Post-radiation CT changes and recurrent nasopharyngeal carcinoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nasopharyngeal carcinoma (NPC) is endemic in Southern Asia. Radiation therapy remains the mainstay of treatment strategies for NPC. Although approximately 19% - 56% of patients develop a recurrent disease 5 years after their primary treatment, recognition of post-radiation changes and early detection of relapse are important in improving the outcome of NPC. Our aim was to analyze the post-radiation changes and recurrent diseases related to NPC using computed tomography (CT) scans and to investigate their relationship.</p><p><b>METHODS</b>CT scans of 510 pathologically proven NPC patients who have been followed up for more than 2 years after radiation were reviewed. The tumor's response to the radiation therapy and its relevance to recurrence were evaluated.</p><p><b>RESULTS</b>For patients who were followed up for more than 2 years, their CT scans-obtained within 3 months, during the 4th to the 6th month, and beyond 7 months after radiation therapy, showed a normal nasopharyngeal cavity with a slight thickening in the wall in 93.5%, 95.0% and 84.8% of the patients respectively. The degree of tumor regression had no significant relevance to the risk of recurrence within the initial 3 months (P = 0.094). During this term, the relapse rates in the cases in which the nasopharyngeal walls were displayed as normal, slightly or moderately thickening, or with obvious residual masses on CT scans were 7.1%, 11.7%, 23.5% and 23.1% respectively. The degree of tumor regression beyond 3 months after radiation therapy had a considerable reverse relevance to the risk of recurrence (P = 0.000). The relapse rates were 13.2%, 14.1%, 10.2% and 2.1%, respectively, in the cases with a normal and a slightly thickening nasopharyngeal wall during the 4th to the 6th month, the 7th to the 12th month, the 13th to the 24th month, and beyond 25 months after radiation. In contrast, the percents in cases with moderate or more aggressive thickening walls in the corresponding periods were 62.5%, 88.9%, 100% and 100%. Within 6 months after radiation therapy, shown by CT scans, the metastatic lymph nodes disappeared, markedly decreased, slightly decreased, or enlarged in 37.4%, 51.8%, 4.7%, and 0.4%, respectively, of the patients. During 6 to 12 months after radiation therapy, the proportions were 78.5%, 19.2%, 0.6% and 1.7% correspondingly. Beyond 12 months, the proportions were 83.7%, 7.9%, 0%, and 8.4%. The regression degree of the malignant nodes after radiation therapy showed a remarkable reverse relevance to the risk of recurrence in lymph nodes (P = 0.000). In the cases with disappearing, markedly decreased, slightly decreased, or enlarged malignant nodes within six months after radiation, the relapse rates were 2.9%, 4.5%, 12.5% and 100%, respectively.</p><p><b>CONCLUSIONS</b>If the nasopharyngeal walls are shown to remain moderately thick on a CT scan beyond 6 months after radiotherapy, the risk of relapse will increase. The baseline images taken within 3 months after radiotherapy and regular follow-up studies are the key to pick up the tumor recurrences in an earlier stage.</p>

Value of multi-slice helical CT in the diagnosis and differential diagnosis of thyroid lesions / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the value of multi-slice helical CT in the differentiation of benign from malignant thyroid lesions.</p><p><b>METHODS</b>The multi-slice helical CT images of 72 patients with 82 thyroid lesions were prospectively studied. The CT features including the margin, density of the lesion and cervical lymph node enlargement were evaluated double-blindly. All the image findings were compared with the pathological results, and analyzed statistically using the Chi-square test.</p><p><b>RESULTS</b>Of 42 benign lesions, 38 (90.5 % ) showed well-defined margin, 13 (30. 9% ) contained low density nodular areas, 3 (7. 1% ) showed granular calcifications, and 2 (4. 8% ) had cervical lymph node enlargement. Of 40 thyroid carcinomas, 37 lesions(92.5% ) had irregular border, no lesion contained low density nodular areas, 14 (35. 0%) showed granular calcifications, and 31 (77. 5% ) had enlarged cervical lymph nodes. Nineteen lesions (55. 9% ) from 34 thyroid carcinoma patients who had undergone contrast enhanced CT scan showed complex density, while only 2(6. 3% ) of 32 benign lesions showed such findings on contrast enhancement. There were statistically significant differences between benign and malignant lesion in margin, low density nodular area, granular calcification, cervical lymph node enlargement and complex density( P <0.01).</p><p><b>CONCLUSION</b>The findings of well-defined margin and low density nodular area in CT image may suggest benign thyroid lesions, whereas the presence of irregular border, granular calcifications and cervical lymph node enlargement as well as complex density may indicate thyroid malignancy.</p>

The significance of multi-slice helical CT multiplanar reconstruction in the diagnoses of laryngeal carcinoma / 中华放射学杂志

Objective To evaluate the significance of multi-slice helical CT with multiplanar reconstruction in laryngeal carcinoma.Methods Thirty-five patients with laryngeal carcinoma were studied by helical CT,MPR were subsequently done.The lesion extent of the axial image findings,MPR findings and the combined image findings were compared with the pathological results respectively.The data were statistically analyzed.Results In the evaluation of the anterior commissure,the axial image findings,MPR findings and the combined image findings were 82.9%,68.6% and 91.4% in accuracy respectively,the results were statistically different(P0.05).The combined images were superior to the axial images and the MPR images in sensitivity,specificity and accuracy of the lesion extent.Conclusion The axial images could show the shape,size,extension of the tumor and the lymphadenopathy,MPR images displayed the shape,size and extension roundly and directly,they were the supplement for the axial images.Axial images combined with MPR could improve the accuracy in the diagnoses of laryngeal carcinoma.