This book, written by leading researchers and medical doctors in the field, provides an overview of intensity modulation technology and its evolution over the last 35 years. Every aspect of IMRT is ...covered, from fundamental concepts to advanced processes and clinical applications, and comprehensive references are included.
What's known on the subject? and What does the study add?
Novel therapeutic methods have emerged in recent years as ‘focal’ treatment alternatives in which cancer foci can be eradicated and greatly ...reducing the associated side‐effects of radical treatment. High‐intensity focused ultrasound (HIFU) seems to result in a well fitted technology, which has proven short‐ to medium‐term cancer control, with a low rate of complications comparable with those of established therapies.
This is an up‐to‐date review of the available literature on HIFU as a definitive treatment of prostate cancer. It describes the technique in a comprehensive approach in terms of technical features, procedure, indications, and gives an overview of its historical background; finally, we present the future applications of HIFU and its development trend.
OBJECTIVES
•
To provide an up‐to‐date review of the available literature on high‐intensity focused ultrasound (HIFU) as a definitive treatment of prostate cancer.
•
To present the technique in a comprehensive approach, comparing the available devices according to the existing evidence in terms of technical features, procedure, indications, and to give an overview of its historical background; and finally, to discuss future applications of HIFU and its development trend.
MATERIALS AND METHODS
•
A systematic literature search was conducted using MEDLINE and EMBASE via Ovid databases (January 2000 to December 2011), to identify studies on HIFU for treatment of prostate cancer.
•
Only English‐language and human‐based full manuscripts that reported on case series studies with >50 participants, patient characteristics, efficacy and safety data were included.
RESULTS
•
No randomised controlled trials were identified by the literature search. We identified 31 uncontrolled studies that examined the efficacy of HIFU as primary treatment and two studies that examined the efficacy of HIFU as salvage treatment.
•
Most treated patients had localised prostate cancer (stage T1–T2); Gleason scores of 2–10 and mean prostate specific antigen (PSA) values of 4.6–12.7 ng/mL. The mean age range of the patients was 64.1–72 years. The mean follow‐up ranged from 6.4 to 76.8 months. Negative biopsy rates ranged from 35 to 95%. PSA nadirs ranged from 0.04 to 1.8 ng/mL. The 5‐year disease‐free survival rates ranged from 61.2 to 95%; 7‐ and 8‐year disease free survival rates ranged from 69 to 84%.
•
The most common complications associated with the HIFU procedure as the primary treatment included: urinary retention (<1–20%); urinary tract infections (1.8–47.9%); stress or urinary incontinence (<1–34.3%); and erectile dysfunction (20–81.6%).
•
Recto‐urethral fistula was reported in <2% of patients.
•
Treatment‐related morbidity appeared to be reduced by the combination of transurethral resection (TURP) of the prostate and HIFU.
CONCLUSIONS
•
Novel therapeutic methods have emerged in recent years as ‘focal’ treatment alternatives, in which cancer foci could be eradicated by greatly reducing the associated side‐effects of radical treatment.
•
HIFU seems to result in short‐ to medium‐term cancer control, with a low rate of complications comparable with those of established therapies.
•
However, longer‐term follow‐up studies are needed to evaluate cancer‐specific and overall survival. If available promising results on HIFU for definitive treatment of prostate cancer are confirmed in future prospective trials, focal therapy could start to challenge the current standard of care.
Key points
A classic unresolved issue in human integrative physiology involves the role of exercise intensity, duration and volume in regulating skeletal muscle adaptations to training.
We employed ...counterweighted single‐leg cycling as a unique within‐subject model to investigate the role of exercise intensity in promoting training‐induced increases in skeletal muscle mitochondrial content.
Six sessions of high‐intensity interval training performed over 2 weeks elicited greater increases in citrate synthase maximal activity and mitochondrial respiration compared to moderate‐intensity continuous training matched for total work and session duration.
These data suggest that exercise intensity, and/or the pattern of contraction, is an important determinant of exercise‐induced skeletal muscle remodelling in humans.
We employed counterweighted single‐leg cycling as a unique model to investigate the role of exercise intensity in human skeletal muscle remodelling. Ten young active men performed unilateral graded‐exercise tests to measure single‐leg V̇O2, peak and peak power (Wpeak). Each leg was randomly assigned to complete six sessions of high‐intensity interval training (HIIT) 4 × (5 min at 65% Wpeak and 2.5 min at 20% Wpeak) or moderate‐intensity continuous training (MICT) (30 min at 50% Wpeak), which were performed 10 min apart on each day, in an alternating order. The work performed per session was matched for MICT (143 ± 8.4 kJ) and HIIT (144 ± 8.5 kJ, P > 0.05). Post‐training, citrate synthase (CS) maximal activity (10.2 ± 0.8 vs. 8.4 ± 0.9 mmol kg protein−1 min−1) and mass‐specific pmol O2•(s•mg wet weight)−1 oxidative phosphorylation capacities (complex I: 23.4 ± 3.2 vs. 17.1 ± 2.8; complexes I and II: 58.2 ± 7.5 vs. 42.2 ± 5.3) were greater in HIIT relative to MICT (interaction effects, P < 0.05); however, mitochondrial function i.e. pmol O2•(s•CS maximal activity)−1 measured under various conditions was unaffected by training (P > 0.05). In whole muscle, the protein content of COXIV (24%), NDUFA9 (11%) and mitofusin 2 (MFN2) (16%) increased similarly across groups (training effects, P < 0.05). Cytochrome c oxidase subunit IV (COXIV) and NADH:ubiquinone oxidoreductase subunit A9 (NDUFA9) were more abundant in type I than type II fibres (P < 0.05) but training did not increase the content of COXIV, NDUFA9 or MFN2 in either fibre type (P > 0.05). Single‐leg V̇O2, peak was also unaffected by training (P > 0.05). In summary, single‐leg cycling performed in an interval compared to a continuous manner elicited superior mitochondrial adaptations in human skeletal muscle despite equal total work.
Key points
A classic unresolved issue in human integrative physiology involves the role of exercise intensity, duration and volume in regulating skeletal muscle adaptations to training.
We employed counterweighted single‐leg cycling as a unique within‐subject model to investigate the role of exercise intensity in promoting training‐induced increases in skeletal muscle mitochondrial content.
Six sessions of high‐intensity interval training performed over 2 weeks elicited greater increases in citrate synthase maximal activity and mitochondrial respiration compared to moderate‐intensity continuous training matched for total work and session duration.
These data suggest that exercise intensity, and/or the pattern of contraction, is an important determinant of exercise‐induced skeletal muscle remodelling in humans.
This paper studies the optical wiretap channel with input-dependent Gaussian noise, in which the main distortion is caused by an additive Gaussian noise whose variance depends on the current signal ...strength. Subject to nonnegativity and peak-intensity constraints on the channel input, we first present a practical optical wireless communication scenario for which the considered wiretap channel is stochastically degraded. We then study the secrecy-capacity-achieving input distribution of this wiretap channel and prove it to be discrete with a finite number of mass points, one of them located at the origin. Moreover, we show that the entire rate-equivocation region of this wiretap channel is also obtained by discrete input distributions with a finite support. Similar to the case of the Gaussian wiretap channel under a peak-power constraint, here too, we observe that under nonnegativity and peak-intensity constraints, there is a tradeoff between the secrecy capacity and the capacity in the sense that both may not be achieved simultaneously. Furthermore, we prove the optimality of discrete input distributions in the presence of an additional average intensity constraint. Finally, we shed light on the asymptotic behavior of the secrecy capacity in the low- and high-intensity regimes. In the low-intensity regime, the secrecy capacity scales quadratically with the peak-intensity constraint. On the other hand, in the high-intensity regime, the secrecy capacity does not scale with the constraint.
The aim of this study is to compare the effectiveness of carbon ion radiation therapy (CIRT), proton radiation therapy (PRT), and photon‐based intensity‐modulated radiation therapy (IMRT) in the ...treatment of sinonasal malignancies. We identified studies through systematic review and divided them into three cohorts (CIRT group/PRT group/IMRT group). Primary outcomes of interest were overall survival (OS) and local control (LC). We pooled the outcomes with meta‐analysis and compared the survival difference among groups using Chi2 (χ2) test. A representative sample of 2282 patients with sinonasal malignancies (911 in the CIRT group, 599 in the PRT group, and 772 in the IMRT group) from 44 observation studies (7 CIRT, 16 PRT, and 21 IMRT) was included. The pooled 3‐year OS, LC, distant metastasis–free survival, and progression‐free survival rates were 67.0%, 72.8%, 69.4%, and 52.8%, respectively. Through cross‐group analysis, the OS was significantly higher after CIRT (75.1%, 95% CI: 67.1%‐83.2%) than PRT (66.2%, 95% CI: 57.7%‐74.6%; χ2 = 13.374, P < .0001) or IMRT (63.8%, 95% CI: 55.3%‐72.3%; χ2 = 23.814, P < .0001). LC was significantly higher after CIRT (80.2%, 95% CI: 73.9%‐86.5%) than PRT (72.9%, 95% CI: 63.7%‐82.0%; χ2 = 8.955, P = .003) or IMRT (67.8%, 95% CI: 59.4%‐76.2%; χ2 = 30.955, P < .0001). However, no significant difference between PRT and IMRT for OS and LC was observed. CIRT appeared to provide better OS and LC for patients with malignancies of nasal cavity and paranasal sinuses. A prospective randomized clinical trial is needed to confirm the superiority of CIRT in the treatment of sinonasal tumors.
Carbon‐ion radiation therapy achieved higher overall survival and local control rates as compared to both proton radiation therapy and photon based intensity‐modulated radiation therapy through meta‐analysis of 2, 282 patients with sinonasal malignancies from the real world. CIRT appeared to provide better OS and LC for patients with malignancies of nasal cavity and paranasal sinuses.
A photon avalanche (PA) effect that occurs in lanthanide-doped solids gives rise to a giant nonlinear response in the luminescence intensity to the excitation light intensity. As a result, much ...weaker lasers are needed to evoke such PAs than for other nonlinear optical processes. Photon avalanches are mostly restricted to bulk materials and conventionally rely on sophisticated excitation schemes, specific for each individual system. Here we show a universal strategy, based on a migrating photon avalanche (MPA) mechanism, to generate huge optical nonlinearities from various lanthanide emitters located in multilayer core/shell nanostructrues. The core of the MPA nanoparticle, composed of Yb
and Pr
ions, activates avalanche looping cycles, where PAs are synchronously achieved for both Yb
and Pr
ions under 852 nm laser excitation. These nanocrystals exhibit a 26th-order nonlinearity and a clear pumping threshold of 60 kW cm
. In addition, we demonstrate that the avalanching Yb
ions can migrate their optical nonlinear response to other emitters (for example, Ho
and Tm
) located in the outer shell layer, resulting in an even higher-order nonlinearity (up to the 46th for Tm
) due to further cascading multiplicative effects. Our strategy therefore provides a facile route to achieve giant optical nonlinearity in different emitters. Finally, we also demonstrate applicability of MPA emitters to bioimaging, achieving a lateral resolution of ~62 nm using one low-power 852 nm continuous-wave laser beam.
The physiology of world-class sprint skiers Sandbakk, Ø.; Holmberg, H.-C.; Leirdal, S. ...
Scandinavian journal of medicine & science in sports,
December 2011, Volume:
21, Issue:
6
Journal Article
Peer reviewed
The present study investigated the physiological characteristics of eight world‐class (WC) and eight national‐class (NC) Norwegian sprint cross country skiers. To measure the physiological response ...and treadmill performance, the skiers performed a submaximal test, a peak aerobic capacity (VO2peak) test, and a peak treadmill speed (Vpeak) test in the skating G3 technique. Moreover, the skiers were tested for G3 acceleration outdoors on asphalt and maximal strength in the lab. The standard of sprint skating performance level on snow was determined by International Ski Federation points, and the training distribution was quantified. WC skiers showed 8% higher VO2peak and twice as long a VO2 plateau time at the VO2peak test, and a higher gross efficiency at the submaximal test (all P<0.05). Furthermore, WC skiers showed 8% higher Vpeak (P<0.05), but did not differ from NC skiers in acceleration and maximal strength. WC skiers performed more low‐ and moderate‐intensity endurance training and speed training (both P<0.05). The current results show that aerobic capacity, efficiency, and high speed capacity differentiate WC and NC sprint skiers and it is suggested that these variables determine sprint skiing performance.
Exercise leads to a robust inflammatory response mainly characterized by the mobilization of leukocytes and an increase in circulating inflammatory mediators produced by immune cells and directly ...from the active muscle tissue. Both positive and negative effects on immune function and susceptibility to minor illness have been observed following different training protocols. While engaging in moderate activity may enhance immune function above sedentary levels, excessive amounts of prolonged, high-intensity exercise may impair immune function. Thus, the aim of the present review was to clarify the inflammatory effects in response to different exercise intensities.
Search was performed on PubMed and was completed on July 31st, 2017. The studies were eligible if they met the predefined inclusion criteria: a) observational or interventional studies, b) conducted in healthy adults (18-65 years), c) written in Portuguese, English or Spanish, d) including moderate and/or intense exercise. Eighteen articles were included. The specific components that were examined included circulating blood levels of cytokines, leukocytes, creatine kinase (CK) and C-reactive protein (CRP). The methodological quality of the included studies was assessed.
Most of the intervention studies showed changes in the assessed biomarkers, although these changes were not consistent. White blood cells (WBC) had an increase immediately after intensive exercise (> 64% VO
), without alteration after moderate exercise (46-64% VO
). The results suggested an elevation of the pro-inflammatory cytokines, namely IL-6, followed by an elevation of IL-10 that were more evident after intense exercise bouts. CRP increased both after intense and moderate exercise, with peak increases up to 28 h. CK increased only after intensive and long exercising.
In summary, intense long exercise can lead, in general, to higher levels of inflammatory mediators, and thus might increase the risk of injury and chronic inflammation. In contrast, moderate exercise or vigorous exercise with appropriate resting periods can achieve maximum benefit.
PDF
