TY - JOUR
T1 - Methods for estimating the site of origin of locoregional recurrence in head and neck squamous cell carcinoma
AU - Due, Anne Kirkebjerg
AU - Vogelius, I.R.
AU - Aznar, Marianne Camille
AU - Korreman, Stine Sofia
PY - 2012/8/1
Y1 - 2012/8/1
N2 - Purpose. Methods to estimate the likely origin of recurrences after radiation therapy for head and neck squamous cell carcinoma are compared.Methods and materials. A total of 25 patients meeting the following inclusion criteria were randomly selected: curatively intended intensity-modulated radiotherapy planned on a positron emission tomography-computed tomography (PET/CT) scan during the period 2005-2009; squamous cell carcinoma in the oral cavity, pharynx or larynx; complete clinical response followed by locoregional recurrence; and a CT scan at recurrence before any salvage therapy. Exclusion criteria were previous cancer in the area, surgery prior to radiotherapy, or a synchronous cancer. Three methods of estimating focal points of recurrence origin and two volume overlap methods assigning the recurrences to the most central target volumes encompassing at least 50% or 95% of the recurrence volumes were tested. Treatment planning and recurrence scans were rigid and deformable co-registered in order to transfer focal points to the treatment planning scan. Double determinations of all volumes, points, and co-registrations were made.Results. The volume overlap methods assigned the recurrences to significantly more peripheral target volumes than focal methods (p<0.0001 for all comparisons of 95% overlap vs. focal methods, p<0.028 for all comparisons of 50% overlap vs. focal methods). Repeated registrations of the same point had higher reproducibility with deformable registration than with rigid registration (median distance 0.31 vs. 0.35 cm, p=0.015). No significant differences were observed among the focal methods.Conclusion. Significant differences between methods were found which may affect strategies to improve radiotherapy based on pattern of failure analyses.
AB - Purpose. Methods to estimate the likely origin of recurrences after radiation therapy for head and neck squamous cell carcinoma are compared.Methods and materials. A total of 25 patients meeting the following inclusion criteria were randomly selected: curatively intended intensity-modulated radiotherapy planned on a positron emission tomography-computed tomography (PET/CT) scan during the period 2005-2009; squamous cell carcinoma in the oral cavity, pharynx or larynx; complete clinical response followed by locoregional recurrence; and a CT scan at recurrence before any salvage therapy. Exclusion criteria were previous cancer in the area, surgery prior to radiotherapy, or a synchronous cancer. Three methods of estimating focal points of recurrence origin and two volume overlap methods assigning the recurrences to the most central target volumes encompassing at least 50% or 95% of the recurrence volumes were tested. Treatment planning and recurrence scans were rigid and deformable co-registered in order to transfer focal points to the treatment planning scan. Double determinations of all volumes, points, and co-registrations were made.Results. The volume overlap methods assigned the recurrences to significantly more peripheral target volumes than focal methods (p<0.0001 for all comparisons of 95% overlap vs. focal methods, p<0.028 for all comparisons of 50% overlap vs. focal methods). Repeated registrations of the same point had higher reproducibility with deformable registration than with rigid registration (median distance 0.31 vs. 0.35 cm, p=0.015). No significant differences were observed among the focal methods.Conclusion. Significant differences between methods were found which may affect strategies to improve radiotherapy based on pattern of failure analyses.
U2 - 10.1007/s00066-012-0127-y
DO - 10.1007/s00066-012-0127-y
M3 - Journal article
SN - 0931-2447
VL - 188
SP - 671
EP - 676
JO - Strahlentherapie
JF - Strahlentherapie
IS - 8
ER -
