CT, computed tomography; MRI, magnetic resonance imaging; US, ultrasonography; PET, positron emission tomography; Sens, sensitivity; Spec, specificity.

CT, computed tomography; MRI, magnetic resonance imaging; US, ultrasonography; PET, positron emission tomography; Sens, sensitivity; Spec, specificity.

A positive PET scan requires a biopsy, and if this is not positive, a repeat biopsy or close clinical follow-up may be required 2 to 3 months later. Standard uptake value (SUV) measurements have a wide overlap between disease recurrence versus nontumor-related FDG accumulation (SUV range, 2.1-36.9 versus 1.5-9.3, respectively).

Role of FDG-PET in Monitoring Therapy

Brun et al.,26 in a study of 47 patients, with two-thirds of these in stage IV disease, showed that the pretreatment SUV was lower in patients with a complete response (8.0 versus 12.0), the 5-year overall survival (OS) was 72% in those who had low FDG activity after 1 to 3 weeks of treatment, and the 5-year OS was only 35% in those who had high FDG uptake in the same period.

Kitagawa et al.27 studied 15 patients who were treated with neoadjuvant chemotherapy and showed that lesions with a pretreatment SUV greater than 7 had residual viable tumor in 3 of 8 cases, whereas all lesions with SUV less than 7 were treated successfully. All 7 tumors with posttreatment SUV less than 4 did not show residual disease and 3 of the 7 tumors with posttreatment SUV greater than 4 did. The same group calculated the sensitivity, specificity, and accuracy of PET-FDG, MRI, and CT in primary lesions and in neck metastases, finding FDG-PET to be more specific (89%) compared with MRI (41%) and CT (59%) in primary lesions but not in nodal metastases (74% versus 85% and 76%, respectively).28

Goerres et al.29 evaluated the detection of residual disease in 26 patients with stage III-IV HNSCC, and PET was performed 6 weeks after the end of combined chemotherapy and radiation therapy. The sensitivity, specificity, and accuracy were 91%, 93%, and 92%, respectively. They also showed that the PET study at 6 weeks often revealed a second primary tumor or a distant metastasis that had not been detected at the time of initial staging.

Kubota et al.30 also concluded that the high negative predictive value of FDG-PET (91%) may be used to prevent additional invasive procedures for the detection of recurrent head and neck cancers after combined radiochemotherapy in most clinical settings.

Radiation Therapy Alone

Greven et al.31 demonstrated, in a study of 45 patients who had FDG-PET before and at 1, 4, 12, and 24 months after highdose radiation therapy, that imaging at 4 months was more reliable than at 1 month. It seems that an interval of 6 to 8 weeks after radiation treatment is most appropriate, but it must be kept in mind that FDG uptake can be significantly high in regions of radiation therapy up to 12 to 16 months after treatment.32

Other PET Tracers

Radiolabeled amino acids, nC-methionine, radiolabeled tyrosine, nC-choline, 18F-thymidine, 64Cu-ATSM [copper (II)-dia-cetyl-bis (N-4-methylthiosemicarbazone)], 18F-fluoromisonidazole, and 18F-2-nitroimidazole (EF5), have been studied as potential imaging agents for head and neck tumors.33-40 Several of these show promise and may be introduced into clinical practice in the future.

A Disquistion On The Evils Of Using Tobacco

A Disquistion On The Evils Of Using Tobacco

Among the evils which a vitiated appetite has fastened upon mankind, those that arise from the use of Tobacco hold a prominent place, and call loudly for reform. We pity the poor Chinese, who stupifies body and mind with opium, and the wretched Hindoo, who is under a similar slavery to his favorite plant, the Betel but we present the humiliating spectacle of an enlightened and christian nation, wasting annually more than twenty-five millions of dollars, and destroying the health and the lives of thousands, by a practice not at all less degrading than that of the Chinese or Hindoo.

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