Patient-Specific Segmentation-Based Treatment Planning vs. NovoTAL for TTFields Therapy in Glioblastoma

PURPOSE/OBJECTIVE(S)

Patients treated with Tumor Treating Fields (TTFields) therapy for glioblastoma (GBM) have array layouts planned by NovoTAL. NovoTAL requires morphometric inputs and maximizes field intensity at the tumor. Patient-specific segmentation-based treatment planning (SBTP) software uses segmentation-based plans to maximize power density at defined regions of interest (ROIs). This technical analysis compared expected local minimum power density (LMiPD; mW/cm3) and local minimum field intensity (LMiFI; V/cm) delivered to ROIs with array layouts planned with SBTP vs NovoTAL. We hypothesized that SBTP has the potential to increase LMiPD and LMiFI to ROIs vs NovoTal.

MATERIALS/METHODS

37 patients from 5 sites who received TTFields therapy for GBM using NovoTAL were included. Treatment plans using the prescribed/treated NovoTAL layouts were created with SBTP. De novo SBTP layouts were also created. Three ROIs representing the original treated GBM (CTV), high risk margin around the GBM (CTV-2), and recurrent GBM (CTV-R) were created. Plans were optimized to CTV. SBTP vs NovoTAL LMiPD and LMiFI volumetrics to ROIs were evaluated. LMiPD and LMiFI were normalized with the delivered current from the treated NovoTAL layout. Layout rankings based on LMiPD and LMiFI, average LMiPD and LMiFI, D95, D5, DVHs, and voxel-by-voxel LMiPD and LMiFI for SBTP derived from NovoTAL layouts were compared to de novo SBTP layouts (paired t-tests).

RESULTS

Average LMiPD (1.551 vs 1.194) and LMiFI (1.115 vs 0.978) to CTV were significantly higher with SBTP vs NovoTAL (P < 0.0001 for each). Average LMiPD (1.445 vs 1.164) and LMiFI (1.197 vs 1.077) to CTV-2 were also higher (P < 0.0001 for each). There was a positive trend to higher average LMiPD (1.203 vs 1.157; P = 0.212) and LMiFI (1.103 vs 1.090; P = 0.311) to CTV-R. Top ranked overall layouts by LMiPD to CTV were SBTP layouts (97%; n = 36). Percent ratio ([SBTP-NovoTAL]/NovoTAL*100) D95 for LMiPD was 34% (to CTV), 24% (to CTV-2), and 5% (to CTV-R) and for LMiFI was 16%, 12%, and 2% respectively. Percent ratio D5 for LMiPD was 31%, 24%, and 3% and for LMiFI was 14%, 9%, and 0%, respectively. For a given percent CTV volume, minimum LMiPD and LMiFI were higher with SBTP (95%, n = 35; DVH curves shifted to right). SBTP yielded higher LMiPD and LMiFI to the majority of voxels within the CTV (95%, n = 35). With SBTP, LMiPD to CTV was significantly higher than to CTV-R (P < 0.001).

CONCLUSION

Overall, these data demonstrate that SBTP compared to NovoTAL yielded higher expected average LMiPD and LMiFI, D95, D5, and percent voxel LMiPD and LMiFI to defined ROIs. Higher LMiPD and LMiFI delivered to CTV vs CTV-R with SBTP suggests a benefit to re-planning if the GBM recurs. Given previous reports showing that higher LMiPD and LMiFI are positively correlated with improved overall and progression free survival, patient-specific SBTP may lead to improved clinical outcomes for GBM patients vs NovoTAL.

Autoimmune pancreatitis – a surgical mistake?

Autoimmune pancreatitis is a specific type of chronic pancreatitis. Its clinical manifestation mimics pancreatic cancer. A multidisciplinary approach is necessary to establish the correct diagnosis. Autoimmune pancreatitis can be diagnosed on the basis of symptomatology, imaging methods, endoscopy, serology and histopathological examination. There are two different forms of autoimmune pancreatitis – type 1 and type 2. Type 1 is lymphoplasmacytic sclerosing pancreatitis and type 2 is idiopathic centroductal sclerosing pancreatitis. The disease most often takes a chronic form with acute exacerbations. In this paper we present two case reports of patients operated on for suspected malignancy of the pancreas, who were subsequently diagnosed with autoimmune pancreatitis based on histopathological examination. The aim of this communication is to point out the diagnostic pitfalls of this disease. Surgical treatment is not considered as a standard therapeutic method according to the current guidelines.

The effect of smoking and elderly age on digital replantation - a multivariate analysis

INTRODUCTION

It is often questioned whether to perform replantation or revision amputation for amputation injuries in elderly patients and smokers. According to the current indication criteria, neither old age nor smoking in the absence of other risk factors are considered to be risk factors for replantation failure. However, many microsurgeons still may make the decision not to perform digital replantation based solely on these factors.

MATERIAL AND METHODS

In order to evaluate the influence of both factors, we provided univariate and multivariate analyses of patients who underwent replantation at our centre during a 10-year period. We divided patients in two groups according to age (< and ≥ 60 years) and smoking status.

RESULTS

In the univariate analysis, there were no differences in immediate results between the two age groups. In the multivariate analysis, no statistical difference was found in neither long-term nor short-term results between the two age groups and between smokers and non-smokers.

CONCLUSION

Smoking and age should not be considered the only risk factors when deciding whether to perform digital replantation.

Intrahepatic cholangiocarcinoma: risk factors affecting survival of operated patients

INTRODUCTION

The aim of this study was to evaluate the results of surgical treatment of intrahepatic cholangiocarcinoma (IHCHCA) in terms of overall survival and disease-free survival, and to analyse and find potential prognostic factors affecting overall survival and disease-free survival.

METHODS

Retrospective evaluation was performed of consecutively enrolled patients operated for IHCHCA from January 2005 to January 2022 (17 years) had undergone surgery. During the monitored period, 38 surgical procedures were performed, of which liver resection was done in 25 cases (65.8%).

RESULTS

The 5-year survival in the radically resected group was 44%, and the 5-year disease-free survival was 32%. Based on univariate and multivariate analysis, radicality of surgery (p=0.01116) and lymph node involvement (p=0.00576) were assessed as negative prognostic factors for overall survival. Radicality of surgery (p=0.018) and administration of adjuvant chemotherapy (p=0.044) were significant negative prognostic factors affecting disease-free survival. However, they lost their significance in the multivariate analysis.

CONCLUSION

Radical surgical resection of the liver remains an essential treatment option for intrahepatic cholangiocarcinoma aimed at achieving a radical procedure with microscopically negative margins.

KEY WORDS

cholangiocarcinoma, resection, recurrence, survival.

Analysis of postoperative complications after open scar hernia hernioplasty - a retrospective analysis of a patient cohort

INTRODUCTION

The aim of this study was to analyse complications associated with inicisional hernia repair surgery and to assess individual risk factors for surgical site infections occurring at the Department of Surgery of the University Hospital Kralovske Vinohrady in 2015.

METHODS

We analysed 138 patients with a focus on risk factors that potentially increase the risk of postoperative infectious complications such as mesh implantation, smoking, diabetes mellitus, ischemic heart disease, malignancies, immunosuppressive therapy and urgency of the procedure.

RESULTS

Based on multivariate logistic regression analysis, acute surgery proved to be a risk factor for infection, and in the ad hoc Fisher test, the ratio was 2.73. Diabetes mellitus as a risk factor reached the limit of significance (p=0.071). No other variables were associated with an increased risk of surgical site infections.

CONCLUSION

Acute surgery was assessed as a significant risk factor for postoperative wound infection. On the contrary, mesh repair was not associated with an increased risk of infection.

Does Convergent Placement of Interlocking Iliosacral Screws into the Body of Vertebra S1 Prevent Screw Migration?

PURPOSE OF THE STUDY To compare the outcomes of parallel and convergent iliosacral screw insertion into the body of vertebra S1 in the treatment of posterior pelvic arch injuries. MATERIAL AND METHODS Radiographs of 120 patients (43 women, 77 men), aged between 14-79 years, treated with iliosacral screw fixation for posterior pelvic ring fractures between 1.1.2009 and 31.12.2019 were reviewed for inclusion in the study. In each case two screws were inserted into the body of vertebra S1. The screws were inserted in either parallel or convergent orientation. Convergent orientation allows the threads of both screws to be interconnected. In this technique, the first screw is inserted into the centre of the body of vertebra S1 as a compression screw. The second screw is inserted as a positioning screw and is placed so that the threads of both screws lock together. We believe that the interlocking of the threads of both screws and contact of the second screw with three cortices (two of the iliac bone and one of the sacrum) increase the stability of the fixation. Migration of loosened screws was measured on radiographs of the pelvis obtained at six weeks and at three, six and twelve months postoperatively. Migration of five millimetres or more within the first six weeks was considered to be clinically significant. Only patients after primary fracture treatment and with a complete one-year follow-up were included in the study. Cases of non-union and failure of osteosynthesis of the anterior pelvic arch and patients with incomplete follow-up were excluded. The incidence of significant screw migration between the two techniques was compared using Fisher's exact test with a 5% level of significance. RESULTS Sixty-three patients (23 women, 40 men) aged 17 to 79 years were included in the study. Parallel screws were used in 24 patients (8 women, 16 men) and convergent screws were used in 39 patients (15 women, 24 men). Clinically significant migration occurred in nine (38%) patients after parallel insertions. In two of these cases there was unstable fixation of the anterior pelvic arch. Migration of convergently placed iliosacral screws occurred in four (10%) cases. In three of these cases this was due to unstable fixation of the anterior pelvic arch. The difference in screw migration between the two groups was shown to be significant (p = 0.0219). DISCUSSION Iliosacral screws ensure sufficient stability of the posterior arch in type B and C pelvic fractures provided that the anterior pelvic arch is stable. Convergent insertion of iliosacral screws may increase the stability of fixation. Minimally invasive surgery with sufficient stability may be advantageous for early treatment of patients after multiple trauma and in elderly patients. The weaknesses of this study are its relatively small number of patients, which prevented reliable statistical analysis of screw migration according to the type of pelvic fractures. The second main limitation is the failure to perform densitometric examination of the skeleton in patients with X-ray proven screw migration for confirmation of osteoporosis as one of the possible causes of fixation failure. CONCLUSIONS The results of the study suggest that convergent insertion of iliosacral screws into S1 is associated with a lower risk of screw migration and subsequent failure of fixation of the posterior pelvic arch. Key words: pelvic fracture, pelvic injury, iliosacral screw, parallel screws, convergent screws, migration of iliosacral screws.

Enhanced recovery after surgery and mini-invasive approaches in rectal cancer surgery - short-term outcomes

INTRODUCTION

The aim of this study was to evaluate short-term outcomes of patients undergoing mini-invasive rectal resection within an ERAS (enhanced recovery after surgery) protocol.

METHODS

A prospectively managed database of patients undergoing rectal operations performed at our department between January 2015 and April 2020 was retrospectively analyzed. An ERAS protocol was implemented into clinical practice at our department in April 2016 and mini-invasive rectal procedures in May 2016. The ERAS group consisted of all patients who underwent mini-invasive rectal resections or amputations within the ERAS protocol. The control group consisted of patients who underwent open procedures and received standard perioperative care. The extracted data included basic patient characteristics, surgical data, postoperative recovery parameters, 30-day morbidity, length of postoperative stay and 30-day rehospitalization.

RESULTS

A total of 110 patients were included in the study: 67 patients in the ERAS group and 43 in the control group. Within the ERAS group 47 patients underwent robotic procedures and 20 had laparoscopic procedures. Patients in the ERAS group had significantly better clinical and laboratory recovery parameters except for postoperative nausea and vomiting. A significantly lower incidence of paralytic ileus (20.9% vs. 3%) and a shorter length of postoperative stay (13 days vs. 9 days) was found in the ERAS group. The rehospitalization rate and 30-day morbidity were not different between the ERAS and control group.

CONCLUSIONS

Implementation of the ERAS protocol in combination with mini-invasive approaches leads to better short-term postoperative outcomes after rectal surgery.

Changes in Nutritional and Functional Status in Longer Stay Patients Admitted to a Geriatric Evaluation and Management Unit

OBJECTIVES

Malnutrition and functional decline are common in older inpatients admitted to subacute care settings. However the association between changes in nutritional status and relevant functional outcomes remains under-researched. This study examined changes in nutritional status, function and mobility in patients admitted to a Geriatric Evaluation and Management (GEM) unit who had a length of stay (LOS) longer than 21 days.

DESIGN

A prospective, observational study.

SETTING

Two GEM units at St Vincent's Hospital Melbourne, Australia.

PARTICIPANTS

Patients admitted to the GEM units who stayed longer than 21 days were included in the study.

MEASUREMENTS

Patients were assessed on admission and prior to discharge using the Subjective Global Assessment (SGA), Functional Independence Measure (FIM) motor domain and the Modified Elderly Mobility Scale (MEMS).

RESULTS

Fifty-nine patients (Mean age 84.0 ± 7 years) met the required length of stay and were included in the study. Fifty-four per cent (n=32) were malnourished on admission (SGA B/C) and 44% (n=26) were malnourished on discharge. Twenty-two per cent (n=13) improved SGA category, 75% remained stable (n=44) and 3% deteriorated (n=2) from admission to discharge. Total Motor FIM scores significantly increased from admission to discharge in both the improved (p<0.001) and stable or deteriorated (p<0.001) nutritional status groups. Subjects who improved in nutritional status had a significantly higher MEMS score at discharge (p<0.001).

CONCLUSION

On admission to the GEM unit, just over half the included patients were rated as malnourished defined by SGA category. Nearly one quarter of the sample had improved their nutritional status at the time of discharge. Improvement in nutritional status was associated with greater improvement in mobility scores. Further studies are required to investigate the effectiveness of nutrition interventions, which will inform models of care aiming to optimise nutritional, functional, and associated clinical outcomes in patients admitted to GEM units.

Raman Characterization of Nitrogen Doped Multiwalled Carbon Nanotubes

N-type multi-walled nanotubes were synthesized by nitrogen doping using pyridine and pyridine-melamine mixtures in chemical vapor deposition, and their donor states were verified by Scanning Tunneling Spectroscopy. Tunneling Electron Microscopy reveals small amounts of residual catalyst and Scanning Electron Microscopy show well aligned mats of the Nitrogen doped nanotubes. Nitrogen is present in the lattice of these MWNTs as pyridine structures and CNx structures. Raman scattering measurements were performed as a function of increasing growth temperature and the results compared to previously studied boron doped multiwalled nanotubes.

Dysphagia lusoria: a case study

Dysphagia lusoria is described in the literature as difficulty swallowing because of a "jest of nature." The "jest of nature" is a birth defect encompassing any aortic root vascular anomaly that causes esophageal dysphagia. Persons with dysphagia lusoria can be categorized according to their specific subclavian anomaly (ie, depending on the presence of an aneurysm, occlusive disease, or esophageal compression). All patients with this anomaly have an aberrant subclavian artery in a transposed position that courses posterior to the esophagus. The operative approach to repair this condition has been controversial. An extrathoracic approach is documented as superior to a repair involving thoracotomy because there is decreased rate of complications that may be associated with a thoracotomy and greater visibility of the subclavian and carotid artery. This case study describes a 25-year-old woman with dysphagia lusoria related to an aberrant right subclavian artery. The report includes a literature review and describes the perioperative approach and nursing care. The use of the preadmission and same-day admission services are supported as is an extrathoracic surgical approach. At follow-up this patient reported no symptoms of dysphagia and showed no evidence of esophageal compression confirming that persons with symptomatic dysphagia lusoria can be managed with positive long-term results.

Raman scattering as a characterization tool for epitaxial GaN thin films grown on sapphire by turbo disk metal-organic chemical vapor deposition

Thin layers of GaN, a few micrometers thick, grown on sapphire substrate, are the basic structure in the rapidly developing GaN-based blue optoelectronics devices. We are looking for nondestructive, effective, and convenient characterization tools for GaN/sapphire. Ordinary Raman scattering measurements have limited use because strong Raman signals from the sapphire substrate overwhelm the GaN Raman features. We describe two techniques for making commercial laser Raman systems serve as convenient characterization tools for GaN/sapphire. One uses a near right-angle laser beam incidence, and the other uses microscope lens focusing. In these two ways the detected GaN Raman signals are much stronger than sapphire features, and correct assignments can be made quickly.

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The Interaction of Various Ligands with Halogen-Bridged Anionic Complexes of Bivalent Platinum and Palladium

The interaction of various unidentate ligands (L) with the halogen-bridged anionic complexes [NEt4]2[M2X6] (M=Pt,Pd; X=Br, I) has been investigated in acetone solution. Compounds of the type [NEt4][MLX3] were isolated in a number of instances when M=Pt, but in only one instance when M=Pd.