Compared to a conventional linear accelerator, the Cyberknife (CK) is a unique system with respect to radiation protection shielding and the variety and number of non-coplanar beams are two key components regarding this aspect. In this work, a framework to assess the direction distribution and modulation factor (MF) of clinically applied treatment beams of a CyberKnife M6 is developed. Database...

PURPOSE The efficacy of accelerated partial breast irradiation (APBI) utilizing brachytherapy or conventional external beam radiation has been studied in early-stage breast cancer treated with breast-conserving surgery. Data regarding stereotactic treatment approaches are emerging. The CyberKnife linear accelerator enables excellent dose conformality to target structures while adjusting for tar...

We examined the adequacy of existing shielding guidelines using five-year clinical data from a busy CyberKnife center. From June 2006 through July 2011, 1,370 patients were treated with a total of 4,900 fractions and 680,691 radiation beams using a G4 CyberKnife. Prescription dose and total monitor units (MU) were analyzed to estimate the shielding workload and modulation factor. In addition, b...

The sequence of incremental dose delivery during a radiotherapy fraction can potentially influence the radiobiological effect. This would be most noticeable during the long fractions characteristic of hypo-fractionated stereotactic radiotherapy and radiosurgery. We demonstrate here the spatio-temporal variation of dose delivery by the CyberKnife to a lung tumor and propose strategies to reduce ...

In the radiation treatment of moving targets with external surrogates, information on tumor position in real time can be extracted by using accurate correlation models. A fuzzy environment is proposed here to correlate input surrogate data with tumor motion estimates in real time. In this study, two different data clustering approaches were analyzed due to their substantial effects on the fuzzy...

© n an ideal radiotherapy procedure, the treatment sysem would continuously adapt the radiation beam deivery to changes in the tumor position. The developent of such a tracking capability has been underway or more than 10 years, beginning with the CyberKnife mage-guided radiosurgery system. In that time, much as been learned about the nature of tumor motion and he technical issues that it prese...

PURPOSE There are two collimation systems associated with the CyberKnife system, the fixed cone collimator and the Iris collimator. The Iris collimator is used more frequently because of its superior flexibility. However, sometimes treatments have to be canceled or postponed due to Iris collimator mechanical failures. The purpose of this study is to investigate the feasibility of switching coll...

•Low-grade papillary serous ovarian carcinoma has unique epidemiologic and disease-specific characteristics•Cyberknife radiotherapy is a unique treatment that may successfully be used to treat unresectable disease•Anastrozole is an effective treatment for hormone receptor-positive low-grade papillary serous ovarian carcinoma.

Introduction Post-stereotactic radiation-induced neoplasms, although relatively rare, have raised the question of benefit regarding CyberKnife® treatments versus the risk of a secondary malignancy. The incidence of such neoplasms arising in the nervous system is thought to be low, given the paucity of case reports regarding such secondary lesions.