Randomized multicenter follow-up trial on the effect of radiotherapy on painful heel spur (plantar fasciitis) comparing two fractionation schedules with uniform total dose: first results after three months’ follow-up

Abstract

BackgroundOur first trial on radiotherapy for painful heel spur published in 2012 comparing the analgesic effect of a standard dose (6 × 1.0Gy within three weeks) to that of a very low one (6 × 0.1Gy within three weeks) resulted in a highly significant superiority of the standard dose arm. In the meantime, experimental data have shown that lower single doses in the range of 0.5 – 0.7Gy might be even more effective than the current standard dose of 1.0 Gy. Therefore, we conducted a second trial comparing the analgesic effect of standard single doses of 1.0Gy to that of low single doses of 0.5Gy using uniform total doses of 6Gy.Patients and methodsOne hundred twenty-seven patients were randomized to receive radiation therapy either with a total dose of 6.0Gy applied in 6 fractions of 1.0Gy twice weekly (standard dose) or with the same total dose applied in 12 fractions of 0.5Gy three times weekly (experimental dose). In all patients lateral opposing 6MV photon beams were used. The results were measured using Visual analogue scale (VAS), Calcaneodynia score (CS) and SF-12 health survey. The first phase of this trial ended after a three months’ follow-up; it will be continued up to 48 weeks.ResultsNine patients had to be excluded after randomization either due to the withdrawal of informed consent to radiotherapy by the patients or radiotherapy with an incorrect dosage. The groups were comparable concerning biographical and disease data. The mean calcaneodynia score (CS) was higher in the experimental group (p = 0.002). After three months’ follow-up, we saw a very favorable pain relief in both arms (decline of VAS score: standard arm 42 points, experimental arm 44 points (n.s.), but we did not notice any statistically significant difference between the arms neither concerning the pain parameters nor the quality of life parameters. No relevant acute side effects were recorded.ConclusionsFavorable laboratory results could not be translated into an enhanced pain relief in our patients. This trial was terminated after the interim analysis (127 patients randomized). Further trials will be necessary to explore the best fractionation schedule.This trial has been approved by the expert panel of the DEGRO as well as by the Ethics committee of the Saarland Physicians’ chamber.Trial registrationCurrent trial registration at German Clinical Trials Register with the number DRKS00004458

Low-Dose Radiotherapy of Painful Heel Spur/Plantar Fasciitis as an Example of Treatment Effects in Benign Diseases

“…This is why these results cannot be extrapolated to LD-EBRT of a painful heel spur. Furthermore, endpoints were not clearly defined, and therapy was started in an acute stage of the disease [25].…”

“…Niewald et al randomized between 6 × 1 Gy twice a week (old "standard dose") and 12 × 0.5 Gy three times a week ("experimental dose") [25]. The aim was not just to get comparable results, but to further improve the analgesic effects.…”

“…Results after 3 months have been issued so far [25], longer follow-up has yet to be published. After 3 months, there were no significant differences neither in the VAS (standard 42.3 vs. experimental 44.4) nor the CS sum score (28 vs. 28.4) nor in the QOL (SF-12) scores.…”

“…"Target volume is the calcaneus, normally with a field size of 6 cm × 8 cm" [32]. "The calcaneus and the plantar aponeurosis were included in the target volume" [25].…”

“…All randomized trial used twice weekly treatments. Only one experimental arm was scheduled three times a week [25].…”