Precise imaging of the primary tumor, the drainage lymph nodes, and possible sites of distant metastases is mandatory to stage a malignant disease, arrive at a treatment recommendation, and ...eventually define an accurate gross tumor and clinical target volume for radiotherapy. Better target definition and delineation on a daily basis is surely important in quality assurance for fractionated radiation therapy. The availability of metabolic images obtained by magnetic resonance (MR) spectroscopy, positron emission tomography (PET), and others impacts on staging, treatment planning, and response monitoring. A broad range of techniques, including dynamic magnetic resonance imaging (MRI), PET, and single-photon emission computed tomography (SPECT), provide measurements of various features of tumor blood flow and microvasculature. Using PET to measure glucose consumption enables visualization of tumor metabolism, and MR spectroscopy techniques provide complementary information on energy metabolism. Changes in protein and DNA synthesis can be assessed through uptake of labeled amino acids and nucleosides. Advanced imaging techniques can be used to assess tumor malignancy, extent, and infiltration, and might provide diagnostic clues to distinguish between lesion types. For the detection of metastatic lymph nodes, lymphotropic nanoparticle-enhanced MRI using ultra-small superparamagnetic iron oxide particles has greater accuracy as compared with conventional techniques and has been instrumental in delineating the lymphatic drainage of the prostate gland. The focus of the present chapter is the impact of PET on radiation treatment planning.
Target volume definition is an interactive process. Based on radiological (and biological) imaging, the radiation oncologist has to outline the GTV, CTV, ITV, and PTV and BTV. In this process, a lot ...of medical and technological aspects have to be considered. The criteria for GTV, CTV, etc. definition are often not exactly standardised, and this leads, in many cases to variability between clinicians; however, exactly defined imaging criteria, imaging with high sensitivity and specificity for tumour tissue and special training could lead to a higher consensus in target volume delineation and, consequently, to lower differences between clinicians. It must be emphasised, however, that further verification studies and cost-benefit analyses are needed before biological target definition can become a stably integrated part of target volume definition.
The ICRU report 50 from 1993 and the ICRU report 62 from 1999 defining the anatomically based terms CTV, GTV and PTV must still be considered as the gold standard in radiation treatment planning; however, further advances in technology concerning signal resolution and development of new tracers with higher sensitivity and specificity will induce a shift of paradigms away from the anatomically based target volume definition towards biologically based treatment strategies. New concept and treatment strategies should be defined based on these new investigation methods, and the standards in radiation treatment planning — in a continuous, evolutionary process — will have to integrate new imaging methods in an attempt to finally achieve the ultimate goal of cancer cure.
Introduction:
Considering the tumor characteristics of the vestibular schwannoma (VS), physician and patient must decide among three major treatment options: radiotherapy (radiosurgery RS or ...stereotactic fractionated radiotherapy SFR), microsurgery, or observation. Based on the data of the literature and our own results, we will discuss the pro and con arguments for the use of RS and SFR in the management of VS.
Material and Methods:
Between 1998 and 2003, 71 patients with 72 VS were treated in our department using a LINAC-RS in 53 cases and SFR in 19 cases. The mean follow-up time was 24 months. RS was indicated in patients with maximal tumor diameter smaller than 1.5 cm and normal hearing function on the contralateral side. SFR was indicated in patients with maximal tumor diameter between 1.5 cm and 2.5 cm or in patients with lesions smaller than 1.5 cm but reduced hearing function on the contralateral side. The treatment was performed using an adapted Siemens-LINAC with 6 MeV photons and the BrainLAB system. In patients treated with RS, a total dose of 12 Gy on 100% isodose on the tumor margins was delivered in one session. In the group treated with SFR we delivered a total dose of 54 Gy in a single dose of 1.8 Gy, 5 fractions/week. The patients were followed for 6 weeks and every 6 months after the treatment by MRI, otolaryngological, and neurological investigations: pure tone audiogram, speech audiogram, vestibularis tests, and facial and trigeminal tests. The treatment results will be discussed in comparison to the data found in the literature.
Results:
Tumor control, defined as no tumor growth in the follow-up MRI, was 100% for the both groups of patients. One year after RS, hearing was worsening in 11/53 (21%) cases treated with RS and 4/19 (21%) patients treated with SFR. An improvement in hearing was registered in 4/53 (7%) patients treated with RS. One patient with serviceable hearing before RS became completely deaf 12 months after the treatment. One patient developed a transitory facial nerve paresis 12 months after RS. A new transitory trigeminal neuralgia was reported in 2/19 (10%) patients treated with SFR. Twelve trials incorporating 1212 patients reported a tumor control rate of 80 to 100% after RS. The rate of hearing loss was between 19% and 31% and of facial paresis 1.5 to 66.5%. In 9 studies incorporating 617 patients treated with SFR, tumor control rate was 92 to 100%, hearing loss after treatment 0 to 39%, and the rate of facial paresis 0 to 3%.
Conclusions:
The question of whether RS or SFR is more advantageous is open for discussion. Future studies will have to define criteria for one or the other treatment method. Radiobiological criteria, clinical outcome, and economical aspects must be taken into consideration.
Introduction:
To evaluate prospectively the clinical results in 121 patients with benign meningiomas treated with stereotactic fractionated radiotherapy (SFR). The gross tumor volume (GTV) was ...delineated using C11-Methionine-PET (MET-PET), CT, and MRI image fusion.
Material and Methods:
In the trial were included 121 patients with meningiomas (81 meningiomas located on the base of the skull) treated with SFR. The treatment was performed using a Siemens Mevatron linear accelerator with 6 MeV photons and the BrainLAB software and hardware system. The GTV was defined based on MET-PET/CT/MRI image fusion in 54 patients and using CT/MRI alone in 67 cases. For GTV delineation MET tumor uptake area on PET, contrast enhancement on MRI and bone changes on CT were considered. The total irradiation dose was 54 Gy (range: 50.4–55.8 Gy) in 1.8 Gy/fraction, 5×/week. Intensity-modulated stereotactic radiotherapy technique was used in 25 cases. MRI and neurological investigations were performed at follow-up 3 months after the end of the SFR and every 6 months. Forty-nine patients with tumors located on the base of the skull were prospectively investigated in the Ophtalmological Department (LMU) before and every 6 months after the treatment.
Results:
The mean follow-up time was 26 months (range: 6–84 months). In 78 patients (65%) the SFR was performed after surgical resection and in 43 cases (35%) the SFR was the first treatment option. In the operated patients a meningioma WHO I was diagnosed in 60 cases and a WHO II tumor in 18 patients. The tumor control rate, evaluated by follow-up MRI, was 96%. Local recurrences were registered in 5/121 patients. They underwent tumor resection. Visual acuity improved after SFR in 24% and got worse in 17%. Visual field showed improvement in 24% and deterioration in 2%. Visual evoked potentials got better in 16% and worse in 1%. Using MET-PET, tumor borders can be defined with a higher precision and, especially in the base of the skull, organs at risk can be spared.
Conclusions:
SFR is a safe treatment option in patients with benign meningiomas. MET-PET helps in GTV delineation, especially in lesions located in the base of the skull.
Vestibular schwannomas (VS) or acoustic neuromas are benign tumors arising from Schwann cells of the vestibular branch of the eighth cranial nerve. The tumor was first described 1910 by Henschen, who ...provided evidence that it originates from the Schwann cells. Nevertheless, the term acoustic neuroma was commonly used. The National Institute of Health decided in 1992 in a Consensus Development Conference: “The term vestibular schannoma is preferred over acoustic neuroma as these tumors are composed of Schwann cells and typically involve the vestibular rather than the acoustic division of the eighth cranial nerve.” Therefore, we will use the term of VS, although acoustic neuroma is still more common in the literature.
Abstract
BACKGROUND AND AIMS
To date, associations between kidney function and brain structural abnormalities have been described in several studies 1. Reports of renal function in relation to ...hippocampal atrophy have been scarce and the majority of studies have been focussed on older end-stage renal disease populations 2. Particularly, with the ageing process, the hippocampus has a greater propensity to atrophy than other cerebral structures.The purpose of this study was to evaluate the relationship between kidney function assessed by estimated glomerular filtration rate (eGFR) and the degrees of hippocampal atrophy among young and midlife adults.
METHOD
In this cross-sectional study, the risk factors for hippocampal atrophy were evaluated in a cohort of 219 non-diabetic chronic kidney disease (CKD) patients, age ≤ 55 years, who had undergone magnetic resonance imaging (MRI) of the brain. The eGFR was calculated using the CKD-EPI formula. Hippocampal volume (HV) was assessed in brain MRIs with the Scheltens’ Medial Temporal Atrophy score, including a 5-stage escalation—0: no atrophy, 1: only widening of choroid fissure, 2: also widening of the temporal horn of lateral ventricle, 3: moderate loss of HV (decrease in height) and 4: severe loss of HV 3.
RESULTS
In our group, the median and interquartile ranges (IQR) of age was 45 (14) years, 57.53% (126 patients) being males. The median eGFR was 100.6 (34.7) mL/min/1.73m2 and 46.75% (102 patients) presented with mild reduction in eGFR (eGFR between 60 to 89 mL/min/1.73m2). In univariable regression analysis, eGFR (R2 = 0.207, P < 0.001), arterial hypertension (R2 = 0.018, P = 0.045), dyslipidaemia (R2 = 0.044, P = 0.002), haematocrit (R2 = 0.021, P = 0.032), natrium levels (R2 = 0.018, P = 0.047), and potassium levels ( R2 = 0.019, P = 0.042) were associated with smaller HV. In multivariable regression analysis, eGFR odds ratio (OR), 0.95; 95% confidence interval (CI), 0.94–0.97; P < 0.001) and serum natrium (OR, 0.91; 95% CI, 0.83–0.98; P = 0.027) were significantly associated with hippocampal atrophy.
CONCLUSION
This cross-sectional study shows that mild decrease in eGFR is independently associated with hippocampal atrophy. Our results suggest that brain imaging tests should be routinely performed in patients with mild reduction of eGFR, as the hippocampal atrophy process appears to be due, in part, to the mild renal dysfunction itself.
Abstract
Background and Aims
Hypokalemia is associated with progression of chronic kidney disease (CKD), although the possible underlying mechanisms are not well established. Several observational ...studies showed that low or even low to normal serum potassium levels predict the decline of kidney function in the general population. However, this hypothesis has not been yet investigated in patients with reduced nephron number as are congenital single kidney (cSK) patients.
Our aim was to prospectively examine the association of plasma potassium with risk of rapid kidney function decline in a cSK patients’ cohort.
Method
A cohort of 67 consecutive patients with cSK (mean age = 44.4+/-15.7 years; males 29p (43.28%)), with a mean estimated glomerular filtration rate (eGFR) = 65.2+/-28 ml/min/1.73m2, were enrolled in this longitudinal observational study. We evaluated the associations of plasma potassium levels with longitudinal kidney function decline by estimated glomerular filtration rate (eGFR). The eGFR was assessed with CKD-EPI formula. The rapid kidney function decline was defined as a fall in eGFR of more than 5 ml/min/1.73 m2/year, according to the KDIGO guidelines.
Results
During a mean follow-up time of 20.16+/-9.3 months, 31.34% (21p) of patients presented decline of eGFR, with a fall of mean – 11.6+/-5.43 ml/min/1.73m2/year. In univariable regression analysis, the decline of eGFR was associated with baseline eGFR (R2=0.09, p=0.013), age (R2=0.31, p<0.001), male gender (R2=0.14, p=0.001), arterial hypertension (R2=0.17, p=0.001), diabetes mellitus (R2=0.13, p=0.003), coronary artery disease (R2=0.12, p=0.005), uric acid (R2=0.23, p<0.001), C-reactive protein (R2=0.09, p=0.011), proteinuria/24h (R2=0.14, p=0.002) and serum potassium (R2=0.29, p<0.001). The serum potassium levels were significantly lower in the group with rapid decline of eGFR, with a mean of 3.62+/-0.41 mmol/L vs. 4.51+/-0.74 mmol/L, p<0.001. In multivariable regression analysis, the association between lower serum potassium levels and risk of rapid eGFR decline remained significant (HR=1.65; 95%CI, 1.105-2.49; p=0.015).
Conclusion
These results suggest that lower serum potassium levels may play a role in rapid kidney function decline in the cSK population. Further research is required to assess whether the higher risk of kidney function decline in cSK individuals could be diminished when optimised serum potassium levels strictly.
Abstract
Background and Aims
To date, endoscopic retrograde colangio-pancreatography (ERCP) represents a major advance in gastro-intestinal endoscopy. The ERCP is a safe and minimally invasive ...therapy for pancreatic-biliary diseases. Adverse events (AEs) associated to ERCP are well described. However, little is known about acute kidney injury (AKI) associated to ERCP. The aim of this study was to evaluate the incidence of post-ERCP AKI and the risk factors for AKI development. The prognostic implication of ERCP-associated AKI in in-hospital mortality has been also assessed.
Method
In this prospective observational study, we evaluated 396 patients who underwent ERCP, from the 3rd January 2019 through the 27th January 2020. AKI was defined as an increase in serum creatinine (SCr) ≥ 0.3 mg/dl or an increase in SCr ≥ 50% and/or by a decrease in urine output to 0.5 ml/kg/hour for 6 hours, in the first 48 hours following ERCP. Logistic uni- and multivariable regression methods were used to determine predictors of AKI and in-hospital mortality. A two-tailed value <0.05 was considered significant.
Results
In the studied group, median age was 69 years, interquartile range IQ =17, 183 (46.21%) patients being males. ERCP-associated AKI was detected in 103 patients (26%). Univariable regression analysis showed that AKI was associated with baseline eGFR (r=0.246, P<0.001), age (r=0.108, P=0.04), Charlson Comorbidity Index (CCI) (r=0.239, P<0.001), and with the following pre-ERCP parameters: systemic inflammatory response syndrome (SIRS) (r=0.125, P=0.012), serum albumin (r= -0.232, P<0.001), C-reactive protein (r=0.246, P<0.001), hematocrit (r= -0.130, P=0.009), platelet count (r=-0.155, P=0.001), total bilirubin level (r=0.230; P<0.001), alaninamino transferase level (r= -0.101, P=0.044), and alcaline phosphatase level (r=0.286, P<0.001). In the multivariable regression analysis, the independent predictors of AKI were: baseline eGFR (adjusted odds ratio (OR) 0.941, 95% confidence interval (CI): 0.927–0.956, P<0.001), CCI score (OR=1.17, 95%CI: 1.05-1.32, P=0.005), SIRS (OR=2.02, 95%CI: 1.009-4.036, P=0.047), total bilirubin (OR=1.08, 95%CI: 1.036-1.123, P<0.001), and alcaline phosphatase (OR=1.002, 95%CI:1.001-1.002, P<0.001). AKI was associated with increased in-hospital mortality (7.76 % versus 0.34 %, P<0.001). In our group, AKI was an independent predictor of in-hospital mortality (OR=9.98 , 95% CI: 1.19-83.26, P=0.03).
Conclusion
In patients undergoing ERCP, AKI was a common complication and an independent risk factor for in-hospital mortality. These findings highlight the importance of early AKI and AKI-related risk factors recognition, in order to minimise the risk for ERCP-associated AKI and to improve the post-ERCP outcome of patients.
