Stella Mook

R-IDEAL : A Framework for Systematic Clinical Evaluation of Technical Innovations in Radiation Oncology

The pace of innovation in radiation oncology is high and the window of opportunity for evaluation narrow. Financial incentives, industry pressure, and patients’ demand for high-tech treatments have led to widespread implementation of innovations before, or even without, robust evidence of improved outcomes has been generated. The standard phase I–IV framework for drug evaluation is not the most efficient and desirable framework for assessment of technological innovations. In order to provide a standard assessment methodology for clinical evaluation of innovations in radiotherapy, we adapted the surgical IDEAL framework to fit the radiation oncology setting. Like surgery, clinical evaluation of innovations in radiation oncology is complicated by continuous technical development, team and operator dependence, and differences in quality control. Contrary to surgery, radiotherapy innovations may be used in various ways, e.g., at different tumor sites and with different aims, such as radiation volume reduction and dose escalation. Also, the effect of radiation treatment can be modeled, allowing better prediction of potential benefits and improved patient selection. Key distinctive features of R-IDEAL include the important role of predicate and modeling studies (Stage 0), randomization at an early stage in the development of the technology, and long-term follow-up for late toxicity. We implemented R-IDEAL for clinical evaluation of a recent innovation in radiation oncology, the MRI-guided linear accelerator (MR-Linac). MR-Linac combines a radiotherapy linear accelerator with a 1.5-T MRI, aiming for improved targeting, dose escalation, and margin reduction, and is expected to increase the use of hypofractionation, improve tumor control, leading to higher cure rates and less toxicity. An international consortium, with participants from seven large cancer institutes from Europe and North America, has adopted the R-IDEAL framework to work toward coordinated, evidence-based introduction of the MR-Linac. R-IDEAL holds the promise for timely, evidence-based introduction of radiotherapy innovations with proven superior effectiveness, while preventing unnecessary exposure of patients to potentially harmful interventions.

Robot-assisted minimally invasive thoraco-laparoscopic esophagectomy for esophageal cancer in the upper mediastinum

BACKGROUND Patients with upper third esophageal cancer or esophageal cancer with upper mediastinal paratracheal lymph node metastases are often precluded from surgery because of technical difficulties. With the aid of robotic surgery, an excellent overview and reach of the thoracic inlet can be accomplished. In this way, patients with upper mediastinal esophageal cancer are eligible for esophageal resection with curative intent. The aim of this study was to review the results of a consecutive series of patients who underwent robot-assisted minimally invasive esophagectomy (RAMIE) for tumors of the upper 1/3 of the esophagus or positive lymph nodes in the upper mediastinum. METHODS Between 2007-2016, 31 patients who underwent RAMIE in the UMC Utrecht for proximal esophageal cancer or proximal thoracic lymphadenopathy were identified from a prospective surgical database. Perioperative characteristics and oncologic outcomes were collected. RESULTS The majority of patients had a squamous cell carcinoma. Clinical tumor stage was cT3 or higher in 25 (81%) of patients. Clinically positive lymph nodes (cN1-3) were observed in 29 (94%) patients. Neoadjuvant treatment was administered in 27 (87%) patients. Median duration of the surgical procedure was 435 min (range 299-874 min). Pulmonary complications were most frequent and occurred in 13 (42%) patients. Median intensive care (ICU stay) was 1 day (range 1-65 days) and median overall postoperative hospital stay was 15 days (range 10-118 days). In hospital mortality was 10%. Causes of mortality were tracheo-neo-esophageal fistula, sepsis after abdominal wall drainage due to leakage of the jejunal fistula resulting in respiratory and kidney failure, after which refraining further treatment resulting in death, and irreversible ARDS in a patient with COPD Gold III needing extracorporeal life support. Radical resection was achieved in 30 (97%) of the patients. Median number of retrieved lymph nodes was 22 (range 9-57). Median time of follow up was 18 months (range 3-81 months). Median disease-free survival was 13 months (range 0-81 months) and median overall survival was 16 months (range 0-81 months). Tumor recurrence occurred in 15 patients (48%) and was locoregional only in 3 patients, systemic only in 5 patients and combined locoregional and systemic in 7 patients. CONCLUSIONS Robot assisted thoraco-laparoscopic esophagectomy with curative intent in patients with upper mediastinal esophageal cancer is feasible, but associated with increased in hospital mortality. Short-term oncologic results are encouraging.

Perioperative chemotherapy versus neoadjuvant chemoradiotherapy for esophageal or GEJ adenocarcinoma: A propensity score‐matched analysis comparing toxicity, pathologic outcome, and survival

To evaluate toxicity, pathologic outcome, and survival after perioperative chemotherapy (pCT) compared to neoadjuvant chemoradiotherapy (nCRT) followed by surgery for patients with resectable esophageal or gastroesophageal junction (GEJ) adenocarcinoma.

Correlation between functional imaging markers derived from diffusion-weighted MRI and 18 F-FDG PET/CT in esophageal cancer

Objective Both the apparent diffusion coefficient (ADC) acquired by diffusion-weighted magnetic resonance imaging (DW-MRI) and the standardized uptake value (SUV), acquired by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), are well-established functional parameters in cancer imaging. Currently, it is unclear whether these two markers provide complementary prognostic and predictive information in esophageal cancer. The aim of this study was to evaluate the correlation between ADC and SUV in patients with esophageal cancer. Materials and methods This prospective study included 76 patients with histologically proven esophageal cancer who underwent both DW-MRI and 18F-FDG PET/CT examinations before treatment. The minimum and mean ADC values (ADCmin and ADCmean) of the primary tumor were assessed on MRI. Similarly, the glucose metabolism was evaluated by the maximum and mean SUV (SUVmax and SUVmean) in the same lesions on 18F-FDG PET/CT images. Spearman’s rank correlation coefficients were used to assess the correlation between tumor ADC and SUV values. Results The tumor ADC and SUV values as measures of cell density and glucose metabolism, respectively, showed negligible nonsignificant correlations (ADCmin vs. SUVmax: r=−0.087, P=0.457; ADCmin vs. SUVmean: r=−0.105, P=0.369; ADCmean vs. SUVmax: r=−0.099, P=0.349; ADCmean vs. SUVmean: r=−0.111, P=0.340). No differences in tumor ADC and SUV values were observed between the different histologic tumor types, stages, and differentiation grades. Conclusion This study indicates that tumor cellularity derived from DW-MRI and tumor metabolism measured by 18F-FDG PET/CT are independent cellular phenomena in newly diagnosed esophageal cancer. Therefore, tumor ADC and SUV values may play complementary roles as imaging markers in the prediction of survival and evaluation of response to treatment in esophageal cancer.

Quantification of variations in intra-fraction motion of esophageal tumors over the course of neoadjuvant chemoradiotherapy based on cine-MRI

To noninvasively quantify variation in intra-fraction motion of esophageal tumors over the course of neoadjuvant chemoradiotherapy (nCRT) using 2D cine-magnetic resonance imaging (MRI) series. Patients treated with nCRT for esophageal cancer underwent six MRI scans. Scans were acquired prior to the start of nCRT, followed by weekly MRI scans during nCRT. Cine-MRI series were acquired in the coronal and sagittal plane (≈1.6 Hz). To be able to quantify intra-fraction motion over a longer time period, a second cine-MRI series was performed after 10 min. Tumor motion was assessed in cranio-caudal (CC), anterior-posterior (AP) and left-right (LR) direction. Motion patterns were analyzed for the presence of deep inhales and tumor drift. A total of 232 cine-MRI series of 20 patients were analyzed. The largest tumor motion was found in CC direction, with a mean peak-to-peak motion of 12.7 mm (standard deviation [SD] 5.6), followed by a mean peak-to peak motion in AP direction of 3.8 mm (SD 2.0) and in LR direction of 2.7 mm (SD 1.3). The CC intra-fraction tumor motion can differ extensively between and within patients. Deep inhales were present in six of 232 scans (3%). After exclusion of these scans, mean CC peak-to-peak motion was12.3 mm (SD 5.2). Correction for tumor drift showed a further reduction to 11.0 mm (SD 4.6). Despite correction for tumor drift, a large variation in tumor motion occurred within patients during treatment. Mean tumor drift during the 10 min interval between the two series was 1.5 mm (SD 1.8), with a maximum of 11.6 mm. Intra-fraction tumor motion was found to be highly variable between and within patients with esophageal cancer over the course of nCRT. Correction for deep inhales and tumor drift reduced peak-to-peak motion. The stochastic nature of both deep inhales and tumor drift indicates that real-time tumor motion management during radiotherapy is a prerequisite to safely reduce treatment margins.

Management of resectable esophageal and gastric (mixed adeno)neuroendocrine carcinoma: A nationwide cohort study.

INTRODUCTION The aim of this study is to provide insight in accuracy of diagnosing, current treatment and survival in patients with resectable esophageal and gastric neuroendocrine- and mixed adenoneuroendocrine carcinomas (NEC, MANEC). METHODS All patients with esophageal or gastric (MA)NEC, who underwent surgical resection between 2006 and 2016, were identified from the Dutch national registry for histo- and cytopathology (PALGA). Patients with a neuroendocrine tumor lower than grade 3 were excluded. Data on patients, treatment and outcomes were retrieved from the patient records. Diagnosis by endoscopic biopsy was compared with diagnosis by resection specimen. Kaplan Meier survival analysis was performed. RESULTS A total of 49 patients were identified in 25 hospitals, including 21 patients with esophageal (MA)NEC and 26 patients with gastric (MA)NEC on resection specimen. Biopsy diagnosis of (MA)NEC was correct in 23/27 patients. However, 20/47 patients with definitive diagnosis of (MA)NEC, were misdiagnosed on biopsy. Neoadjuvant therapy was administered in 13 (62%) esophageal (MA)NECs and 12 (46%) gastric (MA)NECs. Survival curves were similar with and without neoadjuvant therapy. One (4.8%) esophageal (MA)NEC and 4 (15%) gastric (MA)NECs died within 90 days postoperatively. For esophageal (MA)NEC the median overall survival (OS) after surgery was 37 months and 1-, 3- and 5-year OS were 71%, 50% and 35%, respectively. For gastric (MA)NEC, the median OS was 23 months and 1-, 3- and 5-year OS were 62%, 50% and 39%, respectively. CONCLUSION Localized esophageal and gastric (MA)NEC are often misdiagnosed on endoscopic biopsies. After resection, long-term survival was achieved in respectively 35% and 39% of patients.

Detection of distant interval metastases after neoadjuvant therapy for esophageal cancer with 18F-FDG PET(/CT): a systematic review and meta-analysis

Restaging after neoadjuvant therapy aims to reduce the number of patients undergoing esophagectomy in case of distant (interval) metastases. The aim of this study is to systematically review and meta-analyze the diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and 18F-FDG PET/CT for the detection of distant interval metastases after neoadjuvant therapy in patients with esophageal cancer. PubMed/MEDLINE, Embase, and the Cochrane library were systematically searched. The analysis included diagnostic studies reporting on the detection of distant interval metastases with 18F-FDG PET(/CT) in patients with esophageal cancer who received neoadjuvant therapy and both baseline staging and restaging after neoadjuvant therapy with 18F-FDG PET(/CT) imaging. The primary outcome measure was the proportion of patients in whom distant interval metastases were detected by 18F-FDG PET(/CT) as confirmed by pathology or clinical follow-up (i.e. true positives). The secondary outcome measure was the proportion of patients in whom 18F-FDG PET(/CT) restaging was false positive for distant interval metastases (i.e. false positives). Risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Random-effect models were used to estimate pooled outcomes and examine potential sources of heterogeneity. Fourteen studies were included comprising a total of 1,110 patients who received baseline staging with 18F-FDG PET(/CT) imaging of whom 1,001 (90%) underwent restaging with 18F-FDG PET(/CT) imaging. Studies were generally of moderate quality. The pooled proportion of patients in whom true distant interval metastases were detected by 18F-FDG PET(/CT) restaging was 8% (95% confidence interval [CI]: 5-13%). The pooled proportion of patients in whom false positive distant findings were detected by 18F-FDG PET(/CT) restaging was 5% (95% CI: 3-9%). In conclusion,18F-FDG PET(/CT) restaging after neoadjuvant therapy for esophageal cancer detects true distant interval metastases in 8% of patients. Therefore, 18F-FDG PET(/CT) restaging can considerably impact on treatment decision-making. However, false positive distant findings occur in 5% of patients at restaging with 18F-FDG PET(/CT), underlining the need for pathological confirmation of suspected lesions.

Preoperative image-guided identification of response to neoadjuvant chemoradiotherapy in esophageal cancer (PRIDE): a multicenter observational study

BackgroundNearly one third of patients undergoing neoadjuvant chemoradiotherapy (nCRT) for locally advanced esophageal cancer have a pathologic complete response (pCR) of the primary tumor upon histopathological evaluation of the resection specimen. The primary aim of this study is to develop a model that predicts the probability of pCR to nCRT in esophageal cancer, based on diffusion-weighted magnetic resonance imaging (DW-MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT). Accurate response prediction could lead to a patient-tailored approach with omission of surgery in the future in case of predicted pCR or additional neoadjuvant treatment in case of non-pCR.MethodsThe PRIDE study is a prospective, single arm, observational multicenter study designed to develop a multimodal prediction model for histopathological response to nCRT for esophageal cancer. A total of 200 patients with locally advanced esophageal cancer - of which at least 130 patients with adenocarcinoma and at least 61 patients with squamous cell carcinoma - scheduled to receive nCRT followed by esophagectomy will be included. The primary modalities to be incorporated in the prediction model are quantitative parameters derived from MRI and 18F-FDG PET-CT scans, which will be acquired at fixed intervals before, during and after nCRT. Secondary modalities include blood samples for analysis of the presence of circulating tumor DNA (ctDNA) at 3 time-points (before, during and after nCRT), and an endoscopy with (random) bite-on-bite biopsies of the primary tumor site and other suspected lesions in the esophagus as well as an endoscopic ultrasonography (EUS) with fine needle aspiration of suspected lymph nodes after finishing nCRT. The main study endpoint is the performance of the model for pCR prediction. Secondary endpoints include progression-free and overall survival.DiscussionIf the multimodal PRIDE concept provides high predictive performance for pCR, the results of this study will play an important role in accurate identification of esophageal cancer patients with a pCR to nCRT. These patients might benefit from a patient-tailored approach with omission of surgery in the future. Vice versa, patients with non-pCR might benefit from additional neoadjuvant treatment, or ineffective therapy could be stopped.Trial registrationThe article reports on a health care intervention on human participants and was prospectively registered on March 22, 2018 under ClinicalTrials.gov Identifier: NCT03474341.

DW-MRI and DCE-MRI are of complementary value in predicting pathologic response to neoadjuvant chemoradiotherapy for esophageal cancer

Abstract Purpose: To explore the potential benefit and complementary value of a multiparametric approach using diffusion-weighted (DW-) and dynamic contrast-enhanced (DCE-) magnetic resonance imaging (MRI) for prediction of response to neoadjuvant chemoradiotherapy (nCRT) in esophageal cancer. Material and methods: Forty-five patients underwent both DW-MRI and DCE-MRI prior to nCRT (pre), during nCRT (week 2–3) (per) and after completion of nCRT, but prior to esophagectomy (post). Subsequently, histopathologic tumor regression grade (TRG) was assessed. Tumor apparent diffusion coefficient (ADC) and area-under-the-concentration time curve (AUC) were calculated for DW-MRI and DCE-MRI, respectively. The ability of these parameters to predict pathologic complete response (pCR, TRG1) or good response (GR, TRG ≤ 2) to nCRT was assessed. Furthermore the complementary value of DW-MRI and DCE-MRI was investigated. Results: GR was found in 22 (49%) patients, of which 10 (22%) patients showed pCR. For DW-MRI, the 75th percentile (P75) ΔADCpost-pre was most predictive for GR (c-index = 0.75). For DCE-MRI, P90 ΔAUCper-pre was most predictive for pCR (c-index = 0.79). Multivariable logistic regression analyses showed complementary value when combining DW-MRI and DCE-MRI for pCR prediction (c-index = 0.89). Conclusions: Both DW-MRI and DCE-MRI are promising in predicting response to nCRT in esophageal cancer. Combining both modalities provides complementary information, resulting in a higher predictive value.