為探討盆底修復(fù)材料的生物力學(xué)特征，本試驗選取用于女性盆底重建手術(shù)的 4 種盆底修復(fù)材料，分別是全盆底修復(fù)系統(tǒng)（PROLIFT）、經(jīng)閉孔無張力陰道懸吊系統(tǒng)（TVT-O）、經(jīng)陰道懸吊置入系統(tǒng)（IVS）和脫細(xì)胞異體真皮基質(zhì)醫(yī)用組織補片（Renov）。將 4 種盆底修復(fù)材料分別在 Instron4302 萬能材料試驗機上進行拉伸力學(xué)試驗，記錄極限應(yīng)力強度、彈性模量、最大負(fù)荷和最大伸長量。結(jié)果顯示：4 種盆底修復(fù)材料的最大負(fù)荷依次為 TVT-O > IVS > PROLIFT > Renov，TVT-O 最大負(fù)荷顯著高于 PROLIFT和Renov（ P < 0.05）；極限應(yīng)力強度依次為 TVT-O > IVS > PROLIFT > Renov，但 4 種材料組間比較差異無統(tǒng)計學(xué)意義（ P > 0.05）；最大伸長量依次為 TVT-O > PROLIFT > IVS > Renov，TVT-O 和 PROLIFT 的最大伸長量均顯著高于 Renov（ P < 0.05）；彈性模量依次為 IVS > Renov > TVT-O > PROLIFT，但 4 種材料組間比較差異無統(tǒng)計學(xué)意義（ P > 0.05）。可見，4 種盆底修復(fù)材料中，IVS 的彈性模量最高；TVT-O 的力學(xué)強度最高；Renov 的最大負(fù)荷、極限應(yīng)力強度以及最大伸長量均最低；PROLIFT 材料的力學(xué)性能最穩(wěn)定，彈性模量最低，具有良好的延展性和彈性。因此，綜合臨床盆底重建手術(shù)的實際需要，在開發(fā)新型盆底修復(fù)材料時應(yīng)注重其生物力學(xué)性能的考量。
【摘要】 目的 研究千伏級錐形束CT（kV-cone beam CT，kV-CBCT）影像用于鼻咽癌調(diào)強放射治療計劃劑量計算的可行性和精確度?！》椒ā?010年7-9月7例鼻咽癌患者 ，獲取每例患者的第1天放射治療時的kV-CBCT影像。用CIRS062密度模體和患者自身特定區(qū)域亨氏單位值（hounsfield unit，HU）映射的兩種方法重新刻度亨氏單位值-相對電子密度（HU-RED）表，分別進行劑量計算，并與在傳統(tǒng)扇形束CT（FBCT）影像上的原放射治療計劃結(jié)果進行對比，包括輻射劑量分布、靶區(qū)和危及器官的劑量體積直方圖（DVH）。 結(jié)果 kV-CBCT影像的治療計劃和原治療計劃在劑量分布和DVH上有較好的一致性。在劑量分布的比較上采用了γ分析（2%/2 mm標(biāo)準(zhǔn)的通過率），用基于模體的HU-RED表得到的治療計劃與原治療計劃對比，在經(jīng)過等中心冠狀面、矢狀面和橫斷面的通過率分別為92.7%±3.5%、95.1%±3.1%和95.7%±3.4%，用基于患者的HU-RED表得到治療計劃與原治療計劃對比的通過率分別為94.8%±2.7%、96.6%±2.9%和97.4%±2.7%。DVH的統(tǒng)計數(shù)據(jù)表明，兩種方法得到的kV-CBCT治療計劃和原治療計劃相比較，靶區(qū)和危及器官劑量偏差大多數(shù)在2%以內(nèi)。有1例因在橫斷面發(fā)生了明顯的旋轉(zhuǎn)誤差，導(dǎo)致在橫斷面的通過率很低，DVH統(tǒng)計數(shù)據(jù)較原計劃偏差較大?！〗Y(jié)論 kV-CBCT影像可以用來做輻射劑量計算，基于患者自身影像生成的HU-RED表的治療計劃較原治療計劃有更高的符合度。【Abstract】 Objective To evaluate the feasibility and accuracy of dose calculation based on cone beam CT (CBCT) data sets for intensity modulated radiation therapy (IMRT) planning of nasopharyngeal cancer (NPC). Methods Seven NPC patients were selected. The kV-CBCT images for each patient were acquired on the first treatment day. Two correction strategies were used to generate the cone beam HU value vs relative electron density calibration tables which named CIRS062 phantom based HU-RED tables and patient specific HU-RED tables respectively for dose calculation. The dose distributions and dose volume histograms (DVHs) of the target and organs at risk (OAR) based on kV-CBCT images were compared to the plans based on the fan-beam CT (FBCT). Results The DVH and dose distribution comparison between plans based on the FBCT and those on the CBCT showed good agreements. The γ analysis with a criterion of 2 mm/2% was used for the comparison of dose distribution at the coronal plane, sagital plane and cross plane through the isocenter point. The passing rate from phantom based HU-RED tables were (92.7±3.5) %, (95.1±3.1) %, and (95.7±3.4)%, respectively. The passing rates from the patient specific HU-RED tables were (94.8±2.7) %, (96.6±2.9) %, and (97.4±2.7) %, respectively. The dose difference between plans based on CBCT and those based on FBCT was within 2% at most patients by analyzing DVH based parameters. Only one patient who had significant rotation setup error resulted in the low passing rate and disagreement in DVH. Conclusion The CBCT images can be used to do dose calculation in IMRT planning of NPC. The differences between plans based on HU-RED tables generated by specific patient and the original plans are less than those between plans based on CIRS062 phantom based HU-RED tables and the original plans.