The results of this work were presented at the 2009 Annual Conference of the Veterinary Cancer Society in Austin, TX.
REIRRADIATION OF RECURRENT CANINE NASAL TUMORS
Article first published online: 13 DEC 2010
© 2010 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 52, Issue 2, pages 207–212, March/April 2011
How to Cite
BOMMARITO, D. A., KENT, M. S., SELTING, K. A., HENRY, C. J. and LATTIMER, J. C. (2011), REIRRADIATION OF RECURRENT CANINE NASAL TUMORS. Veterinary Radiology & Ultrasound, 52: 207–212. doi: 10.1111/j.1740-8261.2010.01763.x
- Issue published online: 9 MAR 2011
- Article first published online: 13 DEC 2010
- Received April 1, 2010; accepted for publication September 12, 2010.
- late effects;
- nasal tumors;
- radiation therapy;
Canine nasal tumors are typically treated with radiation therapy but most patients develop local recurrence. Our purpose was to evaluate tumor and normal tissue response to reirradiation in nine dogs. The median dose delivered with the first protocol was 50 Gy (range 44–55 Gy) and the median fraction number was 18 (range 15–20). For the second protocol, the median dose was lower intentionally, median of 36 Gy (range 23–44 Gy), without changing the median fraction number of 18 (range 14–20) to avoid late effects. The median time between protocols was 539 days (range 258–1652 days). Median survival was 927 days (95% confidence interval [CI] 423–1767 days). Median time to progression following the first and second courses was 513 days (95% CI 234–1180 days) and 282 days (95% CI 130–453 days), respectively. These were not significantly different (P=0.086). The qualitative response assessment was better for the first course compared with the second (P=0.018). Severity and timing of skin, mucous membrane, and ocular effects were similar for early side effects between the two courses (P>0.05 for all comparisons). All dogs experienced some late side effects, with two out of nine being classified as severe. These severe effects were blindness in each dog, possibly related to tumor recurrence. Reirradiation of canine nasal tumors resulted in a second clinical remission in eight of nine dogs, although the second response was less complete. Acute and late effects for seven of nine patients were not life threatening, indicating that reirradiation of canine nasal tumors may be a viable treatment option after recurrence.