Purpose: To evaluate results on the functional outcome and to determine prognostic factors and long-term response to low-dose megavoltage irradiation.
Patients and methods: A total dose of 6.0 Gy given in two weekly fractions of 1.0 Gy was applied to 305 sites (252 patients). After 6 weeks, 97 sites (31.8%) received a second radiotherapy (RT) course. Assessment system was a function score which was documented before RT, at the end of each RT course, and at 6 weeks and 6 months after treatment. After an observation period of >/= 24 months, a follow-up examination was attempted to evaluate the late response.
Results: At 6-month follow-up, 85.6% responded with a score improvement. The outcome was excellent (score: 90-100) in 135/305 sites (44.3%), good (score: 70-85) in 60/305 sites (19.7%), moderate (score: 45-65) in 63/305 (20.7%) sites, and poor (score: 0-40) in 47/305 sites (15.4%). 231/305 sites (75.7%) had no or mild pain. 296/305 (97,0%) had no or only slight limitations in work and 253/305 (82,9%) in daily activities. 255/305 (83,6%) had no or slight discomfort in gait. The long-term follow-up after a mean observation period of 48.4 months revealed 15 recurrences (7.3%). The patients' age, sex, and the duration of symptoms before initiation of RT (</= 6 months vs. > 6 months) did not prove to be prognostic factors. No early or late toxicity related to the use of RT was detected.
Conclusion: Megavoltage 6-MV photon-beam irradiation is a safe, effective and long-acting treatment modality in the management of heel spur patients. The function score has been proven to be a feasible method in clinical practice for evaluation of treatment outcome.