technetium-tc-99m-tetrofosmin and Nasopharyngeal-Neoplasms

The effectiveness of technetium-99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of the head and neck for detecting recurrence of nasopharyngeal carcinomas (NPC) was evaluated and compared with computed tomography (CT). Both Tc-TF SPECT and CT of the head and neck were performed in 36 NPC patients 4 months after radiotherapy. All 36 then underwent histopathological examinations of nasopharyngeal biopsies. Based on the histopathological results, the sensitivity, specificity, and accuracy of visually interpreted Tc-TF SPECT images, to differentiation of recurrent NPC from benign lesions, were 64%, 96%, and 86%, respectively. The sensitivity, specificity, and accuracy of CT for detecting recurrent NPC were 73%, 88%, and 83%, respectively. The Tc-TF SPECT has a better specificity but a lower sensitivity to differentiate benign lesions and recurrent/residual NPC when compared with CT. Combined Tc-TF SPECT and CT sensitivity and specificity were 100% and 88%, respectively. There are much better either test alone. However, further studies, including a larger NPC patient population, are warranted to determine the exact role and clinical usefulness of Tc-TF SPECT to differentiate benign lesions and recurrent/residual NPC.

Topics: Adolescent; Adult; Aged; Carcinoma; Female; Humans; Male; Middle Aged; Nasopharyngeal Neoplasms; Neoplasm Recurrence, Local; Neoplasm, Residual; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The aim of this study is to evaluate the effectiveness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of head and neck for detecting suspected recurrence of nasopharyngeal carcinomas (NPCs) when magnetic resonance imaging (MRI) findings are indeterminate. MRI was performed 4 months after radiotherapy and 26 NPC patients with indeterminate MRI findings were included. MRI, Tc-99m TF SPECT, and biopsy were performed within 1 week. The final results were based on histopathologic findings and clinical follow-up for at least 6 months. For detecting recurrent NPC in indeterminate MRI findings, the sensitivity, specificity, and accuracy of Tc-99m TF SPECT were 92.3%, 100.0%, and 96.2%, respectively. Based on this result, we can suggest Tc-99m TF SPECT is effective to detect recurrent NPC when MRI findings are indeterminate. However, further studies including a larger NPC patient population are warranted to determine the exact role and clinical usefulness of Tc-99m TF SPECT to differentiate benign lesions and recurrent NPC when MRI findings are indeterminate.

Topics: Adult; Aged; Carcinoma; Diagnosis, Differential; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Nasopharyngeal Diseases; Nasopharyngeal Neoplasms; Neoplasm Recurrence, Local; Organophosphorus Compounds; Organotechnetium Compounds; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The diagnostic accuracy of combined computed tomography (CT) and technetium 99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of head and neck to differentiate recurrent or residual nasopharyngeal carcinomas (NPCs) from benign lesions after radiotherapy was evaluated and compared with positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG).. Four months after radiotherapy, 36 patients with NPC underwent Tc-TF SPECT and CT of head and neck to differentiate recurrent or residual NPC from benign lesions. Histopathologic examinations were performed on nasopharyngeal biopsies of all 36 patients.. Based on the biopsy results, the sensitivity, specificity, and accuracy of Tc-TF SPECT were 64%, 96%, and 86%, respectively, for differentiation of recurrent or persistent NPC from benign lesions. For CT and FDG-PET, the sensitivity, specificity, and accuracy were 73%, 88%, and 83% and 100%, 96%, 97%, respectively. For the 27 patients with NPC whose Tc-TF SPECT and CT results were congruent, the combination of Tc-TF SPECT and CT had the same sensitivity, specificity, and accuracy (100%, 96%, and 96%) as FDG-PET. For the nine patients with NPC with incongruent Tc-TF SPECT and CT results, FDG-PET correctly differentiated two benign lesions from seven recurrent/residual NPCs.. Although, FDG-PET is the best tool for detecting recurrent or residual NPC, combined congruent Tc-TF SPECT and CT results achieved the same accuracy as FDG-PET. Therefore, we concluded that FDG-PET could be considered only when Tc-TF SPECT and CT give incongruent results.

Topics: Adolescent; Adult; Aged; Carcinoma; Diagnosis, Differential; Drug Resistance, Neoplasm; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Nasopharyngeal Neoplasms; Neoplasm Recurrence, Local; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The potential clinical use of technetium-99m labeled sestamibi (Tc-MIBI) and tetrofosmin (Tc-Tfos) to image tumours is currently being evaluated. In this study. the accumulation and efflux of Tc-MIBI and Tc-Tfos in the nasopharyngeal carcinoma cell line CNE-1 were examined in the presence or absence of various inhibitors of P-glycoprotein (PGP) and/or multidrug resistance associated protein (MRP) activity [GG918, PSC833, verapamil (Vrp), cyclosporin A (CsA) and buthionine sulfoximine (BSO)]. Reverse-transcriptase polymerase chain reaction analysis and immunodetection of the CNE-1 cells detected expression of MRP, MRPI and MRP2 but not PGP. Tc-MIBI and Tc-Tfos accumulation was increased (P < 0.0001) and efflux decreased (P < 0.05) in the presence of BSO, CsA, Vrp and PSC833 but not GG918, which is a specific inhibitor of PGP. The absolute accumulation of Tc-MIBI was approximately twofold higher than that seen with Tc-Tfos, whereas the addition of inhibitors caused a much greater suppression of Tc-Tfos transport (>2 times greater than for Tc-MIBI). However, no qualitative differences in inhibitors were seen between Tc-MIBI and Tc-Tfos. These results suggest that both Tc-MIBI and Tc-Tfos are substrates for the MRP transporter and that PSC833, Vrp, CsA and BSO but not GG918 can inhibit MRP activity. These results indicate that Tc-MIBI and Tc-Tfos may be suitable imaging agents for detecting MRP-mediated drug resistance in human cancers.

Topics: ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Carcinoma; Genes, MDR; Humans; Indicators and Reagents; Nasopharyngeal Neoplasms; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reverse Transcriptase Polymerase Chain Reaction; Technetium Tc 99m Sestamibi; Tumor Cells, Cultured

Tc-99m tetrofosmin SPECT imaging of the head and neck was performed on 10 patients with nasopharyngeal carcinoma (NPC) and 10 controls. There was no abnormal nasopharyngeal uptake of tetrofosmin in the 10 controls. In the patients with NPC, 3/10 (30%) of the cases had no abnormal uptake and 7/10 (70%) had increased nasopharyngeal uptake. Considering our preliminary study, we find that Tc-99m tetrofosmin SPECT of the head and neck may be helpful in the detection of NPC. However, further study with a larger number of patients is needed to ascertain the value of Tc-99m tetrofosmin SPECT in such cases.

Topics: Adult; Biopsy; Carcinoma; Female; Head; Humans; Image Processing, Computer-Assisted; Injections, Intravenous; Male; Middle Aged; Nasopharyngeal Neoplasms; Nasopharynx; Neck; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

The intention of this prospective study was to compare the diagnostic potential of technetium-99m sestamibi (MIBI) and a novel radiotracer, 99mTc-Tetrofosmin (Tetro), for the assessment of primary nasopharyngeal carcinoma (NPC) and the differentiation of residual disease from post-therapy changes. A total of 38 patients underwent MIBI and Tetro single-photon emission tomography (SPET) imaging at initial presentation (n=22) or following therapy (n=16). The findings were correlated with computed tomography or magnetic resonance imaging (MRI) on a site-by-site basis. Tumour/background (Tm/Bkg) ratios were obtained on coronal sections. Biopsy (nine patients) and/or 12- to 24-month clinical follow-up data were available in the post-therapy group. All primary disease sites were accurately detected by both imaging studies. Although there was no statistical difference between the two imaging techniques in the detection of primary disease, MIBI was superior to Tetro in the detection of regional lymph node metastases (sensitivity: 95% vs 79%). Tetro and MIBI SPET were true-positive in all patients (n=7) with proven residual/recurrent disease. In nine patients who had no evidence of residual/recurrent tumour, MRI was false-positive in five while Tetro and MIBI SPET were false-positive in two and three patients, respectively. Tm/Bkg ratios were

Topics: Carcinoma; Carcinoma, Squamous Cell; Female; Humans; Lymphatic Metastasis; Male; Middle Aged; Nasopharyngeal Neoplasms; Neoplasm Recurrence, Local; Neoplasm, Residual; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon