Clinical Research Directory

Inclusion Criteria: * Adults aged 19 years or older. * Patients diagnosed with or strongly suspected of having a rectal neuroendocrine tumor on colonoscopy. * Lesion size generally 15 mm or less, without suspected muscularis propria invasion on endoscopy and, when clinically indicated, endoscopic ultrasonography. * No suspected lymph node metastasis or distant metastasis based on abdominal/pelvic imaging or clinical assessment. * Lesions considered appropriate for endoscopic resection. * Ability to understand the purpose and procedures of the study and provide written informed consent. Exclusion Criteria: * Suspected muscularis propria invasion, lymph node metastasis, or distant metastasis on endoscopy, endoscopic ultrasonography, imaging studies, or clinical assessment. * Lesion size greater than 15 mm, or a lesion considered by the investigator to require surgical treatment rather than endoscopic resection. * Conditions that make safe endoscopic submucosal dissection difficult, including inadequate bowel preparation. * Uncontrolled bleeding tendency, severe thrombocytopenia, or uncorrectable coagulation disorder. * Use of antiplatelet or anticoagulant therapy that cannot be appropriately discontinued or adjusted before the procedure. * Severe cardiopulmonary disease, hepatic failure, renal failure, or other conditions considered to make sedation or endoscopic submucosal dissection unsafe. * Pregnancy or breastfeeding. * Inability to provide informed consent or impaired decision-making capacity. * Altered anatomy of the rectum due to previous rectal surgery, radiotherapy, or other conditions that may interfere with standardization of the study procedure. * Any other condition considered by the principal investigator or study investigator to make participation inappropriate.