Tumor volumes in T3 supraglottic cancers treated with radiotherapy in the modern era: A study of the Canadian Head & Neck Collaborative Research Initiative.

PURPOSE: To evaluate the association of primary tumor volume (TV) with overall survival (OS) and disease-free survival (DFS) in T3 N0-3M0 supraglottic cancers treated with intensity-modulated radiotherapy (IMRT). METHODS: This was a retrospective cohort study involving 239 patients diagnosed with T3 N0-3M0 supraglottic cancers between 2002 and 2018 from seven regional cancer centers in Canada. Clinical data were obtained from the patient records. Supraglottic TV was measured by neuroradiologists on diagnostic imaging. Kaplan-Meier method was used for survival probabilities, and a restricted cubic spline Cox proportional hazards regression analysis was used to analyze TV associations with OS and DFS. RESULTS: Mean (SD) of participants was 65.2 (9.4) years; 176 (73.6%) participants were male. 90 (38%) were N0, and 151 (64%) received concurrent systemic therapy. Mean TV (SD) was 11.37 (12.11) cm3 . With mean follow up (SD) of 3.28 (2.60) years, 2-year OS was 72.7% (95% CI 66.9%-78.9%) and DFS was 53.6% (47.4%-60.6%). Increasing TV was associated (per cm3 increase) with worse OS (HR, 1.01, 95% CI 1.00-1.02, p < 0.01) and DFS (HR, 1.01, 95% CI 1.00-1.02, p = 0.02). CONCLUSIONS: Increasing primary tumor volume is associated with worse OS and DFS in T3 supraglottic cancers treated with IMRT, with no clear threshold. The findings suggest that patients with larger tumors and poor baseline laryngeal function may benefit from upfront laryngectomy with adjuvant radiotherapy.

Oncologic Significance of Therapeutic Delays in Patients With Oral Cavity Cancer.

Importance: Oral cavity cancer often requires multidisciplinary management, subjecting patients to complex therapeutic trajectories. Prolonged treatment intervals in oral cavity cancer have been associated with poor oncological outcomes, but there has yet to be a study investigating treatment times in Canada. Objective: To report treatment delays for patients with oral cavity cancer in Canada and evaluate the outcomes of treatment delays on overall survival. Design, Setting, and Participants: This multicenter cohort study was performed at 8 Canadian academic centers from 2005 to 2019. Participants were patients with oral cavity cancer who underwent surgery and adjuvant radiation therapy. Analysis was performed in January 2023. Main Outcomes and Measures: Treatment intervals evaluated were surgery to initiation of postoperative radiation therapy interval (S-PORT) and radiation therapy interval (RTI). The exposure variables were prolonged intervals, respectively defined as index S-PORT greater than 42 days and RTI greater than 46 days. Patient demographics, Charlson Comorbidity Index, smoking status, alcohol status, and cancer staging were also considered. Univariate (log rank and Kaplan-Meier) and multivariate (Cox regression) analyses were performed to determine associations with overall survival (OS). Results: Overall, 1368 patients were included; median (IQR) age at diagnosis was 61 (54-70) years, and 896 (65%) were men. Median (IQR) S-PORT was 56 (46-68) days, with 1093 (80%) patients waiting greater than 42 days, and median (IQR) RTI was 43 (41-47) days, with 353 (26%) patients having treatment time interval greater than 46 days. There were variations in treatment time intervals between institutions for S-PORT (institution with longest vs shortest median S-PORT, 64 days vs 48 days; η2 = 0.023) and RTI (institution with longest vs shortest median RTI, 44 days vs 40 days; η2 = 0.022). Median follow-up was 34 months. The 3-year OS was 68%. In univariate analysis, patients with prolonged S-PORT had worse survival at 3 years (66% vs 77%; odds ratio 1.75; 95% CI, 1.27-2.42), whereas prolonged RTI (67% vs 69%; odds ratio 1.06; 95% CI, 0.81-1.38) was not associated with OS. Other factors associated with OS were age, Charlson Comorbidity Index, alcohol status, T category, N category, and institution. In the multivariate model, prolonged S-PORT remained independently associated with OS (hazard ratio, 1.39; 95% CI, 1.07-1.80). Conclusions and Relevance: In this multicenter cohort study of patients with oral cavity cancer requiring multimodal therapy, initiation of radiation therapy within 42 days from surgery was associated with improved survival. However, in Canada, only a minority completed S-PORT within the recommended time, whereas most had an appropriate RTI. An interinstitution variation existed in terms of treatment time intervals. Institutions should aim to identify reasons for delays in their respective centers, and efforts and resources should be directed toward achieving timely completion of S-PORT.

The protective role of postoperative radiation therapy in low and intermediate grade major salivary gland malignancies: A study of the Canadian Head and Neck Collaborative Research Initiative.

BACKGROUND: The objective of this study was to examine the utility of postoperative radiation for low and intermediate grade cancers of the parotid and submandibular glands. METHODS: The authors conducted a retrospective, Canadian-led, international, multi-institutional analysis of a patient cohort with low or intermediate grade salivary gland cancer of the parotid or submandibular gland who were treated from 2010 until 2020 with or without postoperative radiation therapy. A multivariable, marginal Cox proportional hazards regression analysis was performed to quantify the association between locoregional recurrence (LRR) and receipt of postoperative radiation therapy while accounting for patient-level factors and the clustering of patients by institution. RESULTS: In total, 621 patients across 14 tertiary care centers were included in the study; of these, 309 patients (49.8%) received postoperative radiation therapy. Tumor histologies included 182 (29.3%) acinic cell carcinomas, 312 (50.2%) mucoepidermoid carcinomas, and 137 (20.5%) other low or intermediate grade primary salivary gland carcinomas. Kaplan-Meier LRR-free survival at 10 years was 89.0% (95% confidence interval [CI], 84.9%-93.3%). In multivariable Cox regression analysis, postoperative radiation therapy was independently associated with a lower hazard of LRR (adjusted hazard ratio, 0.53; 95% CI, 0.29-0.97). The multivariable model estimated that the marginal probability of LRR within 10 years was 15.4% without radiation and 8.8% with radiation. The number needed to treat was 16 patients (95% CI, 14-18 patients). Radiation therapy had no benefit in patients who had early stage, low-grade salivary gland cancer without evidence of nodal disease and negative margins. CONCLUSIONS: Postoperative radiation therapy may reduce LLR in some low and intermediate grade salivary gland cancers with adverse features, but it had no benefit in patients who had early stage, low-grade salivary gland cancer with negative margins.

Equity in adjuvant radiotherapy utilization in locally advanced head and neck cancer: A SEER-data based study.

BACKGROUND: Not all patients with locally advanced head and neck cancer (HNC) who are eligible for adjuvant radiotherapy (RT) following upfront surgery appear to receive it. METHODS: Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Selected patients from 2009 to 2018 had locally advanced HNC, underwent upfront surgery, and were eligible for adjuvant RT. Multivariable logistic regression and chi-squared test were used to analyze available patient and tumor characteristics. RESULTS: Of 12 549 patients, 84.5% underwent adjuvant RT, 15.5% did not. Characteristics associated with lowest adjuvant RT utilization included cancers of the larynx (p < 0.0001) and gingivae (p < 0.0001), age 80 and above (p < 0.0001), unpartnered status (p < 0.0001), and residence within a nonmetropolitan area (p < 0.0024). CONCLUSIONS: Tumor subsite, age, partnered status, and rural/urban residence correlate with omission of adjuvant RT in locally advanced HNC.

A shift from simple to sophisticated: using intensity-modulated radiation therapy in conventional nonstereotactic palliative radiotherapy.

PURPOSE OF REVIEW: The authors aimed to highlight trends in, and evidence underlying the use of highly conformal radiotherapy (RT) techniques in conventional nonstereotactic palliative RT. The authors reviewed palliative-intent and curative-intent studies relevant to the use of intensity-modulated radiation therapy (IMRT) for the delivery of nonstereotactic conventional regimens to the brain, head and neck, thorax, abdomen and pelvis, and bone metastases. RECENT FINDINGS: The use of IMRT has become standard with certain indications for brain metastases such as hippocampus-avoiding/limiting whole brain RT. IMRT in the treatment of bone metastases is increasing at many institutions despite limited data comparing its effectiveness with that of fluoroscopy-based and three-dimensional conformal radiation therapy techniques. There is scant data describing the use of IMRT for palliation in other extracranial anatomic sites; guidance for its use in these settings must be gleaned almost exclusively from curative-intent randomized trials, consensus recommendations and contouring atlases. SUMMARY: Consistent with historical technology shifts in RT practice, the uptake of highly conformal techniques such as IMRT for conventional palliative RT will likely outpace rigorous evaluations of their advantages and disadvantages relative to simpler techniques. Opportunities exist in virtually all anatomic sites for observational and randomized studies to evaluate the clinical impacts of these modern techniques in the palliative setting.

Association of Primary Tumor Volume With Survival in Patients With T3 Glottic Cancer Treated With Radiotherapy: A Study of the Canadian Head & Neck Collaborative Research Initiative.

Importance: The association of primary tumor volume with outcomes in T3 glottic cancers treated with radiotherapy with concurrent chemotherapy remains unclear, with some evidence suggesting worse locoregional control in larger tumors. Objective: To evaluate the association of primary tumor volume with oncologic outcomes in patients with T3 N0-N3 M0 glottic cancer treated with primary (chemo)radiotherapy in a large multi-institutional study. Design, Setting, and Participants: This multi-institutional retrospective cohort study involved 7 Canadian cancer centers from 2002 to 2018. Tumor volume was measured by expert neuroradiologists on diagnostic imaging. Clinical and outcome data were extracted from electronic medical records. Overall survival (OS) and disease-free survival (DFS) outcomes were assessed with marginal Cox regression. Laryngectomy-free survival (LFS) was modeled as a secondary analysis. Patients diagnosed with cT3 N0-N3 M0 glottic cancers from 2002 to 2018 and treated with curative intent intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Overall, 319 patients met study inclusion criteria. Exposures: Tumor volume as measured on diagnostic imaging by expert neuroradiologists. Main Outcomes and Measures: Primary outcomes were OS and DFS; LFS was assessed as a secondary analysis, and late toxic effects as an exploratory analysis determined before start of the study. Results: The mean (SD) age of participants was 66 (12) years and 279 (88%) were men. Overall, 268 patients (84%) had N0 disease, and 150 (47%) received concurrent systemic therapy. The mean (SD) tumor volume was 4.04 (3.92) cm3. With a mean (SD) follow-up of 3.85 (3.04) years, there were 91 (29%) local, 35 (11%) regional, and 38 (12%) distant failures. Increasing tumor volume (per 1-cm3 increase) was associated with significantly worse adjusted OS (hazard ratio [HR], 1.07; 95% CI, 1.03-1.11) and DFS (HR, 1.04; 95% CI, 1.01-1.07). A total of 62 patients (19%) underwent laryngectomies with 54 (87%) of these within 800 days after treatment. Concurrent systemic therapy was associated with improved LFS (subdistribution HR, 0.63; 95% CI, 0.53-0.76). Conclusions and Relevance: Increasing tumor volumes in cT3 glottic cancers was associated with worse OS and DFS, and systemic therapy was associated with improved LFS. In absence of randomized clinical trial evidence, patients with poor pretreatment laryngeal function or those ineligible for systemic therapy may be considered for primary surgical resection with postoperative radiotherapy.

Systematic review of brachytherapy for symptom palliation.

PURPOSE: Brachytherapy is most often applied in the curative or salvage setting, but many forms of brachytherapy can be helpful for symptom palliation. Declining utilization is seen, for multiple reasons, such as lack of awareness, insufficient expertise, or poor access to equipment. High level evidence for many types of palliative brachytherapy has been lacking. The objective of the current study was to review the evidence for utilization and efficacy of brachytherapy to palliate symptoms from cancer. MATERIALS AND METHODS: We performed a systematic search in EMBASE and MEDLINE for English-language articles published from January 1980 to May 2022 that described brachytherapy used for a palliative indication in adults with a diagnosis of cancer (any subtype) and at least one symptom related outcome. Individual case reports and conference abstracts were excluded. All publications were independently screened by two investigators for eligibility. RESULTS: The initial search identified 3637 abstracts of which 129 were selected for in-depth review. The number of studies (total number of patients) included in the final analysis varied widely by tumor site with the majority (68.2%) involving either lung or esophageal cancer. Despite a limited number of prospective trials that assessed the efficacy of brachytherapy for symptom management, there was a positive effect on palliation of symptoms across all tumor types. There was no clear trend in the number of publications over time. The most commonly cited symptom indications for palliation by brachytherapy were dysphagia, dyspnea, pain and bleeding. CONCLUSIONS: Brachytherapy can provide palliation for patients with advanced cancer, across different tumor sites and clinical scenarios. However, high level evidence in the literature to support palliative applications of brachytherapy is lacking or limited for many tumor sites. There appears to be a strong publication bias towards positive studies in favor of brachytherapy. Beyond anecdotal reports and individual practices, outcomes research can further our understanding of the role of brachytherapy in palliating advanced cancers of all types, and should be encouraged.

Development of a Curriculum for the Implementation of Stereotactic Radiation Therapy Programs in Middle-Income Countries.

PURPOSE: The aim of this work was to develop a curriculum to be used in the implementation of stereotactic radiation therapy programs in middle-income countries. The curriculum needed to be scalable and flexible to be easily adapted to local situations. METHODS: The curriculum was developed through a partnership between multidisciplinary teams from established clinics in both middle-income and high-income countries. The curriculum development followed a nonlinear progression, allowing greater flexibility throughout the process. A blended learning model was used, combining virtual and in-person interactions. RESULTS: The initial training plan was based on a needs assessment provided by the learners and on the experience of the facilitators with stereotactic radiotherapy. The needs assessment was refined during in-person site visits at each institution which highlighted aspects of the training, such as image guidance workflows and technical specifications, that were not previously emphasized in the curriculum. Both teams found that the in-person visits were important for training purposes, but aspects of the curriculum delivery such as treatment planning and patient selection were well suited to virtual platforms. The training addressed all aspects of the stereotactic program, from patient selection to treatment, and included a review of both technical and clinical workflows. CONCLUSION: The inclusion of contributions from both teams ensured that the curriculum covered the required elements of the stereotactic program implementation, met the needs of the learners, and was relevant to local practices. The nonlinear approach to the curriculum development allowed the flexibility to change the focus as the project progressed. The in-person visits were valuable in conducting a thorough needs assessment.

Cost-Utility Analysis of Radiation Treatment Modalities for Intermediate-Risk Prostate Cancer.

INTRODUCTION: Variable costs of different radiation treatment modalities have played an important factor in selecting the most appropriate treatment for patients with intermediate-risk prostate cancer. METHODS: Analysis using a Markov model was conducted to simulate 20-year disease trajectory, quality-adjusted life years (QALYs) and health system costs of a cohort of intermediate-risk prostate cancer patients with mean age of 60 years. Clinical outcomes on toxicity and disease recurrence were measured and a probabilistic sensitivity analysis was performed, varying input parameters simultaneously according to their distributions. RESULTS: Among the six radiation treatment modalities, including conventionally fractionated intensity-modulated radiation therapy (IMRT), hypofractionated IMRT, IMRT combined with high-dose-rate (HDR) brachytherapy, HDR brachytherapy monotherapy, low-dose-rate brachytherapy monotherapy, and stereotactic body radiotherapy (SBRT), SBRT was found to be more cost-effective when compared with LDR-b and other treatment modalities, resulting in an incremental cost-utility ratio of $2985 per QALY. CONCLUSIONS: Stereotactic body radiotherapy is the most cost-effective radiation treatment modality in treatment of intermediate-risk prostate cancer, while treatment toxicity and cost data are the key drivers of the cost-utility. Further work is required with long-term follow-up for SBRT.

Treatment of Early Stage High-Risk Endometrioid-Type Endometrial Cancer and Patterns of Disease Relapse: A Retrospective Analysis.

PURPOSE: A recently published randomized controlled trial has demonstrated that in patients with endometrial cancer with high-risk features, the addition of chemotherapy to radiation therapy, compared with radiation therapy alone, resulted in a significant improvement in failure-free survival. However, in the study, the effect of chemotherapy was limited to stage III patients, and the benefit was less pronounced in stage I and II patients. Our study aims to investigate the current practice of treatment and clinical outcomes in stage I high-risk endometrioid-type endometrial cancer. METHODS AND MATERIALS: A single-center retrospective study was conducted on patients with stage I high-risk endometrioid-type endometrial cancer without serous or clear cell features who have undergone hysterectomy between 1998 and 2015. Data on patients, tumor, and treatments were collected and correlated with clinical outcomes. RESULTS: A total of 1,572 patients with stage I disease were identified and 46 patients who met the inclusion criteria were selected for final analysis. The median age at diagnosis was 63 years (range, 49-86 years) and median follow-up was 5.9 years. Among the entire cohort, 40 (87.0%) patients underwent adjuvant radiation therapy, of which 36 (78.2%) patients underwent external beam radiation therapy and 4 (8.7%) patients underwent vaginal brachytherapy. Two of the 40 patients who received adjuvant radiation therapy also received adjuvant chemotherapy. Six (13.0%) patients received no adjuvant treatment. Of the 46 patients, the cumulative risk of distant recurrence was 19.6%, and only 1 patient (2.2%) recurred within pelvis (perirectal lymph node). Five-year disease-free survival and overall survival rates were 73.1% and 80.1%, respectively. CONCLUSIONS: Adjuvant radiation therapy in stage I endometrioid-type endometrial cancer patients with high-risk features resulted in high rates of locoregional disease control, and most recurrences occurred at distant sites. Effective systemic therapy may be indicated in this patient population to further reduce the risk of distant relapses and improve survival.

Examining geographic accessibility to radiotherapy in Canada and Greenland for indigenous populations: Measuring inequities to inform solutions.

BACKGROUND: A high cancer burden exists among indigenous populations worldwide. Canada and Greenland have similar geographic features that make health service delivery challenging. We sought to describe geographic access to radiotherapy for indigenous populations in both regions. METHODS: We used geospatial analyses to calculate distance and travel-time from indigenous communities in Canada and Greenland to the nearest radiotherapy center. We calculated the proportion of indigenous communities and populations residing within a 1 and 2-hour drive of a radiotherapy center in Canada, and compared the proportion of indigenous versus non-indigenous populations residing within each drive-time area. We calculated the potential distance and travel-time saved if radiotherapy was available in northern Canada (Yellowknife and Iqaluit), and Greenland (Nuuk). RESULTS: Median one-way travel from indigenous communities to nearest radiotherapy center in Canada was 268 km (3 h when considering any transportation mode), and 4111 km (6 h by plane) in Greenland. In Canada, 84% and 68% of indigenous communities were outside a 1 and 2-hour drive from a radiotherapy center, respectively. Only 2% of the total population in Canada resided outside a 2-hour drive from a radiotherapy center. However, indigenous peoples were 336 times more likely to live more than a 2-hour drive away, compared to non-indigenous peoples. Nearly 3 million km and 4000 h of travel could be saved over a 10-year period for patients with newly diagnosed cancers in Canada, and 7 million km and 10,000 h in Greenland, if radiotherapy was available in Yellowknife, Iqaluit and Nuuk. CONCLUSIONS: Geography is an important barrier to accessing radiotherapy for indigenous populations in Canada and Greenland. A significant disparity exists between indigenous and non-indigenous peoples in Canada. Geospatial analyses can help highlight disparities in access to inform radiotherapy service planning.

Effect of an electronic quality checklist on prescription patterns of prophylactic antiemetic and pain flare medications in the context of palliative radiotherapy for bone metastases.

PURPOSE: International guidelines are available to guide prescription of antiemetic and pain flare medications in patients receiving palliative radiotherapy for bone metastases, but prescription rates are quite variable. We hypothesized that a simple electronic quality checklist could increase the evidence-based use of these medications. MATERIALS AND METHODS: We implemented an electronic quality checklist item in our center for all patients treated with palliative radiotherapy for lumbar spine bone metastases. We retrospectively reviewed patients in the 6-month pre- and post-intervention. Patients were stratified according to if they were treated within a dedicated rapid palliative (RPAL) radiotherapy program or not. Chi-square tests were used to compare rates of antiemetic and pain flare medications pre- and post-intervention and RPAL vs not. RESULTS: A total of 375 patients were identified with 42 (11.2%) treated in dedicated RPAL program. The proportion of patients treated with prophylactic antiemetic and pain flare medications pre-intervention (n = 226) and post-intervention (n = 149) was respectively 34.1% vs 59.1% (p < 0.001) and 26.1% vs 43.0% (p = 0.01). Observed differences for antiemetic prescription rates were greater for patients who were not treated within a dedicated palliative radiotherapy program, but this was not the case for pain flare medications. CONCLUSIONS: Our data shows that a simple quality checklist item can have a significant effect on the evidence-based use of prophylactic antiemetic and pain flare medications in patients treated with palliative radiotherapy for bone metastases. We believe such strategies should be routinely included in other clinical pathways to improve the use of symptom control medications.

A comparison of disease recurrence between robotic versus laparotomy approach in patients with intermediate-risk endometrial cancer.

OBJECTIVE: Advances in minimally invasive surgery, particularly with robotic surgery, have resulted in improved peri-operative outcomes in patients with endometrial cancer. In addition, randomized trials have shown that addition of adjuvant radiotherapy following surgery improves loco-regional disease control among stage I intermediate-risk endometrial cancer patients. We aimed to investigate the efficacy and safety of combined treatment of robotic surgery and adjuvant radiotherapy in this patient population. METHODS: A single-center retrospective study was conducted on stage I endometrioid-type endometrial cancer patients with intermediate-risk features (<50% myometrial involvement and grade 2-3 histopathology, or >50% myometrial involvement and grade 1-2 histopathology) treated with hysterectomy and adjuvant radiotherapy between January 2010 and December 2015. Data on surgery and radiotherapy were collected and correlated with clinical and surgical outcomes using log-rank. Oncologic outcomes were then compared between robotic surgery and laparotomy. RESULTS: A total of 179 intermediate-risk endometrial cancer patients were identified, of whom 135 (75.4%) received adjuvant radiotherapy and were included in the final analysis. Median age at diagnosis was 63 years (range 40-89) and median follow-up was 4.7 years (range 1.1-8.8). Seventy-seven patients (57%) underwent robotic surgery and 58 patients (43%) underwent laparotomy. Surgical staging with lymph node dissection was performed on 79.3% of the patients. The majority of patients (79.3%) received vaginal brachytherapy as part of adjuvant radiotherapy, while 20.7% received external-beam radiotherapy. Among the entire cohort, eight (5.9%) patients recurred and all eight recurrences occurred in the robotic surgery group; no recurrence was found in the laparotomy group. This translated into 5 year disease-free survival of 100% in the laparotomy group, compared with 91.8% in the robotic surgery group (p=0.005). No difference in overall survival was found between the two groups (p=0.51). CONCLUSION: Oncologic outcomes for stage I intermediate-risk endometrial cancer treated with hysterectomy and adjuvant radiotherapy at our institution are comparable to the previously published literature. The higher recurrence rate observed with robotic surgery at our institution has not been observed previously and requires further investigation.

Clinical Specialist Radiation Therapist in Palliative Radiation Therapy: Report of an Orientation, Training, and Support Program.

INTRODUCTION: A clinical specialist radiation therapist (CSRT) position in palliative radiation therapy (RT) was created at our institution. Herein, we report the details of the CSRT's orientation, training, and support program. METHODS: We performed an audit and needs assessment of palliative RT services at our centre. This identified opportunities for improvement that could be facilitated by the CSRT. We defined the CSRT job description including priority responsibilities: (1) optimizing palliative RT services for outpatients and developing a rapid access palliative RT program, (2) optimizing palliative RT services for inpatients at our institution, (3) improving links to community physicians and hospitals caring for patients with advanced cancers. We formed a core resource team to provide ongoing support and to design and implement the orientation and training program. The program involved training in clerical and administrative systems as well as treatment planning and physics training relevant to palliative RT. Clinical placements at several hospitals were arranged in both inpatient and outpatient settings. The CSRT worked with radiation and medical oncologists, palliative care specialists, nurse practitioners, hospitalists, and social workers. RESULTS: Through clinical placements and self-directed learning, the CSRT gained knowledge and competencies in patient care coordination, history taking and physical examination, clinical oncology practice including the evidence-based use of palliative RT and symptom control measures, treatment planning, communication, patient advocacy, and advance care planning. We provided practice resources including office space and a planning station, educational opportunities including workshops in palliative and psychosocial care, and research opportunities including methodologic and research ethics training. DISCUSSION: To our knowledge, this is the first detailed report of its kind for an advanced practice radiation therapy role. We hope our report will inform the design and implementation of programs elsewhere to help prepare individuals for similar roles in palliative RT. CONCLUSION: The CSRT in palliative RT at our institution underwent a comprehensive orientation and training program. Institutions with similar CSRT positions are encouraged to report the details of their own programs.

Access to radiotherapy and its association with cancer outcomes in a high-income country: Addressing the inequity in Canada.

BACKGROUND AND PURPOSE: Canada is a high-income country with universal healthcare. In international comparisons, its overall level of access to radiotherapy appears sufficient. However, challenges exist due to Canada's large geographic area and small population density. The association between access and cancer outcomes nationally has not yet been described. MATERIALS AND METHODS: We quantified geographic accessibility for 2012 using the linear distance from each Canadian health region centroid to the nearest radiotherapy center. We used geospatial analytic techniques to detect clusters of age-standardized all-cancer mortality-to-incidence ratios (MIRs) across health regions, from 2010-2012. Global ordinary least squares (OLS) and geographically-weighted regression (GWR) were conducted to examine relationships between distance and MIR, adjusting for sociodemographic factors. RESULTS: Median distance from health region centroid to nearest radiotherapy center was 101.73 km (range 1.14-2095.12). One cluster of worse outcomes (MIR range 0.45-0.88) involved most of northern Canada, with a second cluster of better outcomes (MIR range 0.40-0.41) in southern British Columbia. In both regression models, regions with longer distance to radiotherapy center (ß = 0.0001), increased smoking (ß = 0.002), and poorer food security (ß = -0.003) were significantly associated with worse outcomes (OLS R2 = 0.70, GWR R2 = 0.74). Distance remained independently associated with MIR for lung and colorectal cancer subgroups, but not breast and prostate. CONCLUSIONS: A clear north-south discordance in cancer outcomes exists in Canada, with poorer outcomes in the north, while radiotherapy centers are concentrated along the south. Increased distance to radiotherapy, along with other sociodemographic and health-system factors, are associated with poorer cancer outcomes. Our study could be replicated, particularly in other high-income countries, to help identify national patterns and regional disparities in access and outcomes.

Long-term results of multicatheter interstitial high-dose-rate brachytherapy for accelerated partial-breast irradiation.

PURPOSE: The purpose of this study was to report the long-term results of women treated in one center with accelerated partial-breast irradiation (APBI) with interstitial high-dose-rate (HDR) brachytherapy. MATERIALS AND METHODS: We analyzed data from women treated in one center with adjuvant interstitial HDR brachytherapy for early-stage breast cancer. Treatment regimen was homogeneous for all women with treatment dose 32Gy in 8 fractions twice daily given to the tumor bed with interstitial HDR brachytherapy. RESULTS: About 364 women were treated with interstitial HDR brachytherapy as APBI from March 2000 to March 2014. Mean age at diagnosis was 62 years. Stage distribution was as follows: T1a = 12%, T1b = 33%, T1c = 40%, T2 = 14%, and Tis = 1%. 97% of patients were N0. 88% had invasive ductal carcinoma. 86% had positive hormone receptor status. 14 ipsilateral breast tumor recurrences were identified with 12 deemed local recurrences and 2 deemed to be second ipsilateral primaries. Actuarial 5-year and 10-year overall survival rates were 95.1% and 92.2%, respectively. Actuarial 5-year and 10-year local relapse-free survival rates were 96.2% and 88.8%, respectively. CONCLUSIONS: The results of this previously unreported series of women treated with a homogeneous APBI method exclusively with interstitial HDR brachytherapy present further data justifying that in appropriately selected women, APBI with interstitial brachytherapy provides rates of local control and survival comparable with whole-breast irradiation.

Surgical Scar Recurrence of Bone Metastases to the Femur: A Case Report.

We report the case of a woman who presented with breast cancer metastases to the femur causing pathologic fracture of the femoral neck requiring surgery. She received adjuvant radiotherapy to the femur at that time that did not include the surgical scar tract. Almost four years after her surgery she presented with biopsy proven skin recurrence of breast cancer on the skin overlying her incision from her femoral surgery. Further imaging confirmed significant soft-tissue disease involving the underlying surgical scar tract. This case provides important information about the possibility of surgical scar recurrence after surgery for bone metastases which could indicate the need to include the area of the surgical scar tract and the entire prosthetic material in the post-operative radiotherapy volume.

Early toxicity and health-related quality of life results of high-dose-rate brachytherapy as monotherapy for low and intermediate-risk prostate cancer.

PURPOSE: To determine the acute toxicity and effect on health-related quality of life of a two-fraction regimen of high-dose-rate (HDR) prostate brachytherapy. METHODS AND MATERIALS: Patients with low- or intermediate-risk prostate cancer were treated with HDR brachytherapy as monotherapy in two implants of 13.5 Gy spaced 7-14 days apart. Patients completed International Prostate Symptom Score (IPSS) and Expanded Prostate Index Composite (EPIC) questionnaires at 1, 3, 6, 9, 12, 16, 20, and 24 months after brachytherapy. Proportion of patients in each IPSS category (mild = 0-7, moderate = 8-18, severe = 19+) was evaluated at each of the intervals above. Paired t tests with baseline values were done for IPSS and EPIC scores. RESULTS: Thirty patients were accrued to the study. Median prostate-specific antigen was 8,7 (range 4.1-17.5). T stages were T1c = 65%, T2a = 21%, and T2b = 14%. Twenty-seven percent of patients had a Gleason score of 6 and 73% had a Gleason score of 7. IPSS categories at baseline, 1, 3, 6, 12, and 24 months were mild (81%, 43%, 58%, 62%, 76%, 64%), moderate (19%, 32%, 29%, 30%, 20%, 29%), and severe (0%, 25%, 13%, 7%, 4%, 6%), respectively. There was a significant decrease in EPIC sexual summary scores at 1, 3, 6, and 12 months of 0 points (p < 0.001), 17 points (p = 0.01), 18 points (p = 0.02), and 17 points (p = 0.01), respectively. CONCLUSIONS: This is the first report of this cohort of patients treated with two-fraction HDR monotherapy. This regimen shows rates of toxicity and health-related quality of life that appear acceptable as compared to other treatment modalities. These results are also comparable with other reports with similar treatment regimens.

Association of bladder dose with late urinary side effects in cervical cancer high-dose-rate brachytherapy.

PURPOSE: The purpose of this work was to study the association between specific urinary sequelae and locally accumulated dose to the bladder wall and bladder neck in the treatment of cervical cancer with multifraction high-dose-rate (HDR) brachytherapy. METHODS AND MATERIALS: A cohort of 60 cervical cancer patients, treated with both external beam and five HDR brachytherapy insertions between 2008 and 2014 at the BC Cancer Agency, was identified. The accumulated dose received over five brachytherapy sessions was evaluated for the bladder wall and bladder neck of each patient using dosimetric parameters calculated from deformably registered image data sets. These parameters were examined as potential predictors of urinary sequelae including hematuria, frequency, urgency, incontinence, stream, nocturia, and dysuria. Two different dichotomization schemes were evaluated for grouping patients into Case and Control groups. The two-sample Student's t test was used for normally distributed samples and the Mann-Whitney nonparametric U test for non-normal distributions. RESULTS: A strong association between dose to the bladder neck and incontinence was found (p = 0.001). A statistically significant association (p < 0.05) was also observed between urgency and certain bladder-wall parameters. CONCLUSIONS: Localized dose to the bladder neck is a potential predictor of urinary incontinence, whereas weaker associations were observed between urgency and some bladder-wall parameters.

Bladder accumulated dose in image-guided high-dose-rate brachytherapy for locally advanced cervical cancer and its relation to urinary toxicity.

The purpose of this study was to estimate locally accumulated dose to the bladder in multi-fraction high-dose-date (HDR) image-guided intracavitary brachytherapy (IG-ICBT) for cervical cancer, and study the locally-accumulated dose parameters as predictors of late urinary toxicity. A retrospective study of 60 cervical cancer patients who received five HDR IG-ICBT sessions was performed. The bladder outer and inner surfaces were segmented for all sessions and a bladder-wall contour point-set was created in MATLAB. The bladder-wall point-sets for each patient were registered using a deformable point-set registration toolbox called coherent point drift (CPD), and the fraction doses were accumulated. Various dosimetric and volumetric parameters were calculated using the registered doses, including [Formula: see text] (minimum dose to the most exposed n-cm3 volume of bladder wall), r V n Gy (wall volume receiving at least m Gy), and [Formula: see text] (minimum equivalent biologically weighted dose to the most exposed n-cm3 of bladder wall), where n = 1/2/5/10 and m = 3/5/10. Minimum dose to contiguous 1 and 2 cm3 hot-spot volumes was also calculated. The unregistered dose volume histogram (DVH)-summed equivalent of [Formula: see text] and [Formula: see text] parameters (i.e. [Formula: see text] and [Formula: see text]) were determined for comparison. Late urinary toxicity was assessed using the LENT-SOMA scale, with toxicity Grade 0-1 categorized as Controls and Grade 2-4 as Cases. A two-sample t-test was used to identify the differences between the means of Control and Case groups for all parameters. A binomial logistic regression was also performed between the registered dose parameters and toxicity grouping. Seventeen patients were in the Case and 43 patients in the Control group. Contiguous values were on average 16 and 18% smaller than parameters for 1 and 2 cm3 volumes, respectively. Contiguous values were on average 26 and 27% smaller than parameters. The only statistically significant finding for Case versus Control based on both methods of analysis was observed for r V3 Gy (p = 0.01). DVH-summed parameters based on unregistered structure volumes overestimated the bladder dose in our patients, particularly when contiguous high dose volumes were considered. The bladder-wall volume receiving at least 3 Gy of accumulated dose may be a parameter of interest in further investigations of Grade 2+ urinary toxicity.