Ablation Therapy of the Biliary Tree: Status and Comprehensive Review.

Malignant biliary obstruction is typically referred to endoscopists for palliation. A curative resection is indeed rarely an option in this condition. Photodynamic therapy and radiofrequency ablation are 2 modalities that can be offered in those patients. Many studies have demonstrated improved stent patency and survival after ablation. Photodynamic therapy is unfortunately very expensive and is associated with photosensitivity; however, it transmits to the entire biliary tree. Radiofrequency ablation is more affordable and easier to apply but requires contact with the tumor to be efficient. This review explores both modalities in terms of their safety and efficacy for bile duct cancer palliation.

Endoscopic submucosal dissection of recurrent, circumferential, distal rectal tumor with severe submucosal fibrosis using multiple clip-line tractions.

Video 1Endoscopic submucosal dissection for a recurrent, circumferential, distal rectal tumor.

Predictors of Success of Pharyngeal Surgery in the Treatment of Obstructive Sleep Apnea: A Narrative Review.

(1) Background: This narrative review aims to explore the predictors of success for pharyngeal surgery in the treatment of obstructive sleep apnea (OSA). An extensive literature search was conducted, identifying relevant studies published up to June 2023, utilizing various databases and key search terms related to OSA, surgical interventions, and predictors of success. The review encompasses both retrospective and prospective studies, case series, and cohort studies to provide a broad understanding of the topic; (2) Methods: Review of English scientific literature on phenotypes of OSA related to predictors of success of pharyngeal surgery; (3) Results: Of 75 articles, 21 were included, in these the following were determined to be factors for surgical success: body mass index (BMI) (8 articles), apnea/hypopnea index (AHI) (8 articles), cephalometry (8 articles), palatine tonsil size (7 articles), Modified Mallampati score (2 articles), genioglossus electromyography (2 articles), Friedman score or upper airway anatomy (3 articles), nasopharyngolaryngoscopy (2 articles), drug-induced sleep endoscopy (DISE) (1 article), oral cavity anatomy (1 article) and oxygen desaturation index (ODI) (1 article); (4) Conclusions: The lack of standardized protocols for the indication of pharyngeal surgery is a reality, however identifying known predictors of surgical success may facilitate homogenizing indications.

Endoscopic Submucosal Dissection (ESD) Offers a Safer and More Cost-effective Alternative to Transanal Endoscopic Microsurgery (TEM): An International Collaborative Study.

BACKGROUND: Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are minimally invasive procedures that treat early rectal cancer (ERC). Both are effective treatments, yet there are very few studies comparing them. The aim of our study was to identify ideal candidates for each procedure. MATERIALS AND METHODS: Between January 2016 and November 2019, 204 ERC patients were managed with either ESD (n=101) or TEM (n=103) at 7 international centers. Data analyzed included clinical success, tumor characteristics, procedure info, and recurrence rates. RESULTS: Median tumor size was 40 mm±23.9 in the ESD group and 56 mm±27.9 in the TEM group, significantly larger in the latter ( P <0.00001). Average procedure time was 131.5±67.9 minutes in ESD group and 104.9±28.4 minutes in TEM group ( P =0.000347). Average hospital stay was 3.3±2.6 days in the ESD group and 4.7±0.7 days in the TEM group ( P <0.00001). Adverse event rate was 6.8% in the ESD group and 24% in the TEM group. There were no significant difference in the rate of en bloc resection, technical success, tumor location, necessity of additional procedures, and tumor recurrence rates. CONCLUSION: Compared with TEM, ESD is a safer procedure with shorter hospital stay and should be offered for patients who have ERC.

Direct determination ofkQfor Farmer-type ionization chambers in a clinical scanned carbon-ion beam using water calorimetry.

Within two studies,kQfactors for two Farmer-type ionization chambers have been experimentally determined by means of water calorimetry in the entrance channel (EC) of a monoenergetic carbon-ion beam (Osinga-Blättermannet al2017Phys. Med. Biol.622033-54) and for a passively modulated spread-out Bragg peak (SOBP) (Holmet al2021Phys. Med. Biol.66145012). Both studies were performed at the Heidelberg Ion Beam Therapy Center (HIT) using the PTB portable water calorimeter but applying different initial beam energies of 429 MeV u-1for the EC and 278 MeV u-1for the SOBP as well as different scanning patterns of the irradiated field. Comparing their results revealed differences between the experimentalkQfactors of up to 1.9% between the EC and the SOBP. To further investigate this unexpected difference, we performed additionalkQdeterminations for the EC of an 278 MeV u-1monoenergetic carbon-ion beam and reevaluated the original data of Osinga-Blättermannet al(2017Phys. Med. Biol.622033-54). This new experimental data indicated no difference between thekQfactors for the EC and the SOBP and the reevaluation led to a substantial reduction of the originally publishedkQfactors for the EC of the 429 MeV u-1beam (Osinga-Blättermannet al2017Phys. Med. Biol.622033-54). Finally, no significant difference between the data for the EC and the data for the SOBP can be found within the standard measurement uncertainty of experimentalkQfactors of 0.8%. The results presented here are intended to correct and replace thekQdata published by Osinga-Blättermannet al(2017Phys. Med. Biol.622033-54) and in Osinga-Blättermann and Krauss (2018Phys. Med. Biol.64015009).

Gastric per-oral endoscopic myotomy versus pyloromyotomy for gastroparesis: An international comparative study.

BACKGROUND AND AIM: Gastroparesis is a potentially debilitating gastric motility disorder with limited treatment options. Highest efficacy treatments include gastric per-oral endoscopic myotomy (GPOEM) and surgical pyloromyotomy. This study compares the efficacy and safety of GPOEM versus laparoscopic pyloromyotomy for refractory gastroparesis. METHODS: Patients who underwent GPOEM or laparoscopic pyloromyotomy for refractory gastroparesis from four centers across the USA and Latin America were included in a dedicated registry. Data collected included patient demographics, imaging, laboratory values, clinical success, gastroparesis cardinal symptom index, procedure time, pre-op and post-op gastric emptying times, adverse events, and hospital length of stay. RESULTS: A total of 102 patients were included (mean age 47; 32.4% male): GPOEM n = 39, surgical pyloromyotomy n = 63.Technical success was 100% in both groups. Clinical success was 92.3% in the GPOEM group and 82.5% in the surgery group (P = 0.164). The GPOEM group had a significantly higher post-op GSCI score reduction by 1.3 units (P < 0.00001), post-op retention reduction at 2 h by 18% (P < 0.00001), post-op retention reduction at 4 h by 25% (P < 0.00001) and a lower procedure time by 20 min (P < 0.00001) as compared with surgery. GPOEM also had a lower hospital length of stay by 2.8 days (P < 0.00001). Adverse events were significantly fewer in the GPOEM group (13%) compared with surgery group (33.3%; P = 0.021). Mean blood loss in the GPOEM group was only 3.6 mL compared with 866 mL in the surgery group. CONCLUSIONS: The GPOEM may be a less invasive, safer, and more efficacious procedural treatment for refractory gastroparesis as compared with surgical pyloromyotomy.

Triple channel analysis of Gafchromic EBT3 irradiated with clinical carbon-ion beams.

Self-developing radiochromic film is widely used in radiotherapy QA procedures. To compensate for typical film inhomogeneities, the triple channel analysis method is commonly used for photon-irradiated film. We investigated the applicability of this method for GafchromicTMEBT3 (Ashland) film irradiated with a clinically used carbon-ion beam. Calibration curves were taken from EBT3 film specimens irradiated with monoenergetic carbon-ion beams of different doses. Measurements of the lateral field shape and homogeneity were performed in the middle of a passively modulated spread-out Bragg peak and compared to simultaneous characterization by means of a 2D ionization chamber array. Additional measurements to investigate the applicability of EBT3 for quality assurance (QA) measurement in carbon-ion beams were performed. The triple-channel analysis reduced the relative standard deviation of the doses in a uniform carbon ion field by 30% (from 1.9% to 1.3%) and reduced the maximum deviation by almost a factor of 3 (from 28.6% to 9.8%), demonstrating the elimination of film artifacts. The corrected film signal showed considerably improved image quality and quantitative agreement with the ionization chamber data, thus providing a clear rationale for the usage of the triple channel analysis in carbon-beam QA.

Water calorimetry-basedkQfactors for Farmer-type ionization chambers in the SOBP of a carbon-ion beam.

The dosimetry of carbon-ion beams based on calibrated ionization chambers (ICs) still shows a significantly higher uncertainty compared to high-energy photon beams, a fact influenced mainly by the uncertainty of the correction factor for the beam qualitykQ. Due to a lack of experimental data,kQfactors in carbon-ion beams used today are based on theoretical calculations whose standard uncertainty is three times higher than that of photon beams. To reduce their uncertainty, in this work,kQfactors for two ICs were determined experimentally by means of water calorimetry for the spread-out Bragg peak of a carbon-ion beam, these factors are presented here for the first time. To this end, the absorbed dose to water in the12C-SOBP is measured using the water calorimeter developed at Physikalisch-Technische Bundesanstalt, allowing a direct calibration of the ICs used (PTW 30013 and IBA FC65G) and thereby an experimental determination of the chamber-specifickQfactors. Based on a detailed characterization of the irradiation field, correction factors for several effects that influence calorimetric and ionometric measurements were determined. Their contribution to an overall uncertainty budget of the finalkQfactors was determined, leading to a standard uncertainty forkQof 0.69%, which means a reduction by a factor of three compared to the theoretically calculated values. The experimentally determined values were expressed in accordance with TRS-398 and DIN 6801-1 and compared to the values given there. A maximum deviation of 2.3% was found between the experiment and the literature.

A Review of Endoscopic Full-thickness Resection, Submucosal Tunneling Endoscopic Resection, and Endoscopic Submucosal Dissection for Resection of Subepithelial Lesions.

Gastrointestinal subepithelial tumors (SETs) are often found while performing routine endoscopy. Recently, there has been the development of new endoscopic techniques such as endoscopic submucosal dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection, all minimally invasive approaches which have made it possible to resect SETs that were previously resected with surgery. This review discusses the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, procedure-related complications, and advantages and disadvantages of these endoscopic techniques.

2D range modulator for high-precision water calorimetry in scanned carbon-ion beams.

Ionization chamber-based dosimetry for carbon-ion beams still shows a significantly higher standard uncertainty than high-energy photon dosimetry. This is mainly caused by the high standard uncertainty of the correction factor for beam quality [Formula: see text]. Due to a lack of experimental data, the given values for [Formula: see text] are based on theoretical calculations. To reduce this standard uncertainty, [Formula: see text] factors for different irradiation conditions and ionization chambers (ICs) can be determined experimentally by means of water calorimetry. To perform such measurements in a spread-out Bragg peak (SOBP) for a scanned carbon-ion beam, we describe the process of creating an almost cubic dose distribution of about 6 × 6 × 6 cm3 using a 2D range modulator. The aim is to achieve a field homogeneity with a standard deviation of measured dose values in the middle of the SOBP (over a lateral range and a depth of about 4 cm) below 2% within a scanning time of under 100 s, applying a dose larger than 1 Gy. This paper describes the optimization and characterization of the dose distribution in detail.

Management of Incidental Pancreatic Cystic Lesions: Integrating Novel Diagnostic and Prognostic Factors With Current Clinical Guidelines.

Owing to increased detection rates, the diagnosis and management of incidental pancreatic cysts has become a common predicament. Up to 13% of patients undergoing cross-sectional imaging studies for other indications are found to have pancreatic cystic lesions. Although most cystic lesions are benign, the malignant potential of several types of pancreatic cysts makes accurate classification vital to directing therapy. To this end, advances in the last decade led to better characterization of pancreatic cyst morphology and hence enhanced the ability to predict underlying histopathology, and biological behavior. Although accurate classification remains a challenge, the utilization of complementary diagnostic tools is the optimal approach to dictate management. The following review includes a description of pancreatic cysts, a critical review of current and emerging diagnostic techniques and a review of recent guidelines in the management of incidental pancreatic cysts.

Hemorrhoid Energy Therapy for Treatment of Deep Chronic Anal Fissures.

Energy therapy is a well-known, minimally invasive treatment for internal hemorrhoids. This treatment has not yet been studied in anal fissures refractory to medical therapy. Anal fissures, such as hemorrhoids, can disrupt the quality of life for patients. Currently, nonsurgical treatments available for anal fissures are only supportive measures. Definitive for chronic anal fissures refractory to medical therapy is internal sphincterotomy. This treatment has chances of relapse and a risk of anal incontinence. We propose the use of hemorrhoid energy therapy with bipolar cautery as a safer, less invasive, and effective therapy for recurrent anal fissures refractory to conservative management.