Hypofractionated radiotherapy combined with targeted therapy or immunotherapy: Dutch survey on current practice, knowledge and challenges

Introduction: With the introduction of tyrosine kinase inhibitors and systemic antibodies, including immune checkpoint inhibitors, the survival of advanced-stage cancer patients has improved for many tumor types. These patients are increasingly referred for radiotherapy, but it is unclear whether radiotherapy combined with these drugs is safe. No international guidelines exist on whether or how to combine these drugs with radiotherapy. Therefore, we investigated the current clinical practice in the Netherlands regarding hypofractionated radiotherapy in patients using targeted drugs and immunotherapy.Materials and methods: We sent a survey to all 21 Dutch radiotherapy institutes. Dedicated radiation oncologists, medical oncologists and pulmonologists were asked to fill out the survey. The questions explored their familiarity with the combination of targeted drugs and immunotherapy with radiotherapy, the encountered clinical difficulties and factors influencing treatment decisions.Results: The survey was filled out by 54 respondents from 19 different institutes. The median annual number of patients per radiation oncologist referred for radiotherapy when using targeted drugs or immunotherapy was 10 and 15, respectively. Despite this high number, only 11% of the radiation oncologists stated that they had sufficient information (resources) for adequate treatment decision making. Among all physicians, 44% stated that there was insufficient knowledge within their institute regarding this topic. Only 17% stated that there was a multidisciplinary protocol available. The application of radiotherapy treatment adaptations (technique, dose, fractionation, field size) varied widely. Generally, there seemed to be no consensus regarding the expected toxicity of combined drug-radiotherapy treatments and the expected risk of tumor flare upon temporary drug discontinuation.Conclusion: There is no consensus amongst involved medical specialties on expected toxicity. Consequently, it is necessary to perform clinical studies examining the safety of combined drug-radiotherapy treatments, to add radiotherapy to phase I-III clinical trials for new drugs and to incorporate outcomes into multidisciplinary, evidence-based guidelines.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Predictive factors for response and toxicity after brachytherapy for rectal cancer; results from the HERBERT study

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Prognostic implications of lateral lymph nodes in rectal cancer: a population-based cross-sectional study with standardized radiological evaluation after dedicated training

Background: There is an ongoing discussion regarding the prognostic implications of the presence, short-axis diameter and location of lateral lymph nodes.Objective: To analyze lateral lymph node characteristics, the role of downsizing on restaging MRI and associated local recurrence rates for patients with cT3-4 rectal cancer after MRI re-review and training.Design: Retrospective population-based cross-sectional study. Settings: This collaborative project was led by local investigators from surgery and radiology departments in 60 Dutch hospitals.Patients: 3057 patients underwent rectal cancer surgery in 2016: 1109 had cT3-4 tumor located ≤8cm from the anorectal junction of which 890 received neoadjuvant therapy. Interventions(s):  NoneMain Outcome Measures: local recurrence and ipsi-lateral local recurrence rates. Results: Re-review identified 314 patients (35%) with visible lateral lymph nodes. 30 of these patients had either only long-stretched obturator (n=13) or external iliac (n=17) nodes and both did not lead to any lateral local recurrences. The presence of internal iliac/obturator lateral lymph nodes (n=284) resulted in 4-year local recurrence and lateral local recurrence rates of 16.4% and 8.8%, respectively. Enlarged (≥7mm) lateral lymph nodes (n=122) resulted in higher 4-year local recurrence (20.8%, 13.1%, 0%, pLimitations: This study was limited by the retrospective design and total number of patients with lateral lymph nodes.Conclusions: The risk of lateral local recurrence due to (enlarged) lateral lymph nodes was confirmed, but without prognostic impact of downsizing after neoadjuvant therapy. These results point towards the incorporation of primary lateral lymph node size into treatment planning. Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Feasibility of Gold Fiducial Markers as a Surrogate for Gross Tumor Volume Position in Image-Guided Radiation Therapy of Rectal Cancer

Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas