prostate rectum space

Total pelvic exenteration (TPE) is a highly invasive surgery associated with high rates of perioperative morbidity and mortality and is commonly performed for several types of locally advanced or recurrent pelvic cancers. It involves multivisceral resection, including the rectum, sigmoid colon, bladder, prostate, uterus, vagina, or ovaries, and urologists normally perform radical cystectomy or radical prostatectomy and urinary diversion in collaboration with colorectal surgeons and gynecologists. In the urological field, robot-assisted surgeries have been widely performed as one of the main minimally invasive procedures because of their superior perioperative or oncological outcomes compared to open or laparoscopic surgeries...

Dose-surface maps (DSMs) provide spatial representations of the radiation dose
to organ surfaces during radiotherapy and are a valuable tool for identifying dose deposition
patterns that are predictive of radiation toxicities. Over the years, many different DSM calculation
approaches have been introduced and used in dose-outcome studies. However, little consideration
has been given to how these calculation approaches may be impacting the reproducibility of studies
in the field...

PURPOSE: Recently, a randomized trial demonstrated that a hyaluronic acid (HA) spacer placed prior to prostate hypofractionated intensity-modulated radiation therapy improved rectal dosimetry and reduced acute grade 2+ gastrointestinal toxicity. However, 26.5% of patients receiving the spacer experienced a minimal clinically important decline (MCID) in bowel quality-of-life (QOL). The purpose of this study is to evaluate whether certain characteristics of the rectal spacer, as determined on post-implant imaging, were associated with change in bowel QOL at 3-months...

PURPOSE: This study aimed to explore an ideal method for hydrogel spacer insertion by analyzing the efficacy and safety of our originally developed apex expansion method. MATERIALS AND METHODS: Overall, 100 patients with low- and intermediate-risk localized prostate cancer treated with stereotactic body radiation therapy were included. A hydrogel spacer was inserted in 64 and 36 patients using the conventional and apex expansion methods, respectively. For dosimetry, we trisected the rectum into the upper rectum, middle rectum, and lower rectum on the sagittal section of magnetic resonance imaging...

PURPOSE/OBJECTIVE(S): Our hybrid intelligence (HI) system, combining natural and artificial intelligence, is effective for auto-contouring H&N and thorax organs at risk (OARs) for radiation therapy (RT) planning with FDA 510(k) clearance. The purpose of this study is to test the HI system to segment a commercially available retroprostatic hyaluronic acid spacer gel (RSG) and pelvic OARs in planning CT images for prostate cancer RT. HYPOTHESIS: HI can achieve clinically acceptable auto segmentation for tissue-equivalent RSG in this domain...

PURPOSE/OBJECTIVE(S): Rectal dose can be significantly decreased after spacer application. An initially fluid spacer (FS) spreads in a predetermined space, whereas the positioning of a viscous spacer is determined by needle guidance. The aim of this study was to evaluate the application a radiopaque viscous spacer (RVS) for prostate cancer radiotherapy (RT). MATERIALS/METHODS: In 30 patients including three centers, 10ml (median) of a RVS was injected between the prostate and anterior rectal wall...

PURPOSE/OBJECTIVE(S): Recently, a randomized trial (NCT04189913) reported that a hyaluronic acid (HA) rectal spacer reduced acute grade 2+ gastrointestinal (GI) toxicity for hypofractionated radiation therapy (RT). However, 26.5% of patients who received the spacer experienced a minimally clinically important difference (MCID; 5 points) in EPIC bowel quality-of-life (QOL). We evaluated whether characteristics of the spacer implant, particularly apical separation, were associated with change in bowel QOL at 3-months and acute grade 1+ GI toxicity...

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles...

Rhabdomyosarcoma(RMS) treatment involves surgery, chemotherapy, and radiotherapy. A radioprotective space between the bladder/prostate and rectum reduces post-radiation complications, as reported in adult patients. Objective: describe pediatric pre-radiotherapy perirectal hyaluronic acid (HA) spacer injection for bladder/prostate RMS. We present a case of a 17-month-old male with bladder/prostate RMS. Before radiotherapy, an HA spacer was injected peri-rectally. Under general anesthesia, a transrectal ultrasound was positioned and 1 ml of HA spacer was injected into the perirectal space...

INTRODUCTION: A rectourethral fistula (RUF) is an infrequent complication that can be iatrogenic in most cases. Multiple surgical interventions were described for RUF repair including transsphincteric, transanal, transperineal, and transabdominal approaches. To this day, there is no consensus on a standardized surgery of choice for acquired RUF. MATERIALS AND SURGICAL TECHNIQUE: Our patient was diagnosed with RUF 4 weeks after undergoing laparoscopic low anterior resection for midrectum adenocarcinoma, with failure of conservative treatment...

IMPORTANCE: Hypofractionated radiation therapy (RT) for prostate cancer has been associated with greater acute grade 2 gastrointestinal (GI) toxic effects compared with conventionally fractionated RT. OBJECTIVE: To evaluate whether a hyaluronic acid rectal spacer could (1) improve rectal dosimetry and (2) affect acute grade 2 or higher GI toxic effects for hypofractionated RT. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was conducted from March 2020 to June 2021 among 12 centers within the US, Australia, and Spain, with a 6-month follow-up...

BACKGROUND: Controversies regarding the anatomical structure of Denonvilliers' fascia and its relationship with surrounding fasciae have sparked a heated discussion, especially concerning whether Denonvilliers' fascia is multilayered. This study aimed to expound on the anatomical structure of Denonvilliers' fascia and its correlation with the peritoneum from the sagittal view and clarify the complex fascial relationship. METHODS: Our study was performed on 20 adult male pelvic specimens fixed in formalin, including 2 entire pelvic specimens and 18 semipelvic specimens...

BACKGROUND: Perirectal spacers may be beneficial to reduce rectal side effects from radiotherapy (RT). Here, we present the impact of a hyaluronic acid (HA) perirectal spacer on rectal dose as well as spacer stability, long-term gastrointestinal (GI) and genitourinary (GU) toxicity and patient-reported outcome (PRO). METHODS: In this phase II study 81 patients with low- and intermediate-risk prostate cancer received transrectal injections with HA before external beam RT (78 Gy in 39 fractions)...

Biodegradable hydrogel-based matrices are becoming more widely utilized for a variety of medical applications, including SpaceOAR which is a hydrogel injected into the recto-prostatic space under ultrasound guidance to protect the rectum during prostate radiation therapy. Although a greater number of these procedures are being performed, there are no case reports on the potential complications which may result. In this report, we present the first case of retrograde embolization of SpaceOAR hydrogel into the right common iliac artery during routine office administration, as well as subsequent interventional angiography, inpatient and outpatient management, and clinical and imaging results at 1...

BACKGROUND: Most patients with splenosis have no clinical symptoms and do not need intervention. Hematospermia and testicular pain occurred in this patient, which was considered to be related to the huge pelvic implantation of the spleen, which was relatively rare in clinical practice, so we hereby report this case. CASE PRESENTATION: A 28-year-old male patient with a history of splenectomy was admitted to the Urology Department of the Second Affiliated Hospital of Anhui Medical University with the chief complaint of "Hematospermia for 1 month and testicular pain for 2 days"...

OBJECTIVES: To report on the usability, safety, symmetry, and effectiveness of hyaluronic acid (HA) injected between the prostate and the rectum for patients undergoing treatment for prostate cancer with external beam radiotherapy (EBRT), and present a novel definition of rectal spacer symmetry that is reproducible and independent of patient anatomy. PATIENTS AND METHODS: 102 consecutive patients with clinical stage of T1c-3b prostate cancer underwent general anaesthesia for fiducial marker insertion and injection of HA into the perirectal space before EBRT...

Current beam orientation optimization algorithms for radiotherapy, such as column generation (CG), are typically heuristic or greedy in nature because of the size of the combinatorial problem, which leads to suboptimal solutions. We propose a reinforcement learning strategy using Monte Carlo Tree Search that can find a better beam orientation set in less time than CG. We utilize a reinforcement learning structure involving a supervised learning network to guide the Monte Carlo Tree Search and to explore the decision space of beam orientation selection problems...

Rectal spacers are commonly used in the radiotherapy for prostate cancers, serving as a means to protect the rectum and surrounding structures from radiation toxicity. Polyethylene Glycol-Based Gels (SpaceOAR ™ and Space-OAR Vue™, Boston Scientific) are the most commonly used rectal spacers. Given their increasingly widespread use and the relative paucity of radiology literature on this topic, it is imperative for the radiologist to recognize both the normal and abnormal placement of these polyethylene glycol-based rectal spacers, particularly as the latter may be associated with suboptimal therapy and/or complications...

Objective: To observe the anatomical architecture of the prostatic part of the neurovascular bundle (NVB) in total mesorectal excision (TME). Methods: A descriptive cohort study and an anatomical observation study were carried out. A total of 38 male patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University between November 2013 and March 2015 were included. A total of 4 hemipelvis were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University...

BACKGROUND: Hypofractionation in prostate radiotherapy is of increasing interest. Steep dose gradients and a large weight on each individual fraction emphasize the need for motion management. Real-time motion management techniques such as multi-leaf collimator (MLC) tracking or couch tracking typically adjust for translational motion while rotations remain uncompensated with unknown dosimetric impact. PURPOSE: The purpose of this study is to demonstrate and validate dynamic real-time rotation-including dose reconstruction during radiotherapy experiments with and without MLC and couch tracking...