What is the predictive value of RECIST criteria following stereotactic lung radiation?

PURPOSE: Response EvaluationCriteriain Solid Tumors (RECIST) is commonly used to assess response to anti-cancer therapies. However, its application after lung stereotactic ablative radiotherapy (SABR) is complicated by radiation-induced lung changes. This study assesses the frequency of progressive disease (PD) by RECIST following lung SABR and correlates this with actual treatment outcomes as determined by longitudinal follow-up. METHODS AND MATERIALS: We reviewed patients treated with lung SABR for primary lung tumors or oligometastases between 2010 and 2015. Patients were treated with SABR doses of 54-60 Gy in 3-8 fractions. All follow-up scans were assessed and the treated lesion was serially measured over time, with the maximum diameter on axial CT slices used for RECIST calculations. Lesions demonstrating PD by RECIST criteria were identified and subsequently followed for long-term outcomes. The final 'gold-standard' assessment of response was based on size changes after PD and, as available, positron emission tomography scan and/or biopsy. RESULTS: Eighty-eight lesions met inclusion criteria. Seventy-five were lung primaries and thirteen were lung metastases. Median follow-up was 52 months (interquartile range: 33-68). Two-thirds (66 %, 58/88) of treated lesions met RECIST criteria for PD; however, local recurrence was only confirmed in 16 % (9/58) of cases. Most lesions that triggered PD by RECIST (47/58, 81 %) were ultimately found not to represent recurrence, while a minority (2/58, 3 %) had an uncertain response. The positive predictive value [PPV] of a RECIST defined PD event was 0.16. If PD was triggered within 12-months post-treatment, PPV was 0.08, compared to 0.21 for lesions triggering PD after 12-months. CONCLUSION: Using RECIST criteria, two-thirds of patients treated with lung SABR met criteria for PD. However, only a minority had recurrence, leading to a poor PPV of RECIST. This highlights the limitations of RECIST in this setting and provides context for physicians when interpreting post-lung SABR imaging.

Stereotactic ablative radiotherapy before resection to avoid delay for early-stage lung cancer or oligometastases during the COVID-19 pandemic: Pathologic outcomes from the SABR-BRIDGE protocol.

BACKGROUND: During coronavirus disease 2019 (COVID-19)-related operating room closures, some multidisciplinary thoracic oncology teams adopted a paradigm of stereotactic ablative radiotherapy (SABR) as a bridge to surgery, an approach called SABR-BRIDGE. This study presents the preliminary surgical and pathological results. METHODS: Eligible participants from four institutions (three in Canada and one in the United States) had early-stage presumed or biopsy-proven lung malignancy that would normally be surgically resected. SABR was delivered using standard institutional guidelines, with surgery >3 months following SABR with standardized pathologic assessment. Pathological complete response (pCR) was defined as absence of viable cancer. Major pathologic response (MPR) was defined as ≤10% viable tissue. RESULTS: Seventy-two patients underwent SABR. Most common SABR regimens were 34 Gy/1 (29%, n = 21), 48 Gy/3-4 (26%, n = 19), and 50/55 Gy/5 (22%, n = 16). SABR was well-tolerated, with one grade 5 toxicity (death 10 days after SABR with COVID-19) and five grade 2-3 toxicities. Following SABR, 26 patients underwent resection thus far (13 pending surgery). Median time-to-surgery was 4.5 months post-SABR (range, 2-17.5 months). Surgery was reported as being more difficult because of SABR in 38% (n = 10) of cases. Thirteen patients (50%) had pCR and 19 (73%) had MPR. Rates of pCR trended higher in patients operated on at earlier time points (75% if within 3 months, 50% if 3-6 months, and 33% if ≥6 months; p = .069). In the exploratory best-case scenario analysis, pCR rate does not exceed 82%. CONCLUSIONS: The SABR-BRIDGE approach allowed for delivery of treatment during a period of operating room closure and was well-tolerated. Even in the best-case scenario, pCR rate does not exceed 82%.

Predicting recurrence risks in lung cancer patients using multimodal radiomics and random survival forests.

Purpose: We developed a model integrating multimodal quantitative imaging features from tumor and nontumor regions, qualitative features, and clinical data to improve the risk stratification of patients with resectable non-small cell lung cancer (NSCLC). Approach: We retrospectively analyzed 135 patients [mean age, 69 years (43 to 87, range); 100 male patients and 35 female patients] with NSCLC who underwent upfront surgical resection between 2008 and 2012. The tumor and peritumoral regions on both preoperative CT and FDG PET-CT and the vertebral bodies L3 to L5 on FDG PET were segmented to assess the tumor and bone marrow uptake, respectively. Radiomic features were extracted and combined with clinical and CT qualitative features. A random survival forest model was developed using the top-performing features to predict the time to recurrence/progression in the training cohort ( n = 101 ), validated in the testing cohort ( n = 34 ) using the concordance, and compared with a stage-only model. Patients were stratified into high- and low-risks of recurrence/progression using Kaplan-Meier analysis. Results: The model, consisting of stage, three wavelet texture features, and three wavelet first-order features, achieved a concordance of 0.78 and 0.76 in the training and testing cohorts, respectively, significantly outperforming the baseline stage-only model results of 0.67 ( p < 0.005 ) and 0.60 ( p = 0.008 ), respectively. Patients at high- and low-risks of recurrence/progression were significantly stratified in both the training ( p < 0.005 ) and the testing ( p = 0.03 ) cohorts. Conclusions: Our radiomic model, consisting of stage and tumor, peritumoral, and bone marrow features from CT and FDG PET-CT significantly stratified patients into low- and high-risk of recurrence/progression.

Resection of a Large Hemorrhagic Mediastinal Lymphangioma in an Adult Patient: A Radiologic-Pathologic Correlation.

Lymphangiomas are rare benign lesions resulting from abnormal proliferation and sequestration of lymphatic tissues that are disconnected from the rest of the lymphatic system. This is a case of a 50-year-old woman with an unusually large mediastinal lymphangioma complicated by hemorrhage. The substantial mass effect and unstable clinical status necessitated urgent operative management. The use of preoperative multimodality radiologic assessment, including CT and MRI, is illustrated throughout this case. Keywords: CT, MR Imaging, Thorax, Lung © RSNA, 2022.

Endoscopic nodal staging in oligometastatic non-small cell lung cancer (NSCLC) being treated with stereotactic ablative radiotherapy (ENDO-SABR).

BACKGROUND: Research in treatment of non-small cell lung cancer (NSCLC) has shown promising results with stereotactic ablative radiotherapy (SABR) of oligometastatic disease, wherein distant disease may be limited to one or a few distant organs by host factors. Traditionally, PET/CT has been used in detecting metastatic disease and avoiding futile surgical intervention, however, sensitivity and specificity is limited to only 81 and 79%, respectively. Mediastinal staging still identifies occult nodal disease in up to 20% of NSCLC patients initially thought to be operative candidates. Endobronchial ultrasound and transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive tool for the staging and diagnosis of thoracic malignancy. When EBUS is combined with endoscopic ultrasound using the same bronchoscope (EUS-B), the diagnostic sensitivity and negative predictive value increase to 84 and 97%, respectively. Endoscopic staging in patients with advanced disease has never been studied, but may inform treatment if a curative SABR approach is being taken. METHODS: This is a multi-centre, prospective, cohort study with two-stage design. In the first stage, 10 patients with oligometastatic NSCLC (lung tumour ± hilar/mediastinal lymphadenopathy) with up to 5 synchronous metastases will be enrolled An additional 19 patients will be enrolled in the second stage if rate of treatment change is greater than 10% in the first stage. Patients will be subject to EBUS or combined modality EBUS/EUS-B to assess bilateral lymph node stations using a N3 to N2 to N1 progression. Primary endpoint is defined as the rate of change to treatment plan including change from SABR to conventional dose radiation, change in mediastinal radiation field, and change from curative to palliative intent treatment. DISCUSSION: If a curative approach with SABR for oligometastatic disease is being explored, invasive mediastinal staging may guide treatment and prognosis. This study will provide insight into the use of endoscopic mediastinal staging in determining changes in treatment plan of NSCLC. Results will inform the design of future phase II trials. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT04852588. Date of registration: April 19, 2021. PROTOCOL VERSION: 1.1 on December 9, 2021.

Surgery crisis simulation during the COVID-19 pandemic.

SummaryCOVID-19 puts health care providers at risk for infection with SARS-CoV-2. Personal protective equipment (PPE) can reduce viral transmission if used properly. We used simulation of an intraoperative crisis involving an infectious outbreak to assess PPE adherence and confidence in PPE use. Simulation of an intraoperative crisis with a patient with COVID-19 revealed gaps in PPE adherence; however, simulation training successfully increased confidence in PPE use and received positive feedback.

Idiopathic Subglottic Stenosis: An Institutional Review of Outcomes With a Multimodality Surgical Approach.

OBJECTIVES: This article reports on a unique cohort of patients with idiopathic subglottic stenosis spilt fairly equally between endoscopic and open surgical approaches. Patients' sequence of operations and reinterventions over time are outlined, offering insight to improve surgical counseling and allow for informative, autonomous patient decision making. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary care academic center. METHODS: Cases of consecutive adults with idiopathic subglottic stenosis managed surgically over a 12-year period (January 2006-December 2017) were retrospectively reviewed. Surgical workflow, complications, and outcomes, including reinterventions and tracheotomy dependence, are reported. RESULTS: Seventy-two patients (71 women; mean age, 50.4 years) with idiopathic subglottic stenosis requiring surgical airway intervention were identified. Six patients underwent tracheotomy prior to attempt at airway stenosis surgery. Initial surgical approach thereafter included endoscopic (73.5%, n = 53) and open (26.4%, n = 19) procedures. Thirty-one patients underwent cricotracheal resection; the reintervention rate was 22.5%. Sixty patients underwent 147 endoscopic procedures; the reintervention rate was 75.5%, and the mean time between dilations was 83 weeks (range, 5-402). Two (2.8%) patients remain tracheotomy dependent. Adverse events were significantly higher in the cricotracheal group, especially with respect to dysphonia and temporary gastrostomy tube placement (P < .01). CONCLUSIONS: Endoscopic and open surgical airway intervention can be employed successfully to avoid tracheotomy dependence and maintain airway patency; however, multiple procedures are usually required, regardless of surgical approach. Cricotracheal reintervention rates are lower than endoscopic dilation but with increased morbidity. Quality-of-life outcomes should be clearly discussed with patients before deciding on a surgical management strategy.

Scoliosis and bronchial obstruction.

Severe scoliosis may have a significant effect on respiratory function. The effect is most often restrictive due to severe anatomical distortion of the chest, leading to reduced lung volumes, limited diaphragmatic excursion and chest wall muscle inefficiency. Bronchial compression by the deformed spine may also occur but is more unusual. Management options include a conservative approach using bracing and physiotherapy in mild cases, as well as surgical correction of the scoliosis in more severe cases. Bronchial stenting has also been used successfully as an alternative to surgical correction, and in cases in which spinal surgery was either unsuccessful or not feasible. The authors present a case involving a 52-year-old woman who exhibited symptomatic compression of the bronchus intermedius by severe residual scoliosis despite previous corrective surgery. She was treated with an indwelling bronchial stent.