Commissioning and quality assurance of HalcyonTM 2.0 linear accelerator.

BACKGROUND: Varian Medical Systems has introduced a new medical linear accelerator called HalcyonTM 2.0, which is based on the ring delivery system (RDS). It is a true IGRT machine having 6MV FFF photon energy. In addition to the planar and MV-CBCT imaging techniques it also has an option of ultra-fast kV-iCBCT which enhances the image reconstruction and improves the visualization of soft tissue. The field portals are shaped by a unique dual layer MLC with special stacked and staggered design which enables high modulation with low radiation leakage. Recently, we have commissioned our first Halcyon 2.0 machine. The aim of this work was to systematically investigate various parameters of a newly installed HalcyonTM 2.0 linear accelerator. MATERIALS AND METHODS: Detailed measurements were conducted as per various guidelines. Also, the measurements were performed to fulfil the national regulatory requirements. Commissioning data of Halcyon 6 MV-FFF beam was performed in a water tank. For absolute measurements, a 0.6-cc waterproof Farmer chamber and electrometer were used. All relative measurements (PDDs, in-line, cross-line and angular profiles) were performed with 0.0125 cc point chamber. RESULTS: All the tests were within the acceptable limit. Measured data were compared with factory data as well as the existing medical linear accelerator of the same category. The obtained results were quite satisfactory. CONCLUSIONS: This study summarizes the commissioning experience with Halcyon linear accelerator. Evaluation of mechanical, radiation safety and dosimetric parameters were performed. The obtained parameters were well below the specified tolerance limits.

Risk factors for early mortality in patients with pulmonary tuberculosis admitted to the emergency room.

BACKGROUND AND OBJECTIVES: Mortality of patients with pulmonary tuberculosis (TB) admitted to emergency departments is high. This study was aimed at analysing the risk factors associated with early mortality and designing a risk score based on simple parameters. METHODS: This prospective case-control study enrolled patients admitted to the emergency department of a referral TB hospital. Clinical, radiological, biochemical and microbiological risk factors associated with death were compared among patients dying within one week from admission (cases) and those surviving (controls). RESULTS: Forty-nine of 250 patients (19.6%) experienced early mortality. Multiple logistic regression analysis showed that oxygen saturation (SaO2) ≤90%, severe malnutrition, tachypnoea, tachycardia, hypotension, advanced disease at chest radiography, severe anaemia, hyponatremia, hypoproteinemia and hypercapnia were independently and significantly associated with early mortality. A clinical scoring system was further designed to stratify the risk of death by selecting five simple parameters (SpO2 ≤ 90%, tachypnoea, hypotension, advanced disease at chest radiography and tachycardia). This model predicted early mortality with a positive predictive value of 94.88% and a negative predictive value of 19.90%. CONCLUSIONS: The scoring system based on simple parameters may help to refer severely ill patients early to a higher level to reduce mortality, improve success rates, minimise the need for pulmonary rehabilitation and prevent post-treatment sequelae.

Endoscopic pilonidal abscess treatment: a novel approach for the treatment of pilonidal abscess.

INTRODUCTION Pilonidal abscess is a common surgical emergency. Conventional treatment with incision and drainage is associated with significant postoperative morbidity. We report our initial experience of using minimally invasive endoscopic technique for the treatment of pilonidal abscesses, referred to as endoscopic pilonidal abscess treatment (EPAT). MATERIALS AND METHODS A prospective database of all patients undergoing EPAT between January 2015 and March 2016 at Whiston Hospital was maintained. Data regarding patient demographics, peroperative variables and postoperative follow-up were recorded. RESULTS Nineteen patients were included, male to female ratio was 53 : 47 and median age of the cohort was 24 years (interquartile range 22-25 years). EPAT was the primary procedure for 10 patients and 9 had EPAT for recurrent pilonidal abscesses. There were no readmissions and none needed further surgery within 6 weeks of having the procedure. In all patients, complete wound healing was achieved within 6 weeks; all reported minimal postoperative pain (median postoperative visual analogue scale score 1) and immediate return to the activities of daily life. Four of the nineteen patients (21%) required definitive intervention for pilonidal disease in the follow-up period. CONCLUSIONS EPAT is a novel, minimally invasive technique for the treatment of acute pilonidal abscesses. It is safe, associated with reduced postoperative morbidity, recurrence rate and quick wound healing. Initial encouraging results require further investigations on a larger group of patients in a multicentre setting.

Is dual-phase abdominal CT necessary for the optimal detection of metastases from renal cell carcinoma?

AIM: To determine whether dual-phase abdominal computed tomography (CT) detected more metastases than portal-phase CT alone in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: Audit committee approval was obtained. A retrospective audit was undertaken in 100 patients who underwent both arterial and portal phase CT. The CT images were independently reviewed by two consultant radiologists. The presence of metastases in the liver, pancreas, and contralateral kidney were recorded for each phase of contrast enhancement. RESULTS: Metastases were identified in the liver in 27 patients, pancreas in 12, and contralateral kidney in 23 patients. Nine of the 27 (33%) liver metastases, three of the 12 (25%) pancreatic metastases, and two of the 23 (9%) renal metastases were only detected in the arterial phase, whilst four of the 27 (15%) liver metastases, three of the 12 (25%) pancreatic metastases, and two of the 23 (9%) renal metastases were only detected in the portal phase. Nine patients (9%) had metastases only visualized in the arterial phase, and six (6%) only in the portal phase. Detection of metastases only visible in the arterial phase led to a change of management in two patients (2%). CONCLUSION: The audit results support our current standard of dual-phase abdominal CT for optimal detection of RCC metastases.

Anti-microbial resistance stratified by risk factor among Escherichia coli strains isolated from the urinary tract at a rural clinic in Central India.

BACKGROUND: The failure of empirical therapy is frequently observed, even in community-acquired urinary tract infections. We, therefore, conducted a prospective, clinic-based study in 2004-2005 to document anti-microbial resistance rates and correlate them with possible risk factors to assist empirical decision-making. MATERIALS AND METHODS: Symptomatic patients with pyuria underwent urine culture. Isolates were identified using standard methods and anti-microbial resistance was determined by disk-diffusion. Ultrasonography was used to detect complicating factors. Patients were stratified by the presence of complicating factors and history of invasive procedures for comparison of resistance rates. STATISTICAL METHOD USED: Chi-square or Fisher exact tests, as appropriate. RESULTS: There were 156 E. coli isolates, of which 105 were community-acquired. Twenty-three community-acquired isolates were from patients with complicating factors while 82 were from patients without any. Fifty-one isolates were from patients who had recently undergone invasive procedures on the urinary tract. Thirty-two community-acquired isolates from reproductive-age women without apparent complicating factors had resistance rates of 50% or above against tetracyclines, Co-trimoxazole, aminopenicillins, Nalidixic acid, Ciprofloxacin and 1 st generation cephalosporins. Resistance rates were significantly higher among isolates from patients subjected to invasive procedures, except against Co-trimoxazole, tetracyclines and Amikacin. CONCLUSION: High rates of anti-microbial resistance in community-acquired uropathogens have made antimicrobial sensitivity testing necessary even in a rural, primary-care setting.

Canalplasty for severe external auditory meatus exostoses.

Exostoses of the external auditory meatus is a well known condition which infrequently requires surgical correction. However, the stenosis caused by severe exostosis can affect quality of life considerably and may require surgical intervention. Canalplasty, in such a situation, is a valid and effective management option. In our series the commonest indication for surgery was recurrent otitis externa. The detailed surgical technique is described and a retrospective analysis of 65 such procedures is presented. There were only two significant complications, both post-operative stenosis, requiring further corrective surgery. In conclusion, canalplasty for the exostosis of the external auditory meatus is a safe surgical option.

Glomus tympanicum tumour: an alternative surgical technique.

Glomus tympanicum tumour is one of the commonest neoplasms of the middle ear. It is more common in females. The most common presenting symptom is pulsatile tinnitus. A retrotympanic mass is found in the middle ear in all the cases. Computed tomography (CT) scan is the investigation of choice, however in difficult cases magnetic resonance imaging (MRI) can be helpful. Surgery is regarded as the gold standard of treatment in spite of the fact that radiation therapy has also been advocated in the literature. In this series 17 cases of glomus tympanicum treated at Gruppo Otologico Piacenza - Rome (Italy) were analysed retrospectively. A simple and safe technique has been described. All the cases were female and treated by surgery. The tumour was removed completely in all the cases and the ossicular chain kept intact. Recurrence was encountered in only one case after nine years. Surgical removal of the tumour is recommended as the treatment of choice with the following advantages: complete removal, a low complication rate, a low recurrence rate, acceptable hearing level and minimum morbidity.

Technique to prevent post-operative CSF leak in the translabyrinthine excision of vestibular schwannoma.

Cerebrospinal fluid (CSF) leak following VS removal is a challenging complication. With experience, it can be seen that anatomical factors such as the extent of pneumatization of the petrous temporal bone and posterior wall of the internal auditory canal play an important role in contributing to CSF leak. Nevertheless, the risk of post-operative CSF leak remains a major concern for both the surgeon and patient. This paper describes a technique, which we have used since 1994, and which has helped us to achieve the lowest reported rate of post-operative CSF leak in translabyrinthine excision of vestibular schwannoma in the world literature.

Is axillary temperature an appropriate surrogate for core temperature?

The ideal technique for measuring temperature should be rapid, painless, reproducible and accurately reflect the core temperature. While axillary temperature is commonly used because of convenience and safety, there are conflicting reports about its accuracy. To determine whether axillary temperature can act as a surrogate for oral/rectal temperatures, a prospective comparative study was conducted. The axillary and rectal temperatures (Group 1: infants < 1 year age) and axillary and oral temperatures (Group 2: children 6-14 years age) were compared using mercury-in-glass thermometers. Various tests of agreement were applied to the data obtained. Rectal and axillary temperatures for infants agreed well; the mean difference (95% limits of agreement) between the two being 0.6 degree C (-0.3 degree C, 1.4 degrees C). Similarly, the mean difference (95% limits of agreement) between oral and axillary measurements for children aged 6-14 years was observed to be 0.6 degree C (-0.4 degree C, 1.4 degrees C). Axillary temperature appears to be an acceptable alternative to rectal/oral temperature measurements in children.

Granular acute lymphoblastic leukemia with hypereosinophilic syndrome.

A four-year-old boy presented with marked peripheral blood eosinophilia (absolute eosinophil count of 54 x 10(9)/1), features of hypereosinophilic syndrome, and acute lymphoblastic leukemia (ALL-L2), the latter characterized by the presence of granular blasts. Blasts were negative for myeloperoxidase, non-specific esterase, acid phosphatase, periodic-acid Schiff stain, and toluidine blue. They exhibited an early pre-B immunophenotype (TdT, CD19, CD10, CD20 and CD22 positive) and stained negative for T (CD7, CD2, CD5 and CD3) and myeloid markers (MPO, CD33 and CD13). Chromosomal analysis revealed a normal karyotype. To the best of our knowledge, this case represents the first report of the coexistence of granular ALL and hypereosinophilic syndrome.

Neutropenic enterocolitis in children with acute lymphoblastic leukemia.

Neutropenic enterocolitis is an acute, life-threatening inflammation of the small and large bowel, often seen in children with malignancies during periods of prolonged or severe neutropenia. During the period 1990-1995, 180 children were treated at the authors' center for acute lymphoblastic leukemia using a standard chemotherapy protocol. Among them, 11 children (6.1%) aged 4 to 12 years, were diagnosed clinically to have neutropenic enterocolitis. Eight had severe neutropenia (absolute neutrophil count < 10(8)/L and 5 had prolonged neutropenia (> 7 days duration). The symptoms included diffuse abdominal pain (10 children), oral mucositis (7), hematochezia (7), diarrhea (6), hematemesis (5), and right lower quadrant tenderness (4). Three children had radiological evidence of free intraperitoneal gas and an additional 3 children were found on surgical exploration to have cecal perforation. Laparotomy was performed on 8 children (73%), 4 of whom survived. Among the 3 children managed conservatively, 1 died awaiting surgical exploration, while the other 2 did well. The overall survival was 55%. The authors recommend an approach to management that respects the heterogeneity of the disease.

Dengue haemorrhagic fever in children in the 1996 Delhi epidemic.

An epidemic of dengue haemorrhagic fever (DHF) occurred in Delhi in 1996. A total of 240 children between the age of 4 months to 13 years of either sex, admitted in one hospital, were evaluated. Two hundred and sixteen (90%) children were from Delhi. A clinical diagnosis of dengue fever (DF) was made in 25 (10%), dengue fever with unusual bleeding (DFB) in 22 (9%), DHF in 80 (33%) and dengue shock syndrome (DSS) in 113 (47%) of the children strictly according to the WHO classification. The age peaked at 8 years. There was no association between various grades of severity of illness and age-groups though girls suffered from more severe illness. No association between severity of malnutrition and severity of illness was observed. Tourniquet test was positive in 40% with DF, 18% with DFB, 62% with DHF and 64% with DSS. In DSS haematemesis was present in 55 (49%), epistaxis in 39 (35%), melaena in 27 (24%) and ecchymosis in 34 (30%) patients. Children diagnosed as DFB had haematemesis and epistaxis in 12 (55%) and 10 (45%) respectively. Intravenous fluid requirement was clearly less in DFB patients than in DHF/DSS patients. Unusual clinical features in the form of jaundice were present in 7 (6%), hepatic encephalopathy in 6 (5%) and dengue encephalopathy in 6 (5%) patients. Dengue 2 virus was isolated from 10 of the 50 patients for whom viral culture was done on C6/36 clone of Aedes albopictus cell line. Eighteen patients suffering from DSS died giving an overall case fatality of 7.5%. The mortality rate in DHF/DSS was 9.3%. It is further suggested that DFB is a distinct entity. Most patients could be classified by the WHO classification if a retrospective packed cell volume was used to assess haemoconcentration. We suggest that development of area-specific criteria for diagnosis and management is desirable.