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

Application of 3D ResSE-Unet-based intelligent delineation of clinical target volume in postoperative radiotherapy for breast cancer / 中华放射医学与防护杂志

Objective:To evaluate the effectiveness and feasibility of 3D ResSE-Unet-based intelligent delineation of clinical target volume (CTV) in postoperative adjuvant radiotherapy for breast cancer.Methods:A total of 974 cases of breast cancer treated in the Cancer Diagnosis and Treatment Center of the Fourth Affiliated Hospital of Guangxi Medical University from September 2018 to June 2022 were enrolled in this study, including 614 cases receiving total mastectomy and 360 cases treated with breast-conserving surgery. They were divided into a training set, a validation set, and a testing set. The training set consisted of 874 cases and was used to build a model of 3D ResSE-Unet-based intelligent CTV delineation. The validation set comprised 40 cases and was used to evaluate the feasibility and effectiveness of the clinical application of AI-based CTV design in the radiotherapy for breast cancer. The testing set was composed of 60 cases and was used to test the accuracy of intelligent CTV. The Wilcoxon rank test was used to compare the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and average surface distance (ASD) obtained using the intelligent delineation model.Results:The intelligent delineation model showed high precision. The CTV of cases treated with total mastectomy (CTV cw) and the CTV of cases treated with breast-conserving surgery (CTV b) had DSCs greater than 0.80 and greater than 0.88, respectively. Therefore, compared with CTV cw, CTV b had a higher DSC (0.91 ± 0.03 vs.0.83 ± 0.05, t = 7.11, P < 0.05). Both CTV cw and CTV b had lower HD 95 [(7.56 ± 3.42) mm vs.(8.77 ± 5.89) mm] and ASD [(1.85 ± 0.71) mm vs.(1.86 ± 0.83)mm], without statistically significant difference ( P > 0.05). The left/right supraclavicular and infraclavicular CTV (CTV2) had DSCs greater than 0.8. CTV2 also had low average HD95 and ASD, without statistically significant difference ( P > 0.05). Conclusions:The 3D ResSE-Unet-based intelligent CTV delineation has better consistency and feasibility in postoperative adjuvant radiotherapy for breast cancer, especially the CTVs after breast-conserving surgery.

Effects of different bladder filling volumes on target area and organs at risk during three-dimensional brachytherapy of postoperative early cervical cancer / 中华放射医学与防护杂志

Objective:To investigate the optimal bladder filling volume in the 3D brachytherapy of postoperative cervical cancer.Methods:Totally 111 early cervical cancer patients with positive incisal margins or insufficient safety boundaries were included. The normal saline 50, 60, 70, 80, 90, and 100 ml were filled into their bladders, and accordingly six groups were determined, and 66, 69, 66, 69, 72, 56 person-times in each group, respectively. The CT-based simulation positioning was performed. According to the ICRU 89 report, high-risk clinical target volume and organs at risk such as bladder and rectum were delineated. The Oncentra planning system was used to prepare the treatment program. The high-risk clinical target volume (HR-CTV), D90, and the D2 cm 3 and D1 cm 3 of organs at risk under different volumes were recorded. Results:Compared to the 60 ml group, the volume and dosage of HR-CTV in the groups of 50, 70, 80, 90, and 100 ml had no significant difference ( P>0.05). The D2 cm 3 and D1 cm 3 of the bladder and rectum of patients in these groups significantly decreased, and the difference was statistically significant ( tbladder = 3.21, 5.83, 2.89, 12.95, 7.96, Pbladder = 0.031, 0.010, 0.041, 0.000, 0.001; trectum = 2.94, 4.66, 2.53, 5.89, 4.13, Prectum = 0.037, 0.024, 0.049, 0.005, 0.028). The pairwise comparison among these groups except for the 60 ml group showed that the volume and dosage of HR-CTV and the D2 cm 3 and D1 cm 3 of bladder and rectum had no significant difference ( P > 0.05). Moreover, the D2 cm 3 and D1 cm 3 of sigmoid colon and small intestine of these groups had no significant difference ( P > 0.05). Conclusions:In the 3D brachytherapy of postoperative early cervical cancer, a bladder filling volume of 60 ml can ensure the volume and dose of HR-CTV and can protect the bladder and rectum compared with other filling volumes.

Biochemical changes in cultivars of sweet oranges infected with citrus tristeza virus / Mudanças bioquímicas em vários cultivares de laranjas doces infectadas com o vírus citrus tristeza

Abstract Citrus fruit production occupies a place of considerable importance in the economy of the world including Pakistan. Tristeza disease caused by Citrus Tristeza Virus (CTV) exists in various forms that may or may not cause symptoms in the plants. The bioactive compounds and antioxidants are naturally present in plants and provide a defense mechanism that is generally accelerated in response to a stress. The objective of the present study was to target and analyze the citrus plants that were CTV positive to observe the changes in the enzymatic and non-enzymatic antioxidants of citrus (Sweet Oranges only). It was observed that in response to CTV infection, both the non-enzymatic antioxidants (total flavonoid, ascorbic acid, phenolic acid) and enzymatic antioxidants (catalase, superoxide dismutase and peroxidase) activities showed an increasing trend overall. The profiling of antioxidants in response to a viral infection may help in the discovery of new biomarkers that can be used as a monitoring tool in disease management.

Resumo As frutas cítricas ocupam um lugar de considerável importância na economia do Paquistão, assim como o resto do mundo. A doença da tristeza causada pelo Vírus da Tristeza dos Citros (CTV) existe em várias formas que podem ou não apresentar sintomas nas plantas. Os compostos bioativos e antioxidantes estão naturalmente presentes nas plantas e fornecem um mecanismo de defesa que é geralmente acelerado em resposta a um estresse. O objetivo do presente estudo foi analisar as alterações causadas pelo CTV nos antioxidantes enzimáticos e não enzimáticos de laranjas doces. Foi observado que, em resposta ao ataque de CTV, os antioxidantes não enzimáticos como flavonoides totais, ácido ascórbico, ácido fenólico e antioxidantes enzimáticos, como as atividades de catalase, superóxido dismutase e peroxidase, geralmente mostram uma tendência crescente. O perfil de antioxidantes em resposta a um ataque viral pode ajudar na descoberta de novos biomarcadores que podem ser usados ​​como uma ferramenta de monitoramento no gerenciamento de doenças.

Measurement of the distance of microfoci from a rectal gross tumor in a pathological specimen / 中国肿瘤临床

Objective: To measure the distance of the lateral, inferior, and superior microfoci from a gross tumor in a pathological speci-men and to provide scientific evidence for margin extension to form the clinical target volume (CTV) in high-dose radiotherapy for rec-tal cancer. Methods: Twenty-eight surgical specimens were collected from patients with rectal cancer who underwent total mesorectal excision (TME) in Hunan Cancer Hospital between October 2016 and April 2017. The nearest distance of the farthest peripheral micro-foci from the gross tumor was measured. The in vivo-in vitro tumor retraction factor (R1) was calculated by measuring the ratio of the tumor's perpendicular depth based on magnetic resonance imaging and immediate surgical specimens. The retraction factor (R2) in the process of pathological specimen makeup was calculated by knot labeling. The distance of microfoci extension was calculated based on that measured in pathological specimens including corrections with R1 and R2 and record as microcarcinoma extension mea-sured in vivo,MEin vivo. Results: Among the 28 pathological specimens, lateral, inferior, and superior microfoci were found in 17 (60.7%), 3 (10.7%), and 0 cases, respectively. The mean R1 was 0.913 and mean R2 was 0.803. The farthest distance measured inferiorly was 28 mm in vivo after correction. The maximum, minimum, and mean measured lateral distances were 12.03 mm, 3.03 mm, and 7.50 mm after correction, respectively. The 95% frequency value was within 10 mm. Conclusions: The lateral microfoci extension was within 10 mm for 95% of the rectal cancer patients. The margin expansion to form the CTV was suggested to be 10 mm for a late-course boost of high-dose radiotherapy for rectal cancer.

Study on improving accuracy of setup errors of supraclavicular field in radiotherapy for breast cancer by breast bracket and moisture-cured resin cushion / 中华放射医学与防护杂志

Objective To explore the effects of improvements on setup error ( SE ) and clinical target ( CTV ) margin of supraclavicular field ( SCF ) by using moisture-cured resin cushion and breast bracket for lower neck fixation in breast cancer patients who underwent post-mastectomy radiotherapy. Methods Totally 13 patients with breast cancer who underwent post-mastectomy radiotherapy were enrolled. All patients were immobilized by breast bracket and moisture-cured resin cushion. Firstly, each patient′s lower neck and head was fixed well by moisture-cured resin cushion, filling the gap between the neck and breast bracket. Secondly,each patient underwent the cone-beam CT ( CBCT) at the first, tenth and twentieth treatment after positioning. Then these CBCT images were registered to the planning CT to determine setup errors in translational and rotational directions, and SCF CTV margins by the systematic and random errors were evaluated. Results The setup errors in x (left-right), y (superior-inferior), z (anterior-posterior) translational directions were (2. 16 ± 1. 25), (1. 50 ± 1. 28), (1. 94 ± 1. 12) mm and (1. 76 ±1. 87)°, (1. 82 ±1. 12)°, (0. 99 ±0. 58)°, respectively in θ (pitch degree),Ф(roll degree),ψ( yaw degree) rotational directions. Non-parametric rank test ( Mann-Whitney U test) was performed with previous data, the differences of the setup error in y, z,θ directions were statistically significant ( Z =4. 152, 3. 415, 2. 053, P<0. 05). The margins from CTV were 4. 07, 4. 03 and 3. 73 mm in x, y and z directions, respectively. Compared with the previous study on SCF, CTV margin required 8, 8 and 6 mm in x, y and z axis directions, the volume of CTV to PTV were decreased by 32. 73% on average. Conclusions Compared with plastic circular pillow alone, moisture-cured resin cushion with breast bracket locating method could reduce setup errors in SCF target region. The margins from CTV to PTV weredecreased to 4. 07, 4. 03 and 3. 73 mm in x, y and z axis directions at least.

Study on improving accuracy of setup errors of supraclavicular field in radiotherapy for breast cancer by breast bracket and moisture-cured resin cushion / 中华放射医学与防护杂志

Objective To explore the effects of improvements on setup error ( SE ) and clinical target ( CTV ) margin of supraclavicular field ( SCF ) by using moisture-cured resin cushion and breast bracket for lower neck fixation in breast cancer patients who underwent post-mastectomy radiotherapy. Methods Totally 13 patients with breast cancer who underwent post-mastectomy radiotherapy were enrolled. All patients were immobilized by breast bracket and moisture-cured resin cushion. Firstly, each patient′s lower neck and head was fixed well by moisture-cured resin cushion, filling the gap between the neck and breast bracket. Secondly,each patient underwent the cone-beam CT ( CBCT) at the first, tenth and twentieth treatment after positioning. Then these CBCT images were registered to the planning CT to determine setup errors in translational and rotational directions, and SCF CTV margins by the systematic and random errors were evaluated. Results The setup errors in x (left-right), y (superior-inferior), z (anterior-posterior) translational directions were (2. 16 ± 1. 25), (1. 50 ± 1. 28), (1. 94 ± 1. 12) mm and (1. 76 ±1. 87)°, (1. 82 ±1. 12)°, (0. 99 ±0. 58)°, respectively in θ (pitch degree),Ф(roll degree),ψ( yaw degree) rotational directions. Non-parametric rank test ( Mann-Whitney U test) was performed with previous data, the differences of the setup error in y, z,θ directions were statistically significant ( Z =4. 152, 3. 415, 2. 053, P<0. 05). The margins from CTV were 4. 07, 4. 03 and 3. 73 mm in x, y and z directions, respectively. Compared with the previous study on SCF, CTV margin required 8, 8 and 6 mm in x, y and z axis directions, the volume of CTV to PTV were decreased by 32. 73% on average. Conclusions Compared with plastic circular pillow alone, moisture-cured resin cushion with breast bracket locating method could reduce setup errors in SCF target region. The margins from CTV to PTV weredecreased to 4. 07, 4. 03 and 3. 73 mm in x, y and z axis directions at least.

Evaluations of set-up errors and target margins for super and middle part of esophageal carcinoma in image guided radiotherapy / 中华放射医学与防护杂志

Objective To investigate the set-up errors of super and middle part of esophageal cancer patients using cone-beam CT (CBCT) during intensity modulated radiotherapy (IMRT),hence determine various margins from CTV to PTV.The corresponding influence on the normal tissues (lung and spinal cord) was also discussed.Methods From December 2012 to December 2013,12 patients with upper and middle segment of esophageal cancer were chosen.Using their 60 sets of weekly acquired CBCT images prior to the treatment,the lateral,longitudinal,and vertical set-up errors of each patient were obtained.Based on these measured errors and the target motions,we adopted new margins to create new PTV.Then IMRT plans were created for the original PTV (5 mm margin in all directions on CTV) and new PTV respectively.On condition of the same target coverage (V95 ≥ 95％),the doses to lungs (V5,V20,V30,D) and spinal cord (D1 cm3) were compared statistically between the original and new plans.Results According to the 60 CBCT scans,the average left-right (RL),superior-inferior (SI),anterior-posterior (AP) set-up errors were (2.02 ± 1.74),(2.03 ± 1.93),and (2.02 ± 1.89) mm respectively.The margins were 5.6 mm (RL),8.5 mm (SI),and 4.7 mm (AP) for the upper esophagus and 6.2 mm (RL),11 mm (SI),and 5.0 mm (AP) for the middle esophagus.Comparison of both lungs and spinal cord suggested significant differences between the two plans (t =-8.23,-5.55,-4.66,-6.87,-4.67,P ＜0.05).Conclusions The margins from CTV to PTV should be created via CBCT-measured set-up errors and previous reports,which can be helpful for clinical treatment.

Detección del virus de la tristeza de los cítricos por serología, microscopía e hibridación in situ / In situ serological, microscopy and hybridization detection of CTV

El virus de la tristeza de los cítricos (CTV) es perjudicial para la citricultura y causa la enfermedad llamada tristeza de los cítricos. Infecta las especies del género Citrus ocasionando la muerte de millones de árboles. Los síntomas son decaimiento rápido (QD) y acanalamiento de tallo (SP). En el trabajo se diagnosticó molecular y serológicamente al CTV en aislados provenientes de Citrus aurantifolia o Lima Tahití (LT) y Citrus madurensis (Lour) o Calamondino (Ca), y se realizaron estudios preliminares de detección viral por medio de microscopía óptica e hibridación in situ. Se utilizó IC-RT-PCR e inmunoimpresión de tejido (IMI) expuesto a los anticuerpos monoclonales 3DF1+3CA5, y con el anticuerpo discriminante MCA 13 con técnica de Enzyme Linked Inmunossorbent Assay Doble Sándwich (Elisa-DAS). La detección por microscopía se realizó sobre secciones de pecíolo de LT y C que se tiñeron con Azure A, y con acetato de uranilo y citrato de plomo. Para la hibridación in situ se empleó una sonda marcada con digoxigenina dirigida hacia el gen de la proteína mayor de la cápside. Los resultados de IC-RT-PCR, IMI y Elisa fueron positivos para LT y C, indicando la presencia de variantes virales de tipo severo. Con microscopía de luz se detectaron inclusiones citoplasmáticas en las células acompañantes y del floema, confirmado con IMI y por hibridación in situ. Se visualizaron inclusiones de partículas virales en el tejido vegetal con microscopía electrónica con cambios en la ultraestructura celular como presencia de grandes vacuolas propias de la infección viral. Este trabajo integra distintas técnicas diagnósticas sobre dos especies cítricas exóticas.

Citrus tristeza virus (CTV) is deleterious for citriculture and causes citrus tristeza disease. CTV infects all citrus species thereby causing the death of millions of trees. Its main symptoms are quick decline (QD) and stem pitting (SP). Serological, molecular and microscopy techniques were used in this work for diagnosing CTV in Citrus aurantifolia or Tahiti Lime (Citrus latifolia Tanaka) (TL) and Citrus madurensis (Lour) or Calamondin (Ca) isolates. Petioles were tissue printed (IMI) and exposed to 3DF1+3CA5 monoclonal antibodies; they were then ELISA buffer extracted and exposed to a discriminant MCA 13 monoclonal antibody in a double-antibody sandwich indirect enzyme-linked immunosorbent assay (DASI-ELISA). Immunocapture reverse transcriptase-polymerase chain reaction (IC-RT-PCR) amplification, using specific major coat protein gene (CPG) primers, was used on the ELISA buffer extracts as template. Optical and electron microscopy were used for detection on transversal sections of petiole and stained with azure A, uranyl acetate or lead citrate. Digoxygenin-labelled major CPG CTV probes were used for in situ hybridisation of petioles printing. All IC-RT-PCR, IMI and ELISA results were positive for both LT and C, indicating the presence of severe viral variants. Light microscopy cytoplasm inclusions were detected in the phloem and accompanying cells, confirmed by IMI and in situ hybridisation. Electron microscopy analysis revealed cellular abnormalities with changes in ultrastructure and the presence of big vacuoles which are characteristic of cytoplasmic viral infection. This is the first work integrating all available diagnostic techniques on these two exotic citric species.