PURPOSE:The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has risen rapidly, because of an epidemic of human papillomavirus infection. The optimal management of early-stage OPSCC with surgery or radiation continues to be a clinical controversy. Long-term randomized data comparing these paradigms are lacking.METHODS:We randomly assigned patients with T1-T2, N0-2 (≤ 4 cm) OPSCC to radiotherapy (RT) (with chemotherapy if N1-2) versus transoral robotic surgery plus neck dissection (TORS + ND) (with or without adjuvant therapy). The primary end point was swallowing quality of life (QOL) at 1-year using the MD Anderson Dysphagia Inventory. Secondary end points included adverse events, other QOL outcomes, overall survival, and progression-free survival. All analyses were intention-to-treat. Herein, we present long-term outcomes from the trial.RESULTS:Sixty-eight patients were randomly assigned (n = 34 per arm) between August 10, 2012, and June 9, 2017. Median follow-up was 45 months. Longitudinal MD Anderson Dysphagia Inventory analyses demonstrated statistical superiority of RT arm over time (P = .049), although the differences beyond 1 year were of smaller magnitude than at the 1-year timepoint (year 2: 86.0 ± 13.5 in the RT arm v 84.8 ± 12.5 in the TORS + ND arm, P = .74; year 3: 88.9 ± 11.3 v 83.3 ± 13.9, P = .12). These differences did not meet the threshold to qualify as a clinically meaningful change at any timepoint. Certain differences in QOL concerns including more pain and dental concerns in the TORS + ND arm seen at 1 year resolved at 2 and 3 years; however, TORS patients started to use more nutritional supplements at 3 years (P = .015). Dry mouth scores were higher in RT patients over time (P = .041).CONCLUSION:On longitudinal analysis, the swallowing QOL difference between primary RT and TORS + ND approaches persists but decreases over time. Patients with OPSCC should be informed about the pros and cons of both treatment options (ClinicalTrials.gov identifier: NCT01590355).

Purpose:In oropharyngeal squamous cell carcinoma (OPSCC), systemic loss of skeletal muscle mass (SMM), or sarcopenia, is a strong prognostic predictor of survival outcomes. However, the relationship between sarcopenia and nutrition-related outcomes is not well understood. This investigation evaluated the prognostic significance of sarcopenia for feeding tube (FT) placement in a cohort of OPSCC patients. Methods and Materials:A retrospective cohort study was conducted with data collected from 194 OPSCC patients treated with definitive radiation therapy (RT) or chemoradiation therapy (CRT). Sarcopenia was assessed from computed tomography imaging at the level of the third cervical (C3) and fourth thoracic (T4) vertebrae. The prognostic nature of pretreatment sarcopenia and its relationship with FT placement was explored using logistic regression. Results:The median age of patients included was 61.0 years, and the majority were male (83%). In this patient cohort, 87.6% underwent concurrent CRT, and 30.9% received a FT over the course of treatment. Sarcopenia was identified at baseline in 72.7% of patients based on C3 SMM measurements and in 41.7% based on measures at the level of T4. Based on measures at both C3 and T4, those with sarcopenia were significantly more likely to receive a FT and had significantly worse freedom from FT placement compared with patients without sarcopenia. Sarcopenia assessed at T4 was a significant predictor of FT placement. Conclusions:SMM measured at T4 may represent a novel and practical biomarker for sarcopenia detection that is associated with the need for FT placement. These findings suggest that the detection of baseline sarcopenia could guide decision-making related to the need for nutritional support in OPSCC patients undergoing RT/CRT.

IMPORTANCE The optimal approach for treatment deescalation in human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCCs) is unknown. OBJECTIVE To assess a primary radiotherapy (RT) approach vs a primary transoral surgical (TOS) approach in treatment deescalation for HPV-related OPSCC. DESIGN, SETTING, AND PARTICIPANTS This international, multicenter, open-label parallel-group phase 2 randomized clinical trial was conducted at 9 tertiary academic cancer centers in Canada and Australia and enrolled patients with T1-T2N0-2 p16-positive OPSCC between February 13, 2018, and November 17, 2020. Patients had up to 3 years of follow-up. INTERVENTIONS Primary RT (consisting of 60 Gy of RT with concurrent weekly cisplatin in node-positive patients) vs TOS and neck dissection (ND) (with adjuvant reduced-dose RT depending on pathologic findings). MAIN OUTCOMES AND MEASURES The primary end pointwas overall survival (OS) compared with a historical control. Secondary end points included progression-free survival (PFS), quality of life, and toxic effects. RESULTS Overall, 61 patients were randomized (30 [49.2%] in the RT arm and 31 [50.8%] in the TOS and ND arm; median [IQR] age, 61.9 [57.2-67.9] years; 8 women [13.6%] and 51 men [86.4%]; 31 [50.8%] never smoked). The trial began in February 2018, and accrual was halted in November 2020 because of excessive toxic effects in the TOS and ND arm. Median follow-up was 17 months (IQR, 15-20 months). For the OS end point, there were 3 death events, all in the TOS and ND arm, including the 2 treatment-related deaths (0.7 and 4.3 months after randomization, respectively) and 1 ofmyocardial infarction at 8.5 months. There were 4 events for the PFS end point, also all in the TOS and ND arm, which included the 3 mortality events and 1 local recurrence. Thus, the OS and PFS data remained immature. Grade 2 to 5 toxic effects occurred in 20 patients (67%) in the RT arm and 22 (71%) in the TOS and ND arm. Mean (SD) MD Anderson Dysphagia Inventory scores at 1 year were similar between arms (85.7 [15.6] and 84.7 [14.5], respectively). CONCLUSIONS AND RELEVANCE In this randomized clinical trial, TOS was associated with an unacceptable risk of grade 5 toxic effects, but patients in both trial arms achieved good swallowing outcomes at 1 year. Long-term follow-up is required to assess OS and PFS outcomes.

Background As new treatments and technologies have been introduced in radiation oncology, the clinical roles of radiation therapists (RTs) have expanded. However, there are few formal learning opportunities for RTs. An online, anatomy, radiology and contouring bootcamp (ARC Bootcamp) originally designed for medical residents was identified as a prospective educational tool for RTs. The purpose of this study was to evaluate an RT edition of the ARC Bootcamp on knowledge, contouring, and confidence, as well as to identify areas for future modification. Methods Fifty licensed RTs were enrolled in an eight-week, multidisciplinary, online RT ARC Bootcamp. Contouring practice was available throughout the course using an online contouring platform. Outcomes were evaluated using a pre-course and post-course multiple-choice quiz (MCQ), contouring evaluation and qualitative self-efficacy and satisfaction survey. Results Of the fifty enrolled RTs, 30 completed the course, and 26 completed at least one of the post-tests. Nineteen contouring dice similarity coefficient (DSC) scores were available for paired pre- and post-course analysis. RTs demonstrated a statistically significant increase in mean DSC scoring pooled across all contouring structures (mean ± SD improvement: 0.09 ± 0.18 on a scale from 0 to 1, p=0.020). For individual contouring structures, 3/15 reached significance in contouring improvement. MCQ scores were available for 26 participants and increased after RT ARC Bootcamp participation with a mean ± SD pre-test score of 18.6 ± 4.2 (46.5%); on a 40-point scale vs. post-test score of 24.5 ± 4.3 (61.4%) (p < 0.001). RT confidence in contouring, anatomy knowledge and radiographic identification improved after course completion (p < 0.001). Feedback from RTs recommended more contouring instruction, less in-depth anatomy review and more time to complete the course. Conclusions The RT ARC Bootcamp was an effective tool for improving anatomy and radiographic knowledge among RTs. The course demonstrated improvements in contouring and overall confidence. However, only approximately half of the enrolled RTs completed the course, limiting statistical power. Future modifications will aim to increase relevance to RTs and improve completion rates.

The purpose of this study is to validate a previously developed algorithm for alerting clinicians when to consider re-CT simulation due to changes in the patient's anatomy during radiation therapy of head and neck cancer. Cone beam computed tomography (CBCT) data were collected prospectively for 77 patients. Each CBCT was mathematically compared to a reference CBCT using the gamma index. We defined the match quality parameter (MQP) as an indicator of CBCT image similarity, where a negative MQP value indicates a poorer CBCT match than the match between the first two CBCT acquired during treatment. If three consecutive MQP values were below a chosen threshold, an "alert" is triggered to indicate action required, for example, possible re-CT simulation. The timing of image review requests made by the radiation therapists and any re-CT/re-plan decisions were documented for each patient's treatment course. The MQP for each patient (including any re-plans) was calculated in a manner that was blinded from the clinical process. The MQP as a function of fraction number was compared to actual clinical decisions in the treatment progress to evaluate alert system performance. There was a total of 93 plans (including re-plans) with 34 positives (action required) and 59 negatives (no action required). The sensitivity of the alert system was 0.76 and the false positive rate was 0.37. Only 1 case out of the 34 positive cases would have been missed by both the alert system and our clinical process. Despite the false negatives and false positives, analysis of the timing of alert triggers showed that the alert system could have resulted in seven fewer clinical misses. The alert system has the potential to be a valuable tool to complement human judgment and to provide a quality assurance safeguard to help improve the delivery of radiation treatment of head and neck cancer.

Background Patients with resected oral cavity squamous cell carcinoma (OCSCC) are often treated with adjuvant radiation (RT) ± concomitant chemotherapy based on pathological findings. Standard RT volumes include all surgically dissected areas, including the tumour bed and dissected neck. RT has significant acute and long-term toxicities including odynophagia, dysphagia, dermatitis and fibrosis. The goal of this study is to assess the rate of regional failure with omission of radiation to the surgically dissected pathologically node negative (pN0) hemi-neck(s) compared to historical control, and to compare oncologic outcomes, toxicity, and quality of life (QoL) profiles between standard RT volumes and omission of RT to the pN0 neck. Methods This is a multicentre phase II study randomizing 90 patients with T1–4 N0–2 OCSCC with at least one pN0 hemi-neck in a 1:2 ratio between standard RT volumes and omission of RT to the pN0 hemi-neck(s). Patients will be stratified based on overall nodal status (nodal involvement vs. no nodal involvement) and use of concurrent chemotherapy. The primary endpoint is regional failure in the pN0 hemi-neck(s); we hypothesize that a 2-year regional recurrence of 20% or less will be achieved. Secondary endpoints include overall and progression-free survival, local recurrence, rate of salvage therapy, toxicity and QoL. Discussion This study will provide an assessment of omission of RT to the dissected pN0 hemi-neck(s) on oncologic outcomes, QoL and toxicity. Results will inform the design of future definitive phase III trials. Trial registration Clinicaltrials.gov identifier: NCT03997643 . Date of registration: June 25, 2019, Current version: 2.0 on July 11 2020.

Background Patients with human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPC) have substantially better treatment response and overall survival (OS) than patients with HPV-negative disease. Treatment options for HPV+ OPC can involve either a primary radiotherapy (RT) approach (± concomitant chemotherapy) or a primary surgical approach (± adjuvant radiation) with transoral surgery (TOS). These two treatment paradigms have different spectrums of toxicity. The goals of this study are to assess the OS of two de-escalation approaches (primary radiotherapy and primary TOS) compared to historical control, and to compare survival, toxicity and quality of life (QOL) profiles between the two approaches. Methods This is a multicenter phase II study randomizing one hundred and forty patients with T1–2 N0–2 HPV+ OPC in a 1:1 ratio between de-escalated primary radiotherapy (60 Gy) ± concomitant chemotherapy and TOS ± de-escalated adjuvant radiotherapy (50–60 Gy based on risk factors). Patients will be stratified based on smoking status (< 10 vs. ≥ 10 pack-years). The primary endpoint is OS of each arm compared to historical control; we hypothesize that a 2-year OS of 85% or greater will be achieved. Secondary endpoints include progression free survival, QOL and toxicity. Discussion This study will provide an assessment of two de-escalation approaches to the treatment of HPV+ OPC on oncologic outcomes, QOL and toxicity. Results will inform the design of future definitive phase III trials. Trial Registration Clinicaltrials.gov identifier: NCT03210103 . Date of registration: July 6, 2017, Current version: 1.3 on March 15, 2019.

Background Transoral surgery (TOS), particularly transoral robotic surgery (TORS) has become the preferred modality in the United States for the treatment of early stage oropharyngeal cancer, largely due to assumptions of fewer toxicities and improved quality of life compared to primary radiotherapy (RT). However, these assumptions are based on retrospective analysis, a subset of which utilize primary RT groups not limited to T1-2 stage tumors for which transoral robotic surgery is FDA approved. Thus, there is potential for underestimating survival and overestimating toxicity, including treatment related mortality, in primary RT. Methods Consecutive cases of early T-stage (T1–T2) oropharyngeal cancer presenting to the London Health Sciences Centre between 2014 and 2018 treated with RT or chemoradiation (CRT) were reviewed. Patient demographics, treatment details, survival outcomes and toxicity were collected. Toxicities were retrospectively graded using the Common Terminology Criteria for Adverse Events criteria. Results A total of 198 patients were identified, of which 82% were male and 73% were HPV-positive. Sixty-eight percent of patients experienced a grade 2 toxicity, 48% a grade 3 and 4% a grade 4. The most frequent toxicities were dysphagia, neutropenia and ototoxicity. The rates of gastrostomy tube dependence at 1 and 2 years were 2.5% and 1% respectively. There were no grade 5 (fatal) toxicities. HPV-positive patients experienced improved 5-year overall survival (86% vs 64%, p = 0.0026). Conclusions Primary RT or CRT provides outstanding survival for early T-stage disease, with low rates of severe toxicity and feeding tube dependence. This study provides a reference for comparison for patients treated with primary transoral surgery.

Purpose: Accurate contouring in head and neck cancer (HNC) is critical. International consensus guidelines recommend the 5 + 5 mm rule for expansions around the primary tumor, wherein high-and low-dose clinical target volumes (CTV-P1 and CTV-P2, respectively) are created using successive 5 mm expansions on the gross tumor volume. To our knowledge, the necessity of a low-dose CTV-P2 has never been assessed; therefore, we evaluated the dosimetric impact of adding a CTV-P2 expansion using the 5 + 5 mm rule compared with contouring with a high-dose CTV-P1 alone. Methods and materials: A retrospective study of clinically delivered (chemo)radiation therapy treatment plans for HNC was conducted. All patients were treated with 70 Gy in 35 fractions using volumetric modulated arc therapy in a single phase. CTV-P2 was retrospectively contoured per guidelines as a 5 mm expansion on CTV-P1 from the clinical plan, carving off specified barriers to spread. We used a 5 mm planning target volume (PTV) expansion. Our primary outcome was whether 95% of the volume of the PTV for the CTV-P2 contour (ie, PTV-P2) received at least 56 Gy. To assess dose falloff, the coverage of a PTV ring structure was created by subtracting PTV-P1 from PTV-P2. Results: Twenty-seven patients from 4 HNC subsites (base of tongue, tonsil, hypopharynx, and supraglottic larynx) were included. In all 108 treatment plans, at least 95% of the PTV-P2 structure received at least 56 Gy. The minimum volume of the PTV-P2 structure receiving at least 56 Gy was 97.4%. Eight of 108 treatment plans had borderline coverage of the PTV ring substructure alone. Conclusions: Adding a CTV-P2 structure using the 5 + 5 mm rule had no dosimetric impact, adds contouring time, adds treatment planning complexity, and could potentially introduce errors. The 5 + 5 mm rule may have value in other settings, such as when smaller PTV margins are used, and warrants further evaluation with prospective or randomized studies. (C) 2019 The Author(s). Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.

We read the ORATOR study by Anthony C Nichols and colleagues, 1 Nichols AC Theurer J Prisman E et al. Radiotherapy versus transoral robotic surgery and neck dissection for oropharyngeal squamous cell carcinoma (ORATOR): an open-label, phase 2, randomised trial. Lancet Oncol. 2019; 20: 1349-1359 Summary Full Text Full Text PDF PubMed Scopus (232) Google Scholar published in The Lancet Oncology, with great interest. The authors designed a phase 2, randomised, controlled trial comparing the functional outcome of radiotherapy (with or without concomitant systemic therapies) with that of transoral robotic surgery (TORS) and neck dissection (with or without adjuvant concomitant chemoradiotherapy) for the treatment of T1–T2, N0–2 oropharyngeal squamous cell carcinoma (OPSCC). Radiotherapy versus transoral robotic surgery and neck dissection for oropharyngeal squamous cell carcinoma (ORATOR): an open-label, phase 2, randomised trialPatients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. Full-Text PDF Sparing of swallowing-related organs in radiotherapy for oropharyngeal squamous cell carcinoma–Authors’ replyWe thank Rosario Mazzola and colleagues for their interest in the ORATOR trial.1 They suggest that quality of life after radiotherapy could be improved by reducing the radiation doses delivered to the swallowing organs at risk and the cochlea. Although reducing these doses might seem beneficial, the actual clinical impact is unclear. A randomised trial from 2018 evaluated cochlear sparing in the setting of radiotherapy for parotid cancers, and found that cochlear avoidance did not translate into reduced rates of clinically relevant hearing loss. Full-Text PDF

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has risen rapidly, due to an epidemic of human papillomavirus (HPV) infection. Radiation therapy (RT) has historically been the standard treatment, but transoral robotic surgery (TORS) has surpassed RT in the US as the most common approach, based on assumptions of reduced toxicity or improved quality of life (QOL). No randomized trials have previously compared these treatments. The ORATOR trial (NCT01590355) enrolled patients with T1-T2 N0-2(≤4 cm) OPSCC amenable to TORS. We randomly assigned patients, stratified by p16 status, to RT (70 Gy/35 fractions, or as chemoradiotherapy [CRT] if N1-2) vs. TORS (± adjuvant RT or CRT based on pathology). The primary endpoint was a definitive comparison of swallowing QOL at 1-year using the MD Anderson Dysphagia Inventory (MDADI), powered to detect a 10-point improvement (a clinically-meaningful change [CMC]) in the TORS arm. Secondary endpoints included adverse events (AEs), other QOL outcomes [including EORTC Head and Neck-35 (H&N-35) scale and other scales], overall and progression-free survival (OS, PFS). Herein we report primary and secondary outcomes with a post-hoc analysis of outcomes by treatment intensity. Between 2012 and 2017, 68 patients were randomized (n=34 in each arm), at 6 centres in Canada and Australia. Median age was 59 years; 87% were male. Primary tumors sites were palatine tonsil (74%) or base of tongue (26%). Arms were well-balanced for baseline factors, including p16 status (88% in each arm). Median follow-up was 27 months. MDADI scores at 1-year were statistically superior in the RT arm (mean ± SD: 86.9 ± 11.4 vs. 80.1 ± 13.0 in the TORS arm; p=0.042), but not meeting the definition of a CMC. For other QOL metrics, outcomes were similar at 1-year. Percutaneous feeding tube rates at 1-year were 3% (n=1) vs. 0% respectively. Rates of treatment-related grade ≥ 2 AEs were similar (91% vs. 100%, p=0.24), with more neutropenia, hearing loss, constipation and tinnitus in the RT arm and more trismus in the TORS arm (all p<0.05). There was one TORS bleeding-related death. The arms were similar in OS (p=0.88) and PFS (p=0.63). Longitudinal QOL analysis over time confirmed the statistical superiority of RT in the MDADI scores (p<0.001), with average differences below the threshold of a CMC. In the RT Arm, 1-year MDADI scores based on treatment intensity were as follows: RT alone 89.5 ± 6.2; CRT alone 88.0 ± 11.5 RT; RT/CRT with salvage surgery 68.0 ± 7 (ANOVA p=0.044). In the TORS arm, the 1-year MDADI scores by treatment intensity were: TORS alone 82.8 ± 10.5; TORS with RT 78.5 ± 11.0; TORS with CRT 80.4 ± 19.6 (ANOVA p=0.760). RT had superior swallowing QOL scores at 1-year compared to TORS, but the difference was not a CMC. Toxicity patterns differed between the arms. Patients with OPSCC should be counselled on the advantages and disadvantages of both modalities.

Background Transoral robotic surgery (TORS) with concurrent neck dissection has supplanted radiotherapy in the USA as the most common treatment for oropharyngeal squamous cell carcinoma (OPSCC), yet no randomised trials have compared these modalities. We aimed to evaluate differences in quality of life (QOL) 1 year after treatment. Methods The ORATOR trial was an investigator-initiated, multicentre, international, open-label, parallel-group, phase 2, randomised study. Patients were enrolled at six hospitals in Canada and Australia. We randomly assigned (1:1) patients aged 18 years or older, with Eastern Cooperative Oncology Group scores of 0-2, and with T1-T2, N0-2 ( <= 4 cm) OPSCC tumour types to radiotherapy (70 Gy, with chemotherapy if N1-2) or TORS plus neck dissection (with or without adjuvant chemoradiotherapy, based on pathology). Following stratification by p16 status, patients were randomly assigned using a computer-generated randomisation list with permuted blocks of four. The primary endpoint was swallowing-related QOL at 1 year as established using the MD Anderson Dysphagia Inventory (MDADI) score, powered to detect a 10-point improvement (a clinically meaningful change) in the TORS plus neck dissection group. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov (NCT01590355) and is active, but not currently recruiting. Findings 68 patients were randomly assigned (34 per group) between Aug 10, 2012, and June 9, 2017. Median followup was 25 months (IQR 20-33) for the radiotherapy group and 29 months (23-43) for the TORS plus neck dissection group. MDADI total scores at 1 year were mean 86.9 (SD 11.4) in the radiotherapy group versus 80.1 (13.0) in the TORS plus neck dissection group (p=0 - 042). There were more cases of netttropenia (six [18%] of 34 patients vs none of 34), hearing loss (13 [38%] vs five 115%1), and tinnitus (12 [35%] vs two [6%]) reported in the radiotherapy group than in the TORS plus neck dissection group, and more cases of trismus in the TORS plus neck dissection group (nine [26%] vs one [3%]). The most common adverse events in the radiotherapy group were dysphagia (n=6), hearing loss (n=6), and mucositis (n=4), all grade 3, and in the TORS plus neck dissection group, dysphagia (n=9, all grade 3) and there was one death caused by bleeding after TORS. Interpretation Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. Copyright (C) 2019 Elsevier Ltd. All rights reserved.

During radiation therapy of head and neck cancer, the decision to consider replanning a treatment because of anatomical changes has significant resource implications. We developed an algorithm that compares cone-beam computed tomography (CBCT) image pairs and provides an automatic alert as to when remedial action may be required. Retrospective CBCT data from ten head and neck cancer patients that were replanned during their treatment was used to train the algorithm on when to recommend a repeat CT simulation (re-CT). An additional 20 patients (replanned and not replanned) were used to validate the predictive power of the algorithm. CBCT images were compared in 3D using the gamma index, combining Hounsfield Unit (HU) difference with distance-to-agreement (DTA), where the CBCT study acquired on the first fraction is used as the reference. We defined the match quality parameter (MQPx ) as a difference between the xth percentiles of the failed-pixel histograms calculated from the reference gamma comparison and subsequent comparisons, where the reference gamma comparison is taken from the first two CBCT images acquired during treatment. The decision to consider re-CT was based on three consecutive MQP values being less than or equal to a threshold value, such that re-CT recommendations were within ±3 fractions of the actual re-CT order date for the training cases. Receiver-operator characteristic analysis showed that the best trade-off in sensitivity and specificity was achieved using gamma criteria of 3 mm DTA and 30 HU difference, and the 80th percentile of the failed-pixel histogram. A sensitivity of 82% and 100% was achieved in the training and validation cases, respectively, with a false positive rate of ~30%. We have demonstrated that gamma analysis of CBCT-acquired anatomy can be used to flag patients for possible replanning in a manner consistent with local clinical practice guidelines.

Purpose:This article presents a fast algorithm for comparing 3‐D anatomy from Cone‐Beam CT (CBCT) imaging using the gamma comparison index and to demonstrate how this can be used to flag patients for possible re‐planning of treatment.Methods:CBCT scans acquired on a Varian linear accelerator during treatment were used as input to the gamma comparator using thresholds of 5 mm distance to agreement and 30 Hounsfield Unit CT number difference. The fraction 1 CBCT study was initially used as the reference. Should there be a re‐plan during treatment, the reference resets to the CBCT study acquired on the day 1 of the re‐plan. Histograms of failing pixels (γ > 1) were generated from each 3‐D gamma map. An indicator of anatomy congruence, the match quality parameter (MQP), was derived from failed pixel histograms using the 90th percentile gamma value. The MQP was plotted versus fraction number and related to actual repeat computed tomography (re‐CT) order dates as decided by a radiation oncologist. From this, decision criteria were derived for the algorithm to “trigger” re‐CT consideration and predictive power was scored using receiver‐operator characteristic (ROC) analysis.Results:The MQP plot generally showed that the on‐line match from CBCT image guidance deteriorated as the treatment progressed due to weight loss and tumor regression. The optimized MQP criteria for triggering re‐CT consideration demonstrated high sensitivity and specificity, consistent with actual re‐CT order dates within ± 3 fractions. Out of 20 patients that were actually re‐planned, the algorithm failed to trigger a re‐CT recommendation only twice and this was caused by CBCT ring artifacts.Conclusion:We have demonstrated that gamma comparisons can be used to evaluate CBCT‐acquired anatomy pairs and, from this, an algorithm can be “trained” to flag patients for possible re‐planning in a manner consistent with local radiation oncology practice.

To quantify time savings for the Radiation Oncologist resulting from the implementation of Medical Directives for two Advanced Practice Radiation Therapists working at an academic cancer centre. Medical directives were obtained for two advanced practice radiation therapy roles at London Regional Cancer Program. One aligned with the head and neck (H&N) disease site team the other with the skin disease site team. Medical directives obtained were determined by the site teams based on need and prior training obtained by the advanced practice therapist (APRT). Prior learning was assessed through concordance data collection and physician lead mentoring. Data was collected for a three month period after implementation of the medical directives. Time for each task was determined by physician survey. Total time savings was determined by total number of tasks multiplied by average task time. Preliminary data collection for the H&N Advanced Practice role from July 2015 to September 2015 shows an average of 12 orders per month for radiotherapy planning completed by the APRT. Additionally, an average of 18.3 referrals per month for medical oncology, dental and speech pathology., An average of 16.7 Image Guided Radiation Therapy (IGRT) approvals were also completed by the APRT per month. This translates to an average savings of 295 minutes saved per month to the Radiation Oncologist after the implementation of medical directives. Data collection for the Skin Advanced Practice role is ongoing, the medical directive having recently been approved, and will be available by January for inclusion. Implementation of medical directives produces direct time savings for the radiation oncologist and has a positive impact on efficiency.

This paper introduces a model that has been developed from first principles to support the analysis of components associated with wet heating control systems commonly found in the UK. Significant progress has been made to reduce the energy consumption of typical heating systems over past decades by replacing components within the heating system with more energy efficient hardware such as condensing boilers. However, to make further reductions in energy usage, heating systems require advanced control needing novel devices incorporating sensors and actuators. The model presented in this paper differentiates from many commercial software packages in that the model allows comparable studies of alternative heating systems that can be used for the analysis of novel devices and control methods to establish their effects on energy usage and thermal comfort. This paper applies the model to simulate and analyse the use of electronic Temperature Regulated Valves (TRVs) that can be retrofitted to radiators for more efficiently controlling the thermal environment in a typical UK dwelling. The paper shows the potential for energy savings from the retrofit of electronic TRV hardware whilst maintaining a comfort level that is acceptable to the user.