Guided placement of zygomatic implants in head and neck cancer patients:implant survival and patient outcomes at 1-3 years of follow-up

Zygomatic implants (ZI) are a valuable option for supporting an obturator prosthesis after maxillary resection. This study was performed to assess the clinical outcomes of a digitally validated guided technique for ZI placement, followed by immediate prosthetic obturation. The primary objective was to evaluate implant survival, while the secondary objective was to assess patient-reported quality of life post-rehabilitation. Twelve patients treated for head and neck cancer received a total of 36 ZI after ablative surgery. The mean duration of ZI follow-up was 30.1 months. The survival rate of ZI placed in non-irradiated patients was 100%, while it was 85% in irradiated patients. Patient-reported outcomes were evaluated using the Liverpool Oral Rehabilitation Questionnaire (LORQv3) and the University of Washington Quality of Life Questionnaire (UW-QOL v4). Most patients reported satisfactory outcomes in the oral function domain of the LORQv3 (mean score 17.7 ± 4.5; possible range 12-48, with lower scores indicating better outcomes). Regarding the UW-QOL v4, the swallowing and chewing domains had the highest scores (mean 97.5 ± 8.7 and 95.8 ± 14.4, respectively; maximum possible score of 100). In conclusion, this treatment approach improves function and quality of life after maxillary ablative surgery. However, irradiated patients showed a noticeable trend of higher implant failure, and this was influenced by tumour position and size impacting the radiation dose to the zygomatic bone.</p

Immediate implant-retained prosthetic obturation after maxillectomy based on zygomatic implant placement by 3D-guided surgery:a cadaver study

Abstract Background The aim of this study was to introduce a complete 3D workflow for immediate implant retained prosthetic rehabilitation following maxillectomy in cancer surgery. The workflow consists of a 3D virtual surgical planning for tumor resection, zygomatic implant placement, and for an implant-retained prosthetic-obturator to fit the planned outcome situation for immediate loading. Materials and methods In this study, 3D virtual surgical planning and resection of the maxilla, followed by guided placement of 10 zygomatic implants, using custom cutting and drill/placement-guides, was performed on 5 fresh frozen human cadavers. A preoperatively digitally designed and printed obturator prosthesis was placed and connected to the zygomatic implants. The accuracy of the implant positioning was obtained using 3D deviation analysis by merging the pre- and post-operative CT scan datasets. Results The preoperatively designed and manufactured obturator prostheses matched accurately the per-operative implant positions. All five obturators could be placed and fixated for immediate loading. The mean prosthetic point deviation on the cadavers was 1.03 ± 0.85 mm; the mean entry point deviation was 1.20 ± 0.62 mm; and the 3D angle deviation was 2.97 ± 1.44°. Conclusions It is possible to 3D plan and accurately execute the ablative surgery, placement of zygomatic implants, and immediate placement of an implant-retained obturator prosthesis with 3D virtual surgical planning.The next step is to apply the workflow in the operating room in patients planned for maxillectomy

Incidental findings during the diagnostic work-up in the head and neck cancer pathway:Effects on treatment delay and survival

Objectives: As a result of the increasing number of diagnostic scans, incidental findings (IFs) are more frequently encountered during oncological work-up in patients with head and neck squamous cell carcinomas (HNSCC). IFs are unintentional discoveries found on diagnostic imaging. Relevant IFs implicate clinical consequences, resulting in delay in oncologic treatment initiation, which is associated with unfavorable outcomes. This study is the first to investigate the incidence and nature of IFs over the years and establish the effect of relevant IFs on delay. Material and methods: This retrospective study compared two time periods (2010 & ndash;2011 and 2016 & ndash;2017), described associations between relevant IFs and delay in carepathway interval (days between first visit and treatment initiation) and assessed the effect of relevant IFs on overall two-year survival. Results: In total, 592 patients were included. At least one IF was found in 61.5% of the patients, most frequently on chest-CT. In 128 patients (21.6%) a relevant IF was identified, resulting for the majority in radiologist recommendations (e.g. additional scanning). Presence of a relevant IF was an independent significant factor associated with delay in treatment initiation. The risk of dying was higher for patients with a relevant IF, although not significant in the multivariable model (HR: 1.46, p = 0.079). Conclusion: In diagnostic work-up for HNSCC patients, relevant IFs are frequently encountered. As the frequency of additional imaging rises over the years, the number of IFs increased simultaneously. These relevant IFs yield clinical implications and this study described that relevant IFs result in significant delay in treatment initiation

Alternative Magnesium Sulfate Dosing Regimens for Women With Preeclampsia: A Population Pharmacokinetic Exposure-Response Modeling and Simulation Study

Magnesium sulfate is the anticonvulsant of choice for eclampsia prophylaxis and treatment; however, the recommended dosing regimens are costly and cumbersome and can be administered only by skilled health professionals. The objectives of this study were to develop a robust exposure-response model for the relationship between serum magnesium exposure and eclampsia using data from large studies of women with preeclampsia who received magnesium sulfate, and to predict eclampsia probabilities for standard and alternative (shorter treatment duration and/or fewer intramuscular injections) regimens. Exposure-response modeling and simulation were applied to existing data. A total of 10 280 women with preeclampsia who received magnesium sulfate or placebo were evaluated. An existing population pharmacokinetic model was used to estimate individual serum magnesium exposure. Logistic regression was applied to quantify the serum magnesium area under the curve-eclampsia rate relationship. Our exposure-response model-estimated eclampsia rates were comparable to observed rates. Several alternative regimens predicted magnesium peak concentration < 3.5 mmol/L (empiric safety threshold) and eclampsia rate ≤ 0.7% (observed response threshold), including 4 g intravenously plus 10 g intramuscularly followed by either 8 g intramuscularly every 6 hours × 3 doses or 10 g intramuscularly every 8 hours × 2 doses and 10 g intramuscularly every 8 hours × 3 doses. Several alternative magnesium sulfate regimens with comparable model-predicted efficacy and safety were identified that merit evaluation in confirmatory clinical trials

Risk of urothelial bladder cancer in Lynch syndrome is increased, in particular among MSH2 mutation carriers

Contains fulltext : 89346.pdf (publisher's version ) (Open Access)BACKGROUND: Colorectal, endometrial and upper urinary tract tumours are characteristic for Lynch syndrome (hereditary non-polyposis colon carcinoma, HNPCC). The aim of the present study was to establish whether carriers of mutations in mismatch repair genes MLH1, MSH2 or MSH6 are at increased risk of urinary bladder cancer. METHODS: Carriers and first degree relatives of 95 families with a germline mutation in the MLH1 (n=26), MSH2 (n=43), or MSH6 (n=26) gene were systematically questioned about the occurrence of carcinoma. The cumulative risk of cancer occurring before the age of 70 years (CR70) was compared to the CR70 of the general Dutch population. Microsatellite instability (MSI) testing and/or immunohistochemistry (IHC) for mismatch repair proteins was performed on bladder tumour tissue. RESULTS: Bladder cancer was diagnosed in 21 patients (90% men) from 19 Lynch syndrome families (2 MLH1, 15 MSH2, and 4 MSH6). CR70 for bladder cancer was 7.5% (95% CI 3.1% to 11.9%) for men and 1.0% (95% CI 0% to 2.4%) for women, resulting in relative risks for mutation carriers and first degree relatives of 4.2 (95% CI 2.2 to 7.2) for men and 2.2 (95% CI 0.3 to 8.0) for women. Men carrying an MSH2 mutation and their first degree relatives were at highest risks: CR70 for bladder and upper urinary tract cancer being 12.3% (95% CI 4.3% to 20.3%) and 5.9% (95% CI 0.7% to 11.1%). Bladder cancer tissue was MSI positive in 6/7 tumours and loss of IHC staining was found in 14/17 tumours, indicating Lynch syndrome aetiology. CONCLUSION: Patients with Lynch syndrome carrying an MSH2 mutation are at increased risk of urinary tract cancer including bladder cancer. In these cases surveillance should be considered.01 juli 201