delineated structures were compared between patient orientations. Motion amplitude was measured as the magnitude of difference in structure centroid position between inhale and exhale. Results: Amplitude of organ motion was larger when the patient was in the prone position compared with supine for all structures except the lower left lobe and left lung as a whole. Across all 12 patients, significant differences in mean motion amplitude between orientations were identified for the right lung (3.0 mm, P Z .01), T2 (0.5 mm, P Z .01) and T12 (2.1 mm, P < .001) vertebrae, the middle third of the esophagus (4.0 mm, P Z .03), and the lung tumor (1.7 mm, P Z .02). Conclusions: Respiration-induced thoracic organ motion was quantified in the prone position and compared with that of the supine position for 12 patients with thoracic lesions. The prone position induced larger organ motion compared with supine, particularly for the lung tumor, likely requiring increases in planning margins compared with supine.

show abstract

“…PBI has been shown to be adequate and may yield better cosmetic results [3] . In contrast to preoperative radiotherapy, when tumor can be visualized and target volumes defined easily [4] , reproducible and standardized techniques to define the cavity and the CTV suitable for PBI are warranted [5] . In the case of target volume definition after lumpectomy, uncertainties may exceed uncertainties from positioning [6] , [7] .…”

Section: Introductionmentioning

confidence: 99%