Integrated feathering for craniospinal irradiation improves patient safety and departmental efficiency.

This paper presents to the dosimetrist audience an integrated feathering technique for craniospinal irradiation which improves dosimetry, physics, physician and therapist efficiencies while increasing patient safety and decreasing portal imaging time. This technique has been presented by other authors in physics journals stressing technical and quality assurance aspects, this article is presented to the treatment planners with a focus on the planning process including field design and weighting, efficiency improvements and patient safety.

The Ability of Bumblebees Bombus terrestris (Hymenoptera: Apidae) to Detect Floral Humidity is Dependent Upon Environmental Humidity.

Flowers produce local humidity that is often greater than that of the surrounding environment, and studies have shown that insect pollinators may be able to use this humidity difference to locate and identify suitable flowers. However, environmental humidity is highly heterogeneous, and is likely to affect the detectability of floral humidity, potentially constraining the contexts in which it can be used as a salient communication pathway between plants and their pollinators. In this study, we use differential conditioning techniques on bumblebees Bombus terrestris audax (Harris) to explore the detectability of an elevated floral humidity signal when presented against different levels of environmental noise. Artificial flowers were constructed that could be either dry or humid, and individual bumblebees were presented with consistent rewards in either the humid or dry flowers presented in an environment with four levels of constant humidity, ranging from low (~20% RH) to highly saturated (~95% RH). Ability to learn was dependent upon both the rewarding flower type and the environment: the bumblebees were able to learn rewarding dry flowers in all environments, but their ability to learn humid rewarding flowers was dependent on the environmental humidity, and they were unable to learn humid rewarding flowers when the environment was highly saturated. This suggests that floral humidity might be masked from bumblebees in humid environments, suggesting that it may be a more useful signal to insect pollinators in arid environments.

How to Respond to a Ransomware Attack? One Radiation Oncology Department's Response to a Cyber-Attack on Their Record and Verify System.

The digitization of healthcare for patient safety and efficiency introduced third party networks into closed hospital systems increasing the probability of cyberattacks and their consequences(1). In April 2021, a major vendor of a Radiation Oncology (RO) record and verify system (RVS) suffered a ransomware attack, affecting our department and many others across the United States. This article summarizes our response to the ransomware event including workflows, team member roles, responsibilities, communications and departmental recovery. The RVS created or housed accurate patient dose records for 6 locations. The immediate response to the ransomware attack was to shut down the system including the ability to treat patients. With the utilization of the hospital EMR and pre-existing interfaces with RVS, the department was able to safely continue patient radiotherapy treatments innovatively utilizing a direct Digital Imaging and Communications in Medicine (DICOM) transfer of patient data to the linear accelerators and implementing paper charting. No patients were treated in the first 24 hours of the attack. Within 48 hours of the ransomware event, 50% of patients were treated, and within 1 week, 95% of all patients were treated using direct DICOM transfer and paper charts. The RVS was completely unavailable for 2.5 weeks and full functionality was not restored for 4.5 weeks. A phased approach was adopted for re-introduction of patient treatments back into the RVS. Human capital costs included communication, outreach, workflow creation, quality assurance and extended clinical hours. Key lessons learned were to have a back-up of essential information, employ 'dry run' emergency training, having consistent parameter requirements across different vendor hardware and software, and having a plan for the recovery effort of restoring normal operations once software is operational. The provided report presents valuable information for the development of cyber-attack preparedness for RO departments.

A phase IB clinical trial of 15 Gy HDR brachytherapy followed by hypofractionated/SBRT in the management of intermediate-risk prostate cancer.

PURPOSE: High dose-rate (HDR) brachytherapy is commonly administered as a boost to external beam radiation therapy (EBRT). Our purpose was to compare toxicity with increasingly hypofractionated EBRT in combination with a single 15 Gy HDR boost for men with intermediate-risk prostate cancer. METHODS AND MATERIALS: Forty-two men were enrolled on this phase IB clinical trial to one of three EBRT dose cohorts: 10 fractions, seven fractions, or five fractions. Patients were followed prospectively for safety, efficacy, and health-related quality of life (Expanded Prostate Index Composite). Efficacy was assessed biochemically using the Phoenix definition. RESULTS: With a median follow up of 36 months, the biochemical disease-free survival was 95.5%. One man developed metastatic disease at 5 years. There was no significant minimally important difference in EPIC PRO for either urinary, bowel, or sexual domains. There was one acute Grade 3 GI and GU toxicity, but no late Grade 3 GU or GI toxicities. CONCLUSION: Fifteen gray HDR brachytherapy followed by a five fraction SBRT approach results in high disease control rates and low toxicity similar to previously reported HDR protocols with significant improvement in patient convenience and resource savings. While mature results with longer follow up are awaited, this treatment approach may be considered a safe and effective option for men with intermediate-risk disease.

Single institution implementation of permanent 131Cs interstitial brachytherapy for previously irradiated patients with resectable recurrent head and neck carcinoma.

PURPOSE: Permanent interstitial brachytherapy is an appealing treatment modality for patients with locoregional recurrent, resectable head and neck carcinoma (HNC), having previously received radiation. Cesium-131 (131Cs) is a permanent implant brachytherapy isotope, with a low average photon energy of 30 keV and a short half-life of 9.7 days. Exposure to medical staff and family members is low; patient isolation and patient room shielding are not required. This work presents a single institution's implementation process of utilizing an intraoperative, permanent 131Cs implant for patients with completely resected recurrent HNC. MATERIAL AND METHODS: Fifteen patients receiving 131Cs permanent seed brachytherapy were included in this analysis. The process of pre-planning, selecting the dose prescription, seed ordering, intraoperative procedures, post-implant planning, and radiation safety protocols are described. RESULTS: Tumor volumes were contoured on the available preoperative PET/CT scans and a pre-implant treatment plan was created using uniform source strength and uniform 1 cm seed spacing. Implants were performed intraoperatively, following tumor resection. In five of the fifteen cases, intraoperative findings necessitated a change from the planned number of seeds and recalculation of the pre-implant plan. The average prescription dose was 56.1 ±6.6 Gy (range, 40-60 Gy). The average seed strength used was 2.2 ±0.2 U (3.5 ±0.3 mCi). Patients returned to a recovery room on a standard surgical floor and remained inpatients, without radiation safety restrictions, based on standard surgical recovery protocols. A post-implant treatment plan was generated based on immediate post-operative CT imaging to verify the seed distribution and confirm delivery of the prescription dose. Patients were provided educational information regarding radiation safety recommendations. CONCLUSIONS: Cesium-131 interstitial brachytherapy is feasible and does not pose major radiation safety concerns; it should be considered as a treatment option for previously irradiated patients with recurrent, resectable HNC.

Avoidance sectors to reduce dosimetric impact of an irreproducible pannus on setup uncertainty in prostate SBRT VMAT: A case study.

This work investigates whether the use of an avoidance sector in a two-arc volumetric modulated arc therapy (VMAT) prostate stereotactic body radiotherapy (SBRT) plan reduces dosimetric variations due to an irreproducible pannus. A morbidly obese patient with favorable-risk prostate cancer elected treatment with SBRT. The patient was treated with the avoidance arcs across the pannus to eliminate reproducibility issues created by daily pannus variability in set up. For post-treatment assessment, the case was planned using Varian Eclipse™ treatment planning system (TPS) with two VMAT arcs with and without 100° avoidance sectors across the pannus. The dose was re-calculated using the external body contour from four daily treatment cone-beam computer tomography scans, and on two virtual body contours created by expanding the pannus region of the external contour by 5 and 10 mm. Dose differences between planned and re-calculated rectal wall mean dose and the V24Gy were numerically larger in the absence of the avoidance sector for all fractions and for both simulated pannus variations, with maximum changes of 2.6% and 1.3%. Maximum point dose variations in the PTV, CTV, rectum, bladder, and femoral heads were 105 cGy or less for all cases, with and without the avoidance sector. The use of an avoidance sector across this large, asymmetrical pannus did not inhibit achieving dose constraints and provided a reduction in dose variability which was nominal in this case for 10 mm variations. Avoidance sectors can be safely implemented in cases with obvious reproducibility concerns in the setting of prostate VMAT SBRT.

Process Mapping and Time Study to Improve Efficiency of New Procedure Implementation for High-Dose Rate Prostate Brachytherapy.

New technologies and procedures have the potential to improve outcomes; however, initial implementation is often associated with a steep learning curve, decreased efficiency, and patient safety implications. Implementation of a real-time, ultrasound-based prostate high-dose rate brachytherapy procedure involved a multidisciplinary team composed of approximately 6-8 team members and numerous complex tasks. To characterize time spent on various aspects of the procedure and improve efficiency, the team developed a detailed process map, time study, and team debriefings. A benchmark was created based on an experienced institution which has performed >100 procedures annually. The process map was analyzed based on clinical tasks and treatment planning tasks. Over the course of 17 cases at a single institution, total procedure time ranged from 222 to 107 minutes. Implementation of the process map resulted in a reduction of total time by 52%. The implementation of a new procedure benefits from the integration and utilization of a process map. We were able to reduce procedure time significantly, which resulted in decreased time under general anesthesia, reduced risk of deep vein thrombosis, improved overall patient safety, patient throughput, and decreases in staffing demands.

SpaceOAR to improve dosimetric outcomes for monotherapy high-dose-rate prostate implantation in a patient with ulcerative colitis.

High-dose-rate (HDR) brachytherapy is an attractive option for patients receiving definitive radiation therapy for prostate cancer with decreased overall dose to the pelvis. However, ulcerative colitis increases rectal toxicity risk and may be a contraindication. A synthetic hydrogel, SpaceOAR (Augmentix Inc., Waltham, MA, USA), can facilitate the use of HDR brachytherapy for patients where rectal toxicity is a limiting factor. SpaceOAR gel (13.19 cc) was utilized in a monotherapy HDR prostate treatment with Ir-192 under transrectal ultrasound guidance, with the intention of decreasing rectal dose. SpaceOAR gel was inserted transperineally into the patient 18 days prior to the procedure. The HDR brachytherapy procedure was tolerated without incident. All planning constraints were met, and the following dosimetry was achieved: Prostate - V100% = 97.3%, V150% = 35%, V200% = 14.5%; Urethra - V118% = 0%; Rectum - D2 cc = 51.6%, V75% = 0 cc. The rectum-catheter spacing was on average between 6-8 mm. Average spacing for our 10 most recent patients without SpaceOAR was 3 mm. SpaceOAR did not hinder or distort ultrasound imaging or increase treatment time. SpaceOAR successfully increases catheter-rectal wall spacing and decreases rectal dose due to improved planning capabilities, while decreasing the likelihood of rectal perforation. One application of this tool is presented to mitigate potential toxicities associated with ulcerative colitis. At five months, one week, and one day follow-up, the patient reported no bowel issues following HDR brachytherapy.

Pancreatic cancer planning: Complex conformal vs modulated therapies.

To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45Gy; with tumor/tumor bed boosted to 50.4Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V30, V35), stomach (D10%), stomach (V45), mean right kidney dose, and right kidney (V15) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V35), and left kidney (V15, V18, V20). VMAT plans decreased small bowel (D10%, D15%), small bowel (V35, V45), stomach (D10%, D15%), stomach (V35, V45), mean liver dose, liver (V35), left kidney (V15, V18, V20), and right kidney (V18, V20). VMAT plans significantly decreased small bowel (D10%, D15%), left kidney (V20), and stomach (V45) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average treatment delivery was within 10minutes for simple and complex 3DCRT, IMRT, and VMAT treatments. This article shows significant improvements in 3D plan performance with complex planning over the more frequently compared 3- or 4-field simple 3D planning techniques. VMAT plans continue to demonstrate potential for the most organ sparing. However, further studies are required to identify if dosimetric benefits associated with inverse optimized planning can be translated into clinical benefits and if these treatment techniques are value-added therapies for this group of patients with cancer.

Clinical implementation and failure mode and effects analysis of HDR skin brachytherapy using Valencia and Leipzig surface applicators.

PURPOSE: The planning procedure for Valencia and Leipzig surface applicators (VLSAs) (Nucletron, Veenendaal, The Netherlands) differs substantially from CT-based planning; the unfamiliarity could lead to significant errors. This study applies failure modes and effects analysis (FMEA) to high-dose-rate (HDR) skin brachytherapy using VLSAs to ensure safety and quality. METHOD: A multidisciplinary team created a protocol for HDR VLSA skin treatments and applied FMEA. Failure modes were identified and scored by severity, occurrence, and detectability. The clinical procedure was then revised to address high-scoring process nodes. RESULTS: Several key components were added to the protocol to minimize risk probability numbers. (1) Diagnosis, prescription, applicator selection, and setup are reviewed at weekly quality assurance rounds. Peer review reduces the likelihood of an inappropriate treatment regime. (2) A template for HDR skin treatments was established in the clinic's electronic medical record system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planner as well as increases the detectability of an error. (3) A screen check was implemented during the second check to increase detectability of an error. (4) To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display, facilitating data entry and verification. (5) VLSAs are color coded and labeled to match the electronic medical record prescriptions, simplifying in-room selection and verification. CONCLUSIONS: Multidisciplinary planning and FMEA increased detectability and reduced error probability during VLSA HDR brachytherapy. This clinical model may be useful to institutions implementing similar procedures.

Optimizing patient positioning for intensity modulated radiation therapy in hippocampal-sparing whole brain radiation therapy.

PURPOSE: Sparing the hippocampus during whole brain radiation therapy (WBRT) offers potential neurocognitive benefits. However, previously reported intensity modulated radiation therapy (IMRT) plans use multiple noncoplanar beams for treatment delivery. An optimized coplanar IMRT template for hippocampal-sparing WBRT would assist in clinical workflow and minimize resource utilization. In this study, we sought to determine the optimal patient position to facilitate coplanar treatment planning and delivery of hippocampal-sparing WBRT using IMRT. METHODS AND MATERIALS: A variable angle, inclined board was utilized for patient positioning. An anthropomorphic phantom underwent computed tomography simulation at various head angles. The IMRT goals were designed to achieve target coverage of the brain while maintaining hippocampal dose-volume constraints designed to conform to the Radiation Therapy Oncology Group 0933 protocol. Optimal head angle was then verified using data from 8 patients comparing coplanar and noncoplanar WBRT IMRT plans. RESULTS: Hippocampal, hippocampal avoidance region, and whole brain mean volumes were 1.1 cm(3), 12.5 cm(3), and 1185.1 cm(3), respectively. The hippocampal avoidance region occupied 1.1% of the whole brain planning volume. For the 30-degree head angle, a 7-field coplanar IMRT plan was generated, sparing the hippocampus to a maximum dose of 14.7 Gy; D100% of the hippocampus was 7.4 Gy and mean hippocampal dose was 9.3 Gy. In comparison, for flat head positioning the hippocampal Dmax was 22.9 Gy with a D100% of 9.2 Gy and mean dose of 11.7 Gy. Target coverage and dose homogeneity was comparable with previously published noncoplanar IMRT plans. CONCLUSIONS: Compared with conventional supine positioning, an inclined head board at 30 degrees optimizes coplanar whole brain IMRT treatment planning. Clinically acceptable hippocampal-sparing WBRT dosimetry can be obtained using a simplified coplanar plan at a 30-degree head angle, thus obviating the need for complex and time consuming noncoplanar IMRT plans.

Evolution of advanced technologies in prostate cancer radiotherapy.

Conventional treatment options for clinically localized, low-risk prostate cancer include radical prostatectomy, external-beam radiotherapy (EBRT) and low-dose-rate brachytherapy. Advances in image-guided radiotherapy (IGRT) since the 1980s, the development of intensity-modulated radiotherapy (IMRT) during the 1990s and evidence from radiobiological models--which support the use of high doses per fraction--have developed alongside novel advanced radiotherapy modalities that include high-dose-rate brachytherapy (HDR-BT), stereotactic body radiotherapy (SBRT) and proton beam therapy. The relationship between the outcomes of and toxicities experienced by patients with prostate cancer treated with HDR-BT, SBRT and particle-beam therapy should provide urologists and oncologists an understanding of the continually evolving technology in prostate radiotherapy. On the basis of published evidence, conventionally fractionated EBRT with IMRT is considered the standard of care over conventional 3D conformal radiotherapy, whereas HDR-BT boost is an acceptable treatment option for selected patients with intermediate-risk and high-risk prostate cancer. SBRT and proton therapy should not be used for patients (regardless of disease risk group) outside the setting of a clinical trial. Finally, comparative effectiveness research should be conducted to provide a framework for evaluating advanced radiotherapy technologies by comparing the benefits and harms of available therapeutic options to optimize the risk:benefit ratio and improve cost effectiveness.

Radiotherapy protocol deviations and clinical outcomes: a meta-analysis of cooperative group clinical trials.

BACKGROUND: Noncompliance with radiotherapy (RT) protocol guidelines has been linked to inferior clinical outcomes. We performed a meta-analysis of cooperative group trials to examine the association between RT quality assurance (QA) deviations and disease control and overall survival (OS). METHODS: We searched MEDLINE and the Cochrane Central Register of Controlled Trials for multi-institutional trials that reported clinical outcomes in relation to RT QA results. Hazard ratios (HRs) describing the association between RT protocol noncompliance and patient outcomes were extracted directly from the original studies or calculated from survival curves. Inverse variance meta-analyses were performed to assess the association between RT QA deviations and OS. A second meta-analysis tested the association between RT QA deviations and secondary outcomes, including local or locoregional control, event-free survival, and relapse. Random-effects models were used in cases of statistically significant (P < .10) effect heterogeneity. The Egger test was used to detect publication bias. All statistical tests were two-sided. RESULTS: Eight studies (four pediatric, four adult) met all inclusion criteria and were incorporated into this analysis. The frequency of RT QA deviations ranged from 8% to 71% (median = 32%). In a random-effects model, RT deviations were associated with a statistically significant decrease in OS (HR of death = 1.74, 95% confidence interval [CI] = 1.28 to 2.35; P < .001). A similar effect was seen for secondary outcomes (HR of treatment failure = 1.79, 95% CI = 1.15 to 2.78; P = .009). No evidence of publication bias was detected. CONCLUSION: In clinical trials, RT protocol deviations are associated with increased risks of treatment failure and overall mortality.

Using qualitative measures to improve quality in radiation oncology.

This article introduces the use of qualitative research techniques in the field of radiation oncology with respect to quality improvement initiatives. The qualitative techniques used in this research include field observations and in-depth, one-on-one interviews with radiation therapy technologists. The observations were conducted in a fast-paced academic institution. This high-pressure, high-throughput environment provided an interesting location for observation of behaviors, workflows, and areas of improvement. Qualitative research is a useful platform for formulating questions and addressing the environment on a larger scale. The information resulting from this research led to immediate changes that improved the efficiency and effectiveness of care provided to patients and identified future initiatives to improve patient safety and the timeliness of care provided. Overall, qualitative research proved to be an exceptional resource for identifying and evaluating a clinical department and demonstrated the usefulness of this method of research for future work.

Intensity-modulated radiation therapy and volumetric-modulated arc therapy for adult craniospinal irradiation--a comparison with traditional techniques.

Craniospinal irradiation (CSI) poses a challenging planning process because of the complex target volume. Traditional 3D conformal CSI does not spare any critical organs, resulting in toxicity in patients. Here the dosimetric advantages of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) are compared with classic conformal planning in adults for both cranial and spine fields to develop a clinically feasible technique that is both effective and efficient. Ten adult patients treated with CSI were retrospectively identified. For the cranial fields, 5-field IMRT and dual 356° VMAT arcs were compared with opposed lateral 3D conformal radiotherapy (3D-CRT) fields. For the spine fields, traditional posterior-anterior (PA) PA fields were compared with isocentric 5-field IMRT plans and single 200° VMAT arcs. Two adult patients have been treated using this IMRT technique to date and extensive quality assurance, especially for the junction regions, was performed. For the cranial fields, the IMRT technique had the highest planned target volume (PTV) maximum and was the least efficient, whereas the VMAT technique provided the greatest parotid sparing with better efficiency. 3D-CRT provided the most efficient delivery but with the highest parotid dose. For the spine fields, VMAT provided the best PTV coverage but had the highest mean dose to all organs at risk (OAR). 3D-CRT had the highest PTV and OAR maximum doses but was the most efficient. IMRT provides the greatest OAR sparing but the longest delivery time. For those patients with unresectable disease that can benefit from a higher, definitive dose, 3D-CRT-opposed laterals are the most clinically feasible technique for cranial fields and for spine fields. Although inefficient, the IMRT technique is the most clinically feasible because of the increased mean OAR dose with the VMAT technique. Quality assurance of the beams, especially the junction regions, is essential.

Clinical experience transitioning from IMRT to VMAT for head and neck cancer.

To quantify clinical differences for volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in terms of dosimetric endpoints and planning and delivery time, twenty head and neck cancer patients have been considered for VMAT using Nucletron Oncentra MasterPlan delivered via an Elekta linear accelerator. Differences in planning time between IMRT and VMAT were estimated accounting for both optimization and calculation. The average delivery time per patient was obtained retrospectively using the record and verify software. For the dosimetric comparison, all contoured organs at risk (OARs) and planning target volumes (PTVs) were evaluated. Of the 20 cases considered, 14 had VMAT plans approved. Six VMAT plans were rejected due to unacceptable dose to OARs. In terms of optimization time, there was minimal difference between the two modalities. The dose calculation time was significantly longer for VMAT, 4 minutes per 358 degree arc versus 2 minutes for an entire IMRT plan. The overall delivery time was reduced by 9.2 ± 3.9 minutes for VMAT (51.4 ± 15.6%). For the dosimetric comparison of the 14 clinically acceptable plans, there was almost no statistical difference between the VMAT and IMRT. There was also a reduction in monitor units of approximately 32% from IMRT to VMAT with both modalities demonstrating comparable quality assurance results. VMAT provides comparable coverage of target volumes while sparing OARs for the majority of head and neck cases. In cases where high dose modulation was required for OARs, a clinically acceptable plan was only achievable with IMRT. Due to the long calculation times, VMAT plans can cause delays during planning but marked improvements in delivery time reduce patient treatment times and the risk of intra-fraction motion.

Pilot study of meaningful use of electronic health records in radiation oncology.

PURPOSE: Adoption and meaningful use of electronic health record (EHR) systems is an important national goal. We undertook a pilot study to determine the level of adoption and barriers to implementation of meaningful use (MU) of EHR systems as defined by the Centers for Medicare & Medicaid Services (CMS) in US radiation oncology practices. MATERIALS AND METHODS: We administered a Web-based survey instrument to a convenience sample of 40 departments of radiation oncology. We determined the current status of EHR system use at each facility, attitudes toward EHR systems, knowledge of MU criteria, plans and barriers to implementation, and whether selected interventions would be helpful with regard to compliance with MU criteria. RESULTS: Twenty-one of 40 radiation oncology facilities completed the survey, for a 53% response rate. Respondents were mostly large academic practices with a median of six (range, one to 32) full-time physicians and 70 (range, eight to 650) patients treated daily. Most facilities (81%) currently used an EHR system. The majority (84%) of facilities were aware of MU criteria, and of these, 67% expected to implement MU-compliant systems by the year 1 reporting deadline of October 1, 2011. The most frequently cited barriers to implementation were high cost, difficulty integrating with hospital systems, and a lack of national guidelines for implementation. CONCLUSION: Most large academic radiation oncology practices have already incorporated EHR systems into practice and plan to meet MU requirements. Further work should focus on assessment of needs for smaller practices. Radiation oncology-specific guidelines may improve widespread adoption.

Implanted dosimeters identify radiation overdoses during IMRT for prostate cancer.

PURPOSE: Image-guided dose-escalated radiotherapy is the standard of care for the treatment of prostate cancer. Although many published methods are available that account for prostate motion during delivery, evidence demonstrating that the planned dose is actually delivered on a daily basis is lacking. We report our initial clinical experience using implantable dosimeters to quantify and adjust the dose received during intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: A total of 20 patients undergoing IMRT with cone-beam computed tomography (CT) image guidance for prostate cancer had the dose verification system with radiopaque metal-oxide-semiconductor field effect transistor dosimeters implanted before treatment planning. All patients underwent planning with CT simulation in the supine position with custom immobilization, and the implanted dosimeters were located in the IMRT plans. The predicted dose for each dosimeter was defined and compared with the wireless readings before and after each treatment session. Investigations by physicians and medical physicists were initiated for two or more discrepancies >6% for any five consecutive fractions or for any discrepancy ≥10%. RESULTS: Using implanted in vivo dosimeters, dose measurements consistently >6% greater than the predicted values were observed during treatment for 3 of 20 prostate cancer patients who received IMRT with daily image guidance. A review of the daily cone-beam CT images revealed acceptable alignment of the prostate target volumes and implanted dosimeters but identified significant anatomic changes within the treated region. Repeat CT simulation and RT planning was performed, with resolution of the dose discrepancies in all 3 cases with the adoption of a new IMRT plan. CONCLUSIONS: Our report illustrates the potential effect of implanted in vivo dosimetry for prostate IMRT and emphasizes the importance of careful planning and delivery with attention to systematic shifts or anatomic changes that could alter the dose distributions.