TITLE:
Radiation Therapy Prophylaxis for Heterotopic Ossification in Non-Hip Sites
AUTHORS:
Ajaykumar B. Patel, Katherine S. Tzou, Megan Single, Laeticia Hollant, Bridget Smart, Katherine Gaines, Courtney E. Sherman, Jennifer L. Peterson, Stephen J. Ko, Laura A. Vallow, Robert C. Miller, Steven J. Buskirk
KEYWORDS:
Heterotopic Ossification, Radiation Therapy, Knee, Elbow
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.9 No.1,
January
5,
2018
ABSTRACT: Background: Radiation therapy prophylaxis for heterotopic
ossification is well-established for the hip, either pre or post-operatively.
There is limited data for this treatment in non-hip sites. We report our
institution’s experience. Methods: From October 2004 to August 2015, a total of 39
non-hip sites in 38 patients were treated with prophylactic radiation therapy
for heterotopic ossification at our institution. An IRB approved retrospective review
was performed. There were 15 patients who received treatments to the elbow, 13
to the knee (1 bilateral for a total of 14 knees), and 10 to other sites (leg
stump (2), pubic symphysis (2), femur (1), foot (1), humerus stump (1),
abdominal wall (1), shoulder (1), thigh (1)). All but 1 patient were treated
with a single fraction treatment with 700 or 800 cGy. One
patient received 2000 cGy in 10 fractions to the abdominal wall for heterotopic
ossification extending from the xiphoid process. Results: Fifteen patients underwent treatment to the elbow with a median follow-up
of 5 months (0 - 99). Median age for this group was 50 years (37 - 69).
Nine (60.0%) patients had evidence of heterotopic ossification prior to
surgery. All (100%) of the elbow patients were free from recurrence at last
follow-up. There were no acute or late toxicities noted. For treatment to the
knee, there were 4 (28.6%) recurrences, all in cases where there were
pre-operative heterotopic ossification. There were two other recurrences in the
non-hip, elbow or knee sites: one patient who received radiation therapy to the
abdominal wall and one patient who underwent treatment to the thigh. Conclusions: Prophylactic
radiation therapy with 700 cGy or 800 cGy in 1 fraction either before or after
surgery remains a safe and effective treatment for both hip and most non-hip
sites. Fractionated treatment may be used for larger treatment fields, however
experience is limited.