Application of a novel computer-assisted surgery system in percutaneous nephrolithotomy:A controlled study

BACKGROUND Most complex renal stones are managed primarily with percutaneous nephrolithotomy(PCNL).However,PCNL is still a great challenge for surgeons because of poor comprehension on complex adjacent structures.Novel techniques are required to assist in planning and navigation.AIM To apply and evaluate the Hisense computer-assisted surgery(CAS)system in PCNL.METHODS A total of 60 patients with complex renal stones were included.Thirty patients in the CAS group had three-dimensional(3 D)virtual models constructed with the CAS system.The model assisted in planning and navigating in the CAS system.Thirty patients in the control group planned and navigated as standard PCNL,without the application of the CAS system.Success rate of one attempt,operation time,initial stone-free rate,decrease in hemoglobin,and complications were collected and analyzed.RESULTS There were no statistically significant differences in the baseline characteristics or planning characteristics.The success rate of one puncturing attempt(90%vs 67%,P=0.028)and the initial stone-free rate(87%vs 63%,P=0.037)were significantly higher in the CAS group.However,there were no statistically significant differences in the operation time(89.20±29.60 min vs 92.33±33.08 min,P=0.859)or in the decrease in hemoglobin(11.07±8.32 g/L vs 9.03±11.72 g/L,P=0.300)between the CAS group and the control group.No statistically significant differences in the incidence of complications(Clavien-Dindo grade≥2)were found.CONCLUSION Compared with standard PCNL,CAS-assisted PCNL had advantages in terms of the puncturing success rate and stone-free rate.The Hisense CAS System was recommended to assist in preoperative planning and intraoperative navigation for an intuitive,precise and convenient PCNL.

Predicting Delivery Error Using a DICOM-RT Plan for Volumetric Modulated Arc Therapy

The purpose of this study was to investigate the prediction of mechanical error using DICOM-RT plan parameters for volumetric modulated arc therapy (VMAT). We created plans for gantry rotation arcs of 360° and 180° (full-arc and half-arc VMAT) for six maxillary sinus cancer cases using a Monaco treatment planning system, and delivered the doses with a linear accelerator. We calculated DICOM-RT plan parameters, including gantry, multileaf collimator (MLC) positions and Monitor Units (MU). We compared plans with regard to gantry angle per MU (degrees/MU) and MLC travel per MU (mm/MU) for each segment. Calculated gantry angle/MLC position speeds and errors were evaluated by comparison with the log file. On average, the half-arc VMAT plan resulted in 47% and 35% fewer degrees/MU and mm/MU than the full-arc VMAT plan, respectively. The root mean square (r.m.s.) gantry and MLC speeds showed a linear relationship with calculated degrees/MU and mm/MU, with coefficients of determination (R2) of 0.86 and 0.72, respectively. The r.m.s. gantry angle and MLC position errors showed a linear relationship with calculated degrees/MU and mm/MU with R2 of 0.63 and 0.76, respectively. Deviations from plan parameters were related to mechanical error for VMAT, and provided quantitative information without the need for VMAT delivery. These parameters can be used in the selection of treatment planning.

^(99m)Tc-MAA肝动脉造影在选择性内放射治疗原发性肝癌的意义

目的 探讨99m锝 MAA(99mTechnetium macroaggregatedalbumin ,99mTc MAA)肝动脉造影在经肝动脉灌注32 磷 玻璃微球 (32 P GMS)治疗手术不能切除的肝细胞癌 (HCC)中的价值。方法 对 2 8例手术证实不能切除的HCC经皮下埋藏药盒行99mTc MAA肝动脉造影 ,测定肺肝分流比 (Lu/Li)和癌 /肝放射比 (T/N) ,并对其中 18例行经肝动脉灌注32 P GMS选择性内放射治疗 (SIRT)。结果 本组99mTc MAA肝动脉造影测定Lu/Li为 7%± 7% (1%～ 2 5 % ) ,T/N为 5± 3(1～ 14) ;接受SIRT治疗的 18例Lu/Li为 4%± 2 % (1%～ 8% ) ,T/N为 4± 2 (1～ 8) ,其中 15例T/N大于或等于 2 ,3例小于 2。无治疗死亡及严重并发症 ,有效率 6 1% (11/ 18) ,中位生存期 5 5个月 ,术后 3、6、9、12个月生存率分别为 94%、47%、34%和 2 7% ;其中T/N大于或等于 2者中位生存期优于T/N小于 2者 ,分别为 6 6个月和 4 1个月 (P =0 0 11) ,Child′sA级中位生存期优于B级者 ,分别为 9 9个月和 3 8个月 (P =0 0 0 4)。结论 99mTc MAA肝动脉造影是选择性内放射治疗HCC的一项重要措施 ,有助于选择合适病例、提高疗效和避免严重并发症的发生。