Radiation therapy and photodynamic therapy for biliary tract and ampullary carcinomas

The purpose of radiation therapy for unresectable biliary tract cancer is to prolong survival or prolong stent patency, and to provide palliation of pain. For unresectable bile duct cancer, there are a number of studies showing that radiation therapy is superior to the best supportive care. Although radiation therapy is used in many institutions, no large randomized controlled trials (RCTs) have been performed to date and the evidence level supporting the superiority of this treatment is low. Because long-term relief of jaundice is difficult without using biliary stenting, a combination of radiation therapy and stent placement is commonly used. As radiation therapy, external-beam radiation therapy is usually performed, but combined use of intraluminal brachytherapy with external beam radiation therapy is more useful for making the treatment more effective. There are many reports demonstrating improved response rates as well as extended survival and time to recurrence achieved by this combination therapy. Despite the low level of the evidence, this combination therapy is performed at many institutions. It is expected that multiinstitutional RCTs will be carried out. Unresectable gallbladder cancer with a large focus is usually extensive, and normal organs with high radio sensitivity exist contiguously with it. Therefore, only limited anticancer effects are to be expected from external beam radiation therapy for this type of cancer. The number of reports on ampullary cancer is small and the role of radiation therapy in this cancer has not been established. Combination treatment for ampullary cancer consists of either a single use of intraoperative radiation therapy, postoperative external beam radiation therapy or intraluminal brachytherapy, or a combination of two or three of these therapies. Intraoperative radiation therapy is superior in that it enables precise irradiation to the target site, thereby protecting adjacent highly radiosensitive normal tissues from irradiation. There are reports showing extended survival, although not significant, in groups undergoing intraoperative or postoperative radiation therapy compared with groups without radiation therapy. To date, there are no reports of large RCTs focusing on the significance of radiation therapy as a postoperative adjuvant treatment, so its usefulness as a postoperative adjuvant treatment is not proven. An alternative treatment is photodynamic therapy. There is an RCT demonstrating that, in unresectable bile duct cancer, extended survival and improved quality of life (QOL) have been achieved through a combination of photodynamic therapy and biliary stenting, compared with biliary stenting alone. Results from large RCTs are desired

Flowcharts for the management of biliary tract and ampullary carcinomas

No strategies for the diagnosis and treatment of biliary tract carcinoma have been clearly described. We developed flowcharts for the diagnosis and treatment of biliary tract carcinoma on the basis of the best clinical evidence. Risk factors for bile duct carcinoma are a dilated type of pancreaticobiliary maljunction (PBM) and primary sclerosing cholangitis. A nondilated type of PBM is a risk factor for gallbladder carcinoma. Symptoms that may indicate biliary tract carcinoma are jaundice and pain in the upper right area of the abdomen. The first step of diagnosis is to carry out blood biochemistry tests and ultrasonography (US) of the abdomen. The second step of diagnosis is to find the local extension of the carcinoma by means of computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP). Because resection is the only way to completely cure biliary tract carcinoma, the indications for resection are determined first. In patients with resectable disease, the indications for biliary drainage or portal vein embolization (PVE) are checked. In those with nonresectable disease, biliary stenting, chemotherapy, radiotherapy, and/or best supportive care is selected

CONSTRUCTING GEOLOGICAL CROSS-SECTIONS TO CONSTRAIN THE THREE-DIMENSIONAL STRATIGRAPHIC ARCHITECTURE OF THE JEZERO DELTA FRONT

International audienceThe NASA Mars2020 rover Perseverance has been traversing series that represent the transition from crater floor lithologies to deposits of the Jezero western delta since Sol 422 of rover operations [1]. During that time, the mission has explored the exposed stratigraphic succession at the delta front, named the Shenandoah formation [2]. Here we analyse Mastcam-Z mosaics and 3D data products derived from Planetary Robotics processing and viewing tools (PRoViP and PRo3D [3]) to map the 3D geometry of key stratigraphic boundaries and document the 3D stratigraphic architecture at the sub-km- to m-scale within the Shenandoah formation

CONSTRUCTING GEOLOGICAL CROSS-SECTIONS TO CONSTRAIN THE THREE-DIMENSIONAL STRATIGRAPHIC ARCHITECTURE OF THE JEZERO DELTA FRONT

International audienceThe NASA Mars2020 rover Perseverance has been traversing series that represent the transition from crater floor lithologies to deposits of the Jezero western delta since Sol 422 of rover operations [1]. During that time, the mission has explored the exposed stratigraphic succession at the delta front, named the Shenandoah formation [2]. Here we analyse Mastcam-Z mosaics and 3D data products derived from Planetary Robotics processing and viewing tools (PRoViP and PRo3D [3]) to map the 3D geometry of key stratigraphic boundaries and document the 3D stratigraphic architecture at the sub-km- to m-scale within the Shenandoah formation