KEY POINTS
- This PRISMA-conducted systematic review identified 12 studies published from 1978–2026 encompassing 448 patients treated with radiotherapy for postoperative groin lymphatic fistulas. Most fistulas followed vascular surgery; only limited evidence involved lymph-node dissection or other operations.
- Treatment schedules were highly heterogeneous: radiotherapy began approximately 7.5–29 days after surgery, fraction doses ranged from 0.06 to 3 Gy, and prescribed total doses ranged from 0.5 to 20 Gy. Several protocols stopped treatment once lymphatic leakage ceased.
- More contemporary reports increasingly used very low doses. Several series using 0.3–0.5 Gy per fraction achieved fistula resolution with cumulative doses ≤4 Gy, while historical regimens commonly used 1–3 Gy per fraction; an indirect 17-patient comparison reported similar closure rates with <0.5-Gy and >1-Gy fractions (81% vs 83%).
- Across individual studies, reported treatment success ranged from 67% to 100%. Examples included 96.4% closure in one series, 93% complete cessation of lymphatic discharge in another, and 100% closure with a mean response time of 5.1 days in a recent series.
- Where reported, complete responses occurred approximately 5–27 days after radiotherapy, with a mean around 11 days. Definitions varied widely, however, including fistula closure, drain removal, cessation of discharge and percentage reduction in secretion, preventing meaningful pooling.
- Treatment-volume definitions were equally inconsistent, ranging from the surgical scar plus 2–3 cm to the lymphocele, drainage tract and regional lymphatic tissues; reported expansion margins varied from 3 mm to 4 cm. Only two reviewed studies used modern VMAT.
- Evidence quality was weak: only 4/11 case series (36%) met the review's prespecified low-risk-of-bias threshold. Adverse-event reporting was sparse; one study reported a 2.4% rate of subsequent pelvic malignancy, without establishing causality.
CLINICAL TAKEAWAY
Low-dose radiotherapy may be a useful option for persistent groin lymphatic fistulas that fail conservative management and might otherwise require embolization or reoperation. The reported responses are impressive, particularly with newer very-low-dose regimens, but there is still no prospective trial, standardized target volume or established dose schedule.