RESUMO
Objective: To develop and validate a bone metastasis prediction model based on skull base invasion (SBI) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC). Methods: This retrospective cohort study enrolled 290 patients with LA-NPC who received intensity-modulated radiation therapy in two hospitals from 2010 to 2020. Patient characteristics were grouped by SBI and hospital. Both unadjusted and multivariate-adjusted models were used to determine bone metastasis risk based on SBI status. Subgroup analysis was performed to investigate heterogeneity using a forest graph. Cox proportional hazard regression analysis was used to screen for risk factors of bone metastasis-free survival (BMFS). A nomogram of BMFS based on SBI was developed and validated using C-index, receiver operating characteristic curve, calibration curves, and decision curve analysis after Cox proportional hazard regression analysis. Results: The incidence of bone metastasis was 14.83% (43/290), 20.69% (24/116), and 10.92% (19/174) in the overall population, SBI-positive group, and SBI-negative group, respectively. In the unadjusted model, SBI was associated with reduced BMFS [HR 2.43 (1.32-4.47), P = 0.004], and the results remained stable after three continuous adjustments (P <0.05). No significant interaction was found in the subgroup analyses (P for interaction >0.05). According to Cox proportional hazard regression analysis and clinical value results, potential risk factors included SBI, Karnofsky performance status, TNM stage, induction chemotherapy, concurrent chemoradiotherapy, and adjuvant chemotherapy. Using a training C-index of 0.80 and a validation C-index of 0.79, the nomogram predicted BMFS and demonstrated satisfactory prognostic capability in 2, 3, and 5 years (area under curve: 83.7% vs. 79.6%, 81.7% vs. 88.2%, and 79.0% vs. 93.8%, respectively). Conclusion: Skull base invasion is a risk factor for bone metastasis in patients with LA-NPC. The SBI-based nomogram model can be used to predict bone metastasis and may assist in identifying LA-NPC patients at the highest risk of bone metastasis.
RESUMO
OBJECTIVE: To observe the exercise single photon emission computed tomography (SPECT) myocardial perfusion imaging of patients with myocardial bridge and assess the association between myocardial ischemia and extent of myocardial systolic compression. METHODS: Seventeen patients with myocardial bridge diagnosed by coronary angiogram were included and underwent exercise SPECT myocardial perfusion imaging. RESULTS: Abnormal SPECT perfusion imaging was evidenced in 12 out of 17 patients with myocardial bridge (2 out of 6 patients with systolic compression induced stenosis < 50%, 3 out of 4 patients with systolic compression induced stenosis between 50% - 75% and 7 out of 7 patients with the systolic compression induced stenosis between 75% - 100%). CONCLUSION: Exercise stress SPECT myocardial perfusion imaging could detect myocardial ischemia in patients with myocardial bridge and abnormal perfusion is positively related to the extent of systolic compression induced stenosis.
