Analysis of Set Up Margin Required during Delivery of Conformal Radiotherapy in Head and Neck Malignancy Using On Board Imaging: Experience from Tertiary Care Center

Background : Adequate dose to Clinical Target Volume is needed to control tumour and to deliver adequate dose without missing the target, this Clinical Target Volume must be encompassed by two margins for uncertainties; first, Internal margin uncertainties and second, set up margin uncertainty will form Planning Target Volume. Three mm setup error of couch location resulted in 38% decrease of minimum target radiation dose and 42 % increase of minimal Spinal Cord and Parotid Gland radiation dose. Aims and Objectives : Objectives of this retrospective study are, before implementation of high precession radiotherapy technique for Head and Neck Malignancy, we want determine optimal 3-dimensional Clinical Target Volume to planning target volume margin and to assess our setup accuracy in our institute, NRS Medical College & Hospital, Kolkata. Material and Methods : We analyzed retrospectively set up error from 691 set Cone Beam CT images of 94 patients. According to Standard Guidelines Target Volume delineated and for creation Clinical Target Volume to Planning target volume margin, we have used 5-7 mm margin around Clinical Target Volume. Results : In 99% patients’ setup deviation were within 0.5 cm. The population systematic error (?) in in Super Inferior; mediolateral; and anterior posterior direction were 0.13 cm, 0.12 cm and 0.14 cm respectively. The population random error in Super Inferior; mediolateral; and anterior posterior direction were 0.021 cm, 0.022 cm and 0.173 cm respectively. Using van Herk formula Clinical Target Volume to Planning Target Volume margin in Super Inferior; mediolateral; and anterior posterior direction were 0.34, 0.47 and 0.32 cm respectively. Corresponding values with Stroom formula 0.28, 0.40 and 0.26 cm respectively. Conclusions : In our study Set up margin of 5mm all around the CTV to create PTV is found to be safe and adequete

A real-world study of paritaprevir/ritonavir-ombitasvir combined with dasabuvir in the treatment of genotype 1b chronic hepatitis C / 中华肝脏病杂志

Objective@#To recognize the efficacy and safety of paritaprevir/ritonavir-ombitasvir combined with dasabuvir (OBV/PTV/RTV+DSV) in the treatment of genotype 1b chronic hepatitis C.@*Methods@#Patients with genotype 1b chronic hepatitis C who were admitted to the People's Hospital of Henan Province, Huashan Hospital of Shanghai and the Fifth Medical Center of the General Hospital of the People's Liberation Army of China between November 2017 to August 2018 were enlisted. All patients received OBV/PTV/RTV+DSV antiviral therapy. HCV RNA levels were measured at baseline, weeks 1, 2, 3, 4, 8, 12, and 24, then 12 weeks, and 24 weeks after completion of treatment; patients’ comorbidity, concomitant medications, and clinical adverse events were recorded.@*Results@#108 patients were enrolled in the study, with an average age of 49.1 years, 44 patients were male (40.8%), 96.3% (104/108) were newly diagnosed, and four patients had previous treatment history, of whom three were treated with IFN and one with IFN + DAA. Ninety-eight cases completed 12 weeks treatment and 89 cases were in follow up for 12 weeks, after discontinuation of the drug. Overall, 89 cases (100%) achieved SVR12.One patient treated with PR and DAA had HCV RNA level of 869175 IU/mL at 4 weeks of treatment, which was significantly higher than the baseline HCV RNA level (301776IU/ML), and was judged as failure of treatment; and follow-up was discontinued. Of all enrolled patients, 19 (17.6%) had underlying diseases and 15 (13.9%) had combined medications. During treatment, adverse events (AE) occurred in 11 patients (10.1%). The main adverse events were pruritus and elevated bilirubin.@*Conclusion@#Combined antiviral therapy (OBV/PTV/RTV+DSV) of 12 weeks are highly effective with good safety profile in the treatment of Chinese patients with genotype 1b chronic hepatitis C.

Molecular survey of porcine teschovirus, porcine sapelovirus, and enterovirus G in captive wild boars (Sus scrofa scrofa) of Paraná state, Brazil / Estudo molecular de teschovírus suíno, sapelovírus suíno e enterovírus G em javalis (Sus scrofa scrofa) de cativeiro no Paraná

Porcine teschovirus (PTV), porcine sapelovirus (PSV), and enterovirus G (EV-G) are infectious agents specific to pig host species that are endemically spread worldwide. This study aimed to investigate the natural infection by these porcine enteric picornaviruses in wild boars (Sus scrofa scrofa) of Paraná state, Brazil, and to evaluate peccaries (Pecari tajacu and Tayassu pecari) as alternative host species for these viruses. Fecal samples (n=36) from asymptomatic wild boars (n=22) with ages ranging from 2 to 7 months old (young, n=14) and 2 to 4 years old (adult, n=8) and from peccaries (6 to 8 months old, n=14) were collected from a farm and a zoo, respectively, both located in Paraná state. Reverse transcription-polymerase chain reaction (RT-PCR) and nested-PCR (n-PCR) assays targeting the 5'non-translated region of the virus genome were used for screening the viruses. Porcine enteric picornaviruses were detected in 12 out of the 22 wild boar fecal samples. According to each of the viruses, EV-G was most frequently (11/22, 50%) detected, followed by PTV (10/22, 45.5%) and PSV (4/22, 18.2%). Regarding the age groups, young wild boars were more frequently (9/14, 64.3%) infected with PTV, PSV, and EV-G than adult animals (3/8, 37.4%). One n-PCR amplified product for each of the viruses was submitted to sequencing analysis and the nucleotide sequences were compared with the related viruses, which showed similarities varying from 97.7% to 100% for PTV, 92.4% to 96.2% for PSV, and 87.1% to 100% for EV-G. Peccaries tested negative for the viruses and in this study they did not represent infection reservoirs. This study is the first to report the molecular detection of PTV, PSV, and EV-G from captive wild boars in a South American country and the first to screen peccaries as alternative host species for porcine enteric picornavirus.

Teschovírus suíno (PTV), sapelovírus suíno (PSV) e enterovírus G(EV-G) são agentes infecciosos específicos da espécie suína que estão endemicamente disseminados em todo o mundo. O objetivo deste estudo foi investigar a infecção natural por estes picornavírus entéricos suínos em javalis (Sus scrofa scrofa) do estado do Paraná, Brasil e avaliar pecaris (Pecari tajacu e Tayassu pecari) como hospedeiros alternativos para estes vírus. Amostras fecais (n=36) de javalis assintomáticos (n=22) com idades de 2 a 7 meses (jovens, n=14) e 2 a 4 anos (adultos, n=8) e de pecaris (6 a 8 meses de idade, n=14) foram coletadas em um cativeiro e zoológico, respectivamente, ambos localizados no estado do Paraná. A transcrição reversa seguida por reações da polimerase em cadeia (RT-PCR) e nested-PCR com alvo na região 5'-não traduzida do genoma viral foram utilizadas para a identificação dos vírus. Picornavírus entéricos suínos foram detectados em 12 das 22 amostras fecais de javalis. De acordo com cada um dos vírus, EV-G foi mais frequentemente (11/22, 50%) detectado, seguido pelo PTV (10/22; 45,5%) e PSV (4/22; 18,2%). Considerando os grupos de idade, javalis jovens foram mais frequentemente (9/14; 64,3%) infectados com PTV, PSV e EV-G do que os javalis adultos (3/8; 37,4%). Um produto amplificado na nested-PCR para cada um dos vírus foi submetido à análise de sequenciamento e as sequências de nucleotídeos foram comparadas com vírus relacionados, o que mostrou que as similaridades variaram entre 97,7% a 100% para o PTV, 92,4% a 96,2% para o PSV e 87,1% a 100% para o EV-G. Os pecaris foram negativos para as viroses investigadas e neste estudo não se apresentaram como hospedeiros alternativos para as infecções. Este estudo é o primeiro a relatar a detecção molecular de PTV, PSV e EV-G em javalis de cativeiro de um país da América Latina e o primeiro a avaliar pecaris como espécie hospedeira alternativa para picornavírus entéricos suínos.

Desarrollo y validación de un método analítico para la detección y cuantificación de plaguicidas organoclorados en grasa de ganado porcino con un sistema GC/PTV/EI/MS² / Development and validation of an analytical method for the detection and quantification of organochlorine pesticides in pork fat with a GC/PTV/EI/MS² system

A capillary gas chromatography/mass spectrometry method was developed based on the requirements of the NMX-EC-17025-IMNC-2006/ISO/IEC17025:2005 and the Commission Decision 2002/657/EC in what regards to organochlorine pesticides measurement in swinish livestock fat: α-BHC, γ-BHC (lindane), β-BHC, δ-BHC, heptachlor, aldrin, heptachlor epoxide, γ-chlordane, α-chlordane, endosulfan I, p,p'-DDE, dieldrin, endrin, endosulfan II, p,p'-DDD, endrin aldehyde, p,p'-DDT, endosulfan sulfate, methoxychlor and mirex, in order to suggest a technological alternative that the NOM-021-ZOO-1995 may determine, and fulfill the NOM-004-ZOO-1994. The optimization in the selection of the precursor ion for each pesticide was done changing the pressure in the ion trap increasing the ions product signals, and achieving MS² measurements with higher sensitivity that overcome to electronic capture detectors (ECD). The decision limit CCα and detection capability CCβ fulfilled the maximum residue limits (MRL) for both regulations with r > 0.990 and recoveries between 70-110%.

Se desarrolló un método empleando un sistema de cromatografía gaseosa-espectrometría de masas, de acuerdo con los requisitos de la NMX-EC-17025-IMNC-2006/ISO/IEC17025:2005 y la decisión de la Comisión 2002/657/EC, para la medición de plaguicidas organoclorados en grasa de ganado porcino: α-BHC, γ-BHC (lindano), β-BHC, δ-BHC, heptacloro, aldrín, heptacloro epóxido, γ-clordano, α-clordano, endosulfán I, p,p'-DDE, diedrín, endrín, endosulfán II, p,p'-DDD, endrín aldehido, p,p'-DDT, endosulfán sulfato, metoxicloro y mirex, con el fin de proponer una alternativa tecnológica para la determinación de la NOM-021-ZOO-1995, y dar cumplimiento a la NOM-004-ZOO-1994. La optimización en la selección del ion precursor de cada plaguicida se realizó variando la presión en la trampa de iones para incrementar las señales de los iones producto, logrando mediciones por MS² con sensibilidad superior a los detectores de captura electrónica (ECD). Los límites de decisión (CCα) y capacidad de detección (CCβ), cumplen con los límites máximos de residuos (MRL) para ambas regulaciones con r > 0.990 y recuperaciones entre 70-110%.

PTV Margins for Prostate Treatments with an Endorectal Balloon / 대한방사선종양학회지

PURPOSE: To determine the appropriate prostate planning target volume (PTV) margins for 3-dimensitional (3D) conformal radiotherapy (CRT) and intensity-modulated radiation therapy (IMRT) patients treated with an endorectal balloon (ERB) under our institutional treatment condition. MATERIALS AND METHODS: Patients were treated in the supine position. An ERB was inserted into the rectum with 70 cc air prior to planning a CT scan and then each treatment fraction. Electronic portal images (EPIs) and digital reconstructed radiographs (DRR) of planning CT images were used to evaluate inter-fractional patient's setup and ERB errors. To register both image sets, we developed an in-house program written in visual C++. A new method to determine prostate PTV margins with an ERB was developed by using the common method. RESULTS: The mean value of patient setup errors was within 1 mm in all directions. The ERB inter-fractional errors in the superior-inferior (SI) and anterior-posterior (AP) directions were larger than in the left-right (LR) direction. The calculated 1D symmetric PTV margins were 3.0 mm, 8.2 mm, and 8.5 mm for 3D CRT and 4.1 mm, 7.9 mm, and 10.3 mm for IMRT in LR, SI, and AP, respectively according to the new method including ERB random errors. CONCLUSION: The ERB random error contributes to the deformation of the prostate, which affects the original treatment planning. Thus, a new PTV margin method includes dose blurring effects of ERB. The correction of ERB systematic error is a prerequisite since the new method only accounts for ERB random error.

Analysis on the Effect of Field Width in the Delineation of Planning Target Volume for TomoTherapy / 의학물리

The Hi-Art system for TomoTherapy allows only three (1.0 cm, 2.5 cm, 5.0 cm) field widths and this can produce different dose distribution around the end of PTV (Planning target volume) in the direction of jaw movement. In this study, we investigated the effect of field width on the dose difference around the PTV using DQA (Delivery quality assurance) phantom and real clinical patient cases. In the analysis with DQA phantom, the calculated dose and irradiated films showed that the more dose was widely spreaded out in the end region of PTV as increase of field width. The 2.5 cm field width showed a 1.6 cm wider dose profile and the 5.0 cm field width showed a 4.2 cm wider dose profile compared with the 1.0 cm field width in the region of 50% of maximum dose. The analysis with four patient cases also showed the similar results with the DQA phantom which means that more dose was irradiated around the superior and inferior end of PTV as an increase of field width. The 5.0 cm field width produced the remarkable high dose distribution around the end region of PTV and we could evaluate the effect quantitatively with the calculation of DVH (Dose volume histogram) of the virtual PTVs which were delineated around the end of PTV in the direction of jaw variation. From these results, we could verify that the margin for PTV in the direction of table movement should be reduced compared with the conventional margin for PTV when the large field such as 5.0 cm was used in TomoTherapy.

The Dosimetric Effect on Real PTV and OARs at Various Image Fusion Protocol for Pituitary Adenomas / 의학물리

The purpose of this study is to verify the dosimetric effect on real PTV (planning target volume) coverage and safety of OARs (organs at risk) at various image fusion protocol-based radiosurgery plan for pituitary adenomas. Real PTV coverage and its variation was acquired and maximum dose and the volume absorbing above threshold dose were also measured for verifying the safety of optic pathway and brainstem. The protocol that can reduce superior-inferior uncertainty by using both axial and coronal MR (magnetic resonance) image sets shows relatively lower values than that of case using only axial image sets. As a result, the image fusion protocol with both axial and coronal image sets can be beneficial to generate OAR-weighted radiosurgery plan.

Comparion of stability in titanium implants with different surface topographies in dogs

STATEMENT OF PROBLEM: A few of studies which compared and continuously measured the stability of various surface treated implants in the same individual had been performed. PURPOSE: We aim to find the clinical significance of surface treatments by observing the differences in the stabilization stages of implant stability. MATERIAL AND METHODS: Eight different surface topographies of dental implants were especially designed for the present study. Machined surface implants were used as a control group. 4 nano-treated surface implants (20 nm TiO2 coating surface, heat-treated 80 nm TiO2 coating surface, CaP coating surface, heat treated CaP coating surface) and 3 micro-treated surface implants [resorbable blast media (RBM) surface, sandblast and acid-etched (SAE) surface, anodized RBM surface] were used as experiment groups. All 24 implants were placed in 3 adult dogs. Periotest(R) & ISQ values measured for 8 weeks and all animals were sacrificed at 8 weeks after surgery. Then the histological analyses were done. RESULTS: In PTV, all implants were stabilized except 1 failed implants. In ISQ values, The lowest stability was observed at different times for each individual. The ISQ values were showed increased tendency after 5 weeks in every groups. After 4 to 5 weeks, the values were stabilized. There was no statistical correlation between the ISQ values and PTV. In the histological findings, the bone formation was observed to be adequate in general and no differences among the 8 surface treated implants. CONCLUSIONS: In this study, the difference in the stability of the implants was determined not by the differences in the surface treatment but by the individual specificity.

Bone response of three different surface implants : Histomorphometric, perio test value and resonance frequency analysis in beagle dogs / 대한치과보철학회지

STATEMENT OF PROBLEM: The intial stability for osseointegration of implant has been an interesting factor. Especially, in the case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve implant fixation to bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. PURPOSE: The aims of this study are to perform a histologic and histomorphometric comparison of the healing characteristics of three different surfaces and the comparison of resonance frequency analysis (RFA) values measured by Osstell(TM) and perio-test values (PTV) measured by Periotest. MATERIAL AND METHODS: A total of 24 screw titanium implants (Dentium Co., Seoul, Korea) with 6mm in length and 3.4mm in diameter, were placed in the mandible of 4 beagle dogs. Implants were divided into three groups following the surface treatment methods: Group I is machined(control group). Group II is anodically oxidized. Group III is coated 500nm in thickness with hydroxyapatite(HA) by ion beam assisted deposition(IBAD) on the anodized oxidization. Bone blocks from 2 dogs were caught after 3 weeks of covered healing and another blocks from 2 dogs after 6 weeks. RFA values and PTV were measured right after insertion and at 3 and 6weeks. Histomorphometric analysis was made with Kappa Image Base System to calculate bone-to-implant contact (BIC) and bone area inside the threads. Pearson's correlation analyses were performed to evaluate the correlation between RFA and PTV, BIC and bone area ratio of three different surfaces at 3 and 6 weeks. RESULTS: 1) In all surface treatment methods, the RFA values decreased and the PTV values increased until 6 weeks in comparison to initial values. 2) At 3 weeks, no significant difference was found from bone-to-implant contact ratio and bone area ratio of three different surface treatment methods(P>0.05). However, at 6 weeks, different surface treatment methods showed significantly different bone-toimplant contact ratio and bone area ratio(P<0.05). 3) In the implants with the IBAD on the anodic oxidization, significant difference was found between the 3 weeks and the 6 weeks bone area ratio(P<0.05). 4) Correlation was found between the RFA values and the bone area ratio at 3 and 6 weeks with significant difference(P<0.05). CONCLUSIONS: These results indicate that the implants with the IBAD on the anodic oxidization may have a high influence on the initial stability of implant.

The influencing factors of periotest. value and implant stability quotient / 대한치과보철학회지

STATEMENT OF PROBLEM: Periotest. and OsstellTM were known as the most objective and quantitative mobility tests available for evaluating stability of implant in vivo. Although a correlation between PTV widely used and ISQ recently introduced exist, a PTV was corresponded to various ISQ. A correct evaluation of implant stability could be obtained only after one has a thorough understanding of the limitations of devices and factors that affect measurements. PURPOSE: The purpose of this study was to investigate the causes of variables in the values obtained with these two tests. MATERIAL AND METHOD: A total of 333 implants: 134 Bra.nemark, 5 Silhouette and 194 ITI implants were investigated. Result: 1. There was a correlation between PTV and ISQ (Spearman correlation =0.39, p<0.0001) 2. The factors that affected ISQ were diameter of implant fixture, location of implant and implant system (submerged type vs non-submerged type). 3. The factors that affected PTV were diameter of implant fixture, location of implant, and elapsed time after implant placement. 4. There was no significant difference between different surface treatments of RBM, smooth surface and ti-unite on PTV and ISQ. 5. In radiographic finding, no saucerization or bone resorption has been detected in implants with ISQ values that were above the average level of each PTV. These higher values had higher bone densities around the implant fixture. Saucerization was observed in the most impants with ISQ values that were below the average level of each PTV. CONCLUSION: There was a correlation between ISQ and PTV. However, each measuring methods had factors influencing the measured values. PTV were less sensitive to marginal bone resorption and influenced with the striking point on an implant to the level of bone. With ISQ, the height of implant from bone level to transducer should be considered.

The influencing factors of periotest. value and implant stability quotient / 대한치과보철학회지

STATEMENT OF PROBLEM: Periotest. and OsstellTM were known as the most objective and quantitative mobility tests available for evaluating stability of implant in vivo. Although a correlation between PTV widely used and ISQ recently introduced exist, a PTV was corresponded to various ISQ. A correct evaluation of implant stability could be obtained only after one has a thorough understanding of the limitations of devices and factors that affect measurements. PURPOSE: The purpose of this study was to investigate the causes of variables in the values obtained with these two tests. MATERIAL AND METHOD: A total of 333 implants: 134 Bra.nemark, 5 Silhouette and 194 ITI implants were investigated. Result: 1. There was a correlation between PTV and ISQ (Spearman correlation =0.39, p<0.0001) 2. The factors that affected ISQ were diameter of implant fixture, location of implant and implant system (submerged type vs non-submerged type). 3. The factors that affected PTV were diameter of implant fixture, location of implant, and elapsed time after implant placement. 4. There was no significant difference between different surface treatments of RBM, smooth surface and ti-unite on PTV and ISQ. 5. In radiographic finding, no saucerization or bone resorption has been detected in implants with ISQ values that were above the average level of each PTV. These higher values had higher bone densities around the implant fixture. Saucerization was observed in the most impants with ISQ values that were below the average level of each PTV. CONCLUSION: There was a correlation between ISQ and PTV. However, each measuring methods had factors influencing the measured values. PTV were less sensitive to marginal bone resorption and influenced with the striking point on an implant to the level of bone. With ISQ, the height of implant from bone level to transducer should be considered.