Balogova S, Périé S, Kerrou K, Grahek D, Montravers F, Angelard B, Susini B, El Chater P, St Guily J Lacau, Talbot J N
Department of Nuclear Medicine, Hopital Tenon AP-HP and Université Pierre et Marie Curie, Paris, France.
Mol Imaging Biol. 2008 Nov-Dec;10(6):364-73. doi: 10.1007/s11307-008-0155-2. Epub 2008 Jul 31.
The clinical usefulness of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in head and neck squamous cell carcinoma (HNSCC) is now well-documented. However, its sensitivity is greater than its specificity due to false-positive results in inflammatory or infectious lesions, which are frequent in this area, in particular after treatment by surgery and/or radiotherapy. O-2-fluoro-(18F)-ethyl-L-thyrosine (FET) has been reported not to be taken up by such lesions, and a preliminary study indicated that this may be clinically useful in HNSCC. We performed a prospective study to compare the diagnostic performances of FDG and FET PET/CT in the different settings of HNSCC.
Twenty-seven patients (20 men and seven women, aged 48-76, among 30 patients included) and 69 suspected cancer sites are now evaluable on basis of postsurgical histology and/or follow-up greater than 6 months; 15 patients were referred for initial staging and 12 during posttherapy follow-up, a recurrence being suspected in eight of them. FDG and FET PET/CT were performed on two different days, the patient fasting for 6 h, 1 h after injection of 5 MBq/kg of body mass of each radiopharmaceutical. Both PET/CT examinations were blind read more than 6 months after the end of inclusions in a random order for each tracer and with a time interval greater than 1 month between FDG and FET PET/CT blind readings.
Overall diagnostic performances, derived from blind reading: FDG PET/CT on a per patient basis: sensitivity 100%, specificity 71%, accuracy 93%; FDG PET/CT on a per site basis: sensitivity 95%, specificity 63%, accuracy 83%; FET PET/CT on a per patient basis: sensitivity 70%, specificity 100%, accuracy 78%; FET PET/CT on a per site basis: sensitivity 64%, specificity 100%, accuracy 78%. At site level, sensitivity was significantly greater with FDG (p<0.02) and specificity with FET (p<0.01). The statistical level of significance was not reached at patient level.
Although its good specificity was confirmed, FET did not appear to be suited as a first-line PET tracer in HNSCC imaging and cannot replace FDG for staging due to insufficient sensitivity. However, it was useful in a few selected cases to favor a wait and see attitude when a FDG+ FET- focus was discovered in patients referred for systematic FDG PET during follow-up. In contrast, second primary cancers should not be ruled out if FDG was clearly positive in the lungs or the digestive tract.
2-脱氧-2-[F-18]氟-D-葡萄糖正电子发射断层扫描（FDG-PET）在头颈部鳞状细胞癌（HNSCC）中的临床应用现已得到充分证明。然而，由于炎症或感染性病变中出现假阳性结果，其敏感性高于特异性，而这些病变在该区域很常见，尤其是在接受手术和/或放疗后。据报道，O-2-氟-（18F）-乙基-L-酪氨酸（FET）不会被此类病变摄取，一项初步研究表明，这在HNSCC中可能具有临床应用价值。我们进行了一项前瞻性研究，以比较FDG和FET PET/CT在HNSCC不同情况下的诊断性能。
根据术后组织学检查和/或超过6个月的随访，目前27例患者（20例男性和7例女性，年龄48-76岁，纳入的30例患者中）和69个疑似癌症部位可进行评估；15例患者被转诊进行初始分期，12例在治疗后随访期间进行评估，其中8例怀疑有复发。FDG和FET PET/CT在不同的两天进行，患者禁食6小时，在注射每千克体重5 MBq的每种放射性药物后1小时进行检查。两次PET/CT检查均在纳入结束后6个月以上进行盲法读取，每种示踪剂按随机顺序进行，FDG和FET PET/CT盲法读取之间的时间间隔大于1个月。
盲法读取得出的总体诊断性能：基于每位患者的FDG PET/CT：敏感性100%，特异性71%，准确性93%；基于每个部位的FDG PET/CT：敏感性95%，特异性63%，准确性83%；基于每位患者的FET PET/CT：敏感性70%，特异性100%，准确性78%；基于每个部位的FET PET/CT：敏感性64%，特异性1
