**Background:** Chronic radiation proctitis (CRP) is a known complication of pelvic radiotherapy, occurring in 5–20% of patients who undergo such treatment. Rectal bleeding, the most common symptom, affects over 80% of CRP patients and can lead to anemia requiring hospitalization and blood transfusions. Various endoscopic treatments exist, including argon plasma coagulation (APC), Nd:YAG laser, and radiofrequency ablation, but many carry risks of tissue necrosis, ulceration, and bleeding recurrence. The 940 nm diode laser has affinity for hemoglobin and good coagulation properties with shallow tissue penetration, potentially offering a safer alternative. This study aimed to evaluate the safety, efficacy, and cost efficiency of endoscopic non-contact diode laser therapy for CRP.
**Methods:** This retrospective analysis included 24 patients (median age 78, range 67–90) treated at the University of Padova Medical Center between 2010 and 2021. All patients had undergone high-dose radiotherapy for prostate cancer and presented with rectal bleeding more than 3 months after radiation. CRP severity was graded based on endoscopic criteria (presence of fresh blood, telangiectasia distribution, surface area involved). Patients were classified as grade B (moderate, 19 patients) or grade C (severe, 5 patients). Treatment was performed without sedation using a high-power diode laser (Medilas D. Multibeam Dornier MedTech, France; 940 nm wavelength, maximum power 60 W) with non-contact fibers at 30 W power setting in continuous fibertom mode. Sessions were scheduled monthly until complete healing. Follow-up included rigid anoscopy and rectoscopy at 3 months, and telephone contact for long-term follow-up. Cost analysis included disposable materials and equipment but excluded staff costs.
**Key Results:** Patients underwent a median of 2 sessions (mean 3.25 ± 3.2, range 1–14). Mean energy delivered was 1591 ± 1344 J per session. No adverse events, including ulcers, were reported. Complete remission of bleeding was achieved in 21/24 (88%) patients, and improvement in an additional 2 patients, yielding a global improvement rate of 23/24 (96%). Of the 6 patients receiving blood transfusions before treatment, only 1 required transfusions after treatment (83% resolution). Hemoglobin levels were significantly higher after treatment (mean 10.6 ± 3.0 g/dL before vs. 12.5 ± 1.7 g/dL after, p = 0.001, n = 16). One patient (4%) experienced recurrence after remission, which was successfully treated with an additional laser session. Mean follow-up was 34 ± 26 months. Ten patients continued antiplatelet or anticoagulant therapy without interruption. The mean cost per session was EUR 473.4, with sessions lasting approximately 30 minutes.
**Clinical Implications:** This study demonstrates that non-contact diode laser therapy is a safe, effective, and cost-efficient treatment for bleeding CRP. Key advantages include: (1) no requirement for sedation or hospitalization, allowing outpatient treatment; (2) no need to suspend antiplatelet or anticoagulant therapy, which is particularly important in elderly patients with cardiovascular comorbidities; (3) low risk of complications, especially ulceration and tissue necrosis, compared to other endoscopic modalities like APC (which has reported ulcer rates up to 47%); and (4) relatively low cost per session. The 940 nm diode laser's affinity for hemoglobin and shallow tissue penetration make it well-suited for treating superficial vascular lesions. The study is limited by its retrospective design, small sample size, lack of a control group, and single-center setting. Further prospective studies on larger case series are warranted to confirm these findings.