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Purpose To determine whether cine computed tomography (CT) can serve as an alternative to four-dimensional (4D)-CT by providing tumor motion information and producing equivalent target volumes when contoured upon for radiation treatment planning without a respiratory surrogate. Methods and Materials Cine CT images from a commercial CT scanner were used to form maximum intensity projection (MIP) and respiratory-averaged CT (RACT) image sets. These image sets then were used together to define targets for radiotherapy. Phantoms oscillating under irregular motion were used to assess differences between contouring on cine CT and 4D-CT. We also retrospectively reviewed image sets for 27 patients at our institution who received stereotactic radiotherapy for stage I non-small cell lung cancer. Patients were included if tumor motion was greater than 1 cm. Lesions were first contoured using MIP and RACT image sets processed from cine CT, then with 4D-CT MIP and 10-phase image sets. Mean ratios of volume magnitude were compared with intraobserver variation, mean centroid shifts were calculated, and volume overlap was assessed with the normalized Dice similarity coefficient index. Results The phantom studies demonstrated that cine CT captured a greater extent of irregular tumor motion than 4D-CT, producing a larger tumor volume. The patient studies demonstrated that gross tumor defined on cine imaging was similar to or slightly larger than that defined on 4D-CT. Conclusions Cine CT is a promising alternative to 4D-CT for stereotactic radiation treatment planning.

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Purpose: To present a retrospective analysis of the efficacy, toxicity, and quality of life (QoL) of patients treated with OARExtreme-sparing stereotactic body radiotherapy (SBRT) in previously-irradiated head and neck cancer.Materials/Methods: From 11/2012 to 7/2015, 60 patients with in-field recurrence of head and neck cancer underwent re-irradiation with SBRT. Retreatment sites included the aerodigestive tract (43%), lateral neck (22%), and skull base (35%). The median prior RT dose was 63.6 Gy with a median time from prior irradiation of 16.5 months. The median volume treated was 61.0 cc. Patients were treated with 40 Gy in the definitive setting or 35 Gy in the post-operative setting in five fractions. Dose constraints to the OARExtreme were calculated with a BED calculator using an alpha/beta ratio of 3 to reduce the risk of late toxicities. QoL data was collected from patients at the time of consultation and at subsequent follow up appointments using the MD Anderson Dysphagia Inventory (MDADI) and Symptom Inventory (MDASI).Results: The 1- and 2- year rates of local, regional, and distant control and overall survival were 79/79, 74/70, 74/71, and 59/45%, respectively. Late grade 3 toxicities were seen in 3% in the group treated to the aerodigestive tract and 1% in the group treated to the skull base. No grade 4 or 5 toxicities were observed. Patients with skull base re-irradiation maintained a stable QoL score after radiation treatment, while patients treated to the aerodigestive tract demonstrated a slight impairment associated with worsening dysphagia, compared to their pretreatment baseline. All groups experienced an increase in xerostomia.Conclusions: OARExtreme-sparing SBRT is able to achieve excellent tumor coverage while protecting the organs at highest risk of re-irradiation-related complications. The potential for lower toxicities and maintained QoL with this treatment makes it a promising option for salvage of recurrent head and neck cancer.SummaryLocal control and overall survival rates for recurrent head and neck cancer remain poor, despite the use of local therapy. In addition, re-irradiation with conventional radiation therapy confers a high rate of grade 3 and higher late toxicities. SBRT appears to improve the therapeutic ratio in this patient population, and treatment planning with a focus on sparing OARExtreme may further decrease the rates of morbidity in these patients.

By combining incident learning and process failure-mode-and-effects-analysis (FMEA) in a structure-process-outcome framework we have created a risk profile for our radiation medicine practice and implemented evidence-based risk-mitigation initiatives focused on patient safety. Based on reactive reviews of incidents reported in our departmental incident-reporting system and proactive FMEA, high safety-risk procedures in our paperless radiation medicine process and latent risk factors were identified. Six initiatives aimed at the mitigation of associated severity, likelihood-of-occurrence, and detectability risks were implemented. These were the standardization of care pathways and toxicity grading, pre-treatment-planning peer review, a policy to thwart delay-rushed processes, an electronic whiteboard to enhance coordination, and the use of six sigma metrics to monitor operational efficiencies. The effectiveness of these initiatives over a 3-years period was assessed using process and outcome specific metrics within the framework of the department structure. There has been a 47% increase in incident-reporting, with no increase in adverse events. Care pathways have been used with greater than 97% clinical compliance rate. The implementation of peer review prior to treatment-planning and use of the whiteboard have provided opportunities for proactive detection and correction of errors. There has been a twofold drop in the occurrence of high-risk procedural delays. Patient treatment start delays are routinely enforced on cases that would have historically been rushed. Z-scores for high-risk procedures have steadily improved from 1.78 to 2.35. The initiatives resulted in sustained reductions of failure-mode risks as measured by a set of evidence-based metrics over a 3-years period. These augment or incorporate many of the published recommendations for patient safety in radiation medicine by translating them to clinical practice.

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