Publications by authors named "Martijn Intven"

Stereotactic body radiation therapy (SBRT) may be a non-invasive strategy to treat patients with pancreatic oligometastases from renal cell carcinoma (RCC). We analyzed 11 patients treated with MR-guided SBRT to 31 pancreatic oligometastases. At a median follow-up of 31.

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Background & Purpose: Deep learning (DL) based auto-segmentation has shown to be beneficial for online adaptive radiotherapy (OART). However, auto-segmentation of clinical target volumes (CTV) is complex, as clinical interpretations are crucial in their definition. The resulting variation between clinicians and institutes hampers the generalizability of DL networks.

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Background And Purpose: Patients with cardiac implantable electronic devices (CIED patients) are often ineligible for online magnetic resonance-guided radiotherapy (MRgRT), most likely due to the absence of established guidelines. Existing radiotherapy (RT) and magnetic resonance imaging (MRI) guidelines offer an opportunity to construct MRgRT protocols, promoting equitable access. Our objective was to present such a workflow, share multi-institutional experiences treating CIED patients with MRgRT on a 1.

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Purpose: Dose-escalated radiation therapy is increasingly used in the treatment of pancreatic cancer; however, approaches to target delineation vary widely. We present the first North American cooperative group consensus contouring atlas for dose-escalated pancreatic cancer radiation therapy.

Methods And Materials: An expert international panel comprising 15 radiation oncologists, 2 surgeons, and 1 radiologist was recruited.

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Article Synopsis
  • International guidelines for imaging follow-up after pancreatic resection for pancreatic ductal adenocarcinoma (PDAC) are inconsistent, leading to varied follow-up strategies globally.
  • The study aimed to compare clinical outcomes, including treatment for recurrence and survival rates, between patients who received either symptomatic follow-up or routine imaging after PDAC surgery across 33 international centers.
  • A total of 333 patients were analyzed, showing that 29% had symptomatic follow-up while 71% underwent routine imaging, with overall survival rates being examined through statistical methods to identify the impact of the follow-up strategy on patient outcomes.
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Article Synopsis
  • Inadequate treatment of enlarged lateral lymph nodes (LLNs) in rectal cancer patients leads to higher local recurrence rates, but LLN dissection (LLND) may help reduce this risk.
  • This study will evaluate the outcomes of a standardized treatment approach after multidisciplinary training, aiming for a 50% reduction in local recurrence rates among patients with rectal cancer and enlarged LLNs.
  • The trial involves 200 patients and will assess important outcomes such as local recurrence rates, morbidity, disease-free survival, and quality of life over three years post-surgery, with ethical approval from a Dutch medical ethics board.
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Introduction: Postoperative pancreatic fistula (POPF) occurs in 25% of patients undergoing a high-risk pancreatoduodenectomy (PD) and is a driving cause of major morbidity, mortality, prolonged hospital stay and increased costs after PD. There is a need for perioperative methods to decrease these risks. In recent studies, preoperative chemoradiotherapy in patients with pancreatic ductal adenocarcinoma (PDAC) reduced the rate of POPF seemingly due to radiation-induced pancreatic fibrosis.

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Purpose: Standardized patient-reported outcomes (PRO) monitoring during and after rectal cancer treatment provides insight into treatment-related toxicities patients experience and improves health-related quality-of-life as well as overall survival. We aimed to select a subset of the PRO version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) for standardized monitoring of treatment-related symptomatic toxicities in rectal cancer.

Methods: We used a mixed methods approach including a literature review, and semi-structured interviews with health care providers (HCPs) involved in rectal cancer care and rectal cancer patients.

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Background: The effectiveness of radiotherapy for pancreatic cancer is debated. Patient-derived organoids (PDOs) already mimicked clinical radiation response in other cancer types, which could be valuable in pancreatic cancer as well. This study aimed to investigate whether PDOs can be used to model RT response in pancreatic cancer and to explore the presence of a dose-response correlation.

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Radiation therapy (RT) initiates a local and systemic immune response which can induce antitumor immunity and improve immunotherapy efficacy. Neutrophils are among the first immune cells that infiltrate tumors after RT and are suggested to be essential for the initial antitumor immune response. However, neutrophils in tumors are associated with poor outcomes and RT-induced neutrophil infiltration could also change the composition of the tumor microenvironment (TME) in favor of tumor progression.

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Background And Purpose: Magnetic Resonance Imaging (MRI) guided stereotactic body radiotherapy (SBRT) of liver metastases is an upcoming high-precision non-invasive treatment. Interobserver variation (IOV) in tumor delineation, however, remains a relevant uncertainty for planning target volume (PTV) margins. The aims of this study were to quantify IOV in MRI-based delineation of the gross tumor volume (GTV) of liver metastases and to detect patient-specific factors influencing IOV.

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Purpose: This systematic review provides an overview of literature on the impact of magnetic resonance-guided radiation therapy (MRgRT) on patient-reported outcomes (PROs) in patients with prostate cancer (PC).

Methods And Materials: A systematic search was performed in October 2023 in PubMed, EMBASE, and Cochrane Library. The Patient, Intervention, Comparison, Outcomes, and Study design (PICOS) framework was used to determine eligibility criteria.

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Background And Purpose: Treatment planning for MR-guided stereotactic body radiotherapy (SBRT) for pancreatic tumors can be challenging, leading to a wide variation of protocols and practices. This study aimed to harmonize treatment planning by developing a consensus planning protocol for MR-guided pancreas SBRT on a 1.5 T MR-Linac.

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Purpose: Hepatic Arteriography and C-Arm CT-Guided Ablation of liver tumors (HepACAGA) is a novel technique, combining hepatic-arterial contrast injection with C-arm CT-guided navigation. This study compared the outcomes of the HepACAGA technique with patients treated with conventional ultrasound (US) and/or CT-guided ablation.

Materials And Methods: In this retrospective cohort study, all consecutive patients with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) treated with conventional US-/CT-guided ablation between 1 January 2015, and 31 December 2020, and patients treated with HepACAGA between 1 January 2021, and 31 October 2023, were included.

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Importance: In 2018, the first online adaptive magnetic resonance (MR)-guided radiotherapy (MRgRT) system using a 1.5-T MR-equipped linear accelerator (1.5-T MR-Linac) was clinically introduced.

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Background: Postoperative pancreatic fistula remains the leading cause of significant morbidity after pancreatoduodenectomy for pancreatic ductal adenocarcinoma. Preoperative chemoradiotherapy has been described to reduce the risk of postoperative pancreatic fistula, but randomized trials on neoadjuvant treatment in pancreatic ductal adenocarcinoma focus increasingly on preoperative chemotherapy rather than preoperative chemoradiotherapy. This study aimed to investigate the impact of preoperative chemotherapy and preoperative chemoradiotherapy on postoperative pancreatic fistula and other pancreatic-specific surgery related complications on a nationwide level.

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Background: Novel definitions suggest that resectability status for pancreatic ductal adenocarcinoma (PDAC) should be assessed beyond anatomical criteria, considering both biological and conditional factors. This has, however, yet to be validated on a nationwide scale. This study evaluated the prognostic value of biological and conditional factors for staging of patients with resectable PDAC.

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Importance: Neoadjuvant short-course radiotherapy was routinely applied for nonlocally advanced rectal cancer (cT1-3N0-1M0 with >1 mm distance to the mesorectal fascia) in the Netherlands following the Dutch total mesorectal excision trial. This policy has shifted toward selective application after guideline revision in 2014.

Objective: To determine the association of decreased use of neoadjuvant radiotherapy with cancer-related outcomes and overall survival at a national level.

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In the past years several developments have occurred in the care for patients with pancreatic cancer in the Netherlands. New palliative chemotherapy strategies using FOLFRINOX or gemcitabine/nab-paclitaxel were introduced for patients with advanced disease. Due to centralization of pancreatic surgery, introduction of neoadjuvant therapy, and the implementation of standardized postoperative care more patients became enable for resection, postoperative mortality decreased, and survival improved.

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The utilization of stereotactic body radiation therapy for the treatment of liver metastasis has been widely studied and has demonstrated favorable local control outcomes. However, several predictive factors play a crucial role in the efficacy of stereotactic body radiation therapy, such as the number and size (volume) of metastatic liver lesions, the primary tumor site (histology), molecular biomarkers (e.g.

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Introduction: Online adaptive magnetic resonance-guided radiotherapy (MRgRT) is a promising treatment modality for pancreatic cancer and is being employed by an increasing number of centers worldwide. However, clinical outcomes have only been reported on a small scale, often from single institutes and in the context of clinical trials, in which strict patient selection might limit generalizability of outcomes. This study presents clinical outcomes of a large, international cohort of patients with (peri)pancreatic tumors treated with online adaptive MRgRT.

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This work reports on the first seven patients treated with gating and baseline drift correction on the high-field MR-Linac system. Dosimetric analysis showed that the active motion management system improved congruence to the planned dose, efficiently mitigating detrimental effects of intrafraction motion in the upper abdomen.

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Background: Pelvic insufficiency fractures (PIFs) are a late complication of radiotherapy for pelvic malignancies. We evaluated the incidence, radiologic findings, clinical course, and outcome of PIFs in patients treated with neoadjuvant (chemo)radiotherapy ((C)RT) for rectal cancer.

Material And Methods: Data of patients diagnosed with rectal cancer from a large teaching hospital treated from 2002 to 2012 were extracted from the Dutch Cancer Registry.

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Objective: To develop a prediction model for long-term (≥5 years) disease-free survival (DFS) after the resection of pancreatic ductal adenocarcinoma (PDAC).

Background: Despite high recurrence rates, ~10% of patients have long-term DFS after PDAC resection. A model to predict long-term DFS may aid individualized prognostication and shared decision-making.

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