Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy01:26

Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy

1000
Sigmoidoscopy and laparoscopy are distinct medical procedures that enable physicians to internally inspect different parts of the GI tract. Although they serve different purposes, each is essential for diagnosing and, in some cases, treating various medical conditions.
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...
1000
Assessment of the Rectum and Anus01:25

Assessment of the Rectum and Anus

1.7K
Evaluating the rectum and anus plays a crucial role in conducting a thorough physical examination of the gastrointestinal system. Although it may be uncomfortable and often embarrassing for the patient, it holds immense diagnostic value, particularly in detecting gastrointestinal diseases and abnormalities. This guide will explain how to perform this assessment using inspection and palpation methods.
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
1.7K
Endoscopic Procedures II: Colonoscopy01:25

Endoscopic Procedures II: Colonoscopy

1.1K
The colon, or large intestine, is the final segment of the digestive system. Its primary functions include absorbing water and vitamins produced by gut bacteria and transforming waste from liquid to solid to form stool. In adults, the large intestine is approximately 5 feet long and consists of four main sections:
1.1K
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy01:26

Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy

587
This lesson explores three gastrointestinal imaging techniques: radionuclide testing, colonic transit studies, and virtual colonoscopy.
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and...
587
One-Compartment Open Model for IV Bolus Administration: Estimation of Clearance00:56

One-Compartment Open Model for IV Bolus Administration: Estimation of Clearance

469
Clearance is a key pharmacokinetic parameter that quantifies the volume of body fluid from which a drug is entirely removed within a specific time frame. It is crucial in assessing how a drug is eliminated from the body and has critical clinical applications.
In the one-compartment open model for intravenous (IV) bolus administration, clearance is estimated by dividing the elimination rate by the plasma drug concentration. This equation leverages the elimination rate constant and the apparent...
469

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Evaluation of patient setup accuracy using optical surface guidance in postoperative radiotherapy for patients with breast cancer after breast-conserving surgery.

The British journal of radiology·2026
See all related articles

Related Experiment Video

Updated: Mar 22, 2026

Intraoperative Assessment of Resection Margins in Oral Cavity Cancer: This is the Way
04:45

Intraoperative Assessment of Resection Margins in Oral Cavity Cancer: This is the Way

Published on: May 10, 2021

4.5K

Setup Error Differences and Margin Expansion Among Rectal Cancer Segments: Consistency Evaluation Between EPID and

Bao Wan1, Jiangtao Han1, Qian Wu1

  • 1Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Cancer Reports (Hoboken, N.J.)
|March 21, 2026
PubMed
Summary

Setup errors in rectal cancer radiotherapy differ by tumor location. Image guidance techniques, electronic portal imaging device (EPID) and iSCOUT, show consistency, with iSCOUT potentially replacing EPID.

Keywords:
image‐guidedradiotherapyrectal cancersetup error

More Related Videos

Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer
12:45

Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer

Published on: February 12, 2022

6.9K
The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors
04:09

The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors

Published on: February 13, 2026

74

Related Experiment Videos

Last Updated: Mar 22, 2026

Intraoperative Assessment of Resection Margins in Oral Cavity Cancer: This is the Way
04:45

Intraoperative Assessment of Resection Margins in Oral Cavity Cancer: This is the Way

Published on: May 10, 2021

4.5K
Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer
12:45

Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer

Published on: February 12, 2022

6.9K
The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors
04:09

The Pocket-Creation Procedure of Endoscopic Submucosal Dissection for Large Rectal Laterally Spreading Tumors

Published on: February 13, 2026

74

Area of Science:

  • Radiation Oncology
  • Medical Physics
  • Cancer Imaging

Background:

  • Accurate patient setup is crucial for effective radiotherapy, especially for rectal cancer.
  • Image-guided radiotherapy (IGRT) techniques minimize setup errors.
  • Comparing different IGRT methods like electronic portal imaging device (EPID) and iSCOUT is essential for optimizing treatment accuracy.

Purpose of the Study:

  • To investigate setup errors in upper, middle, and lower rectal cancer patients.
  • To evaluate the consistency between EPID and iSCOUT image-guided techniques.
  • To determine optimal planning target volume (PTV) margins based on rectal cancer location.

Main Methods:

  • Retrospective analysis of 277 rectal cancer patients treated with radiotherapy.
  • Categorization into upper, middle, and lower rectal cancer groups.
  • Calculation and comparison of setup errors and PTV margins between EPID and iSCOUT.

Main Results:

  • Significant differences in setup errors were observed in the anterior-posterior (Z) direction between upper and lower rectal cancers (p=0.013).
  • Discrepancies existed between EPID and iSCOUT in the left-right (X) and superior-inferior (Y) directions.
  • EPID and iSCOUT measurements showed strong correlation (p<0.001) with 95% consistency limits within millimeters.

Conclusions:

  • Different margin expansions in the Y direction are recommended based on rectal cancer segment.
  • iSCOUT demonstrates reliable consistency with EPID and can be used as an alternative.
  • Optimizing PTV margins improves treatment precision for rectal cancer patients.