Case Report: Definitive radiotherapy for inoperable anal Buschke-Löwenstein tumors: two cases with literature review.

Background: Buschke-Löwenstein tumors (BLTs), also known as giant condyloma acuminatum, are rare HPV-related lesions with benign histology but locally aggressive behavior, high recurrence rates, and risk of malignant transformation. Complete surgical excision is the standard treatment; however, surgery may be infeasible in advanced, recurrent, or anatomically complex cases. Evidence for radiotherapy as a primary treatment is limited. Case presentation: We report two patients with inoperable anal BLTs treated using modern volumetric-modulated arc therapy (VMAT). Patient 1 received concurrent chemoradiotherapy (30 Gy in 15 fractions) and achieved a marked clinical response with grade 2 acute radiomucositis. Patient 2 underwent definitive radiotherapy alone (45 Gy in 25 fractions) resulting in a partial clinical response at early follow-up, with minimal toxicity. Both treatments were well tolerated. We performed a literature review of published cases of BLTs treated with radiotherapy between 2000 and 2025, which demonstrated heterogeneous treatment approaches but generally favorable clinical responses and acceptable toxicity. Conclusions: Radiotherapy using contemporary VMAT techniques is feasible, safe, and effective for selected patients with inoperable BLTs. When surgery is not possible, radiotherapy alone or combined with chemotherapy may provide early clinical tumor regression with limited toxicity. These findings, combined with existing literature, support consideration of radiotherapy in multidisciplinary management of this rare condition.