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Proton beam therapy (PBT), because of its unique physics of no–exit dose deposition in the tissue, is an exciting prospect. The phenomenon of Bragg peak allows protons to deposit their almost entire energy towards the end of the path of the proton and stops any further dose delivery. Braggs peak equips PBT with superior dosimetric advantage over photons or electrons because PBT doesn’t traverse the target/body but is stopped sharply at an energy dependent depth in the target/body. It also has no exit dose. Because of no exit dose and normal tissue sparing, PBT is hailed for its potential to bring superior outcomes. Pediatric malignancies is the most common malignancy where PBT have found utmost application. Nowadays, PBT is also being used in the treatment of other malignancies such as carcinoma prostate, carcinoma breast, head and neck malignancies, and gastrointestinal (GI) malignancies. Despite advantages of PBT, there is not only a high cost of setting up of PBT centers but also a lack of definitive phase-III data. Therefore, we review the role of PBT in current day practice of oncology to bring out the nuances that must guide the practice to choose suitable patients for PBT.

The use of radiation therapy after mastectomy (PMRT) has been limited to those patients who are at significant risk of cancer recurring in the chest wall or in the nodal basins. The use of PMRT has been widely accepted for patients with four or more positive lymph nodes, [1],[2] but there is still controversy regarding the value of PMRT for those with one to three positive nodes. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations for the benefit of community oncologists.

Purpose: The aim of this study was to compare the delineation and treatment planning of 2 Phase based (end-expiration and end-inspiration) internal gross tumor volume (IGTV) with 10-phase based (four-dimensional [4D]) IGTV. Materials and Methods: Patients with lung tumors at different sites were selected for the study. The location of the tumor in Groups A, B, C were at the upper lobe (attached to the chest wall), middle lobe, and lower lobe, respectively. We contoured the GTV on each of the 10 respiratory phases of the 4D computed tomography (4DCT) data set. The combination of these GTVs produced the IGTV “All Phases.” GTV was also generated on the extreme respiratory phases. The combination of these two GTVs produced IGTV “2 Phases.” Treatment planning was done, and dose to organs at risks (OARs) were compared in both cases. Results: The average volume of IGTV “2 Phases” and IGTV “All Phases” for Group A were nearly same. However, for Group B and Group C, IGTV “2 Phases” were smaller than the IGTV “All Phases.” Lung-GTV doses were less in “exp-insp” phases than in “4DCT” for Groups B, C, whereas it was same for “expiration-inspiration” and “4DCT” in Patient A. Conclusion: Patients with tumor upper lobe tumor have no difference in tumor coverage and OARs sparing in the 2 Phase and all phases but middle lobe and lower lobe have a greater excursion during respiration and hence greater all phases IGTV.

We proposed a method to reduce the volume of normal tissues irradiated by low doses in patients receiving CSI with RapidArc (RA) using Avoidance-Sector technique (RA+AS) and to compare its dosimetric implications with RA using full-arc (RA+FA) and 3D conformal technique (3DCRT). Four patients of CSI were retrospectively planned with 3DCRT, RA+FA, and RA+AS. Conformity-Index (CI), Homogeneity-Index (HI), and Paddick Gradient-Index (GI) were calculated. Quantitative evaluation was done using DVH analysis for PTVs and OARs. When compared with 3DCRT, GI, CI, and HI were favorable to RA based techniques. In comparison with 3DCRT the doses to OARs were lower with RA+AS with the difference being statistically significant in most instances. RA+AS significantly decreases the dose to OARs and their volumes receiving low doses in comparison with RA+FA and 3DCRT.

PurposeA retrospective study was undertaken to analyse set-up variations in patients being treated with post-operative radiation therapy for carcinoma of gall bladder by image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) scans and paired kilovoltage beam portals (kVps).Materials and methodsThree consecutive patients receiving post-operative radiation therapy for carcinoma of gall bladder were studied. A total of 32 imaging studies were performed. The immobilisation system was an all-in-one system along with a thermoplastic mask, with knees either resting on the knee rest or in a vacuum cushion. The CBCT scans and kVps were reviewed in an off-line mode. The surrogate markers used for matching during co-registration were 12th rib, coeliac trunk, vertebral bodies and canal. Individual readings were used to calculate mean shifts (m); the mean of these means (M) was calculated to arrive at the systematic error in each direction and its standard deviation (Σ) was calculated. The margins for set-up error (SM) were then calculated.ResultsThere were a total of 32 readings of which 21 were CBCTs and 11 were kVps. The mean shifts in each direction for each patient were 0·06, 0·25 and 0·15 cm in vertical, longitudinal and lateral directions, respectively. The resultant planning target volume margins calculated were 0·24, 0·9 and 0·47 cm in vertical, longitudinal and lateral directions.ConclusionsIGRT for upper abdominal malignancies using CBCT and kVps is a useful method to keep the margins for set-up error low. The use of surrogates for matching should be relevant to the target volume. Good immobilisation system helps in keeping the margins low.

Introduction: While planning radiation therapy (RT) for a carcinoma of the urinary bladder (CaUB), the intra-fractional variation of the urinary bladder (UB) volume due to filling-up needs to be accounted for. This internal target volume (ITV) is obtained by adding internal margins (IM) to the contoured bladder. This study was planned to propose a method of acquiring individualized ITVs for each patient and to verify their reproducibility. Methods: One patient with CaUB underwent simulation with the proposed ‘bladder protocol’. After immobilization, a planning CT scan on empty bladder was done. He was then given 300 ml of water to drink and the time (T) was noted. Planning CT scans were performed after 20 min (T+20), 30 min (T+30) and 40 min (T+40). The CT scan at T+20 was co-registered with the T+30 and T+40 scans. The bladder volumes at 20, 30 and 40 min were then contoured as CTV20, CTV30 and CTV40 to obtain an individualized ITV for our patient. For daily treatment, he was instructed to drink water as above, and the time was noted; treatment was started after 20 min. Daily pre- and post-treatment cone beam CT (CBCT) scans were done. The bladder visualized on the pre-treatment CBCT scan was compared with CTV20 and on the post-treatment CBCT scan with CTV30. Results: In total, there were 65 CBCT scans (36 pre- and 29 post-treatment). Individualized ITVs were found to be reproducible in 93.85% of all instances and fell outside in 4 instances. Conclusions: The proposed bladder protocol can yield a reproducible estimation of the ITV during treatment; this can obviate the need for taking standard IMs.

Introduction: Recent revision of the International Federation of Gynecology and Obstetrics (FIGO) staging system for the cervix encourages use of computerized tomography (CT) and magnetic resonance imaging and does not recommend cystoscopy as a mandatory investigation. But the revision has not defined which patients should undergo cystoscopy. Our study aims to revisit the role of CT scan and cystoscopy for detecting bladder invasion so that we can select patients for cystoscopy. Methods: We reviewed case records of all cervical cancer patients who underwent abdominopelvic CT scan besides standard FIGO staging workup (including cystoscopy) and treatment with radiotherapy or concurrent chemoradiotherapy between years 2003 and 2005. Patients showing bladder invasion on CT scan or cystoscopy were identified and separately analyzed. Considering cystoscopy as the standard reference investigation, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CT scan for bladder invasion were calculated. Results: A total of 305 case records were analyzed. Median age of the patients was 50 years (range, 25-85 years). Forty-three (14%) patients had bladder invasion on CT scan, and 17 (5.5%) had cystoscopy-confirmed invasion. No patient showing absence of bladder invasion on CT scan showed cystoscopy-confirmed invasion. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CT scan for bladder invasion were 100%, 92%, 40%, 100%, and 92%, respectively. The median overall survival of patients with CT-detected bladder invasion versus cystoscopy-confirmed invasion was 13 months versus 4 months, respectively (P = 0.007). Conclusions: Our results show that for cervical cancer, cystoscopy is not required in patients without any bladder invasion on CT scan. In the revised FIGO staging system, use of cystoscopy may be limited to patients having suspicious bladder invasion on CT scan. This will benefit both patient population and gynecologic oncologists, especially in developing countries with limited resources.

The present work demonstrates the first application of Brillouin light scattering to probe elastic excitations in highly anisotropic polymer thin films. Both the in-plane and out-of-plane longitudi...

We investigated the acoustic properties in the sub-GHz frequency regime of a multilayer system comprising alternating 100-nm scale TiO2/poly(methyl methacrylate) (PMMA) layers through a laser photoacoustic method, impulsive stimulated thermal scattering (ISTS). The acoustic dispersion curves were determined, and the mechanical properties were extracted from the experimental results.

Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs, but it can also affect other parts of the body. TB remains one of the leading causes of death in developing countries, and its recent resurgences in both developed and developing countries warrant global attention. The number of deaths due to TB is very high (as per the WHO report, 1.5 million died in 2013), although most are preventable if diagnosed early and treated. There are many tools for TB detection, but the most widely used one is sputum smear microscopy. It is done manually and is often time consuming; a laboratory technician is expected to spend at least 15 min per slide, limiting the number of slides that can be screened. Many countries, including India, have a dearth of properly trained technicians, and they often fail to detect TB cases due to the stress of a heavy workload. Automatic methods are generally considered as a solution to this problem. Attempts have been made to develop automatic approaches to identify TB bacteria from microscopic sputum smear images. In this paper, we provide a review of automatic methods based on image processing techniques published between 1998 and 2014. The review shows that the accuracy of algorithms for the automatic detection of TB increased significantly over the years and gladly acknowledges that commercial products based on published works also started appearing in the market. This review could be useful to researchers and practitioners working in the field of TB automation, providing a comprehensive and accessible overview of methods of this field of research.

Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

We apply time-resolved interferometric imaging to study laser-driven focused shock waves on the microscale. Shock waves are generated in a 10 μm-thick layer of water by sub-nanosecond laser pulses focused into a ring of 100 μm radius. Imaging is performed with a Mach-Zehnder interferometer by time-delayed femtosecond pulses. We obtain a series of images tracing the converging shock wave as it collapses to a focal point and then reemerges as a divergent shock wave eventually leaving behind a cavitation bubble at the focus. Quantitative analysis of interferograms yields density and shock velocity values that match the water Hugoniot data found in the literature. In a separate development, we captured the propagation of cracks in a glass substrate initiated by focused shock waves. The results open the prospect of spatially resolved studies of shock-compressed materials in a small-scale all-optical experiment.

The authors thank Dr. Gagan Saini and coworkers [1] for their astute comments on cranio-spinal irradiation (CSI) treatment using Volumetric Modulated Arc Therapy (VMAT). Indeed no data related to V5Gy for lungs were reported in our paper on CSI [2], this metric being a reported predictor for radiation induction pneumonitis. To complete the lack of information, the rV5Gy (volume of lungs spared from doses > 5 Gy) values a rising from the CSI plans in our study are in average 850 cm (range 610–1590 cm), or 51% if the common V5Gy parameter is analysed. We are cognizant that several other dose-metrics, other than the one proposed by Saini et al. [1] might also be of value when assessing the pneumonitis probability. In the two other articles, where the end point is the radiation induction pneumonitis, V5Gy remains highly correlated with other parameters as rV65Gy [3] or V10Gy–V20Gy and MLD [4]. We have also to stress that the dose prescriptions of the lung and oesophageal cancers series [3–5] cited by the authors are indisputably higher than what are used in CSI treatments (from 12 Gy to 36 Gy). This fact inevitably changes the global lung irradiation: if no high doses are delivered to the lungs, it is not clear, at least from literature, if the V5Gy remains as significant for radiation induction pneumonitis, or it plays mainly a role for damage recover from high dose irradiation. Moreover, other non-radiation related factors, such as those proposed by Wang et al. [3] may consequentially increase the risk of lung toxicity in non-CSI series. Some additional difficulties could derive from the lung volumes described in the two Wang papers [3,4] (average of 3649 and 3349 cm of both lungs together, with maximum volumes of 6459 and 7871 cm), strongly higher with respect to our patients (average of 2495 cm, excluding the child, with a maximum value of 3030 cm). The second important point mentioned by Dr. Saini [1] was related to the dose calculation accuracy in the low dose regions, 322 Letters to the Editor / Radiotherapy and Oncology 102 (2012) 321–323

Cylindrically or spherically focusing shock waves have been of keen interest for the past several decades. In addition to fundamental study of materials under extreme conditions, cavitation, and sonoluminescence, focusing shock waves enable myriad applications including hypervelocity launchers, synthesis of new materials, production of high-temperature and high-density plasma fields, and a variety of medical therapies. Applications in controlled thermonuclear fusion and in the study of the conditions reached in laser fusion are also of current interest. Here we report on a method for direct real-time visualization and measurement of laser-driven shock generation, propagation, and 2D focusing in a sample. The 2D focusing of the shock front is the consequence of spatial shaping of the laser shock generation pulse into a ring pattern. A substantial increase of the pressure at the convergence of the acoustic shock front is observed experimentally and simulated numerically. Single-shot acquisitions using a streak camera reveal that at the convergence of the shock wave in liquid water the supersonic speed reaches Mach 6, corresponding to the multiple gigapascal pressure range 30 GPa.

To study the effect of respiration (end expiration [EE] and end inspiration [EI]) on tumor and normal structure doses and volumes in carcinoma lung. Five patients with squamous cell carcinoma of the lung were selected for this retrospective study. Computerized tomography (CT) data set was subsequently obtained for all patients in EE and EI phases of the respiratory cycle. Gross tumor volume, clinical target volume, planning target volume (PTV) and organs at risk were delineated in both EE and EI on CT data sets. Prescribed dose was 60 Gy in 30 fractions for all patients. The PTV coverage and organs at risks (OARs) were evaluated using radiation therapy oncology group conformity indices (CI) and homogeneity indices (HI) and volume doses respectively. The CI and HI were comparable for both phases. Volumes of all OARs were comparable except the lung. OAR doses were almost same in both phases. Significantly higher normal lung volume was found in the EI phase. Based on our dosimetric data and statistical analysis we conclude that both EE and EI are dosimetrically comparable.

Purpose: The aim of this study was to compare the delineation and treatment planning of two phase‐based (the end‐expiration and the endinspiration phases) IGTV (Internal Gross Tumor Volume) with ten‐phase based (4D) IGTV. Methods: Two patients with lung tumors at different sites were selected for the study.The location of the tumor in Patient A was at the upper lobe(attached to the chest wall) of the left lung.In patient B the location was the middle lobe of right lung.We contoured the GTV on each of the ten respiratory phases of the 4D‐CT data set.The combination of these GTVs produced the IGTV .GTV was also generated on the extreme respiratory phases 0% phase = peak inhalation, 50% phase = peak exhalation).The combination of these two GTVs produced IGTV .Treatment planning was done and dose to OARs were compared in both end expiration inspiration(EEI) and 4DCT study set. Results: IGTV (175cc)and IGTV (180 cc) for Patient A were nearly same. But for Patient B, IGTV (80cc) was smaller than the IGTV (181 cc).C.I.(Conformity Index) was found better in EEI and 4DCT in Patient A than in Patient B due to the limitation of the AAA algorithm in the low density region.Lung‐GTV doses were less in EEI scan than in 4DCT for Patient B whereas it was the same for EEI and 4DCT in Patient A. Conclusion: The study shows the patients with tumor in upper lobe have no difference in tumor coverage and OARs sparing in the EEI and 4DCT. However,tumors in middle lobe have a greater excursion during respiration and hence greater all phase IGTV.We suggest performing a 4D scan and EEI scan both,for these categories of patients in order to include the tumor excursion due to breathing. Conflict of Interest: Nil; Funding Support: Required if possible

Primary rhabdoid tumor of lung is a rare histological and clinical entity. Lung tumors with rhabdoid features have been included as variants of large-cell carcinoma in the 1999 World Health Organization (WHO) classification of lung tumors. A large-cell carcinoma with a rhabdoid phenotype (LCCRP) is unusual, with only 38 cases reported till date. We report the clinical details of one such case that was treated with pneumonectomy and adjuvant chemotherapy. We also present a review of the literature. To identify relevant articles, we searched PubMed, Ovid, and IngentaConnect databases using the key words ′rhabdoid,′ ′lung cancer,′ and ′primary rhabdoid tumor of lung.′