Diseases, Treatments, and Imaging Pitfalls

Question 1

Autoimmune and cancer

Answer 1

Most often dealt with by medical physicists

Question 2

Examples of autoimmune diseases

Answer 2

Rheumatoid arthritis (joints), Systemic Lupus Erythematosus (vasculitis), Crohn’s Disease (small bowel/colon), Diffuse Toxic Goiter (thyroid), Psoriasis (skin), Aplastic anemia (blood cell lines)

Question 3

Diffuse Toxic Goiter (Grave’s Disease)

Answer 3

T- and B-cells produce antibodies to the TSH receptor, stimulates uptake of iodine, growth of thyroid follicles and production of thyroid hormone (hyperthyroidism). “Goiter” refers to a chronic enlargement of the thyroid gland.

Question 4

Symptoms of Hyperthyroidism

Answer 4

Weight loss with normal appetite, Nervousness / irritability / sleeplessness, Heat intolerance / sweating, Tremors, Diarrhea, Menstrual abnormalities, Palpitations (irregular heartbeat)

Question 5

Exophthalmos

Answer 5

Can be a complication of hyperthyroidism. Eye bulges out of socket.

Question 6

Treatment of Toxic Goiter

Answer 6

Drugs (propylthiouracil) and beta blockers (short-term), Ablation with radioactive iodine

Question 7

Characteristics of Cancer

Answer 7

Dedifferentiation, Neovascularity (independent vessel generation), Invasiveness, Metastasis

Question 8

Carcinoma vs Sarcoma vs Lymphoma

Answer 8

Cancer of epithelial tissues like glands and skins vs cancer of bone and soft tissues vs Cancer of lymphatic tissue

Question 9

Glioma vs Neuroendocrine tumor

Answer 9

Tumor of glial (supporting brain) cells vs Actual cancer of the neurons from embryo

Question 10

TNM System for Cancer Classification

Answer 10

T: extent of tumor, N: lymph node involvement, M: metastasis. Brain and blood do not have TNM designation.

Question 11

Stage System for cancer classification (defunct)

Answer 11

0 - very localized cancer, IV - completely metastatic

Question 12

T Designations for Cancer

Answer 12

TX - cannot be evaluated, T0 - no primary tumor, Tis - non-invasive carcinoma, and T1~4 for size and extent of primary tumor

Question 13

“Summary Staging” for cancer classification

Answer 13

In situ, localized (contained within the organ), regional (spread to nearby organs), and distant (spread far)

Question 14

RECIST

Answer 14

Response Evaluation Criteria In Solid Tumors is an imaging-based method for quantifying the changes in solid tumor size and other parameters in response to radiation or drug therapy. Graded as Complete Response, Partial Response, Stable Disease or Progressive Disease.

Question 15

Breast cancer therapy

Answer 15

Characterized by microcalcifications. Treatments include lumpectomy (cutting away small lumps to preserve breast), mastectomy + lymph node dissection, LINAC/IMRT, brachytherapy (introducing radioisotopes to body), and chemotherapy like estrogen receptor blockers

Question 16

Cervical cancer therapy

Answer 16

Therapy options include surgery (hysterectomy: removal of uterus), brachytherapy, external beam therapy for invasive disease. Isotopes include cesium-137 and Iridium-192 (74 days).

Question 17

Lung cancer therapy

Answer 17

Treatments include surgery (lobectomy, wedge resection, pneumonectomy), external beam, chemotherapy if metastatic

Question 18

Prostate cancer therapy

Answer 18

Symptoms of prostate cancer include frequency of urination and difficulty in urination. Blood Prostate Specific Antigen is high. Treatments include resection of prostate, cryosurgery (freezing), external beam, radioactive implants (brachytherapy, includes iodine-125 or palladium-103)

Question 19

Brain tumor therapy

Answer 19

Resection, chemotherapy, gamma knife, brachytherapy

Question 20

Thyroid cancer therapy

Answer 20

2:1 female-male ratio. Tc-99m pertechnetate scintigraphy can identify this cancer. Total body diagnostic I-131 scan to identify metastasis and kill.

Question 21

Hodgkin’s Disease (Lymphoma)

Answer 21

Characterized by enlarged lymph glands near neck, groin. Treated with external beam radiation therapy, great prognosis

Question 22

Non-Hodgkin’s Lymphoma

Answer 22

About 200 / 100,000 per year in U.S (7 – 8 times more common than Hodgkin’s Disease), diffuse disease involving lymph nodes and bone marrow. T-cell and B-cell types. Gallium-67 citrate scintigraphy and PET with F18-FDG. Immunotherapy with monoclonal antibodies against B-cells (MAB); radioimmunotherapy: I-131 MAB or Y-90 MAB

Question 23

Intraocular Melanoma

Answer 23

Cancer of the eye, can be treated with enucleation (eye removal). Radiation therapy can be an effective treatment that preserves vision and the eye. Episcleral plaque therapy (disk of radioactive substance attached near eye) with Iodine-125 or Palladium-103.

Question 24

Organomegaly

Answer 24

Due to outlet obstruction, tissue hypertrophy. Splenic hypertrophy can be caused by sickle cell anemia or portal vein obstruction.

Question 25

Replacement

Answer 25

Primary tumors can replace normal tissue with neoplastic processes. Hepatic steatosis (“fatty liver”) is an example of non-tumor replacement.

Question 26

Benign vs metastatic on radiographs/CT

Answer 26

For benign, regularly shaped and encapsulated, calcification is extensive; for metastatic, irregular shape and spread out, invasion of nearby tissues, calcification is sporadic

Question 27

Types of abnormal gas or liquid collection

Answer 27

Gas: pneumothorax, pneumomediastinum, bacterial overgrowth, dead tissues; Liquid: internal bleeding, obstruction, ascites (fluid in abdomen), inflammation, cysts

Question 28

Streaking artifact on CT

Answer 28

Metal or other hard substances cause this artifact

Question 29

Ferromagnetic material on MRI

Answer 29

Can cause dark bands, if magnet causes the slice to be outside of slice selection.

Question 30

Movement during MRI

Answer 30

Can cause multiple images of the body to smear across

Question 31

Movement during CT

Answer 31

Can cause parts of the screen to look like it’s “breaking off”

Question 32

Variant Anatomy

Answer 32

When body naturally has different stuff than normal, like extra bone, etc.