Proposal of a diagnostic algorithm for radiation-induced dropped head syndrome in long-term childhood cancer survivors based on a prospective study in a specialized clinical setting and a review of the literature.

Purpose: To prospectively assess the incidence of Dropped Head Syndrome (DHS) in childhood cancer survivors (CCS) and to develop and evaluate a diagnostic algorithm for DHS.

Methods: A systematic literature search for DHS in combination with neck radiotherapy (RT) exposure was performed. Analyses and a combination of the most common examination methods were integrated into a diagnostic algorithm. Almost all CCSs visiting the local late effects clinic between May 2020 and April 2022 were included in the study. CCS exposed to neck RT with doses ≥ 19 Gy received standardized clinical and neurological assessment and, in case of abnormal results, an MRI scan to confirm muscle atrophy.

Results: Two hundred and five CCS were included of whom 41 received RT to the neck with ≥ 19 Gy. In the entire cohort and in the subgroup receiving RT, 2.4% and 12% of CCS were affected by DHS, respectively. Results of clinical and neurological assessment correlated well with MRI results. Neck circumference and neck/thigh ratio were lower after neck RT. Over 50% of CCS experienced neck disability and pain.

Conclusions: A relevant proportion of CCS exposed to neck RT is affected by DHS. High concordance of MRI results with the neurological examination supports the clinical value of the diagnostic algorithm. Measurement of neck circumference might be an easy tool for assessment of neck muscle atrophy in survivors at risk.

Implications For Cancer Survivors: Integration of a diagnostic algorithm for DHS in standard long-term follow-up care facilitates diagnosis as well as initiation of early treatment and obviates the need for invasive examinations.