Accurate and reproducible patient setup is a prerequisite to fractionated radiotherapy. To evaluate the applicability and technical performance of a commercial 3D surface imaging system for repositioning of breast cancer patients, measurements were performed in a rigid anthropomorphic phantom as well as in healthy volunteers. The camera system records a respiration-gated surface model of the imaged object, which may be registered to a previously recorded reference model. A transformation is provided, which may be applied to the treatment couch to correct the setup of the patient. The system showed a high stability and detected pre-defined shifts of phantoms and healthy volunteers with an accuracy of 0.40 +/- 0.26 mm and 1.02 +/- 0.51 mm, respectively (spatial deviation between pre-defined shift and suggested correction). The accuracy of the suggested rotational correction around the vertical axis was always better than 0.3 degrees in phantom measurements and 0.8 degrees in volunteers, respectively. Comparison of the suggested setup correction with that detected by a second and independently operated marker-based optical system provided consistent results. The results demonstrate that the camera system provides highly accurate setup corrections in a phantom and healthy volunteers. The most efficient use of the system for improving the setup accuracy in breast cancer patients has to be investigated in routine patient treatments.

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Helical tomotherapy is feasible and fast for WAI. Tomotherapy enabled excellent coverage of the PTV and effective sparing of liver, kidneys and bone marrow.

BackgroundLate cardiac toxicities caused by (particularly left-sided) breast radiotherapy (RT) are now recognized as rare but relevant sequelae, which has prompted research on risk structure identification and definition of threshold doses to heart subvolumes. The aim of the present review was to critically discuss the clinical evidence on late cardiac reactions based on dose-dependent outcome reports for mean heart doses as well as doses to cardiac substructures.MethodsA literature review was performed to examine clinical evidence on radiation-induced heart toxicities. Mean heart doses and doses to cardiac substructures were focused upon based on dose-dependent outcome reports. Furthermore, an overview of radiation techniques for heart protection is given and non-radiotherapeutic aspects of cardiotoxicity in the multimodal setting of breast cancer treatment are discussed.ResultsBased on available findings, the DEGRO breast cancer expert panel recommends the following constraints: mean heart dose <2.5 Gy; DmeanLV (mean dose left ventricle) < 3 Gy; V5LV (volume of LV receiving ≥5 Gy) < 17%; V23LV (volume of LV receiving ≥23 Gy) < 5%; DmeanLAD (mean dose left descending artery) < 10 Gy; V30LAD (volume of LAD receiving ≥30 Gy) < 2%; V40LAD (volume of LAD receiving ≥40 Gy) < 1%.ConclusionIn addition to mean heart dose, breast cancer RT treatment planning should also include constraints for cardiac subvolumes such as LV and LAD. The given constraints serve as a clinicians’ aid for ensuring adequate heart protection. The individual decision between sufficient protection of cardiac structures versus optimal target volume coverage remains in the physician’s hand. The risk of breast cancer-specific mortality and a patient’s cardiac risk factors must be individually weighed up against the risk of radiation-induced cardiotoxicity.