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.