Therapeutic cannabis use by patients with cancer in Canada: A national survey of the experiences, opinions and information needs of Radiation Therapists.

PURPOSE: To understand the experiences, opinions and information needs of Canadian Radiation Therapists when caring for cancer patients who are taking cannabis for therapeutic purposes (CTP). METHODS: The study employed prospective data collection, via a single cross-sectional web-based questionnaire. After REB approval, the questionnaire was distributed electronically to all Radiation Therapists across Canada. The questionnaire was open for a one month accrual, with reminders sent at two and four weeks. The raw data was aggregated using standard descriptive statistics. The response differences between naturally occurring demographic cohorts was determined using inferential statistics. RESULTS: Two hundred and eighty two Therapists completed the questionnaire (25.6%), of which 19.1% reported being approached by patients to talk about cannabis more than once per month and 4.4% reported initiating a conversation with patients about cannabis. There were no differences between the provinces or catchment areas regarding how common or socially acceptable cannabis use by patients was. Confidence in discussing cannabis was strongly positively correlated with ratings of current knowledge (r² 0.77). Of the respondents, 99.9% believed that their radiation therapy training did not prepare them to support patients using cannabis. CONCLUSIONS: The data revealed that patients more frequently seek out guidance for CTP than Therapists initiate those discussions. This lack of Therapist willingness to begin cannabis conversations was associated with the low levels of knowledge. Almost all Therapists recognized the limitations of their knowledge and expressed interest in receiving further information about cannabis. The findings of this study strongly advocate for the development of educational tools to meet Therapists clinical needs.

The dosimetric underpinning of bladder filling criteria for prostate image-guided volumetric modulated arc therapy.

OBJECTIVES: Repeated CT simulation imaging is common at our institution due to failure to achieve acceptable bladder filling in patients undergoing prostate radiotherapy. There is operational value in re-assessing the validity of the bladder filling assessment criteria by comparing the quality of two plans optimized based on either an "Accepted" or "Rejected" bladder status. METHODS: Twenty prostate patients with repeated CT simulation imaging were included. For each patient, a VMAT plan created using the "Rejected" bladder was compared with the "Accepted" bladder plan. Then, delivered dose to bladder was estimated using ≥4 CBCTs to measure number of fractions with major bladderdose violation (>5% difference) for both plans. Bladder heights of fractions without major bladder dose violations were compared to those with a violation to determine a threshold height for bladder filling acceptability. RESULTS: Using the "Accepted" bladder plans for treatment resulted in 30/175 fractions with major dose violations. These 30 bladders were significantly shorter than those without major violation (mean 28 vs 43mm, p < 0.05). The "Rejected" bladder plans delivered a lower dose to the bladder by ≥5% than the '"Accepted" bladder plans in 59% of fractions, and the number of fractions with major dose violations was 17. CONCLUSIONS: Using a shorter bladder for plan optimization resulted in better bladder sparing during treatment and improved compliance to protocol specific bladder dose constraints. A bladder height range of 20-40 mm measured between the bladder dome and the superior aspect of the symphysis pubis is recommended for prostate radiotherapy requiring a full bladder protocol. ADVANCES IN KNOWLEDGE: Using real patient data from simulation and treatment, this study established a range of bladder height that can be measured easily in a clinical setting for assessing adequacy of bladder filling for prostate radiotherapy.

Could knowledge of patient demographics facilitate a personalized approach to radiation therapy patient education?

INTRODUCTION: Using patient demographics to tailor cancer patient education processes results in improved patient outcomes. However, there is little information on how to successfully tailor radiation therapy (RT) educational content and delivery. The aim of this quality improvement project was to describe the information preferences of a diverse group of patients undergoing RT and determine if different RT education processes were associated with certain patient demographics. MATERIALS AND METHODS: An educational needs assessment questionnaire, based on a validated tool, was offered to all patients undergoing RT on a single day. Questionnaire sections included demographics and questions regarding the importance of topics related to RT treatments, desired mode of information delivery, quantity of information, desired timing of information, and satisfaction with information received. Patients were also asked to answer qualitative questions focused on what was working well and what could be improved. Participants' responses were cohorted based on demographic groupings (age, gender, education level) and were tested for statistically significant differences and associations. RESULTS: 130 patients completed the questionnaire. Compared to those over 60 years, more participants who were 50 - 59 years old thought the topics were 'very important' (96% vs 77%, p<0.001) and wanted a higher quantity of information about the topics (80% vs 66%, p<0.001). More participants over 70 years old preferred pamphlets compared to those less than 70 years (48% vs 30%, p<0.047) while more participants under 50 years old preferred one-on-one sessions compared to those older than 50 years (40% vs 25%, p<0.038). Fewer participants <50 years wanted information at their first meeting with the Radiation Oncologist compared to those older than 50 years (57% vs 73%, p<0.001). Compared to the male cohort, more female participants felt the information topics were more important (83% vs 74%, p<0.0001) and had more unmet education needs (29% vs 17%, p<0.001). Compared to those with post-secondary education, more participants with primary or high school education desired a higher quantity of information (76% vs 65%, p<0.001), preferred to receive that information using pamphlets (43% vs 32%, p=0.006) and wanted all the information at the first opportunity (81% vs 67%, p<0.001). CONCLUSIONS: This quality improvement project found that age, gender and education level influenced patient preferences for information quantity, delivery mode and timing of RT education. These findings are promising and support further evaluations to determine a more precise definition of the personal factors that could help to individualize our approach to educating patients receiving RT.

Pre-radiotherapy pain intensity and health-related quality of life in patients with bone metastases at various vertebral levels.

PURPOSE: The spine is the most common site of bone metastasis from cancer and can be divided into 5 locational subsections, varying in mobility. The purpose of this research was to determine if the mobility of the metastases-bearing vertebral segment influenced pre-treatment pain intensity or health-related quality of life (HR-QoL) for patients about to receive palliative radiation therapy for painful spine metastasis. METHODS: This study was a retrospective chart review of patients referred to the Palliative Radiation Oncology Program, about to receive radiation therapy for vertebral metastasis between January 2014 and June 2016. The main variables included patient-reported Edmonton Symptom Assessment Score pain intensity, the EQ-5D score for HR-QoL and the location of the vertebral metastasis (categorized using the SINS mobility score (mobile, junctional, semi-rigid, or rigid)). Various patient, disease and treatment characteristics were also collected, and entered into a multivariate analysis. RESULTS: The eligible sample included 196 patients. Spinal metastases were distributed with approximately equal frequency (~27%) between the junctional, mobile and semi-rigid spine segments. Rigid spine was the least common site for spinal metastases (19%). Patients with metastatic disease in the mobile spine regions experienced greater pre-treatment pain compared to patients with disease in junctional subsections (Odds Ratio [OR] 1.37; p0.012). No relationship between HR-QOL and spinal mobility was found. Multivariate analysis also revealed that spinal metastases from a primary lung diagnosis reported worse pre-treatment pain compared to those from genitourinary cancers (OR 1.15; p0.05). Only age significantly influenced HR-QoL (75-95yrs vs. 35-55yrs; p0.041). CONCLUSIONS: Patients referred to an RT clinic for the treatment of painful spinal metastases have a different distribution of disease throughout the spine compared to those referred for surgery or SBRT. Those with metastases in mobile spine segments were more likely to experience severe pre-treatment pain than those with metastases in junctional segments. Although further corroboration is needed, our results suggest that the mobility of the metastasis-bearing spinal section could be added to the existing list of predictors that aid clinicians in identifying patients that will benefit from closer follow-up or early intervention.

The Raystation conversation: Multidisciplinary perceptions about training, leadership, and communication during implementation of new technology.

PURPOSE: There is very little information guiding cancer centres as they plan for costly and time consuming implementation programs for new technology. The purpose of this research was to explore the perspectives of multiple professional groups directly involved in the implementation of a next generation treatment planning system at a large academic cancer centre . METHODS: This research was a single centre, prospective study using a qualitative design and three-phased approach (interviews, questionnaire, and focus groups). The target population included radiation therapists, oncologists, and physicists that received Raystation training during initial clinical implementation. RESULTS: Training was received positively by most respondents, but the lengthy lead-up time between training and clinical use led to decreased confidence with the software across all professional groups. Multidisciplinary training was not considered useful when learning tool function, but would have been helpful when practicing on clinically relevant cases. Respondents appreciated the proactive communication, as well as the multidisciplinary leadership implementation strategy. Therapist 'Super Users' emerged as a pivotal leadership and communication role in the successful implementation of Raystation. CONCLUSIONS: This research provided valuable multidisciplinary insight into the implementation of Raystation. The multidisciplinary leadership team and proactive communication strategy were considered vital to the success of the implementation. Learner suggestions - such as increasing the number of Therapist 'Super Users', minimizing training-to-clinical lead time, and the creation of practice cases that are more relevant to daily clinical duties - should be incorporated into future training programs for similar new technology.

Prostate or bone? Comparing the efficacy of image guidance surrogates for pelvis and prostate radiotherapy using accumulated delivered dose.

INTRODUCTION: This study assessed the impact of dosimetry to both the target and normal tissue when either bony anatomy (BA) or prostate (PRO) was used as surrogates for image guidance for pelvis and prostate radiotherapy using a dose accumulation process. METHODS: Thirty patients who were prescribed 50-54Gy to the pelvic lymph nodes (PLN) and 78Gy to the prostate/seminal vesicles were included. Daily acquired CBCTs were rigidly registered to the CT using BA and PRO to simulate two different treatment positions. The accumulated delivered dose (DAcc) of PLN, prostate, bladder and rectum for each surrogate were compared with the planned dose. Deviation from the planned dose (ΔDAcc-Plan) of >5% was considered clinically significant. RESULTS: Prostate was displaced from bony anatomy by > 5 mm in 96/755 fractions (12.7%). Deviation between the mean DAcc and the planned dose for PLN and prostate was <2% when either BA or PRO was used. No significant deviation from planned dose was observed for bladder (p > 0.2). In contrary, DAcc for rectum D50 was significantly greater than the planned dose when BA was used (Mean ΔDAcc-Plan = 6%). When examining individual patient, deviation from the planned dose for rectum D50 was clinically significant for 18 patients for BA (Range: 5-21%) and only 8 patients for PRO (Range: 5-8%). CONCLUSIONS: The use of either BA or PRO for image guidance could deliver dose to PLN and prostate with minimal deviation from the plan using existing PTV margins. However, deviation for rectum was greater when BA was used.

Cannabis and Radiation Therapy: A Scoping Review of Human Clinical Trials.

INTRODUCTION: It is estimated that at least 20% of Canadian patients with cancer use cannabis to alleviate symptoms of their disease and/or cope with the side effects of their treatment. Most patients want to learn more about cannabis from their healthcare team, but most oncology professionals feel too uninformed to make recommendations. The purpose of this scoping review was to address this oncology professionals' knowledge gap, by summarizing the literature on evaluations of the benefits and harms of cannabis use before, during, or after radiation therapy (RT). METHODS AND MATERIALS: A literature search was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines, using multiple electronic databases and combinations of key terms. To be included, studies must address the use of cannabis in patients undergoing RT. In vitro and in vivo evaluations, reviews, and editorials were excluded. Eligible full text manuscripts were then subjected to a formal risk of bias assessment using the Cochrane RoB 2.0 or ROBINS-I frameworks. RESULTS: A total of 48 records were identified, and 8 articles were included after vetting. These 8 studies suggest that the use of cannabinoids may calm anxious patients about to start RT, reduce nausea and vomiting consistent with the contemporary standard of care, reduce the symptoms of relapse for patients with glioma, and provide symptom relief >3 years after head and neck RT but not during or immediately. Six of these studies contained a high risk of bias (eg lack of randomization, poor blinding, and subjective outcome assessments). Most studies reported mild episodes of drowsiness and dry mouth with Δ9tetrahydrocannabinol, but substantial rates of dizziness, fatigue, and disorientation were also seen. It is important to note that these studies did not measure the impact of long-term cannabis consumption. CONCLUSIONS: The existing body of literature evaluating the use of cannabinoids by patients undergoing RT is very limited. Well-designed randomized controlled trials are urgently needed, which address the significant design flaws of previous studies and evaluate the impact of phytocannabinoids in patients undergoing RT.

Can Conformity-Based Volumetric Modulated Arc Therapy Improve Dosimetry and Speed of Delivery in Radiation Therapy to Lumbosacral Spine Compared with Conventional Techniques?

PURPOSE: Volumetric modulated arc therapy (VMAT) has generally been perceived as too time and resource intensive for palliative radiation therapy mainly because of the need for extensive organs at risk contouring. Dose-limiting conformity-based objectives can be automatically generated and are commonly used to conform isodoses closely around the target volumes during inverse planning. The aim of this study was to determine if conformity-based objectives can be used to create VMAT plans for lumbosacral spine palliative radiation therapy without organs at risk contours, which will improve conformity, dose homogeneity, and speed of delivery compared with standard forward planning approaches. METHODS: A total of 25 patients were retrospectively replanned using three different planning techniques: (1) anterior-posterior parallel opposed pair (POP); (2) single isocenter anterior-posterior half-beam block junctioned to three fields, posterior and two laterals (JUNC); and (3) VMAT single arc. Treatment volume included L1-S5 vertebrae prescribed to 20 Gy in five fractions. Conformality index, homogeneity index, contour, planning, and treatment time were compared for each technique. RESULTS: Planning target volume V95 ≥95% was maintained for all 75 replans. VMAT was superior to POP and JUNC in terms of conformality (POP 2.0 vs. JUNC 1.8 vs. VMAT 1.2; P < .01) and homogeneity (POP 1.1 vs. JUNC 1.1 vs. VMAT 1.0; P < .01). Planning times for POP were the lowest (3.2 minutes). VMAT and POP had similar delivery times (1.5 minutes), which were approximately half the JUNC delivery time (3.2 minutes). CONCLUSIONS: Conformity-based VMAT was dosimetrically superior to conventional field-based planning and reduced delivery time. This reduction in normal tissue dose as well as reduced time spent on the treatment couch can potentially improve the quality of life in palliative patients receiving radiotherapy to the lumbosacral spine.

Transperitoneal laparoscopic prostatectomy does not increase small bowel within the target volume for postoperative radiotherapy.

PURPOSE: Laparoscopic or robot assisted laparoscopic radical prostatectomy is often performed via a transperitoneal approach for prostate cancer, in contrast to open retropubic radical prostatectomy. Theoretically transgressing the peritoneum may introduce small bowel loops into the pelvis, increasing the risk of small bowel injury with adjuvant radiotherapy. We compared the incidence of small bowel within the planning target volume for radiotherapy to the prostate bed in patients who underwent open retropubic and laparoscopic radical prostatectomy. MATERIALS AND METHODS: A total of 25 patients recently treated with laparoscopic radical prostatectomy prospectively provided consent to undergo radiotherapy planning computerized tomography simulation to assess the incidence of small bowel within the prostate bed planning target volume. These studies were compared to radiotherapy planning computerized tomography in 50 patients who underwent open retropubic radical prostatectomy and received adjuvant or salvage radiotherapy for prostate cancer. For all computerized tomography images 1 blinded observer delineated the distal small bowel loops and 1 blinded radiation oncologist delineated the superior extent of clinical and planning target volumes. RESULTS: The overlap rate between small bowel and planning target volume was 16% in the laparoscopic and open radical prostatectomy groups (p = 0.579). CONCLUSIONS: There is no difference between transperitoneal laparoscopic and open retropubic radical prostatectomy in the incidence of small bowel within the planning target volume for radiotherapy to the prostate bed. Thus, patients who undergo transperitoneal laparoscopic radical prostatectomy do not face a higher risk of toxicity or compromise due to adjuvant or salvage radiotherapy should they require it.

Prostate delineation using CT and MRI for radiotherapy patients with bilateral hip prostheses.

BACKGROUND AND PURPOSE: Prostate cancer patients with bilateral hip prostheses (b-HP) are rare, but pose unique challenges for high-dose radiotherapy. The purpose of this study was to determine the effect of b-HP on prostate delineation using CT and MR. METHODS AND MATERIALS: The planning CT and MR of 7 patients with b-HP were co-registered. Four observers delineated the prostate on both data sets, blinded to the volumes delineated by their peers and those on the alternate image set. Inter-modality differences and inter-observer variability were quantified by calculating 3D volume overlaps. The effect of prostheses physical extent on these variables was evaluated. MR geometric distortion was explored using the differences in vector distances between three intra-prostatic markers (IPMs) on CT and MR. RESULTS: Prostate volumes on CT were consistently larger than MR volumes in all patients when averaged over the 4 observers (+10% to +46%, p<0.001). The mean inter-modality volume overlap was 1.59, which varied significantly between patients (1.35 to 1.82, p=0.04). There was a trend toward smaller inter-observer variability in the MR volumes (1.95 vs. 1.71, p=0.08). No differences could be identified between the IPM vectors on CT and MR. CONCLUSIONS: Although limited by a small sample size, this study found that MR prostate volumes were significantly smaller than those from CT for b-HP patients. The largest differences between CT and MR prostate volumes and the greatest inter-observer variability on CT tended to be seen in patients with the largest prostheses. b-HP do not appear to cause measurable MR geometric distortions in the sequences used.

Inter-professional variability in the assignment and recording of acute toxicity grade using the RTOG system during prostate radiotherapy.

BACKGROUND AND PURPOSE: To compare the routine acute toxicity documentation practices of therapists and oncologists using the RTOG lower GI and GU scales. METHODS AND MATERIALS: Ninety consecutive prostate radiotherapy patients were identified. The weekly urinary and rectal acute toxicity grades routinely documented by therapists and oncologists were collected retrospectively from radiotherapy charts. These data were paired together, and compared between the professional groups. RESULTS: Only RTOG acute toxicity grades between 0 and 2 were recorded by either group. The overall rate of documentation was high (97% therapists/86% oncologists), but the rate of quantitative documentation was low from the oncologists (46%) who used a free-form text field for recording purposes. There was no significant difference in the incidence of maximum grade of acute toxicity reported by either professional group (p>0.1). There was good RTOG score concordance between the observer groups (kappa=0.756), with pair-wise absolute agreement in 76%. Pair-wise discrepancies between the observers were commonly attributable to differences in the time/date of assessment. CONCLUSIONS: Despite some methodological limitations, this study found that therapist-assessed RTOG acute toxicity grades demonstrated a good level of agreement with the grades assigned by their oncologist colleagues.

The Educational Utility of Blogging for MRI Technologists.

INTRODUCTION: The value of a blog as an educational tool is thought to be underestimated by health care professionals. This research aimed to explore the MRI educational utility of blogs, and to determine who was participating in writing those blogs. It was hoped that this research would increase awareness of alternative education formats that would be useful for MRI technologists. METHODS: Between March and April of 2017, an online blog search was performed using MRI-related keywords. Strict exclusion criteria were then applied. Two coders independently used lean coding to analyse selected blog posts and organized the codes into themes. Data were tested for intercoder reliability. RESULTS: Researchers analysed 39 posts from 9 blogs and identified the following themes: focus on MRI techniques and technologies, knowledge dissemination, sharing of experience, collaborative learning, authorship, and informal writing. Bloggers, self-identified as practitioners or scholars, communicated about research projects and used an informal writing style. Evidence of intentional teaching of MRI-specific content and sharing of professional and personal experiences was found. Communication between authors and readers from most of the MRI professions was observed, with the exception of MRI technologists. CONCLUSIONS: This research found that MRI-related blogs provide a credible and accessible forum for the sharing and discussion of knowledge, experiences, and ideas. Although many MRI professionals author blogs, MRI technologists do not seem to participate in this form of communication. As social media gains in popularity within the medical radiation technologist profession, it is hoped that more MRI technologists will make use of blogging to facilitate learning, collaboration, and communication.

Comparison of 3 image-guided adaptive strategies for bladder locoregional radiotherapy.

The objective of this study was to compare the dosimetric differences of a population-based planning target volume (PTV) approach and 3 proposed adaptive strategies: plan of the day (POD), patient-specific PTV (PS-PTV), and daily reoptimization (ReOpt). Bladder patients (n = 10) were planned and treated to 46 Gy in 23 fractions with a full bladder in supine position by the standard strategy using a population-based PTV. For each patient, the adaptive strategy was executed retrospectively as follows: (1) POD-multiple distributions of various PTV sizes were generated, and the appropriate distribution based on the bladder of the day was selected for each fraction; (2) PS-PTV-population-based PTV was used for the first 5 fractions and a new PTV derived using information from these fractions was used to deliver the remaining 18 fractions; and (3) ReOpt-distribution was reoptimized for each fraction based on the bladder of the day. Daily dose was computed on all cone beam computed tomographies (CBCTs) and deformed back to the planning computed tomography (CT) for dose summation afterward. V95_Accu, the volume receiving an accumulated delivered dose of 43.7 Gy (95% prescription dose), was measured for comparison. Mean V95_Accu (cm3) values were 1410 (standard deviation [SD]: 227), 1212 (SD: 186), 1236 (SD: 199), and 1101 (SD: 180) for standard, POD, PS-PTV, and ReOpt, respectively. All adaptive strategies significantly reduced the irradiated volume, with ReOpt demonstrating the greatest reduction compared with the standard (- 25%), followed by PS-PTV (- 16%) and POD (- 12%). The difference in the magnitude of reduction between ReOpt and the other 2 strategies reached statistical significance (p = 0.0006). ReOpt is the best adaptive strategy at reducing the irradiated volume because of its frequent adaptation based on the daily geometry of the bladder. The need to adapt only once renders PS-PTV to be the best alternative adaptive strategy.

Patterns of practice of adaptive re-planning for anatomic variances during cone-beam CT guided radiotherapy.

PURPOSE: Substantial, unanticipated anatomic variances during cone-beam CT (CBCT)-guided radiotherapy can potentially impact treatment accuracy and clinical outcomes. This study assessed patterns of practice of CBCT variances reported by RTTs and subsequent interventions for multiple-disease sites. METHODS: A chart review was conducted at a large cancer centre for patients treated with daily online CBCT-guided radiotherapy. Patients selected for review were identified via RTT-reported variances that then triggered offline multi-disciplinary assessment. Cases were categorized by the type of anatomic variance observed on CBCT and any further interventions recorded such as un-scheduled adaptive re-planning. RESULTS: Over a 1-year period, 287 variances from 261 patients were identified (6.2% of the 4207 patients treated with daily CBCT-guided radiotherapy), most often occurring within the first 5 fractions of the treatment course. Of these variances, 21% (59/287) were re-planned and 3.5% (10/287) discontinued treatment altogether. Lung was the most frequent disease-site (27% of 287 variances) reported with IGRT-related variances although head and neck and sarcoma were most frequently re-planned (19% of 59 re-plans for each site). Technical or clinical rationales for re-planning were not routinely documented in patient medical records. All disease-sites had numerous categories of variances. Three of the four most frequent categories were for tumor-related changes on CBCT, and the re-planning rate was highest for tumor progression at 25%. Normal tissue variances were the second most frequency category, and re-planned in 14% of those cases. CONCLUSION: RTTs identified a wide range of anatomic variances during CBCT-guided radiotherapy. In a minority of cases, these substantially altered the care plan including ad hoc adaptive re-planning or treatment discontinuation. Improved understanding of the clinical decisions in these cases would aid in developing more routine, systematic adaptive strategies.

Implementing Workshops to Improve Radiation Therapists' Knowledge and Attitudes about Sexual Health Issues in Cancer Patients.

OBJECTIVES: Although it is widely acknowledged that radiotherapy treatments can have a negative impact on a patient's sexual health, this aspect of side effect management is not commonly addressed by radiation therapists or by other cancer specialists. It is important for radiation therapists to recognize and address possible sexual health issues to provide a holistic approach to care. This quality-improvement project was designed to help radiation therapists discuss the sexual health needs of patients undergoing radiotherapy by improving their clinical knowledge, skills, and comfort level about the topic. METHODS: This study used a cross-sectional descriptive prequestionnaire/postquestionnaire design, in which data were collected from a nonrandom sample of radiation therapists at a single urban radiation therapy center. Participants attended two 90-minute sexual health education workshops specifically designed for radiation therapists and completed online preworkshop/postworkshop questionnaires. All questions were quantitative in nature. The survey consisted of multiple-choice, multiple-select, and five-point Likert-scale questions. Descriptive analysis was used for data analysis. RESULTS: The results of this improvement project indicated that participants had introductory-level knowledge about how cancer treatments can impact patients' sexual health. Although there is potential for some changes in the general knowledge levels of the participants after the initiative, two general workshops about the topic are not enough to have radiation therapists feel comfortable enough with the topic to change their clinical practice. CONCLUSION: This project identified that although radiation therapists acknowledge the importance of discussing sexual health concerns as part of delivering holistic health care, lack of knowledge and expertise with the topic is a main barrier to initiating conversations. To help prepare radiation therapists, education and training initiatives, which build on knowledge and offer opportunities to develop and apply practical skills in both simulated and real-life situations, should be created. This can help to increase confidence in the sexual health counseling provided, which may result in more radiation therapists frequently engaging in these important sexual health conversations.

Quantification of interobserver variability in image registration using cone beam CT for partial bladder radiotherapy-a comparison between lipiodol and bladder wall surface.

OBJECTIVE:: The use of lipiodol or bladder wall surface (BWS) for image guidance has improved the treatment quality for partial bladder irradiation. Currently, this procedure is manually performed by different users. This study assessed the interobserver variability of using image guidance for partial bladder irradiation. METHODS:: 7 observers were prospectively recruited to manually register 5 cone beam CTs (CBCT) from each of 20 bladder cancer patients with lipiodol injected for tumor demarcation. Lipiodol and BWS were used to register the CBCT to pre-treatment reference images, and displacement values in three directions were collected. Mean difference among observers and the 95% limit of agreement were calculated to measure interobserver variability. Margin required and the resultant treatment volume were compared between the surrogates. RESULTS:: A total of 4200 displacement values were collected for analysis. Lipiodol was superior to BWS, with a mean difference among observers of <2 mm and a 95% limit of agreement of <5 mm in all directions. Of the three directions, greatest variability was observed in the superior-inferior direction for both surrogates, hence requiring a larger margin than the other two directions. After applying the corresponding margin, the mean volume of BWS-planning target volume was calculated to be significantly larger than lipiodol-planning target volume (166 cm3vs 134 cm3, p < 0.05). CONCLUSIONS:: The use of lipiodol achieved a higher interobserver agreement than BWS. A larger margin in the superior-inferior direction is recommended due to greater interobserver variability observed in this direction for both surrogates. ADVANCES IN KNOWLEDGE:: The uncertainty associated with the image registration by multiple observers for bladder image-guided radiotherapy is quantified for two surrogates.

A Phase 1 Pilot Study of Preoperative Radiation Therapy for Prostate Cancer: Long-Term Toxicity and Oncologic Outcomes.

PURPOSE: Neoadjuvant radiation therapy (RT) improves disease control in various cancers and has become an established oncologic treatment strategy. During 2001 to 2004, we conducted a phase 1 pilot study assessing the role of short-course preoperative RT (PreORT) for men with unfavorable intermediate- and high-risk localized prostate cancer. Herein, we present long-term follow-up toxicity and oncologic outcomes. METHODS AND MATERIALS: Eligible patients had histologically proven prostate cancer, cT1-T2N0M0 disease, prostate-specific antigen >15 to 35 ng/mL regardless of Gleason score, or prostate-specific antigen 10 to 15 ng/mL with Gleason score ≥7. Patients received 25 Gy in 5 consecutive daily fractions (5 Gy per fraction) to the prostate only, followed by radical prostatectomy within 14 days after RT completion. Primary outcomes were intraoperative morbidity and late genitourinary (GU) and gastrointestinal toxicities. RESULTS: In total, 15 patients were enrolled; 14 patients completed PreORT followed by radical prostatectomy, which also included bilateral lymph node dissections in 13 cases. Median follow-up was 12.2 years (range, 6.7-16.3). Late GU toxicity was common, with 2 patients (13.3%) experiencing G2 toxicity and 6 patients (40%) G3 toxicity. There were no patients with G4 to G5 late GU toxicity. Late gastrointestinal toxicity was infrequent, with only 1 patient (6.7%) experiencing transient G2 proctitis. At last follow-up, 8 (53.3%) and 6 (40%) patients experienced biochemical and metastatic disease recurrence, respectively. CONCLUSIONS: The use of PreORT in men with high-risk prostate cancer is associated with unexpected high rates of late GU toxicity. Future studies examining the role of RT preradical prostatectomy must cautiously select RT technique and dose schedule. Importantly, long-term follow-up data are essential to fully determine the therapeutic index of PreORT in the management of localized disease.

The effect of changing technique, dose, and PTV margin on therapeutic ratio during prostate radiotherapy.

PURPOSE: To quantify the dosimetric and radiobiological changes seen when using intensity-modulated radiation therapy (IMRT) or planning target volume (PTV) margin reduction with consistent planning parameters in a representative sample of localized prostate cancer patients. METHODS AND MATERIALS: Twenty patients were randomly selected from a cohort that received 79.8 Gy using six-field conformal radiotherapy. Using the clinical contours, PTV margin, planning system, and dose constraints, five-field IMRT plans were generated for 79.8, 83.8, and 88.0 Gy. The 88.0-Gy IMRT plan was then reoptimized with a PTV margin reduced to 3 mm. These plans were then compared using various dosimetric and radiobiological endpoints calculated for various alpha/beta. RESULTS: Intensity-modulated RT resulted in greater conformity to the PTV (p < 0.001). No improvement in mean normal tissue complication probabilities in the rectal wall (NTCPrw) was seen, and the modified therapeutic ratio (TR(mod)) was largely unchanged between six-field conformal and IMRT for the majority of the patients. When IMRT was used to escalate dose, NTCPrw increased by 9% at each 5% prescription increase (p < 0.001). Reducing the posterior PTV margin from 7 mm to 3 mm for an IMRT plan reduced the mean NTCPrw by 12% (p < 0.001) and resulted in a trend toward increased TR(mod)(p = 0.005). Changes in TR(mod) between conformal and IMRT planning or PTV reduction showed large interpatient variability. CONCLUSIONS: Changing from conformal to IMRT, or from PTV(10-7) to PTV(3), did not produce a uniform interpatient increase in TR(mod)when the CTV contained the prostate alone. Radiobiological benefits of these two methods seem to be dependent on the particular anatomy of individual patients, supporting the use of patient-specific margin, planning, and dose prescription strategies.

A randomized comparison of interfraction and intrafraction prostate motion with and without abdominal compression.

BACKGROUND AND PURPOSE: To quantify inter- and intrafraction prostate motion in a standard VacLok (VL) immobilization device or in the BodyFix (BF) system incorporating a compression element which may reduce abdominal movement. MATERIALS AND METHODS: Thirty-two patients were randomly assigned to VL or BF. Interfraction prostate motion >3 mm was corrected pre-treatment. EPIs were taken daily at the start and end of the first and last treatment beams. Interfraction and intrafraction prostate motion were measured for centre of mass (COM) and individual markers. RESULTS: There were no significant differences in interfraction (p0.002) or intrafraction (p0.16) prostate motion with or without abdominal compression. Median intrafraction motion was slightly smaller than interfraction motion in the AP (7.0 mm vs. 7.6 mm) and SI direction (3.2 mm vs. 4.7 mm). The final image captured the maximal intrafraction displacement in only 40% of fractions. Our PTV incorporated >95% of total prostate motion. CONCLUSIONS: Intrafraction motion became the major source of error during radiotherapy after online correction of interfraction prostate motion. The addition of 120 mbar abdominal compression to custom pelvic immobilization influenced neither interfraction nor intrafraction prostate motion.

"I'm Just Guessing These Answers!" An Evaluation of the (In)Accuracy of Patient-Reported Medical History Collected as Part of a Breast Imaging Program.

INTRODUCTION: Hundreds of thousands of Ontario women receive breast screening imaging each year. The patient's medical history is a vital tool used to personalize breast screening approaches. This study evaluated the accuracy of self-reported medical and imaging history in patients about to receive breast imaging procedures in a large urban Canadian hospital. The patient experience with using a blank screening form vs. a novel prefilled screening form was also evaluated. METHODS AND MATERIALS: The study was conducted in two phases. Phase 1 compared patient-reported information (via the blank screening form) to information previously captured in the Radiology Information and Picture Archiving Communication Systems to assess data accuracy. In phase 2, study questionnaires were used to collect data on the patients' experience with the screening form in two cohorts (between the blank and a novel prefilled screening form). RESULTS: Data accuracy: for mammography (n = 60), 40% of the patients could accurately recall when and where their last mammogram was performed. For breast ultrasound (n = 43) and breast magnetic resonance imaging (n = 20), significantly fewer patients could accurately recall the date their last test was performed (14% and 10%, respectively). Of those who had previous breast surgery (n = 18), 100% were able to recall whether the surgery resulted in a benign or malignant diagnosis, and 61% were able to accurately recall the year they had the breast surgery. PATIENT EXPERIENCE: Of the returned questionnaires, 65 provided feedback on the blank screening form while 55 provided feedback on the prefilled form. Ninety percent preferred to fill out the new prefilled screening form. The themes acknowledged a general improvement in the screening form, a decrease in frustration associated with having to recall their medical history, and the patients felt that the institution better understood their medical history. CONCLUSIONS: The findings of this research indicate that asking patients to complete a blank medical screening form is a highly inaccurate method of gathering that important information. When that information was prefilled for the patient to review and update, patient frustration and stress were decreased, while satisfaction and confidence in the organization were increased.