Abstract Objective The role of Primary Tumor Volume (PTV) in Nasopharyngeal Carcinoma (NPC) treated with Volumetric Modulated Arc Therapy (VMAT) is still unclear. The aim of this study was to access the effect of PTV in prognosis prediction of nasopharyngeal carcinoma in era of VMAT. Methods Between January 20 and November 2011, 498 consecutive NPC patients with stage I-IVA disease who received VMAT at a single center were retrospectively analyzed. Receiver Operating Characteristic (ROC) was performed to access the cut-off point of PTV. Univariate Kaplan-Meier and multivariate Cox regression analyses were used to evaluate prognostic value for PTV. The Propensity Score Matching (PSM) was used to adjust baseline potential confounders. Results The 5-year Locol-Regional Failure-Free (L-FFR), Distant Failure-Free Survival (D-FFR), Disease-Free Survival (DFS) and Overall Survival (OS) were 90.6%, 83.7%, 71.5% and 79.3%, respectively. Before PSM, the 5-year L-FFR, D-FFR, DFS, OS rates for NPC patients with PTV ≤ 38 mL vs. PTV > 38 mL were 94.1% vs. 90.4% (p= 0.063), 87.9% vs. 76.3% (p< 0.001), 78.5% vs. 58.5% (p< 0.001) and 86.3% vs. 66.7% (p< 0.001) respectively. Multivariate analysis showed PTV was an independent prognostic factor for D-FFS (p= 0.034), DFS (p= 0.002) and OS (p= 0.001). PTV classified was still an independent prognostic factor for OS after PSM (HR = 2.034, p= 0.025. Conclusions PTV had a substantial impact on the prognosis of NPC patients treated with VMAT before and after PSM simultaneously. PTV > 38 mL may be considered as an indicator of the clinical stage of nasopharyngeal carcinoma. Level of evidence III. (PTV (NPC (VMAT unclear 2 2011 49 IIVA I IVA analyzed ROC (ROC cutoff cut off KaplanMeier Kaplan Meier (PSM confounders 5year year 5 LocolRegional Locol Regional FailureFree Failure Free LFFR, LFFR L FFR , (L-FFR) DFFR, DFFR D (D-FFR) DiseaseFree Disease (DFS (OS 906 90 6 90.6% 837 83 7 83.7% 715 71 71.5 793 79 3 79.3% respectively FFR, L-FFR D-FFR vs 941 94 1 94.1 904 4 90.4 p (p 0.063, 0063 0.063 0 063 0.063) 879 87 9 87.9 763 76 76.3 p< 0.001, 0001 0.001 001 785 78 78.5 585 58 58.5 863 86 86.3 667 66 66.7 DFFS FFS 0.034, 0034 0.034 034 0.034) 0.002 0002 002 0.001. . HR 2034 2.034 0025 025 0.025 simultaneously III 201 (L-FFR (D-FFR 90.6 8 83.7 71. 79.3 94. 90. 006 0.06 06 87. 76. 000 0.00 00 78. 58. 86. 66. 003 0.03 03 203 2.03 02 0.02 83. 79. 0.0 2.0 0. 2.

RESUMO Objetivos Avaliar o potencial da aplicação da tecnologia de impressão 3D na medição da área de defeito ósseo acetabular em pacientes adultos diagnosticados com displasia do desenvolvimento do quadril (DDH). Métodos 23 casos de DDH que requereram cirurgia de substituição total do quadril foram incluídos neste estudo. O exame pré-operatório confirmou os filmes pélvicos padrão Crowe, incluindo 3 casos de Crowe I, 7 Crowe II, e 13 Crowe III. A tecnologia de impressão 3D foi utilizada para imprimir o modelo de quadril antes da operação. Com base no modelo pré-impresso, o planejamento pré-operatório e os procedimentos cirúrgicos foram estabelecidos. A área dos defeitos ósseos acetabulares foi medida, a prótese de tamanho selecionado foi registrada, e a cirurgia foi realizada (grupo A). A área do defeito ósseo acetabular real e o tamanho da prótese também foram registrados (grupo B). Resultados Os resultados comparativos indicaram que a área real do defeito acetabular medida intraoperativamente e a área medida usando a tecnologia de impressão 3D não diferiu significativamente para todos os participantes (todos P>0,05). Conclusão O modelo pré-operatório pode medir com precisão a área de defeito ósseo acetabular para DDH. É relevante desenvolver implantes individualizados para pacientes com DDH tratados com a técnica de impressão 3D. Nível de Evidência IV: Série de casos.

ABSTRACT Objectives Evaluate the application value of 3D printing technology in measuring acetabular bone defect area in adult patients diagnosed with developmental dysplasia of the hip (DDH). Methods 23 cases of DDH requiring total hip replacement surgery were enrolled in this study. Preoperative examination confirmed the standard pelvic plain films Crowe, including 3 cases of Crowe I, 7 Crowe II, and 13 Crowe III. The 3D printing technology was used to print the hip model before the operation. Based on the pre-printed model, pre-operative planning and surgical procedures were established. The area of the acetabular bone defects was measured, the selected size prosthesis was recorded, and the surgery was performed (group A). The actual acetabular bone defect area and the prosthesis size were also recorded (group B). Results The comparative results indicated that the actual acetabular defect area measured intraoperatively and the area measured using the 3D printing technology did not significantly differ for all participants (all P>0.05). Conclusion Preoperative model can accurately measure the acetabular bone defect area for DDH. It is significant to develop individualized implants for DDH patients treated with the 3D printing technique. Level of Evidence IV: Case series.