washington & leaver: principles and practice of radiation therapy,
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Washington & Leaver: Principles and Practice of Radiation Therapy,. Chapter 35: Digestive System Tumors. At what age should a person of average risk have his or her first screening colonoscopy?. a.30 b.40 c.50 d.60. ANS:C. - PowerPoint PPT PresentationTRANSCRIPT
Washington & Leaver: Principles and Practice of Radiation Therapy,
• Chapter 35: Digestive System Tumors
At what age should a person of average risk have his or her first screening colonoscopy?
• a. 30• b. 40• c. 50• d. 60
ANS: C• According to the American Cancer
Society screening guidelines for the early detection of colorectal cancer, beginning at age 50, it is recommended that an average-risk person undergoes an annual fecal occult blood test or fecal immunochemical test, a flexible sigmoidoscopy and double contrast barium enema every 5 years, and a colonoscopy every 10 years.
A three-field technique using hinge angles of 120 degrees can be used in the treatment
of which cancer?
• a. esophageal• b. gastric• c. rectal• d. hepatic
ANS: A• A variety of off-cord field arrangements
can be used, depending on the location of the tumor. The most common field arrangements are oblique and lateral radiation portals. Many institutions use a three-field approach: an anterior field and two posterior-wedged obliques, especially for lesions of the thoracic esophagus.
Familial adenomatous polyposis (FAP) and hereditary
nonpolyposis colorectal syndrome (HNPCC) are most closely associated with which
type of cancer?• a. esophageal• b. pancreatic• c. colorectal• d. anal
ANS: C• Other principal factors in the
development of colon cancer include the following: chronic ulcerative colitis, carcinomas arising in preexisting adenomatous polyps, and the hereditary cancer syndromes. These syndromes are FAP and HNPCC.
Gastroesophageal reflux disease (GERD) is
associated with cancer of which anatomic region?
• a. esophagus• b. stomach• c. liver• d. colon
ANS: A• Long-standing gastroesophageal
reflux disease called GERD is associated with the development of adenocarcinomas of the distal esophagus.
What is the treatment of choice for most anal cancers?I. surgery II. ChemotherapyIII. radiation therapy
• a. I only• b. III only• c. I and II• d. II and III • e. I, II, and III
ANS: D• Combination radiation therapy and
chemotherapy (5-FU and mitomycin C) is advocated as the preferred method of treatment and considered the standard of care for most patients.
The Whipple is a surgical procedure associated with cancer of which
organ?
• a. pancreas• b. esophagus• c. stomach• d. colon
ANS: A• The most common potentially
curative surgical procedure for pancreatic cancer is a pancreaticoduodenectomy (Whipple procedure).
The vermiform appendix is most closely associated with which portion of the digestive
tract?
• a. ileum• b. cecum• c. duodenum • d. rectum
ANS: B• The vermiform appendix is a
diverticulum of the cecum
What is the dose-limiting structure of most concern for
radiation treatments of colorectal cancers?
• a. spinal cord• b. bladder• c. normal colon• d. small bowel
ANS: D• For irradiation of the pelvis, the
dose-limiting structure or organ-at-risk (OAR) is the small bowel. The small bowel dose should be less than 45 Gy.
What is the dose-limiting structure of most concern for radiation treatments of the
esophagus?• a. normal esophagus• b. heart• c. spinal cord• d. trachea
ANS: C• Careful dosimetry planning is
necessary to avoid overdosing the spinal cord when treating esophageal cancers. AP/PA fields are used initially; as cord tolerance is approached, an off-cord technique is implemented.
What is the most common histologic type of cancers that occur in the lower third of the
esophagus?
a. Adenocarcinomab. transitional cell carcinomac. squamous cell carcinomad. renal cell carcinoma
ANS: A• The most common pathologic types of
esophageal cancer are squamous cell carcinoma and adenocarcinoma. Squamous cell carcinomas are found most frequently in the upper and middle thoracic esophagus. Adenocarcinoma typically occurs in the distal esophagus and gastroesophageal junction; however, it can occur in other regions of the esophagus.
What substance is responsible for the brown color of feces?
a. bilirubinb. colic. Pepsind. undigested food
ANS: A• An obstruction of the biliary
system results in excess bilirubin to be excreted in urine and less bilirubin to enter the bowel. This results in patients having dark urine and light-colored stools.
Which of the following cancers is most common in the United
States?
a. esophagusb. Stomachc. Liverd. Colorectal
ANS: D• Cancer of the colon is ranked third
in incidence when comparing men and women separately.
Which of the following cancers has the highest incidence of cancer-related deaths in the
United States?
a. Esophagusb. stomach c. colorectal d. anal
ANS: C• Colorectal cancer is the second
leading cause of cancer death in the United States, accounting for approximately 53,000 deaths annually.
Which of the following is not a risk factor for anal
cancer?
• a. diet• b. human papillomavirus• c. anal intercourse• d. immunosuppression
ANS: A• The etiologic factors for the
development of anal cancer are associated with genital warts, genital infections, human papillomaviruses, anal intercourse in men or women before age 30, and immunosuppression
Which of the following cancer sites can be treated with endocavitary radiation
therapy?
a. esophagusb. stomach c. rectum d. liver
ANS: C• Endocavitary radiation therapy is a
sphincter-preserving procedure done for curative intent in a select group of patients with low- to middle-third rectal cancers that are confined to the bowel wall.
Which of the following methods may reduce the dose to the small bowel during radiation therapy?
I. supine positioning II. prone positioning
III. full bladder IV. empty bladder
• a. I and III• b. I and IV• c. II and III• d. II and IV
ANS: C• The reduction of the small-bowel
dose is achieved through patient positioning and positioning devices, bladder distention, multiple-shaped fields, and dosimetric weighting.
What condition is an iron-deficient anemia characterized by esophageal webs, atrophic glossitis, and spoon-shaped,
brittle fingernails?• a. Barrett esophagus• b. Gardner syndrome• c. Plummer-Vinson syndrome• d. tenesmus
ANS: C• Plummer-Vinson syndrome (also
known as Paterson-Kelly syndrome) is an iron-deficient anemia characterized by esophageal webs, atrophic glossitis, and spoon-shaped, brittle fingernails.
What condition is most closely associated to
gastroesophageal reflux?
• a. Barrett esophagus• b. Gardner syndrome• c. Plummer-Vinson syndrome• d. tenesmus
ANS: A• Barrett esophagus is a condition in
which the distal esophagus is lined with a columnar epithelium rather than a stratified squamous epithelium. This mucosal change usually occurs with gastroesophageal reflux.
What condition is most closely associated to adenomatous
polyposis?
• a. Barrett esophagus• b. Gardner syndrome• c. Plummer-Vinson syndrome• d. tenesmus
ANS: B• Patients with Gardner syndrome
have adenomatous polyposis of the large bowel and other abnormal growths, such as upper gastrointestinal polyps, periampullary tumors, lipomas, and fibromas.
TRUE/FALSE
Men are more at risk of developing anal cancer than women.
ANS: F• Cancers of the anus occur more
often in women than in men
Most esophageal cancers are discovered in early stages.
ANS: F• Esophageal cancer is usually
diagnosed at an advance stage and is nearly a uniformly fatal disease.
Pancreatic cancer is highly curable with combined therapies.
ANS: F• Pancreatic cancer has a high
mortality rate and is considered one of the deadliest malignancies.
Radiation treatment portals of the lower third of the esophagus
typically include the supraclavicular lymph nodes.
ANS: F• Regional spread to draining lymphatics is a
common early presentation and must be taken into consideration in the design of the radiation field. The cervical, supraclavicular, mediastinal, and subdiaphragmatic (celiac axis) lymph node regions are at risk. The degree to which these nodal groups are at risk depends on the location of the primary tumor. Supraclavicular nodes are involved more often with a proximal lesion than a distal lesion.
The treatment volume for colon cancers typically includes pelvic
lymph nodes.
ANS: T• The treatment fields for colon
cancer patients are typically designed to encompass the primary tumor volume and pelvic lymph nodes, shrinking the field to treat the primary target volume to a higher dose.