Heatmaps to Assess Tumor Motion Probability with MRcine in Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

Intrafraction motion affects tumor position during radiation for head and neck cancers (HNC) and can be assessed using magnetic resonance cine (MR-cine). Heatmaps - visual representation of patient specific temporal tumor location akin to internal target volume (ITV) - were analyzed to demonstrate the variation of population-based motion margins in primary oropharyngeal (OP) and laryngeal/hypopharyngeal (LH) sites with the goal to provide insights towards personalized margins.

MATERIALS/METHODS

MR-cine were performed for LH and OP HNC patients as part of simulation protocol. Images (900-1500 slices) were acquired across 3-5 minutes per patient. Gross target volumes were propagated on T1 contrast sagittal sequence using deformable image registration then adjusted manually. Tumor locations were integrated across all frames and displayed as heatmaps representing location probability. To determine individualized motion, a baseline contour representing average tumor rest position was expanded both isotropically and directionally in 1 mm increments in a novel analysis to define the contribution of each increment on target coverage. To assess directional dependence, displacements from rest position were evaluated in 4 planes from centroid: (A) 12 o'clock (OC) to 6OC (capturing volumetric shift in a portion of superior, posterior and inferior directions), B) 3OC-9OC, C) 6OC-12OC, D) 9OC-3OC. Histograms demonstrating the proportion of scan time the tumor was within expansions were generated, with expansion margins for 25%-95% coverage analyzed by patient. Wilcoxon-rank-sum test was performed to compare motion by site.

RESULTS

Motion was evaluated in 66 patients (LH n = 27, OP n = 39). In LH, a median (med) isometric expansion of 8.5mm to achieve 95% target was required, with large variations observed for minimum (min): 2.8mm and maximum (max):23.5mm. Smaller differences were observed for OP with med of 5.3mm, (min:1.9mm, max:14.6mm). At 75%, 50% and 25% coverage, expansions for LH (med: 4.8 min: 1.9 max: 17.3; med: 3.8 min: 1.2 max: 12.9; med: 3.3, min: 0.6, max: 9.3) were not significantly different than OP (med: 3.8, min: 1.7, max: 10.9; med: 3.1 min: 1.3, max: 9.4; med: 2.1, min: 0.7, max: 8.4), suggesting larger but infrequent shifts in LH. Directional tumor displacement varied widely (Table 1), and by site and points describing the need for personalized margins.

CONCLUSION

Current literature as well as the analysis in this study indicate a wide range of motion - both in magnitude and duty cycle - between and within HN sub-sites not captured on CT simulation. Moving forward, motion based heatmaps based on MR-cine may serve as visualization tool for ITV contouring or to generate personalized motion margins.

Predictors of Tumor Dynamics during a 6-Week Course of Chemoradiotherapy for Glioblastoma

PURPOSE/OBJECTIVE(S)

Our prior imaging studies have shown geometrically meaningful inter-fraction tumor dynamics specific to glioblastoma (GBM). We aim to identify predictors associated with tumor dynamics during a 6-week course of concurrent chemoradiotherapy (CRT) for GBM.

MATERIALS/METHODS

Patients enrolled in a prospective serial magnetic resonance imaging (MRI) study were reviewed. All patients were treated with 54-60 Gy in 30 fractions. The gross tumor volume (GTV) included the surgical cavity and T1c enhanced residual tumor; clinical tumor volume (CTV) included GTV with a 15mm isotropic expansion, respecting anatomical boundaries; planning target volume (PTV) was 4mm expansion. MRIs were obtained at RT planning (F0), fraction 10 (F10), and fraction 20 (F20). Tumor dynamic metrics (relative to F0) assessed included the GTV volume (Vrel), Hausdorff distance (dH) and migration distance (dM). dH is the average distance between two datasets in metric space. dM is the maximum linear displacement of the GTV in any direction. Factors to be determined associated with tumor dynamics included: age, sex, corpus callosum (CC) involvement, extent of surgery (gross total resection (GTR), subtotal resection (STR) or biopsy alone (Bx)), MGMT methylation and IDH mutation status.

RESULTS

A total of 129 patients were reviewed. Median GTV was 20.9cc at F0, 17.6cc at F10 (Vrel 0.85), and 16.1cc at F20 (Vrel 0.78). Patients without CC involvement had more marked GTV volume reduction: Vrel 0.82 vs 1.02 with CC involvement at F10 (P = 0.05), and Vrel 0.77 vs 0.88 with CC involvement at F20 (P = 0.03). Patients with GTR (vs STR vs Bx) had more marked GTV volume reduction across all time points: Vrel 0.78, 0.85 and 1.07 respectively at F10 (P = 0.001), and Vrel 0.69, 0.80, 1.04 respectively at F20 (P = 0.001). The median dH was 8.1mm at F10 and 9.2mm at F20. Patients with CC involvement (vs without CC involvement) had a larger dH: 54% vs 25% had dH>10mm respectively at F10 (P = 0.03), and 73% vs 28% had dH>10mm respectively at F20 (P<0.005). Patients with a GTR had smaller dH at both F10 (P = 0.02) and F20 (P = 0.006). At F20, 20%, 47% and 37% of patients with GTR, STR and Bx had dH>10mm (P = 0.04). The median dM were 4.7mm at F10 and 4.7mm at F20. Patients with CC involvement (vs without CC involvement) had larger dM: 41% vs 12% had dM >10mm respectively at F10 (P = 0.01), and 45% vs 9% had dM >10mm respectively at F20 (P<0.001). Patients with GTR had smaller dM at F10 (P = 0.03) and F20 (P0.002). At F20, 0%, 25% and 19% of patients with GTR, STR and Bx had dM>10mm (P = 0.002). Age, sex, MGMT methylation and IDH mutation status were not associated with Vrel, dH and dM at F10 and F20.

CONCLUSION

We identified CC involvement and extent of surgery to be associated with tumor dynamics at F10 and F20 over the course of CRT for GBM. This offers opportunities to better select patients who may benefit from earlier/ more frequent RT replan/ adaptation to ensure adequate tumor coverage, or to reduce RT toxicities.

175 Rare Complications and Management of Port Site Hernias (PSH) Following Robotic-Assisted Radical Prostatectomy (RARP)

Robot-assisted surgery has become increasingly prevalent in surgical practice and is very commonly performed in urological cancers especially of the prostate gland. Robotic surgical techniques are safe and reproducible; however, they have their associated complications. Risk factors such as the nature of cancer, learning curve of the surgery, experience of the surgeon and patient characteristics have been implicated for potential complications. Complications can range from bleeding, infection, bowel injury, ureteric and nerve damage. Port site hernias (PSH) are an infrequent complication with a reported incidence varying from 0.2–4.8%. Although uncommon, they can result in high morbidity due to bowel incarceration and strangulation.

We report two cases of PSH from our large district general hospital, both at the supraumbilical port site after robotic assisted radical prostatectomy (RARP). The first case presented with complete evisceration and strangulation of a segment of small bowel and the second with bowel incarceration and small bowel obstruction. Our cases highlight potentially rare but severe complications of RARP that should be promptly recognised and urgently treated to prevent significant patient morbidity and mortality.

Correction to: Comparison of the clinical effectiveness and safety between the use of denosumab vs bisphosphonates in renal transplant patients

The original version of this article, published on 03 January 2020 contained a mistake. An author's name was misspelled.

Comparison of the clinical effectiveness and safety between the use of denosumab vs bisphosphonates in renal transplant patients

A retrospective chart review was conducted on 85 renal transplant patients aged 19-88 years, treated with denosumab or bisphosphonate therapy. Bone densitometry measures were compared between treatment groups at baseline; at years 1, 2, and 3; and at final follow-up (average of 3.4 years). Both bisphosphonate and denosumab treatments increased lumbar spine bone density; however, the effect of denosumab was greater compared with that of bisphosphonate treatment. Denosumab treatment increased femoral neck BMD, whereas bisphosphonate treatment had a mean decrease in femoral neck BMD at final follow-up. Thus, our study provides evidence for the efficacy of denosumab treatment in renal transplant patients. Caution around hypocalcemia is warranted. We recommend more prospective studies to analyze the effects of long-term antiresorptive therapy in patients with a renal transplant.

INTRODUCTION

To compare the clinical effectiveness and safety between the use of denosumab and bisphosphonates on bone density and incidence of adverse events in renal transplant patients.

METHODS

A retrospective chart review was conducted on 85 renal transplant patients aged 19-88 years, treated with denosumab or bisphosphonate therapy. Bone densitometry measures were compared between treatment groups at baseline; years 1, 2, and 3; and at final follow-up (average of 3.4 years).

RESULTS

Absolute change in lumbar spine and femoral neck BMD over the treatment period was 0.029 ± 0.075 g/cm² and - 0.003 ± 0.064 g/cm², respectively, in the bisphosphonate group. Absolute change in lumbar spine and femoral neck BMD at final follow-up was 0.072 ± 0.094 g/cm² and 0.025 ± 0.063 g/cm², respectively, in the denosumab group. Denosumab resulted in significantly greater increases in lumbar spine BMD (0.045 g/cm² greater in the denosumab group). Similarly, the absolute change in BMD at the femoral neck was 0.022 g/cm² greater in the denosumab group as compared with the bisphosphonate group. The denosumab group had one event of severe hypocalcemia following first injection and one report of hospitalized pneumonia. No serious adverse events were reported in the bisphosphonate group.

CONCLUSIONS

Both treatments increased lumbar spine BMD; however, the effect of denosumab was greater compared with that of bisphosphonate treatment. Our study provides evidence for the efficacy of denosumab treatment in renal transplant patients. Caution around hypocalcemia is warranted. We recommend more prospective studies to analyze the effects of long-term antiresorptive therapy in patients with a renal transplant.

An architectural understanding of natural sway frequencies in trees

The relationship between form and function in trees is the subject of a longstanding debate in forest ecology and provides the basis for theories concerning forest ecosystem structure and metabolism. Trees interact with the wind in a dynamic manner and exhibit natural sway frequencies and damping processes that are important in understanding wind damage. Tree-wind dynamics are related to tree architecture, but this relationship is not well understood. We present a comprehensive view of natural sway frequencies in trees by compiling a dataset of field measurement spanning conifers and broadleaves, tropical and temperate forests. The field data show that a cantilever beam approximation adequately predicts the fundamental frequency of conifers, but not that of broadleaf trees. We also use structurally detailed tree dynamics simulations to test fundamental assumptions underpinning models of natural frequencies in trees. We model the dynamic properties of greater than 1000 trees using a finite-element approach based on accurate three-dimensional model trees derived from terrestrial laser scanning data. We show that (1) residual variation, the variation not explained by the cantilever beam approximation, in fundamental frequencies of broadleaf trees is driven by their architecture; (2) slender trees behave like a simple pendulum, with a single natural frequency dominating their motion, which makes them vulnerable to wind damage and (3) the presence of leaves decreases both the fundamental frequency and the damping ratio. These findings demonstrate the value of new three-dimensional measurements for understanding wind impacts on trees and suggest new directions for improving our understanding of tree dynamics from conifer plantations to natural forests.

Afatinib in advanced pretreated non-small-cell lung cancer- a Canadian experience

Background

Afatinib, an irreversible epidermal growth factor receptor tyrosine kinase inhibitor (egfr tki), is approved for first-line therapy in advanced EGFR mutation-positive non-small-cell lung cancer (nsclc) and has previously demonstrated activity after failure of chemotherapy and reversible egfr tkis, with improved response and progression-free survival, compared with placebo. Outcomes in pretreated patients with advanced nsclc receiving afatinib through a Canadian special access program (sap) are reported here.

Methods

Patients with nsclc progressing after at least 1 line of chemotherapy and an egfr tki were eligible to enrol in the sap. Characteristics of patients from the two largest accruing Canadian centres were retrospectively reviewed, including demographics, disease and treatment data, and patient outcomes.

Results

The 53 patients who received afatinib (57% women, 51% never-smokers, 26% of East Asian ethnicity, and 66% with adenocarcinoma) had a median age of 59 years. EGFR mutations were documented in 25%, and EGFR wild-type in 8%. All patients had received prior egfr tki treatment, with 42% achieving a response. Patients took afatinib for a median of 2 months (range: 0-26 months); 17% required 1 or more dose reductions. Of 47 evaluable patients receiving afatinib, 10 experienced tumour shrinkage, and 11, stable disease. Median survival from afatinib initiation was 5 months (95% confidence interval: 2 months to 8 months). Grade 3 or greater diarrhea, rash, paronychia, and stomatitis were seen in 9%, 11%, 6%, and 4% of patients respectively.

Conclusions

In an unselected population of pretreated patients with advanced nsclc after tki failure, median survival with afatinib therapy was 5 months. Through a sap, afatinib demonstrated activity in clinical practice, with manageable toxicity.

Bridging Barriers, Building Partners: Success of a Multistakeholder Collaborative Effort in Building and Implementing a Free Mammography Programme for Underprivileged Malaysian Women

Background and context: Research has revealed two large problems in the Malaysian breast cancer control context. First, a large disparity existed in diagnostic stages of Malaysian patients during first presentation; with a large percentage of patients presenting in Stage 3 or 4. Second, patients presenting in later stages of disease were revealed to be of lower socioeconomic backgrounds. Shortcomings are thus thought to exist in the capability of women from lower socioeconomic groups to access breast cancer screening. To address these gaps, the National Cancer Society of Malaysia conceptualized and put together a multistakeholder collaborative project. Aim: The aim of this project was to build, finance and implement a free mammography program for underprivileged Malaysian women. Strategy/Tactics: To ensure geographic equity in provision of this program, 14 individual private hospitals in 10 different states in peninsular Malaysia were negotiated with and agreed to provide the mammogram at highly competitive prices. To address transport and other costs which may have acted as a barrier for patients to attend their screening, transportation costs for groups going for their screening was also subsidized. Additional stakeholders' engaged were nongovernmental organizations (NGOs) especially those working with the economically underprivileged such as religious and other community NGOs. They were roped in as partners to spread the message, identify eligible participants and schedule visits. Some NGOs carried this out as part of their own outreach activities; reserving specific days at the screening centers for themselves. Program/Policy process: The program consisted of a free mammogram provided to Malaysian women above 40 years of age who were determined to be underprivileged; defined for this program as those having a monthly household income below the poverty line (RM5000). If the mammogram was found to be suspicious, a confirmatory breast ultrasound was also performed sans payment. Once conceptualized, the program was successfully pitched by NCSM to ETIQA Insurance, a large Malaysian insurer, who agreed to fund this project as part of their sustainable corporate social responsibility (CSR) initiative. In total, the program funded mammograms for 5000 women over a period of 1 year from July 2017 to July 2018. NCSM advertised the program through various channels; including traditional media, social media, and at various outreach programs and events. Outcomes/What was learned: The program has run for 8 months and has already screened 3550 women nationwide. The multistakeholder collaborative effort has been highly successful at creating awareness on breast cancer screening and providing accurate breast cancer screening for a large number of underprivileged women, some for the first time in their lives.

Complex interventions can increase osteoporosis investigations and treatment: a systematic review and meta-analysis

Osteoporosis is affecting over 200 million people worldwide. Despite available guidelines, care for these patients remains sub-optimal. We developed an osteoporosis tool to address the multiple dimensions of chronic disease management. Findings from its evaluation showed a significant increase from baseline in osteoporosis investigations and treatment, so we are revising this tool to include multiple chronic conditions including an update of evidence about osteoporosis. Our objectives were to conduct a systematic review of osteoporosis interventions in adults at risk for osteoporosis. We searched bibliometric databases for randomized controlled trials (RCTs) in any language evaluating osteoporosis disease management interventions in adults at risk for osteoporosis. Reviewer pairs independently screened citations and full-text articles, extracted data, and assessed risk of bias. Analysis included random effects meta-analysis. Primary outcomes were osteoporosis investigations and treatment, and fragility fractures. Fifty-five RCTs and one companion report were included in the analysis representing 165,703 patients. Our findings from 55 RCTs and 18 sub-group meta-analyses showed that complex implementation interventions with multiple components consisting of at least education + feedback + follow-up significantly increased the initiation of osteoporosis medications, and interventions with at least education + follow-up significantly increased the initiation of osteoporosis investigations. No significant impact was found for any type of intervention to reduce fracture. Complex interventions that include at least education + follow-up or feedback have the most potential for increasing osteoporosis investigations and treatment. Patient education appears to be an important component in osteoporosis disease management.

Management of pinna haematoma study (MaPHaeS): A multicentre retrospective observational study

OBJECTIVES

To assess current variation in the management of pinna haematoma (PH) and its effect on outcomes.

DESIGN

Multicentre retrospective observational record-based study.

SETTING

Eleven hospitals around the UK.

PARTICIPANTS

Eighty-three patients above the age of 16 with PH.

OUTCOME MEASURES

The primary outcome measure was recurrence rate of PH over a 6-month period post-treatment, assessed by treatment type (scalpel incision vs needle aspiration). Secondary outcome measures assessed the impact of other factors on recurrence, infection and cosmetic complications of PH over a period of 6 months.

RESULTS

After adjusting for confounding factors, involvement of the whole ear, and management within an operating theatre were associated with a lower rate of recurrence of pinna haematoma. The drainage technique, suspected aetiology, choice of post-drainage management, grade and specialty of practitioner performing drainage, the use of antibiotic cover and hospital admission did not affect the rate of haematoma recurrence, infection or cosmetic complications.

CONCLUSIONS

Where possible PH should be drained in an operating theatre. Multicentre randomized controlled trials are required to further investigate the impact of drainage technique and post-drainage management on outcome.

Pathology-based staging for HPV-positive squamous carcinoma of the oropharynx

OBJECTIVE

The rapid worldwide rise in incidence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has generated studies confirming this disease as an entity distinct from traditional OPSCC. Based on pathology, surgical studies have revealed prognosticators specific to HPV-positive OPSCC. The current AJCC/UICC staging and pathologic nodal (pN)-classification do not differentiate for survival, demonstrating the need for new, HPV-specific OPSCC staging. The objective of this study was to define a pathologic staging system specific to HPV-positive OPSCC.

METHODS

Data were assembled from a surgically-managed, p16-positive OPSCC cohort (any T, any N, M0) of 704 patients from five cancer centers. Analysis was performed for (a) the AJCC/UICC pathologic staging, (b) newly published clinical staging for non-surgically managed HPV-positive OPSCC, and (c) a novel, pathology-based, "HPVpath" staging system that combines features of the primary tumor and nodal metastases.

RESULTS

A combination of AJCC/UICC pT-classification and pathology-confirmed metastatic node count (⩽4 versus ⩾5) yielded three groups: stages I (pT1-T2, ⩽4 nodes), II (pT1-T2, ⩾5 nodes; pT3-T4, ⩽4 nodes), and III (pT3-T4, ⩾5 nodes), with incrementally worse prognosis (Kaplan-Meier overall survival of 90%, 84% and 48% respectively). Existing AJCC/UICC pathologic staging lacked prognostic definition. Newly published HPV-specific clinical stagings from non-surgically managed patients, although prognostic, showed lower precision for this surgically managed cohort.

CONCLUSIONS

Three loco-regional "HPVpath" stages are identifiable for HPV-positive OPSCC, based on a combination of AJCC/UICC primary tumor pT-classification and metastatic node count. A workable, pathologic staging system is feasible to establish prognosis and guide adjuvant therapy decisions in surgically-managed HPV-positive OPSCC.

The Brain Metastases Symptom Checklist as a novel tool for symptom measurement in patients with brain metastases undergoing whole-brain radiotherapy

PURPOSE

We evaluated the feasibility, reliability, and validity of the Brain Metastases Symptom Checklist (bmsc), a novel self-report measure of common symptoms experienced by patients with brain metastases.

METHODS

Patients with first-presentation symptomatic brain metastases (n = 137) referred for whole-brain radiotherapy (wbrt) completed the bmsc at time points before and after treatment. Their caregivers (n = 48) provided proxy ratings twice on the day of consultation to assess reliability, and at week 4 after wbrt to assess responsiveness to change. Correlations with 4 other validated assessment tools were evaluated.

RESULTS

The symptoms reported on the bmsc were largely mild to moderate, with tiredness (71%) and difficulties with balance (61%) reported most commonly at baseline. Test-retest reliability for individual symptoms had a median intraclass correlation of 0.59 (range: 0.23-0.85). Caregiver proxy and patient responses had a median intraclass correlation of 0.52. Correlation of absolute scores on the bmsc and other symptom assessment tools was low, but consistency in the direction of symptom change was observed. At week 4, change in symptoms was variable, with improvements in weight gain and sleep of 42% and 41% respectively, and worsening of tiredness and drowsiness of 62% and 59% respectively.

CONCLUSIONS

The bmsc captures a wide range of symptoms experienced by patients with brain metastases, and it is sensitive to change. It demonstrated adequate test-retest reliability and face validity in terms of its responsiveness to change. Future research is needed to determine whether modifications to the bmsc itself or correlation with more symptom-specific measures will enhance validity.

NLRP3 regulates a non-canonical platform for caspase-8 activation during epithelial cell apoptosis

Nod-like receptor, pyrin containing 3 (NLRP3) is characterized primarily as a canonical caspase-1 activating inflammasome in macrophages. NLRP3 is also expressed in the epithelium of the kidney and gut; however, its function remains largely undefined. Primary mouse tubular epithelial cells (TEC) lacking Nlrp3 displayed reduced apoptosis downstream of the tumor necrosis factor (TNF) receptor and CD95. TECs were identified as type II apoptotic cells that activated caspase-8, tBid and mitochondrial apoptosis via caspase-9, responses that were reduced in Nlrp3-/- cells. The activation of caspase-8 during extrinsic apoptosis induced by TNFα/cycloheximide (TNFα/CHX) was dependent on adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC) and completely independent of caspase-1 or caspase-11. TECs and primary human proximal tubular epithelial cells (HPTC) did not activate a canonical inflammasome, caspase-1, or IL-1β secretion in response to TNFα/CHX or NLRP3-dependent triggers, such as ATP or nigericin. In cell fractionation studies and by confocal microscopy, NLRP3 colocalized with ASC and caspase-8 in speck-like complexes at the mitochondria during apoptosis. The formation of NLRP3/ASC/caspase-8 specks in response to TNFα/CHX was downstream of TNFR signaling and dependent on potassium efflux. Epithelial ASC specks were present in enteroids undergoing apoptosis and in the injured tubules of wild-type but not Nlrp3-/- or ASC-/- mice following ureteric unilateral obstruction in vivo. These data show that NLRP3 and ASC form a conserved non-canonical platform for caspase-8 activation, independent of the inflammasome that regulates apoptosis within epithelial cells.