MRI better delineates the soft tissue extension of tumor, including perineural spread of disease. The use of advanced MRI techniques such as diffusion-weighted imaging may provide further information and increase sensitivity of identifying the recurrent tumor [108]. Combined pre- and postcontrast imaging provides the best opportunity to correctly identify and delineate recurrence and distinguish that from treatment change. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the routine use of MRI orbits, face, and neck without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment-related change, and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margins and the soft tissue extent of the tumor. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. US Neck US allows for the detection and localization of recurrence following treatment of major salivary gland tumors as well as regional nodal staging. US can additionally serve as guidance for fine-needle aspiration for diagnosis of recurrent disease [108]. Evaluation of the treated neck is complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Furthermore, US has limited
Staging and Post Therapy Assessment of Head and Neck Cancer. MRI better delineates the soft tissue extension of tumor, including perineural spread of disease. The use of advanced MRI techniques such as diffusion-weighted imaging may provide further information and increase sensitivity of identifying the recurrent tumor [108]. Combined pre- and postcontrast imaging provides the best opportunity to correctly identify and delineate recurrence and distinguish that from treatment change. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the routine use of MRI orbits, face, and neck without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment-related change, and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margins and the soft tissue extent of the tumor. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. US Neck US allows for the detection and localization of recurrence following treatment of major salivary gland tumors as well as regional nodal staging. US can additionally serve as guidance for fine-needle aspiration for diagnosis of recurrent disease [108]. Evaluation of the treated neck is complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Furthermore, US has limited