Application of PET-LINAC in Biology-guided Radiotherapy / 中国医疗器械杂志

Biology-guided radiotherapy (BgRT) is a novel technique of external beam radiotherapy, combining positron emission tomography-computed tomography (PET-CT) with a linear accelerator (LINAC). The key innovation is to utilize PET signals from tracers in tumor tissues for real-time tracking and guiding beamlets. Compared with a traditional LINAC system, a BgRT system is more complex in hardware design, software algorithm, system integration and clinical workflow. RefleXion Medical has developed the world's first BgRT system. Nevertheless, its actively advertised function, PET-guided radiotherapy, is still in the research and development phase. In this review study, we presented a number of issues related to BgRT, including its technical advantages and potential challenges.

Uso de PET-CT en el delineado de volumen en la planificación del tratamiento con radiación / Use of PET-CT in the one delineated of volume in the planning of the one radiant treatment

El tratamiento con radioterapia, consiste en irradiar de forma homogénea el tumor, evitando irradiar los órganos cercanos. El desarrollo de la tecnología en el campo de la medicina, ha permitido que se cumpla este principio, con buenos resultados de respuesta objetiva, que se traduce en el control de la enfermedad de los pacientes con cáncer. La Tomografía axial computarizada por emisión de positrones (PET-CT) consigue una mayor precisión en el delineado del volumen blanco o tumoral. El propósito de este estudio fue analizar la influencia del uso del PET-CT en el delineado de volúmenes a tratar en la planificación del tratamiento con radiaciones.Se diseñó un estudio piloto con dos pacientes preparados para radioterapia por neoplasias malignas, a los cuáles se les realizó un TAC simple y un PET-CT y observadores independientes realizaron la delimitación del tumor. Se examinó la consistencia entre los observadores y las mediciones en las imágenes.El uso del PET-CT favoreció la delimitación del volumen a irradiar lo que disminuye el riesgo para los órganos vecinos.

The treatment with radiotherapy consists on irradiating in a homogeneous way the tumor, avoiding to irradiate the near organs. The development of the technology in the field of the medicine, it has allowed that this principle is completed, with good results of objective answer what allows the control of the illness of the patients with cancer. The computerized axial tomography by positrons emission (PET-CT) it gets a bigger precision in the one delineated of the white volume or tumoral. The purpose of this study was to analyze the influence of the use of the PET-CT in the one delineated of volumes to try in the planning of the treatment with radiations.A study pilot was designed with two prepared patients for radiotherapy for malignant diseases, to those which they were carried out a simple TAC and a PET-CT and independent observers carried out the delimitation of the tumor. The consistency was examined between the observers and the mensuration in the images.The use of the PET-CT favors the delimitation of the volume to irradiate what diminishes the risk for the neighboring organs.

Advances in magnetic resonance imaging guided radiation therapy / 生物医学工程学杂志

Image-guided radiation therapy using magnetic resonance imaging (MRI) is a new technology that has been widely studied and developed in recent years. The technology combines the advantages of MRI imaging, and can offer online real-time tracking of tumor and adjacent organs at risk, as well as real-time optimization of radiotherapy plan. In order to provide a comprehensive understanding of this technology, and to grasp the international development and trends in this field, this paper reviews and summarizes related researches, so as to make the researchers and clinical personnel in this field to understand recent status of this technology, and carry out corresponding researches. This paper summarizes the advantages of MRI and the research progress of MRI linear accelerator (MR-Linac), online guidance, adaptive optimization, and dosimetry-related research. Possible development direction of these technologies in the future is also discussed. It is expected that this review can provide a certain reference value for clinician and related researchers to understand the research progress in the field.

Braquiterapia adaptativa guiada por resonancia magnética para el cáncer cervical localmente avanzado: experiencia del Hospital Carlos Van Buren / MRI-guided adaptive brachytherapy for locally advanced cervical cancer: experience at Carlos Van Buren Hospital

Introducción y objetivos: El tratamiento estándar para pacientes con cáncer cervical localmente avanzado (CCLA) se basa en radioterapia externa y quimioterapia concomitante seguida de braquiterapia adaptativa guiada por imágenes (BTAGI). El objetivo de este estudio fue describir los resultados del protocolo de BTAGI de resonancia magnética del Servicio de Oncología del Hospital Carlos Van Buren. Métodos: En pacientes con CCLA tratadas con Radioquimioterapia concomitante seguida de BTAGI de resonancia magnética se evaluó la reducción tumoral, parámetros dosimétricos y la toxicidad aguda. Resultados: Se evaluó la reducción tumoral entre el diagnóstico y el momento de la braquiterapia en 34 pacientes. Todas las pacientes completaron el tratamiento de radioterapia externa. Veinticuatro pacientes recibieron 3 sesiones de braquiterapia. Dosis equivalentes totales > 80 Gy se logro en todos los pacientes. Doce pacientes presentaron reducción del volumen tumoral mayor al 70%. La mediana de las dosis equivalentes totales prescritas al D2cc de vejiga fue 73.9 Gy, al recto 65.6 Gy y al intestino fue de 69.1 Gy. Una paciente presento toxicidad gastrointestinal grado ≥ 3. No hubo diferencias estadísticamente significativas al comparar pacientes que recibieron dosis equivalentes totales desde los 85 Gy con las que recibieron menor dosis respecto a toxicidad gastrointestinal (p=0.33) y genitourinaria (p=0.97). Conclusión: La braquiterapia adaptativa guiada por resonancia magnética se puede realizar en el sistema público de salud y cumplir con las recomendaciones internacionales requeridas para el tratamiento estándar del CCLA.

Introduction and purpose: External beam radiation therapy with concomitant chemotherapy followed by adaptive image-guided brachytherapy (IGABT) is the standard of care for patients with locally advanced cervical cancer (LACC). The purpose of this study was to describe the local outcomes of the magnetic resonance IGABT protocol at the radiation oncology department of the Carlos Van Buren Hospital. Methods: Tumor reduction, dosimetric parameters and acute toxicity were evaluated in patients with LACC treated with concomitant radiochemotherapy followed by magnetic resonance IGABT. Results: Tumor reduction between diagnosis and brachytherapy was evaluated in 34 patients. All patients completed external radiation therapy treatment. Twenty-four patients received 3 sessions of brachytherapy. All patients received a total equivalent dose > 80 Gy. Twelve patients showed a tumor volume reduction greater than 70%. The median total equivalent dose prescribed to the bladder D2cc was 73.9 Gy, the rectum 65.6 Gy, and the intestine 69.1 Gy. One patient presented grade ≥ 3 gastrointestinal toxicity. No statistically significant differences were found when comparing patients who received total equivalent doses larger than 85 Gy with those who received lower doses regarding gastrointestinal (p = 0.33) and genitourinary (p = 0.97) toxicity. Conclusion: MRI-guided adaptive brachytherapy can be performed in the public health system and achieve the international recommendations required as standard of care treatment of LACC.

Image-Guided BrachyAblation (IGBA) en hepatocarcinoma: descripción de la técnica y reporte del primer caso en Chile / Image-guided brachyablation for hepatocarcinoma: report of one case

Eighty percent of hepatocarcinomas are inoperable at the moment of diagnosis. Liver transplantation is the treatment of choice in these cases, but local therapies are another alternative. Among these, Image-Guided BrachyAblation is a safe choice. We report a 76-year-old male with a hepatocarcinoma, who was considered inoperable due to the high surgical risk of the patient. A local treatment with Image-Guided BrachyAblation was decided. A brachytherapy needle was placed in the tumor under computed tomography guidance and a 15 Gy single dose was delivered from an Iridium-192 source. The patient had no immediate complications and at one month of follow up he continued without incidents.

Current status of stereotactic body radiotherapy for the treatment of hepatocellular carcinoma / 영남의대학술지

Stereotactic body radiotherapy (SBRT) is an advanced form of radiotherapy (RT) with a growing interest on its application in the treatment of hepatocellular carcinoma (HCC). It can deliver ablative radiation doses to tumors in a few fractions without excessive doses to normal tissues, with the help of advanced modern RT and imaging technologies. Currently, SBRT is recommended as an alternative to curative treatments, such as surgery and radiofrequency ablation. This review discusses the current status of SBRT to aid in the decision making on how it is incorporated into the HCC management.

Efficacy and dosimetry analysis of image-guided radioactive ¹²⁵I seed implantation as salvage treatment for pelvic recurrent cervical cancer after external beam radiotherapy / 부인종양

OBJECTIVE: To investigate the efficacy of image-guided radioactive 125I seed (IGRIS) implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy (EBRT), and analyze the influence of clinical and dosimetric factors on efficacy. METHODS: From July 2005 to October 2015, 36 patients with PRCC received IGRIS. We evaluated local progression-free survival (LPFS) and overall survival (OS). RESULTS: The median follow up was 11.5 months. The 1- and 2-year LPFS rate was 34.9% and 20%, respectively. The multivariate analysis indicated recurrence site (central or pelvic wall) (hazard ratio [HR]=0.294; 95% confidence interval [CI]=0.121–0.718), lesion volume (HR=2.898; 95% CI=1.139–7.372), D 90 (HR=0.332; 95% CI=0.130–0.850) were the independent factors affecting LPFS. The 1- and 2-year OS rate was 52.0% and 19.6%, respectively. The multivariate analysis suggested pathological type (HR=9.713; 95% CI=2.136–44.176) and recurrence site (HR=0.358; 95% CI=0.136–0.940) were the independent factors affecting OS. The dosimetric parameters of 33 patients mainly included D 90 (128.5±47.4 Gy), D 100 (50.4±23.7 Gy) and V 100 (86.7%±12.9%). When D 90 ≥105 Gy or D 100 ≥55 Gy or V 100 ≥91%, LPFS was extended significantly, but no significant difference for OS. The 79.2% of 24 patients with local pain were suffering from pain downgraded after radioactive 125I seed implantation. CONCLUSION: IGRIS implantation could be a safe and effective salvage treatment for PRCC after EBRT, which could markedly release the pain. Recurrence site, tumor volume and dose were the main factors affected efficacy. Compared with central recurrence, it was more suitable for patients with pelvic wall recurrent cervical cancer after EBRT.

Interfraction variation and dosimetric changes during image-guided radiation therapy in prostate cancer patients

PURPOSE: The aim of this study was to identify volume changes and dose variations of rectum and bladder during radiation therapy in prostate cancer (PC) patients. MATERIALS AND METHODS: We analyzed 20 patients with PC treated with helical tomotherapy. Daily image guidance was performed. We re-contoured the entire bladder and rectum including its contents as well as the organ walls on megavoltage computed tomography once a week. Dose variations were analyzed by means of Dmedian, Dmean, Dmax, V₁₀ to V₇₅, as well as the organs at risk (OAR) volume. Further, we investigated the correlation between volume changes and changes in Dmean of OAR.

The use of tissue fiducial markers in improving the accuracy of post-prostatectomy radiotherapy

PURPOSE: The aim of this retrospective study was to investigate the use of a radiopaque tissue fiducial marker (TFM) in the treatment of prostate cancer patients who undergo post-prostatectomy radiotherapy (PPRT). TFM safety, its role and benefit in quantifying the set-up uncertainties in patients undergoing PPRT image-guided radiotherapy were assessed. MATERIALS AND METHODS: A total of 45 consecutive PPRT patients underwent transperineal implantation of TFM at the level of vesicourethral anastomosis in the retrovesical tissue prior to intensity-modulated radiotherapy. Prostate bed motion was calculated by measuring the position of the TFM relative to the pelvic bony anatomy on daily cone-beam computed tomography. The stability and visibility of the TFM were assessed in the initial 10 patients. RESULTS: No postoperative complications were recorded. A total of 3,500 images were analysed. The calculated prostate bed motion for bony landmark matching relative to TFM were 2.25 mm in the left-right, 5.89 mm in the superior-inferior, and 6.59 mm in the anterior-posterior directions. A significant 36% reduction in the mean volume of rectum receiving 70 Gy (rV₇₀) was achieved for a uniform planning target volume (PTV) margin of 7 mm compared with the Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group recommended PTV margin of 10 mm. CONCLUSION: The use of TFM was safe and can potentially eliminate set-up errors associated with bony landmark matching, thereby allowing for tighter PTV margins and a consequent favourable reduction in dose delivered to the bladder and rectum, with potential improvements in toxicities.

Set-up errors in head and neck cancer treated with IMRT technique assessed by cone-beam computed tomography: a feasible protocol

PURPOSE: To investigate set-up errors, suggest the adequate planning target volume (PTV) margin and image-guided radiotherapy frequency in head and neck (H&N) cancer treated with intensity-modulated radiotherapy (IMRT) assessed by kV cone-beam computed tomography (CBCT). METHODS: We analyzed 360 CBCTs in 60 patients with H&N cancer treated with IMRT. The target delineation was contoured according to ICRU62. PTVs were generated by adding a 3–5 mm margin in all directions to the respective clinical target volumes. The kV CBCT images were obtained at first three days of irradiation and weekly thereafter. The overall mean displacement, range, systematic (∑) and random (σ) errors were calculated. Adequate PTV margins were calculated according to the van Herk formula (2.5∑ + 0.7r). RESULTS: The mean of set-up errors was less than 2 mm in any direction. The overall frequency of set-up displacements greater than 3 mm was 3.9% in medial-lateral (ML) direction, 8% in superior-inferior (SI) direction, and 15.5% in anterior-posterior (AP) direction. The range of translations shifts was 0–9 mm in ML direction, 0–5 mm in SI direction and 0–10 mm in AP direction, respectively. After systematic set-up errors correction, the adequate margin to overcome the problem of set-up errors was found to be less than 3 mm. CONCLUSION: Image-guided kV CBCT was effective for the evaluation of set-up accuracy in H&N cancer. The kV CBCT at first three fractions and followed-by weekly appears adequate for reducing significantly set-up errors in H&N cancer treated with IMRT technique. Finally, 3–5 mm PTV margins appear adequate and safe to overcome the problem of set-up errors.

Accuracy of different image registration methods in image-guided adaptive brachytherapy for cervical cancer / 南方医科大学学报

OBJECTIVE@#To compare the accuracy of different methods for image registration in image-guided adaptive brachytherapy (IGABT) for cervical cancer.@*METHODS@#The last treatment planning CT images (CT1) and the first treatment planning CT images (CT2) were acquired from 15 patients with cervical cancer and registered with different match image qualities (retained/removed catheter source in images) and different match regions [target only (S Group)/ interested organ structure (M Group)/body (L Group)] in Velocity3.2 software. The dice similarity coefficient (DSC) between the clinical target volumes (CTV) of the CT1 and CT2 images (CTVCT1 and CTVCT2, respectively) and between the organs-at-risk (OAR) of the two imaging datasets (OARCT1 and OARCT2, respectively) were used to evaluate the image registration accuracy.@*RESULTS@#The auto-segmentation volume of the catheter source using Velocity software based on the CT threshold was the closest to the actual volume within the CT value range of 1700-1800 HU. In the retained group, the DSC for the OARs of was better than or equal to that of the removed group, and the DSC value of the rectum was significantly improved ( < 0.05). For comparison of different match regions, the high-risk target volume (HRCTV) and the low-risk target volume (IRCTV) had the best precision for registration of the target area, which was significantly greater than that of M group and L group ( < 0.05). The M group had better registration accuracy of the target area and the best accuracy for the OARs. The DSC values of the bladder and rectum were significantly better than those of the other two groups ( < 0.05).@*CONCLUSIONS@#The CT value range of 1700-1800 HU is optimal for automatic image segmentation using Velocity software. Automatic segmentation and shielding the volume of the catheter source can improve the image quality. We recommend the use of interested organ structures regions for image registration in image-guided adaptive brachytherapy for cervical cancer.

Strategic application of radiotherapy for hepatocellular carcinoma

With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT. An essential feature of IGRT is that it allows image guidance therapy through in-room images obtained during radiation delivery. Compared with 3D-conformal RT, distinctions of IMRT are inverse treatment planning process and use of a large number of treatment fields or subfields, which provide high precision and exquisitely conformal dose distribution. These modern RT techniques allow more precise treatment by reducing inter- and intra-fractional errors resulting from daily changes and irradiated dose at surrounding normal tissues. More recently, particle therapy has been actively investigated to improve effectiveness of RT. This review discusses modern RT strategies for HCC, as well as optimal selection of RT in multimodal approach for HCC.

Target organ damage among subjects with high­normal blood pressure in a Nigerian tertiary health institution

Background: There is paucity of data on the relationship between high ­ normal blood pressure (BP) and target organ damage (TOD) in sub-Saharan Africa including Nigeria. This study therefore, aimed to assess target organ damage (TOD) among subjects with high ­ normal BP in comparison with hypertensives and subjects with optimal BP. Materials and Methods: The study was crosssectional and comparative conducted at Aminu Kano Teaching Hospital, Kano on eligible subjects aged 18 years and above. Three groups comprising of randomly selected subjects (high -normal (group 1), hypertension (group 2) and optimal BP (group 3)), with each group having 100 in number were studied. Funduscopy and relevant investigations including transthoracic echocardiography were carried out. High ­ normal BP was defined as systolic BP of 130 -139mmHg and/or diastolic BP of 80-89mmHg. Results: The mean age of subjects in group 1 was 27.32 ± 8.20 years and 60% were female, 34.04±6.25 years for group 2 and 53% were female, and 52.81 ± 13.3 years for group 3 and 56% were female (P = < 0.001). The most prevalent TOD was left ventricular hypertrophy,present in 62% of hypertensives, 14% of those with high-normal BP and 2% of those with optimal BP(P = <0.001). Micro albuminuria and slight increase in creatinine were found in 12.9% and 6% of subjects with high-normal BP; 25.7% and 25% of hypertensives and 4.1% and 3% of subjects with optimal BP. The study found a significant progressive increase in both cardiovascular disease risk factors and target organ damage (TOD) as BP increased across the blood pressure categories from optimal BP to high ­ normal BP and to hypertension (P = <0.05). Conclusion: Subjects with high-normal BP had significantly higher prevalence of both TOD and cardiovascular disease risk factors than those with optimal BP but lower than hypertensives, suggesting that efforts to control BP should start early to reduce the complications of high BP

Quality of Life after post-prostatectomy intensity modulated radiation therapy to the prostate bed with or without the use of gold fiducial markers for image guidance or higher total radiotherapy doses

ABSTRACT Purpose To evaluate quality of life (QoL) after post-prostatectomy intensity modulated radiation therapy (IMRT) in the "adjuvant" setting starting within 4 months of radical prostatectomy for adverse features; and "salvage" setting for a PSA≥0.2ng/mL. Materials and Methods Retrospective review of 130 patients who underwent IMRT to the prostate bed±gold fiducial marker placement for image guidance to 64.8-72.0Gy (median, 70.2Gy) between 2004 and 2013. Higher doses were defined as 70.2-72.0Gy and lower doses were defined as 64.8-68.4Gy. Androgen deprivation therapy (ADT) was given to 4/48 (8%) adjuvant patients and 9/82 (11%) salvage patients. International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM), and Expanded Prostate Cancer Index Composite-26-bowel (EPIC-26-bowel) questionnaires were used to assess urinary, sexual, and bowel QoL, respectively. Results Median follow-up was 46 months. There were better urinary (p=0.03) and sexual (p=0.002) QoL scores with adjuvant IMRT relative to salvage IMRT. The use of prostate bed fiducial markers did not significantly affect urinary, sexual, or bowel QoL (p=0.39, p=0.49, and p=0.40, respectively). Higher total radiotherapy doses did not significantly affect urinary, sexual, or bowel QoL (p=0.21, p=0.61, and p=0.36, respectively). Conclusions There was no significant change in urinary, sexual, and bowel sexual QoL with post-prostatectomy IMRT regardless of whether prostate bed fiducial markers or higher total radiotherapy doses were used. QoL with IMRT in the present study compares favorably with prior reports for three-dimensional conformal radiation therapy.

Synthesis of ultrasound contrast agents: characteristics and size distribution analysis (secondary publication)

PURPOSE: The purpose of this study was to establish a method for ultrasound (US) contrast agent synthesis and to evaluate the characteristics of the synthesized US contrast agent. METHODS: A US contrast agent, composed of liposome and sulfur hexafluoride (SF₆), was synthesized by dissolving 21 μmol 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine (DPPC, C₄₀H₈₀NO₈P), 9 μmol cholesterol, and 1.9 μmol of dihexadecylphosphate (DCP, [CH₃(CH₂)15O]₂P(O)OH) in chloroform. After evaporation in a warm water bath and drying for 12-24 hours, the contrast agent was synthesized using the sonication process by the addition of a buffer and SF₆ gas. The size distribution of the bubbles was analyzed using dynamic light scattering measurement methods. The degradation curve was evaluated by assessing the change in the number of contrast agent bubbles using light microscopy immediately, 12, 24, 36, 48, 60, 72, and 84 hours after synthesis. The echogenicity of the synthesized microbubbles was compared with commercially available microbubbles (SonoVue, Bracco). RESULTS: contrast agent was synthesized successfully using an evaporation-drying-sonication method. Most bubbles had a mean diameter of 154.2 nm and showed marked degradation 24 hours after synthesis. Although no statistically significant differences were observed between SonoVue and the synthesized contrast agent, a difference in echogenicity was observed between the synthesized contrast agent and saline (P<0.01). CONCLUSION: We successfully synthesized a US contrast agent using an evaporation-dryingsonication method. These results may help future research in the fields of anticancer drug delivery, gene delivery, targeted molecular imaging, and targeted therapy.

Validez diagnóstica de la endosonografía biliopancreática en el diagnóstico de colangitis aguda secundaria a obstrucción biliar / Diagnostic Validity of Biliopancreatic Endosonography in the Diagnosis of Acute Cholangitis Secondary to Biliary Obstruction

Resumen El diagnóstico de las colangiopatías obstructivas por endosonografía biliopancreática (EUS, por sus siglas en inglés) se ha estudiado en profundidad, y existe un extenso reconocimiento de su papel para el diagnóstico de coledocolitiasis, tumores de la encrucijada biliopancreática y síndromes de compresión extrínseca de la vía biliar. La colangitis, la complicación más frecuente de la obstrucción biliar y responsable de gran parte de su morbimortalidad, no se ha relacionado en forma suficiente con los hallazgos endosonográficos. Nuestro estudio buscó definir la validez diagnóstica de la endosonografía en los pacientes con colangitis aguda con el fin de limitar la morbimortalidad del retraso diagnóstico. Se realizó un estudio descriptivo, analizando las historias clínicas de pacientes sometidos a endosonografía biliopancreática, por ictericia obstructiva de cualquier etiología, y quienes posteriormente fueron llevados a colangiopancreatografía retrógrada endoscópica (CPRE) para manejo de obstrucción biliar. Comparamos los hallazgos endosonográficos compatibles con colangitis aguda (engrosamiento de la vía biliar de 1,5 mm o más, presencia de halo pericolangítico de al menos 1,5 cm de longitud y presencia de contenido de ecogenicidad mixta en el interior de la vía biliar) con el drenaje purulento durante la CPRE. Se encontró una alta frecuencia de estos hallazgos en los pacientes con colangitis, y el engrosamiento de las paredes de la vía biliar fue el más común, en el 92,6% de los casos, seguido por la presencia de halo pericolangítico en el 59,3% de los casos y contenido ductal en el 66,7% de los casos. Igualmente, se encontró asociación ascendente de las frecuencias con grado de severidad de la colangitis. Resulta recomendable realizar estudios con un mayor poder estadístico que permitan validar nuestros resultados para una futura inclusión de la EUS en el algoritmo diagnóstico de las guías de práctica clínica en colangitis aguda.

Abstract Diagnosis of obstructive cholangiopathy with biliopancreatic endosonography (BUS) has been extensively studied, and its role in the diagnosis of choledocholithiasis, biliopancreatic junction tumors and extrinsic biliary compression syndromes is widely recognized. Endosonographic diagnosis of cholangitis, a more frequent complication of biliary obstruction which is responsible for much of its morbidity and mortality, has not been sufficiently studied. Our study's objective is to define the diagnostic validity of endosonography for patients with acute cholangitis in order to limit morbidity and mortality due to diagnostic delay. This is a descriptive study that analyzes clinical histories of patients who underwent biliopancreatic endosonography because of obstructive jaundice of any etiology and who later underwent endoscopic retrograde cholangiopancreatography (ERCP) to manage biliary obstruction. We compared endosonographic findings compatible with acute cholangitis: thickening of the bile duct of 1.5 mm or more, periportal halo sign of at least 1.5 cm in length, mixed echogenicity of bile duct content, and purulent drainage during ERCP. Patients with cholangitis most frequently presented thickened gallbladders (92.6% of cases) periportal halo signs (59.3% of cases) and mixed echogenicity of bile duct content (66.7% of cases). We also found an ascending association of frequencies with the degree of severity of cholangitis. Studies with greater statistical power are needed for validation of our results and for future inclusion of EUS in the diagnostic algorithm for clinical practice guidelines in cases of acute cholangitis.

Automatic detection of liver tumor motion by fluoroscopy images

Background: A method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement

Materials and Methods: The method was based on the following idea: [i] Before treatment, a series of fluoroscopic images corresponding to different breathing phases and tumor positions were acquired after patient set-up; [iii] The wavelet transform method and Canny edge detection algorithm were used to detect motion trajectory of the diaphragm; [iv] The motion curves of center of lipiodol in the images were obtained by mathematical morphology and median filtering algorithm. The method was evaluated using by five sequences of fluoroscopic images from TACE patients who received transcatheter arterial chemoembolization therapy

Results: The position of liver tumor was significantly affected by respiratory motion; the motion trajectories of the diaphragm and lipiodolagreed well with the manually marked locations in amplitude and period; the motion trajectories of the diaphragm and lipiodol almost had similar period and amplitude in one treatment fraction. The respiratory period and amplitude of the same patient in different fractions had no significant differences; however, the difference was obvious for different patients. The proposed lipiodol detection methods can effectively reflect the relevant rules of tumor location caused by respiratory movement

Conclusion: Direct tracking of liver tumor motion in fluoroscopic images is feasible. The automatic detection method can reflect the characteristics of respiratory and tumor motions, which can save much time and significantly improve measurement precision compared with manual measurement

Long-term results of post-operative pelvic image guided intensity modulated radiotherapy in gynecological malignancies

Objective: To assess late clinical outcomes with image guided intensity modulated radiotherapy [IG- IMRT] in gynecological malignancies

Patients and methods: We have been practicing IG IMRT for gynecological malignancies since January 2009. Here we are presenting our experience with this modern technique at median follow up of 38 months. During whole treatment bladder filling protocol was followed, Both target volumes and critical structures were contoured according to RTOG guidelines. Dose prescribed to clinical target volume [postop bed and nodal volume] was 50.4 Gy in 28 fractions. Cone beam CT [CBCT] scans were taken to quantify the status of target volume and normal structures

Results: 80 patients were evaluated and analyzed who were treated from January 2009 to December 2014. Median age of our patients was 56.5 years. Out of eighty forty four patients [55%] were of carcinoma endometrium and the rest 36 [45%] were of carcinoma cervix. None of our patients experienced late grade 3 or 4 bladder toxicity Although late grade 3 and 4 bowel and rectal toxicity was experienced by single patient. 2.5% patients developed local recurrence, 5% patient developed nodal with distant metastases and 6.25% only distant metastases. Three ol our patients developed lung cancer as second primary during follow up. 76.2% patients are alive with regulaf follow up

Conclusions: Our study concluded that IG IMRI increases patient compliance and reduces long-term side effects in post-operative gynecological malignancies without compromising local-regional control, disease free survival and overall survival

Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer

PURPOSE: To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. MATERIALS AND METHODS: We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. RESULTS: The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. CONCLUSION: As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.

Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer

PURPOSE: To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. MATERIALS AND METHODS: We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. RESULTS: The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. CONCLUSION: As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.