Keilty et al reported a nomogram for predicting the risk of hearing loss after chemoradiation for a pediatric tumor of the CNS or head-and-neck. The authors are Princess Margaret Cancer Centre and Hospital for Sick Children Toronto.
Patient selection: pediatric patient treated for a CNS or head and neck tumor
Parameters:
(1) age at radiation therapy in years
(2) time since radiation therapy in years
(3) cisplatin dose in mg per square meter
(4) carboplatin dose in mg per square meter
(5) RT dose in Gray
|
Age at Radiation Therapy
|
Points
|
|
< 3
|
28.2
|
|
>= 3
|
0
|
points for time since radiation =
= 6.26 * (years)
points for radiation dose =
= 1.52 * (dose)
points for cisplatin dose =
= 3.633 * ((dose) / 100)
points for carboplatin dose =
= 8.97 * ((dose) / 1000)
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 266.8
value of X =
= (0.03223 * (score)) - 4.152
probability of severe hearing loss (SIOP Grade 3 or 4) =
= 1 / (1 + EXP((-1) * X))
