A Clinical Study on Alleviating Hemorrhoids-related Symptoms of Pelvic Radiation Therapy

Radiation therapy (RT) is a main treatment method to improves local control and overall survival for cervical cancer patients with high-risk factors. External beam radiation therapy (EBRT) is particularly important, which plays a crucial role for patients either after surgery or for those ineligible for surgery. In intensity-modulated radiation therapy (IMRT) era, 90-95% of patients with pelvic malignancies, including gynecological tumors, still develop varying degrees of radiation-induced intestinal injury. Radiation-induced rectal injury (RRI) is still one of the most common complications of radiation to the pelvis, but which is also the most difficult to treat.

However, whether from the symptoms or the pelvic radiation therapy plans, current studies on RRI generally combine the rectum and anal canal. Therefore, the so-called "Radiation-induced rectal injury" is not purely "rectal injury," but includes "radiation-induced rectal and anal canal injury." In addition, the radiation of perianal muscles can also lead to symptoms related to the rectum during pelvic radiation therapy. According to current contouring guidelines, whether for gynecologic tumors or other pelvic malignancies, the anal canal is regarded together with the rectum as the same organ at risk (OAR) when formulating pelvic EBRT plans, and a unified dose constraint standard is applied. The anal canal and its surrounding muscles are not assessed separately.

The tolerance dose of the rectum is generally considered to be around 50 Gy, however, anal canal-related symptoms may occur at lower doses, particularly in patients with a history of hemorrhoids. During the early phase of radiotherapy, hemorrhoids-associated symptoms such as perianal pain, hemorrhoidal prolapse, rectal bleeding, and perianal skin breakdown may occur. These symptoms are more likely attributable to the aggravation of pre-existing hemorrhoids rather than radiation-induced rectal injury. Hemorrhoidal disease (HD) is one of the most common gastrointestinal disorder managed in outpatient clinics. Although it is not a life-threatening condition, it can persistently and severely impact quality of life and increase the healthcare burden on society.

Anal canal toxicity should not be a neglected side-effect of pelvic radiation therapy, and greater attention need to be paid to the occurrence of acute hemorrhoid-related symptoms, particularly for cervical cancer patients with hemorrhoids. The investigators tried to develop anal canal-sparing technique to reduce the irradiated dose to anal canal for cervical cancer patients with hemorrhoids who needed postoperative pelvic radiation therapy.

Minimizing acute toxic effects is of considerable importance to improve quality of life because it has been correlated with late toxic effects in patients with pelvic radiation therapy. Herein, the investigators design a multicenter, double-blind randomized controlled trial in which cervical cancer patients with hemorrhoids were randomly assigned to receive anal canal-sparing or standard postoperative pelvic radiation therapy, in either combined with brachytherapy or not.

The primary objectives are to compare the incidence of hemorrhoidal symptom and differences in quality of life (QoL) scores during radiotherapy between the two arms. Concurrently, the study will explore the practical implementation methodology of the anal canal-sparing technique.

Inclusion criteria

• Treated with hysterectomy (including total abdominal hysterectomy, vaginal hysterectomy, radical hysterectomy, or laparoscopically assisted vaginal hysterectomy) within 6 weeks prior to study initiation.
• Histologically proven diagnosis of cervical carcinoma, including squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma.
• Requirement for postoperative adjuvant concurrent chemoradiotherapy (CCRT).
• Age > 18 years.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
• History of hemorrhoids prior to radiotherapy, with no hemorrhoid-related symptoms for at least 4 weeks before radiation therapy initiation.
• Abdominal/pelvic MRI, chest CT, or PET-CT performed before surgery or study enrollment to confirm staging and exclude patients with distant metastasis.
• Adequate bone marrow, renal, and hepatic function.
• Agreement to undergo anal canal MRI before radiation therapy initiation.
• Patient must provide study-specific informed consent form (ICF) prior to study entry.

Exclusion criteria

• Cervical cancer patients who do not meet the criteria for adjuvant radiation therapy.
• Without a confirmed history of hemorrhoids.
• Patients contraindicated for MRI (e.g., due to incompatible metallic implants, claustrophobic syndrome, or other contraindications).
• Patients who refuse to undergo anal canal MRI.
• Patients with radiographically visible residual disease post-surgery requiring boost during the pelvic EBRT.
• History of other malignancies.
• Prior pelvic radiotherapy resulting in overlapping radiation fields.
• History of allergic reaction to platinum-based chemotherapy agents.
• Severe and/or active comorbidities precluding tolerance of concurrent chemoradiotherapy.