Magnetic resonance-guided stereotactic body radiation therapy for pancreatic oligometastases from renal cell carcinoma.

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.

Radiation response assessment of organoids derived from patients with pancreatic cancer.

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.

The Effect of Radiation Treatment of Solid Tumors on Neutrophil Infiltration and Function: A Systematic Review.

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.

Treatment planning for MR-guided SBRT of pancreatic tumors on a 1.5 T MR-Linac: A global consensus protocol.

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.

The effect of surface roughening on the success of orthodontic mini-implants: A systematic review and meta-analysis.

Introduction: Orthodontic mini-implants are a widely accepted treatment modality in orthodontics; however, the failure rate is moderately high. Surface roughening is the golden standard in conventional oral implantology, and this may prove beneficial for orthodontic mini-implants as well. The objective of this systematic review is to assess the effect of surface roughening on the success rate of orthodontic mini-implants in both adolescent and adult patients undergoing orthodontic treatment.

Clinical outcomes after online adaptive MR-guided stereotactic body radiotherapy for pancreatic tumors on a 1.5 T MR-linac.

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.

Gating and intrafraction drift correction on a 1.5 T MR-Linac: Clinical dosimetric benefits for upper abdominal tumors.

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.

Predicting Long-term Disease-free Survival After Resection of Pancreatic Ductal Adenocarcinoma: A Nationwide Cohort Study.

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.

Towards Response ADAptive Radiotherapy for organ preservation for intermediate-risk rectal cancer (preRADAR): protocol of a phase I dose-escalation trial.

Introduction: Organ preservation is associated with superior functional outcome and quality of life (QoL) compared with total mesorectal excision (TME) for rectal cancer. Only 10% of patients are eligible for organ preservation following short-course radiotherapy (SCRT, 25 Gy in five fractions) and a prolonged interval (4-8 weeks) to response evaluation. The organ preservation rate could potentially be increased by dose-escalated radiotherapy.

Precision radiotherapy using MR-linac for pancreatic neuroendocrine tumors in MEN1 patients (PRIME): a protocol for a phase I-II trial, and systematic review on available evidence for radiotherapy of pNETs.

Background: Surgical resection is the standard of care for the treatment of pancreatic neuro-endocrine tumors (pNETs) in patients with Multiple Endocrine Neoplasia Type 1 (MEN1). However, surgery can cause significant short- and long-term morbidity. Magnetic resonance-guided radiotherapy (MRgRT) is a potential effective treatment with little side effects.

Factors Associated with Esthetic Outcomes of Flapless Immediate Placed and Loaded Implants in the Maxillary Incisor Region-Three-Year Results of a Prospective Case Series.

Flapless immediate implant placement and provisionalization (FIIPP) is often associated with an increased risk of buccal soft-tissue recession. This study aims to assess the 3-year esthetic outcome. In 100 consecutive patients, one maxillary incisor, with or without a pre-extraction buccal bone defect (≤5 mm), was replaced by an implant installed in a maximal palatal position (buccal gap ≥2 mm).

Feasibility of online radial magnetic resonance imaging for adaptive radiotherapy of pancreatic tumors.

Background And Purpose: Online adaptive magnetic resonance (MR)-guided treatment planning for pancreatic tumors on 1.5T systems typically employs Cartesian 3D w magnetic resonance imaging (MRI). The main disadvantage of this sequence is that respiratory motion results in substantial blurring in the abdomen, which can hamper delineation accuracy.

Intrafraction motion analysis in online adaptive radiotherapy for esophageal cancer.

Intrafraction motion during magnetic resonance (MR)-guided dose delivery of esophageal cancer tumors was retrospectively analyzed. Deformable image registration of cine-MR series resulted in gross tumor volume motion profiles in all directions, which were subsequently filtered to isolate respiratory and drift motion. A large variability in intrafraction motion patterns was observed between patients.

Feasibility of delivered dose reconstruction for MR-guided SBRT of pancreatic tumors with fast, real-time 3D cine MRI.

Background And Purpose: In MR-guided SBRT of pancreatic cancer, intrafraction motion is typically monitored with (interleaved) 2D cine MRI. However, tumor surroundings are often not fully captured in these images, and motion might be distorted by through-plane movement. In this study, the feasibility of highly accelerated 3D cine MRI to reconstruct the delivered dose during MR-guided SBRT was assessed.

Dosimetric impact of intrafraction motion under abdominal compression during MR-guided SBRT for (Peri-) pancreatic tumors.

. Intrafraction motion is a major concern for the safety and effectiveness of high dose stereotactic body radiotherapy (SBRT) in the upper abdomen. In this study, the impact of the intrafraction motion on the delivered dose was assessed in a patient group that underwent MR-guided radiotherapy for upper abdominal malignancies with an abdominal corset.

Detecting Interval Distant Metastases With 18F-FDG PET/CT After Neoadjuvant Chemoradiotherapy for Locally Advanced Esophageal Cancer.

Purpose: Patients with esophageal cancer can develop distant metastases between the start of neoadjuvant chemoradiotherapy (nCRT) and planned surgery (ie, interval distant metastases). 18F-FDG PET/CT restaging after nCRT detects interval distant metastases in ~8% of patients. This study aimed to identify patients for whom 18F-FDG PET/CT restaging after nCRT could be omitted using an existing prediction model predicting for interval distant metastases or by using clinical stage groups.

Intrafraction pancreatic tumor motion patterns during ungated magnetic resonance guided radiotherapy with an abdominal corset.

Background: Stereotactic body radiotherapy (SBRT) has been shown to be a promising therapy for unresectable pancreatic tumors. However, intrafraction motion, caused by respiratory motion and organ drift, is one of the main concerns for efficient dose delivery in ungated upper abdominal radiotherapy. The aim of this study was to analyze the intrafraction gross tumor volume (GTV) motion in a clinical cohort.

Online adaptive MR-guided stereotactic radiotherapy for unresectable malignancies in the upper abdomen using a 1.5T MR-linac.

Background: Introduction of online adaptive MR-guided radiotherapy enables stereotactic body radiation therapy (SBRT) of upper abdominal tumors. This study aimed to evaluate the feasibility of MR-guided SBRT on a 1.5 T MR-linac in patients with unresectable upper abdominal malignancies.

Does the pre-operative buccal soft tissue level at teeth or gingival phenotype dictate the aesthetic outcome after flapless immediate implant placement and provisionalization? Analysis of a prospective clinical case series.

Background: Immediate implant placement (IIP) often is related to mid-buccal recession in literature. To draw conclusions about the behavior of the soft tissues following IIP, pre-operative aesthetic measurements have to be taken into account. The aim of analysis of these prospective clinical case series data was to elucidate whether the pre-operative buccal soft tissue level (STL) or gingival phenotype influence the 1-year pink aesthetic outcome after performing flapless immediate implant placement and provisionalization (FIIPP) maxillary incisor cases.

Risk Factors for Tumor Positive Resection Margins After Neoadjuvant Chemoradiotherapy for Esophageal Cancer: Results From the Dutch Upper GI Cancer Audit: A Nationwide Population-Based Study.

Objective: To identify risk factors for tumor positive resection margins after neoadjuvant chemoradiotherapy (nCRT) followed by esophagectomy for esophageal cancer.

Summary Background Data: Esophagectomy after nCRT is associated with tumor positive resection margins in 4% to 9% of patients. This study evaluates potential risk factors for positive resection margins after nCRT followed by esophagectomy.

Planning target volume margin assessment for online adaptive MR-guided dose-escalation in rectal cancer on a 1.5 T MR-Linac.

Purpose: This study assessed the margins needed to cover tumor intrafraction motion during an MR-guided radiotherapy (MRgRT) dose-escalation strategy in intermediate risk rectal cancer.

Methods: Fifteen patients with rectal cancer were treated with neoadjuvant short-course radiotherapy, 5x5 Gy, according to an online adaptive workflow on a 1.5 T MR-linac.

Combined effect of undersized surgical technique and axial compression on the primary implant stability and host bone architecture.

Aim: The aim of this study was to investigate the combined effect of the lateral-compression of host-bone (undersized-osteotomy-preparation) and axial-compression of host-bone (not drilling the full length of the implant) on the primary-implant-stability and the host-bone-architecture.

Materials And Methods: In this experimental-study, 44 dental implants (diameter-4.2 mm; length-10 mm; Dyna®) were installed in the femoral-condyles of four cadaver-goats using four different surgical approaches (11 implant/surgical approach; n = 11).

Magnetic Resonance Guided Radiation Therapy for Pancreatic Adenocarcinoma, Advantages, Challenges, Current Approaches, and Future Directions.

Introduction: Pancreatic adenocarcinoma (PAC) has some of the worst treatment outcomes for any solid tumor. PAC creates substantial difficulty for effective treatment with traditional RT delivery strategies primarily secondary to its location and limited visualization using CT. Several of these challenges are uniquely addressed with MR-guided RT.

Review of MR-Guided Radiotherapy for Esophageal Cancer.

In this review, we outline the potential benefits and the future role of MRI and MR-guided radiotherapy (MRgRT) in the management of esophageal cancer. Although not currently used in most clinical practice settings, MRI is a useful non-invasive imaging modality that provides excellent soft tissue contrast and the ability to visualize cancer physiology. Chemoradiation therapy with or without surgery is essential for the management of locally advanced esophageal cancer.