Analysis of Retrospective Versus Prospective Peer Review in a Multisite Academic Radiation Department.

Purpose: Our multisite academic radiation department reviewed our experience with transitioning from weekly primarily retrospective to daily primarily prospective peer review to improve plan quality and decrease the rate of plan revisions after treatment start.

Methods And Materials: This study was an institutional review board-approved prospective comparison of radiation treatment plan review outcomes of plans reviewed weekly (majority within 1 week after treatment start) versus plans reviewed daily (majority before treatment start, except brachytherapy, frame-based radiosurgery, and some emergent plans). Deviations were based on peer comments and considered major if plan revisions were recommended before the next fraction and minor if modifications were suggested but not required.

Variability of Low-Z Inhomogeneity Correction in IMRT/SBRT: A Multi-Institutional Collaborative Study.

Dose-calculation algorithms are critical for radiation treatment outcomes that vary among treatment planning systems (TPS). Modern algorithms use sophisticated radiation transport calculation with detailed three-dimensional beam modeling to provide accurate doses, especially in heterogeneous medium and small fields used in IMRT/SBRT. While the dosimetric accuracy in heterogeneous mediums (lung) is qualitatively known, the accuracy is unknown.

Age and Sex Divergence in Hematopoietic Radiosensitivity in Aged Mouse Models of the Hematopoietic Acute Radiation Syndrome.

The hematopoietic system is highly sensitive to stress from both aging and radiation exposure, and the hematopoietic acute radiation syndrome (H-ARS) should be modeled in the geriatric context separately from young for development of age-appropriate medical countermeasures (MCMs). Here we developed aging murine H-ARS models, defining radiation dose response relationships (DRRs) in 12-month-old middle-aged and 24-month-old geriatric male and female C57BL/6J mice, and characterized diverse factors affecting geriatric MCM testing. Groups of approximately 20 mice were exposed to ∼10 different doses of radiation to establish radiation DRRs for estimation of the LD50/30.

Dosimetric evaluation of high-Z inhomogeneity used for hip prosthesis: A multi-institutional collaborative study.

Purpose: A multi-institutional investigation for dosimetric evaluation of high-Z hip prosthetic device in photon beam.

Methods: A bilateral hip prosthetic case was chosen. An in-house phantom was built to replicate the human pelvis with two different prostheses.

Analysis of Virtual Versus In-Person Prospective Peer Review Workflow in a Multisite Academic Radiation Oncology Department.

Purpose: In radiation oncology, peer review is a process where subjective treatment planning decisions are assessed by those independent of the prescribing physician. Before March 2020, all peer review sessions occurred in person; however due to the COVID-19 pandemic, the peer-review workflow was transitioned from in-person to virtual. We sought to assess any differences between virtual versus in-person prospective peer review.

A dosimetric comparison of whole-lung treatment techniques in the pediatric population.

To demonstrate the dosimetric advantages and disadvantages of standard anteroposterior-posteroanterior (S-AP/PAAAA), inverse-planned AP/PA (IP-AP/PA) and volumetry-modulated arc (VMAT) radiotherapies in the treatment of children undergoing whole-lung irradiation. Each technique was evaluated by means of target coverage and normal tissue sparing, including data regarding low doses. A historical approach with and without tissue heterogeneity corrections is also demonstrated.

Correlation between target volume and electron transport effects affecting heterogeneity corrections in stereotactic body radiotherapy for lung cancer.

Recently, stereotactic body radiotherapy (SBRT) for lung cancer is conducted with heterogeneity-corrected treatment plans, as the correction greatly affects the dose delivery to the lung tumor. In this study, the correlation between the planning target volume (PTV) and the dose delivery is investigated by separation of the heterogeneity correction effects into photon attenuation and electron transport. Under Institutional Review Board exemption status, 74 patients with lung cancer who were treated with SBRT were retrospectively evaluated.

Evaluation of rotational errors in treatment setup of stereotactic body radiation therapy of liver cancer.

Purpose: To evaluate the dosimetric impact of rotational setup errors in stereotactic body radiotherapy (SBRT) treatment of liver tumors and to investigate whether translational shifts can compensate for rotation.

Methods And Materials: The positioning accuracy in 20 patients with liver malignancies treated with SBRT was reevaluated offline by matching the patients' cone-beam computed tomography (CT) scans (n=75) to the planning CT scans and adjusting the 3 rotational angles (pitch, roll, and yaw). Systematic and random setup errors were calculated.

A simple method for dose fusion from multimodality treatment of prostate cancer: brachytherapy to external beam therapy.

Purpose: Suboptimal dosage evaluated from postimplant dosimetry of prostate brachytherapy creates conundrum that needs resolution. This pilot study was undertaken to explore the feasibility of summing and visualizing radiation dosage from multimodality treatment.

Methods And Materials: Four weeks after (125)I permanent prostate seed implant, CT scans were performed on the whole pelvis of patients using our standard protocol for prostate planning.

Development of a porcine delayed wound-healing model and its use in testing a novel cell-based therapy.

Purpose: A delayed full-thickness wound-healing model was developed and used for examining the capacity of adipose-derived stem cells (ASCs), either alone or in platelet-rich fibrin gels, to promote healing.

Methods And Materials: Four pigs received electron beam radiation to the dorsal skin surface. Five weeks after radiation, subcutaneous fat was harvested from nonirradiated areas and processed to yield ASCs.

Treatment delays using an automated afterloading low-dose-rate brachytherapy system.

Purpose: Low-dose-rate (LDR) brachytherapy is an integral treatment modality in radiation oncology. Clinical efficacy is based on experience with manual source loading and continuous dose delivery. With remote afterloading technology, sources may be loaded and unloaded during the treatment course to prevent radiation exposure to nursing staff members and visitors.

The role of Gamma Knife Radiosurgery in the management of unresectable gross disease or gross residual disease after surgery in ependymoma.

Purpose/objective: To evaluate the efficacy and the toxicity of Gamma Knife (GK)-based stereotactic radiosurgery (SRS) in the management of gross disease in ependymoma.

Materials And Methods: Eight patients with 13 ependymomas were treated with GK-based SRS in our institution for gross disease. Five patients were treated for recurrent disease that developed after surgery and external beam radiotherapy (EBRT), two received SRS to the gross disease after surgery and EBRT, and one received SRS alone (in a 1.

Lung cancer radiation therapy: Monte Carlo investigation of "under dose" by high energy photons.

Loss of electronic equilibrium in lung tissue causes a build-up region in the tumor. Increasing the photon energy increases the depth at which electronic equilibrium is reestablished within the lung tumor. This study uses the Monte Carlo code PENELOPE for simulations of radiation treatment of tumor surrounded by lung.