Lung Cancer in the Non-smoker: A Patient View Focused on the Hopes and Challenges Facing the Non-smoker Population.

A patient view paper focused on hopes and challenges facing the never smoker lung cancer population - from lived experience, unexpected diagnosis, treatment and subsequent immersion in lung cancer research and patient advocacy over many years, citing examples, references and events organised to explore the subject by UK research institutions. MATERIAL/METHODS: Based on lived experience, invited patient perspective conference presentations including National Cancer Research Institute (NCRI) never smoker lung cancer research strategy event opening presentation and subsequent article, includes references to relevant papers/findings and points raised during research events/group discussions, alongside personal experiences and beliefs. RESULTS: Discussions with clinicians, events, surveys, meetings and virtual discussions all revealed a dearth of evidence available to identify the best way to deal with this patient cohort at almost every aspect of their experience - from missed/late diagnosis, to screening potential (non-existent), mutation driven treatments (what about those ineligible?), and psychosocial/psychological aspects given their different life stage from older traditional lung cancer patients. CONCLUSION: More effort and focus are needed to better understand what is driving these cases, how best to detect them sooner and respond/refer to treatments as well as developing screening methods alongside increased public and healthcare professional awareness raising and tools to support clinicians in earlier detection.

Credibility assessment of patient-specific biomechanical models to investigate proximal junctional failure in clinical cases with adult spine deformity using ASME V&V40 standard.

Computational models are increasingly used to assess spine biomechanics and support surgical planning. However, varying levels of model verification and validation, along with characterization of uncertainty effects limit the level of confidence in their predictive potential. The objective was to assess the credibility of an adult spine deformity instrumentation model for proximal junction failure (PJF) analysis using the ASME V&V40:2018 framework. To assess model applicability, the surgery, erected posture, and flexion movement of actual clinical cases were simulated. The loads corresponding to PJF indicators for a group of asymptomatic patients and a group of PJF patients were compared. Model consistency was demonstrated by finding PJF indicators significantly higher for the simulated PJF vs. asymptomatic patients. A detailed sensitivity analysis and uncertainty quantification were performed to further establish the model credibility.

Intra-articular stabilisation of the equine cricoarytenoid joint.

REASONS FOR PERFORMING STUDY: The success of laryngoplasty is limited by abduction loss in the early post operative period. OBJECTIVE: To determine the efficacy of polymethylmethacrylate (PMMA) in stabilising the cricoarytenoid joint (CAJ) and reducing the force on the laryngoplasty suture. HYPOTHESIS: Injection into the cricoarytenoid joint resists the forces produced by physiological laryngeal air flows and pressures thereby reducing the force experienced by the laryngoplasty suture. METHODS: Ten cadaver larynges were collected at necropsy and PMMA was injected into one CAJ at selected random. Each larynx was subjected to physiological conditions with with constant (static) or cycling (dynamic) flow. The specimens were tested sequentially in each of 4 conditions: 1) bilateral full abduction (Control 1); 2) transection of the suture on the side without PMMA; 3) bilateral abduction achieved by replacing the suture (Control 2); and 4) cutting the suture on the PMMA side. Tracheal pressure and flow and pressure in the flow chamber were recorded using pressure and flow transducers. The strain experienced by each suture during bilateral abduction (Controls 1 and 2) was measured. Statistical comparison of the 4 conditions was performed using a mixed effect model with Tukey's post hoc test for multiple comparisons. The strain gauge data were analysed by paired comparison of the regression slopes. RESULTS: In the static and dynamic states, tracheal pressure increased and tracheal flow decreased when the suture on the non-cement side was cut (P < 0.05). There was no significant difference in any outcome measure between PMMA injected into the CAJ and bilaterally abducted specimens (Controls 1 and 2) for either condition. The rate of increase in strain with increasing translaryngeal pressure was significantly less on the suture with PMMA placed in the CAJ (P = 0.03). CONCLUSIONS: These data provide strong evidence that injecting PMMA into the CAJ resists the collapsing effect of physiological airflows and pressures in vitro and reduces the force experienced by the laryngoplasty suture during maximal abduction. POTENTIAL RELEVANCE: Augmentation of prosthetic laryngoplasty with this technique may reduce arytenoid abduction loss in the early post operative period.

Merkel cell (neuroendocrine) carcinoma of the anal canal: report of a case.

Merkel cell tumors are rare neuroendocrine tumors typically found on sun-exposed areas such as extremities. We describe the case of a 42-year-old female with a Merkel cell tumor arising in the anal canal. The tumor was initially thought to represent a hemorrhoid arising during pregnancy and was excised locally after confirmation of extensive metastatic disease. The patient died 13 months after diagnosis with extensive metastatic disease involving the liver. In our search of the world literature there are several reports of neuroendocrine tumors in the rectum; however, no cases of documented Merkel cell tumors arising in the anal canal have been reported. These tumors seem to behave in a very aggressive manner when found in other atypical areas. The presentation symptoms were perianal discomfort and bleeding. Local excision may be the only surgical treatment necessary to control symptoms, given the propensity to early metastases and short life expectancy.

Dose to radiation therapists from activation at high-energy accelerators used for conventional and intensity-modulated radiation therapy.

The increased beam-on times which characterize intensity-modulated radiation therapy (IMRT) could lead to an increase in the dose received by radiation therapists due to induced activity. To examine this, gamma ray spectrometry was used to identify the major isotopes responsible for activation at a representative location in the treatment room of an 18 MV accelerator (Varian Clinac 21EX). These were found to be 28Al, 56Mn, and 24Na. The decay of the dose rate measured at this location following irradiation was analyzed in terms of the known half-lives to yield saturation dose rates of 9.6, 12.4, and 6.2 microSv/h, respectively. A formalism was developed to estimate activation dose (microSv/week) due to successive patient irradiation cycles, characterized by the number of 18 MV fractions per week, F, the number of MU per fraction, M, the in-room time between fractions, td (min), and the treatment delivery time t'r (min). The results are represented by the sum of two formulas, one for the dose from 28Al 1.8 x 10(-3) F M (1-e(-03t'(r))/t'r and one for the dose from the other isotopes approximately 1.1 x 10(-6) F(1.7) Mt(d). For conventional therapy doses are about 60 microSv/week for an 18 MV workload of 60,000 MU/week. Irradiation for QA purposes can significantly increase the dose. For IMRT as currently practiced, lengthy treatment delivery times limit the number of fractions that can be delivered per week and hence limit the dose to values similar to those in conventional therapy. However for an IMRT regime designed to maximize patient throughput, doses up to 330 microSv/week could be expected. To reduce dose it is recommended that IMRT treatments should be delivered at energies lower than 18 MV, that in multienergy IMRT, high-energy treatments should be scheduled in the latter part of the day, and that equipment manufacturers should strive to minimize activation in the design of high-energy accelerators.

Selection of patients for resection of hepatic metastases: improved detection of extrahepatic disease with FDG pet.

A rapidly emerging clinical application of positron emission tomography (PET) is the detection of tumor tissue at whole-body studies performed with the glucose analogue 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). High rates of recurrence after partial hepatic resection in patients with colorectal cancer liver metastases indicate that current presurgical imaging strategies are failing to show extrahepatic tumor deposits. Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the lungs, it is particularly useful for identification and characterization of extrahepatic disease. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Several sources of benign and physiologic increased activity at FDG PET emphasize the need for careful correlation with findings of other imaging studies and clinical findings. FDG PET can improve the selection of patients for partial hepatic resection and thereby reduce the morbidity and mortality associated with inappropriate surgery.

Value of double-contrast barium enema performed immediately after incomplete colonoscopy.

OBJECTIVE: The purpose of this study was to evaluate the ease, completeness, and clinical utility of double-contrast barium enema (DCBE) performed immediately after incomplete colonoscopy. SUBJECTS AND METHODS: During a 30-month period, a prospective study was performed in 103 patients (79 women, 24 men) to determine the ease and completeness of DCBE immediately after failed colonoscopy and any additional useful information provided by the enema. The ease with which DCBE was performed was graded from 1 (easy) to 10 (difficult). RESULTS: DCBE revealed the entire colon in 97 patients (94%). Incomplete DCBE was a result of obstruction and incontinence in three patients each. The mean score for ease of performing DCBE was 5.0. In 14 patients (14%), significant additional diagnostic information was provided by the immediate DCBE. In eight patients, abnormalities were identified on DCBE that had not been seen at colonoscopy (five malignant neoplasms, one diverticular mass, two extrinsic masses, and multiple strictures). In four patients, a suspected colonoscopic abnormality was excluded with DCBE findings; and in two patients, a colonoscopic abnormality was further characterized with DCBE. CONCLUSION: Immediate DCBE after incomplete colonoscopy allows complete colonic evaluation in most cases, often adds vital diagnostic information, and eliminates repeated bowel preparation and unnecessary delay in diagnosis.

Detection of unsuspected colonic abnormalities using the pneumocolon technique during small bowel meal examination.

AIMS: The pneumocolon technique in small bowel meal examination is used to obtain double-contrast views of the distal ileum. The purpose of this study was to determine the proportion of cases in which an overhead pneumocolon radiograph demonstrated clinically relevant findings in the colon. METHODS: The overhead pneumocolon radiographs in 151 patients who underwent small bowel meals were evaluated retrospectively. A chart review was performed on those patients with positive colonic findings to determine if the suspected abnormalities affected patient management. RESULTS: Colonic abnormalities were identified in 34 of the 151 patients. One patient had a previously undiagnosed ascending colonic cancer; 17 had evidence of acute or chronic colitis; 13 had diverticulosis; one had a caecal polyp; one had an ileosigmoid fistula; one had a filling defect in the ascending colon. In 25 cases the colonic abnormality was visible only on the pneumocolon radiograph and not on the preceding single-contrast images. Management was altered by the colonic findings in seven cases. False-positive findings occurred in two cases. CONCLUSIONS: A routine overhead radiograph following use of the pneumocolon technique is a useful adjunct to small bowel meal examination as it can yield unsuspected and clinically significant colonic findings.Chou, S. (2000). Clinical Radiology55, 459-464.

Intraarterial catheter-directed thrombolysis: urokinase versus tissue plasminogen activator.

The purpose of this study was to evaluate the differences between tissue plasminogen activator (TPA) and urokinase (UK) in the management of ischemic limbs. A total of 58 limbs (24 in the TPA group and 34 in the UK group) in 53 patients were studied prospectively. The two groups were based on the surgeon's preference for lytic agent. The dose regimen for UK was 150,000 IU/hr over 1/2 to 2 hr followed by a continuous infusion of 50,000 IU/hr. TPA was given as a 5-mg bolus followed by 1 mg/hr. Both groups received heparin at a rate of 400 IU/hr through the side arm of the arterial sheath. There was no significant difference in efficacy between UK and TPA, but TPA acted faster and had a higher incidence of bleeding complications.

Detective quantum efficiency of an amorphous selenium detector to megavoltage radiation.

The spatial frequency dependent detective quantum efficiency (DQE(f)) of a high-resolution selenium-based imaging system has been measured at megavoltage energies. These results have been compared with theoretical calculations. The imaging system was a video tube with a 5 microm amorphous selenium (a-Se) target which was irradiated by 1.25 MeV gamma-rays. The modulation transfer function (MTF) decreased rapidly with spatial frequency (determined by spread of electrons in the build-up material) while the noise power spectrum was constant as a function of spatial frequency. The DQE obtained from these MTF and noise power measurements was compared with a Monte Carlo model of the pulse height spectrum of the detector. The DQE(0) model accounted for the interaction of x rays with the detector as well as the energy-dependent gain (charge generated/energy deposition). Good agreement between the calculated and measured DQE(0) was found. The model was also used to estimate the DQE(f) of a metal plate + a-Se detector which was compared with a metal plate + phosphor system of the same mass thickness. The DQE(f) s of both detectors are very similar, indicating that the choice of which detector is better will be based upon criteria other than DQE(f), such as read-out approach, ease of manufacture or sensitivity.

Sensitivity of amorphous selenium to x rays from 40 kVp to 18 MV: measurements and implications for portal imaging.

Recently, the clinical application of electronic portal imaging devices has enabled more frequent verification of patient setup for radiation treatment. However, the image quality has sometimes proven to be inadequate, motivating the investigation of alternative sensors with better image quality. Amorphous selenium (a-Se) is potentially one such sensor since the electrostatic image formation process has high resolution. To fully evaluate the potential of a-Se for portal imaging, it is necessary to investigate all the imaging properties at high x-ray energies. Here, measurements of the sensitivity of a-Se to incident x-ray spectra ranging in energy from 40 kVp to 18 MV and for a-Se thicknesses ranging from approximately 10 to 300 microns under full buildup conditions are described. When x rays or energetic electrons deposit energy in a photoconductor with an applied electric field, F, electrons and holes are released. The x-ray conversion sensitivity may be defined as 1/W +/-, where W +/- is the energy required to release an electron-hole pair. Consistent with the results of previous investigators, W +/- is found to vary approximately with F-2/3. Unexpectedly, over the energy range of 40 kVp to 18 MV, W +/- was found to decrease by a factor of nearly 3. These dependencies are compared to the predictions of two competing charge recombination models, geminate and columnar. The results are explained by a microdosimetric model in which the sensitivity at megavoltage energies is governed by geminate recombination, but at lower energies, both mechanisms are involved. Thus, the sensitivity of a-Se to x rays spanning the diagnostic and radiotherapy range has been measured and the physical basis for this behavior established.

A prospective blinded randomized trial comparing oral sodium phosphate and polyethylene glycol solutions for bowel preparation prior to barium enema.

PURPOSE: A prospective blinded randomized trial to compare oral sodium phosphate (NaP) solution with polyethylene glycol (PEG) preparations as bowel preparation prior to barium enema examination. PATIENTS AND METHODS: One hundred and ten patients consented to take part and each patient was randomly assigned to receive either NaP (Oral Fleet Prep) or PEG (Lyteprep). The barium enemas were reviewed by two radiologists blinded to the type of bowel preparation the patient had received. The colon was divided into six segments and each segment was assessed for the amount of stool and water present, the adequacy of coating, the ability to exclude inflammatory bowel disease and the presence of polyps. A score of 0-3 (failure to good) was assigned per segment on each of these criteria. RESULTS: The average individual score for the NaP group was 89.2. The average individual score for the PEG group was 88.81. No significant difference was found in the quality of bowel cleansing between the two agents. In particular there was no significant difference in the scores for water retention (two-tailed P = 0.748) and the difference for the quality of coating was considered not quite significant (two-tailed P = 0.0818). CONCLUSION: Oral sodium phosphate cleans the colon as well as polyethylene glycol solutions. The use of NaP will result in significant cost savings and improved patient compliance.

Whipple's disease presenting with lung involvement.

A 31 year old man presented with nonspecific symptoms and a chest radiograph showing several pulmonary nodules which rapidly enlarged. Bronchoscopic examination showed endobronchial lesions, histological examination of which led to the diagnosis of Whipple's disease. The patient made a gradual recovery with prolonged antibiotic therapy and the pulmonary lesions reduced in size. This is the first reported case of Whipple's disease presenting with large pulmonary nodules and endobronchial lesions and is notable for the absence of gastrointestinal features.

Measurement of quantum noise in fluoroscopic systems for portal imaging.

In fluoroscopic portal imaging systems, a metal plate is bonded to a phosphor screen and together these act as the primary x-ray sensor. The light from the screen is collected and imaged by a lens on the target of a video camera. The demagnification (M) between the large area of the phosphor being imaged and the small active area of the video camera results in poor optical coupling between the screen and the video camera. Consequently x-ray quantum noise is small compared to other noise sources. By reducing the demagnification, the light from the screen is collected more efficiently, so we were able to increase the x-ray quantum noise relative to other noise sources and thus unambiguously identify it. The noise power spectrum was measured as a function of M to determine the relationship between the x-ray quantum noise. shot noise, and amplifier noise. It was found by extrapolation to clinical demagnifications that the amplifier noise dominates x-ray quantum noise, at all spatial frequencies, but the shot noise was less than the x-ray quantum noise at low spatial frequencies. For low spatial frequencies, this implies that a secondary quantum sink can be avoided. If amplifier noise could be sufficiently reduced, x-ray quantum limited images could be obtained in clinical systems at low spatial frequencies.

Mathematical modeling of water permeability of surgical fabrics for vascular use.

The purpose of this study was to derive new mathemtic formulae that could be used reliably to predict water permeability of surgical fabrics before they are made and tested for water permeability. Such a theoretical prediction of water permeability, Qprd, of surgical fabrics is needed for not only timely characterization but also for assisting in more efficient future design and development of better surgical fabrics. Two mathematic formulae, Qw and Qk, were derived from the Buckingham Pi Theorem, in which relevant fiber and fabric parameters were placed into dimensionless pi groups and computed for 25 commercial and experimental vascular fabrics. Linear regression analysis of the relationship between these pi groups with water permeability on the woven and knitted grafts yielded coefficients for the corresponding pi groups that were required for constructing appropriate mathematic formulae to predict water permeability of vascular fabrics. When proper sources of the experimentally determined water permeability, Qexp, were chosen for comparison, we found that 86% of woven fabrics (6 of 7) and 77% of knitted fabrics (14 of 18) had their Qprd within 10% of their Qexp. This high percentage of close matching (within 10%) between Qprd and Qexp should be considered satisfactory because the experimental error for obtaining Qexp is generally higher than 10%. The difference between Qprd and Qexp ranged from as small as 0.27% to as high as 74.2%, depending on the type of fabrics and source of Qexp.(ABSTRACT TRUNCATED AT 250 WORDS)

Colon cancer detection: an algorithm using endoscopy and barium enema.

A review of findings on flexible sigmoidoscopy (FS), colonoscopy and selected double-contrast barium enema (DCBE) radiographs from a group of 66 patients with rectal bleeding was performed to test the value of an algorithm in the detection of colonic cancers and polyps. In this algorithm the FS findings would direct patients either to colonoscopy or to a modified DCBE which focused attention on the colon proximal to the sigmoid. Only patients with neoplasms diagnosed by FS, or by MDCBE after negative FS, would proceed to colonoscopy. The study population contained four cancers, 11 polyps > 5 mm and 11 polyps < or = 5 mm; FS+MDCBE missed four polyps, all < 5 mm. For polyps > 5 mm and cancer, FS+MDCBE had a sensitivity of 100%, a specificity of 82%, a negative predictive value of 1.0 and a positive predictive value of 0.62. Using the algorithm, 24 patients (36%) would have required colonoscopy. The results suggest that FS+MDCBE is a potentially valuable method for screening patients for colonic neoplasia.

Morbidity after anterior cervical decompression and fusion. The influence of the donor site on recovery, and the results of a trial of surgibone compared to autologous bone.

The Cloward procedure is a routine approach to decompress and fuse the cervical spine. This paper looks at two aspects of the operation. Firstly the morbidity due to the hip wound is assessed, and alternatives to the use of autologous bone graft discussed. Secondly one Neurosurgical Unit's experience in the use of surgibone--an animal bone substitute harvested from steers and fashioned in dowels--is described. In this trial it was not found to be a satisfactory substitute to autologous bone.

Low-energy imaging with high-energy bremsstrahlung beams: analysis and scatter reduction.

The contrast and zero spatial frequency signal-to-noise ratio produced by a method for radiation therapy portal imaging known as low-energy imaging with high-energy bremsstrahlung beams have been mathematically analyzed. The analysis makes extensive use of Monte Carlo techniques and incorporates the detector, the spectrum, phantom, and geometry. The analysis is validated through comparison with measured data including subject contrast measurements and the attenuation of the beam with lead. Scatter reduction is found to be potentially the most effective method to improve contrast and SNR for a film based system. A large fraction of the scatter detected is of a much higher energy than that found in diagnostic radiology. Hence, traditional antiscatter grids, such as those used in diagnostic radiology, are ineffective. The analysis and theory from the literature are applied to design a new grid which is more appropriate for this application. The grid produces a modest improvement according to a contrast-detail study.