PT  - JOURNAL ARTICLE
AU  - Yuanfan Xu
AU  - Caineng Cao
TI  - <strong>Locoregional extension patterns of nasopharyngeal carcinoma detected by 18F-FDG PET/MR</strong>
DP  - 2022 Jun 01
TA  - Journal of Nuclear Medicine
PG  - 3100--3100
VI  - 63
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/63/supplement_2/3100.short
4100  - http://jnm.snmjournals.org/content/63/supplement_2/3100.full
SO  - J Nucl Med2022 Jun 01; 63
AB  - 3100 Introduction: To define the locoregional extension patterns of nasopharyngeal carcinoma (NPC) by positron emission tomography (PET)/magnetic resonance imaging (MRI) and to improve clinical target volume (CTV) delineation.Methods: Between May 2017 and March 2021, 331 consecutive patients with nonmetastatic NPC who underwent pretreatment, simultaneous whole-body PET/MRI for staging were included in this study.Results: The high risk regions included basis of sphenoid bone, prestyloid compartment, prevertebral muscle, foramen lacerum, medial pterygoid plate, sphenoidal sinus, clivus, petrous apex and foramen ovale. When the high risk regions were invaded, the incidence rates of tumor invasion into the medium risk regions increased. In contrast, when the high risk regions were not involved, the incidence rates of tumor invasion into the medium risk regions were mostly less than 10% excluding the poststyloid compartment and oropharynx. With reference to 2013 updated consensus guidelines of the neck node levels for head and neck tumors, level IIa (77.3%, 256/331), level IIb (75.8%, 251/331) and level VIIa (71.3%, 236/331) were the most frequently involved levels, followed by levels III (42.6%), Va (13.9%), IVa (8.8%), IVb (3.6%), Ib (3.6%), Vb (2.4%), VIIb (2.4%), VIII (1.8%), Vc (0.9%) and Xa (0.3%). Skip lymph nodes metastasis occurred in only 1.9% of patients.Conclusions: For NPC, primary disease and regional lymph nodes spread follow an orderly pattern and a skip pattern of lymph node metastasis was unusual. Involved level radiotherapy might be feasible for cervical lymph node levels below the caudal border of cricoid cartilage and level VIIb.