CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of recurrent tumor and the evaluation of regional nodal disease. CT is also used to monitor treatment changes and assess for treatment complications such as infection or osteoradionecrosis. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Much like MRI, it has an overall low sensitivity and positive predictive value [123] for detecting recurrence. Posttreatment CECT has been shown to detect local failure and nodal recurrence earlier than clinical examination alone [124,125]. A reported high NPV of 97.7% suggests that CT is helpful in excluding recurrence [123]. CT imaging also allows for excellent delineation of osseous anatomy, including bony destruction that can be seen in the context of recurrence or as a complication of treatment such as in osteoradionecrosis. FDG-PET/CT confers increased sensitivity compared to CECT in detecting recurrence and confers similarly to slightly increased specificity [117,119,126-128]. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. The puffed-cheek technique, consisting of requesting that the patient inflate their cheeks with pursed lips while undergoing CT examination, allows for a greater delineation of oral cavity tumors, particularly those along the gingiva and buccal mucosa. The maneuver allows for the separation of the tumor from normal mucosa and provides a clearer picture of the size and extent of disease [40].
Staging and Post Therapy Assessment of Head and Neck Cancer. CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of recurrent tumor and the evaluation of regional nodal disease. CT is also used to monitor treatment changes and assess for treatment complications such as infection or osteoradionecrosis. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Much like MRI, it has an overall low sensitivity and positive predictive value [123] for detecting recurrence. Posttreatment CECT has been shown to detect local failure and nodal recurrence earlier than clinical examination alone [124,125]. A reported high NPV of 97.7% suggests that CT is helpful in excluding recurrence [123]. CT imaging also allows for excellent delineation of osseous anatomy, including bony destruction that can be seen in the context of recurrence or as a complication of treatment such as in osteoradionecrosis. FDG-PET/CT confers increased sensitivity compared to CECT in detecting recurrence and confers similarly to slightly increased specificity [117,119,126-128]. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. The puffed-cheek technique, consisting of requesting that the patient inflate their cheeks with pursed lips while undergoing CT examination, allows for a greater delineation of oral cavity tumors, particularly those along the gingiva and buccal mucosa. The maneuver allows for the separation of the tumor from normal mucosa and provides a clearer picture of the size and extent of disease [40].