Teaching Ultrasound at the Point of Care in Times of Social Distancing.

Point-of-care ultrasound has become an integral aspect of critical care training. The Bedside Assessment by Sonography In Critical Care Medicine Curriculum was established at the University of Toronto to train critical care trainees in basic echocardiography and general critical care ultrasound. During the coronavirus disease (COVID-19) pandemic, our program needed to adapt quickly to ensure staff safety and adherence to infection-control protocols. In this article, we share our experience and reflect on the challenges and benefits of shifting from a primarily in-person teaching model to a hybrid model of remote and in-person teaching. Curricular changes were threefold: the transition to entirely web-based interactive didactic teaching and online imaging interpretation modules, the recruitment of sonographers at multiple academic sites as instructors to facilitate in-person practices with lower instructor to trainee ratio, and the use of a mobile application for informal group case-based discussions. Challenges included lost opportunities for scanning healthy volunteers, variability in attendance at online lectures, and a lower number of study submissions for review. However, curricular changes enabled maintenance of directly observed practice, high levels of engagement with recorded content, and an expansion of our reach to a global audience. We believe that future curricula should combine high-quality online curriculum and resources with the ongoing in-person delivery of key elements of curriculum to allow for direct observation and feedback as well as the maintenance of self-directed point-of-care ultrasound portfolios.

Prospective evaluation of pretreatment and intratreatment FDG PET-CT SUV stability in primary head and neck cancer.

PURPOSE: To evaluate standardized uptake value (SUV) stability on pretreatment and intratreatment 18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in patients undergoing definitive CRT for head and neck cancer (HNC). METHODS: Primary tumor and nodal volumes of interest (VOIs) from HNC patients were contoured on the pretreatment and intratreatment PET-CT by two independent observers. SUV stability was measured with intersection calculations (DICE, overlap fraction, center to center) between the VOIs at threshold levels of 50%, 60%, 70%, 80%, and 90% of the SUV maximum. RESULTS: The mean calculated DICE of the 50%, 60%, 70%, 80%, 90% SUV threshold was 0.53, 0.48, 0.41, 0.28, and 0.12, respectively. The mean calculated overlap fraction was 0.71, 0.65, 0.58, 0.43, and 0.2, respectively. Center-center difference demonstrates spatial variability of 7.8, 8.2, 8.6, 9.5, and 11.2 mm for these SUV subvolumes of interest. CONCLUSIONS: HNC subvolumes defined by SUV thresholding technique in FDG PET-CT imaging do not remain physically stable during (chemo)RT. HIGHLIGHTS: All pretreatment and intratreatment SUV thresholds (50%-90%) overlap indexes are low during the course of (chemo)radiation. Pretreatment and intratreatment center to center variation further corroborates that all FDG threshold volumes do not remain stable during treatment. No difference in SUV threshold stability was seen between p16 positive and negative tumors.

Local control and fracture risk following stereotactic body radiation therapy for non-spine bone metastases.

AIMS: To report local control and toxicity rates for patients treated with stereotactic body radiotherapy (SBRT) for non-spine bone metastases. METHODS AND MATERIALS: Eighty-one patients with 106 non-spine bone metastases were treated between 2011 and 2014 and retrospectively reviewed. Indications included: oligometastases (63%), oligoprogression (17.3%), retreatment (2.4%) or other (17.3%). Cumulative incidence function was used to assess local recurrence and fracture probability. Bivariate relationships were investigated based on selected patient, tumour and dose-volume factors. RESULTS: Mean follow-up was 13 months (range, 0.25-45.6) and the median patient age was 66.4 years (range, 36-86). Most patients were male (60.5%) and the predominant histology prostate cancer (32%). Bone metastases were most commonly located in the pelvis (41.5%) and almost half sclerotic. The most common prescriptions were 30 Gy/5 (30.2%) and 35 Gy/5 (42.5%). The cumulative incidence of local recurrence at 6,18 and 24 months respectively was 4.7%, 8.3% and 13.3% with a mean time to local recurrence of 11.8 months (range, 3.9-23.4). A significant association was found between local recurrence and volume of the PTV (p = 0.02), with larger PTVs having a greater risk of local failure. Fracture was observed radiographically in the treatment volume in 9/106 (8.5%) of treated lesions and the mean time to fracture was 8.4 months (range, 0.7-32.5 months). With respect to predictors, a trend was observed for lytic lesions (p = 0.11) and female gender (p = 0.09). CONCLUSIONS: The results of this study confirm that SBRT yields high rates of long-term local control for non-spine bone metastases with a low fracture risk.

Computed Tomography Evaluation of Density Following Stereotactic Body Radiation Therapy of Nonspine Bone Metastases.

INTRODUCTION: Stereotactic body radiation therapy allows for the precise delivery of high-dose radiation to disease sites and is becoming increasingly used to treat nonspine bone metastases. Previous studies have shown that remineralization of lytic bone metastases follows after conventional radiotherapy. The objective of this study was to investigate changes in bone density in nonspine bone metastases following stereotactic body radiation therapy. METHODS: A retrospective review was conducted for all patients treated with stereotactic body radiation therapy to nonspine bone metastases between May 2011 and April 2014. A minimum of 1 pretreatment and 1 posttreatment computed tomography scan was required. An independent musculoskeletal radiologist contoured the lesions on the most representative computed tomography slices. Density was measured in Hounsfield units and analyzed using pretreatment and posttreatment ratios. RESULTS: Forty sites were treated (55% lytic, 30% sclerotic, and 15% mixed). The median follow-up duration was 7 months. Lytic osseous metastases from renal cell carcinoma progressed during initial follow-up imaging and then returned to baseline. Of 9 lytic lesions not from renal cell carcinoma, 6 showed an immediate increase in density and 2 remained stable. Six of 7 sclerotic lesions from prostate cancer showed decreased density throughout all follow-ups. CONCLUSION: Stereotactic body radiation therapy is efficacious in the remineralization of lytic and demineralization of sclerotic nonspine bone metastases.

Radiological changes on CT after stereotactic body radiation therapy to non-spine bone metastases: a descriptive series.

BACKGROUND: In recent years, stereotactic body radiation therapy (SBRT) has become increasingly used for the management of non-spine bone metastases. Few studies have examined the radiological changes in bone metastases after treatment with SBRT and there is no consensus about what constitutes radiologic response to therapy. This article describes various changes on CT after SBRT to non-spine bone metastases in eight selected cases. METHODS: A retrospective review was conducted for patients treated with SBRT to non-spine bone metastases between November 2011 and April 2014 at Sunnybrook Health Sciences Centre. A musculoskeletal radiologist identified eight illustrative cases of interest and provided a description of the findings. RESULTS: Different radiological changes following SBRT were described, including: remineralization of lytic bone metastases, demineralization of sclerotic bone metastases, pathologic fracture, size progression and response in different lesions, as well as lung fibrosis after SBRT to a rib metastasis. CONCLUSIONS: We reviewed the radiological images of eight selected cases after SBRT to nonspine bone metastases and a number of characteristic findings were highlighted. We recommend future studies to correlate radiologic changes with clinical outcomes including pain relief, toxicity and long-term local control.

SBRT Treatment of Multiple Recurrent Auricular Squamous Cell Carcinomas Following Surgical and Conventional Radiation Treatment Failure.

The treatment of recurrent skin cancers of the head and neck following curative doses of radiotherapy and/or surgery is usually palliative radiation therapy (RT) but with mediocre control rates leading to symptomatic local recurrences. We present a 93-year-old male treated with 50 Gy in five fractions for a subauricular cutaneous squamous cell carcinoma who initially underwent partial auriculectomy and accelerated concomitant boost radiotherapy (60 Gy in 21 fractions over 23 days), and then two additional surgeries ending with completion auriculectomy. Re-irradiation with SBRT was well tolerated despite prior high-dose therapy.

Tumor shrinkage associated with whole-mount histopathologic techniques in oral tongue carcinoma.

Shrinkage artifact of tumor tissue from histologic processing has not been rigorously quantified, particularly where the entire tumor is represented in a whole-mount specimen. Fourteen patients underwent partial-glossectomy for oral tongue carcinoma (OTC). Specimens were embedded into agar, cut into 3 mm blocks and photographed (macroscopic image), prior to histopathologic processing. Histology slides were digitized. Contours were made of tumor on both image sets and area plotted against block position. Volume estimates were mathematically derived based on these plots. The tumors shrank in volume by 20.2% (p=0.0006) on average; shrinkage by area ranged for all image pairs 0-48%. Tumor volume>median was significant in absolute shrinkage (p=0.002) but not percent shrinkage (p=0.42). Age, gender, and T stage were independent of shrinkage. This data shows whole-mount techniques produce shrinkage artifact in OTC that varies between tumors and blocks in the same tumor. In order to account for shrinkage, measurement must be performed case-by-case.

Tumor Response After Stereotactic Body Radiation Therapy to Nonspine Bone Metastases: An Evaluation of Response Criteria.

PURPOSE: To evaluate the applicability of the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and University of Texas MD Anderson (MDA) Cancer Center criteria in the setting of stereotactic body radiation therapy (SBRT) to nonspine bone metastases. METHODS: Patients who were treated with SBRT to nonspine bone metastases were identified by retrospective chart review. An independent musculoskeletal radiologist evaluated response to treatment using computed tomography (CT) scans. RESULTS: Thirty-three patients were treated to 42 nonspine bone metastases. The most common primary cancer cites were renal cell carcinoma (RCC) (33.3%), lung (24.2%), and prostate (18.2%). Bone metastases were either mainly lytic (57.1%), mainly sclerotic (28.6%), or mixed (14.3%). When lytic and sclerotic lesions were evaluated according to RECIST 1.1, local control (LC) was 83%, 85%, 88%, and 80% for those with CT imaging between months 1 to 3, 4 to 6, 7 to 9, and 10 to 12, respectively. When evaluated by the MDA criteria by density, LC within each time period was slightly greater. Overall LC decreased considerably when evaluated by MDA in terms of size. CONCLUSIONS: Consensus definitions of response are required as they have implications on clinical trials and disease management. Without consistent response criteria, outcomes from clinical trials cannot be compared and treatment efficacy remains undetermined.

Patient preferences for oropharyngeal cancer treatment de-escalation.

BACKGROUND: The excellent prognosis of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinomas (SCCs) against severe chemoradiotherapy (CRT) toxicities has opened discussion of deintensification trials. The purpose of this study was to describe the perspective of patients with HPV-positive and HPV-negative disease toward such studies. METHODS: Fifty-one patients with oropharyngeal SCC (post-CRT) underwent semistructured interviews contrasting toxicities of radiotherapy (RT) alone and CRT. Patients were asked what potential difference in cancer survival was acceptable to prefer RT over CRT. Initially, survival rate was the same for both treatments, then the RT rate was reduced until the preference switched. Treatment experience and preference for deintensified CRT were collected. RESULTS: Ninety-percent of patients initially selected RT, but 69% switched to CRT after 0% to 5% reduction in survival. Patients that rated their treatment experience as mild would accept lower survival versus severe treatment (p = .02). Eighty-one percent of patients (33 of 40) indicated they preferred reduced chemotherapy in CRT. CONCLUSION: Patients accept little difference in survival between treatments to avoid toxicity.