ONCOLOGY

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ONCOLOGY

• By
• Michael Townsend

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Oncology

• Ga67 Tumor, Planar
• Ga67 Tumor, SPECT
• Monoclonal Antibody Imaging
• Peptide Imaging
• Breast Imaging
• Lymphoscintigraphy / SLN location
• Tumor PET

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Ga67 Tumor, Planar

• Ga67 has been found to be efficacious in a few
  histologic types of cancer. These include
  bronchogenic carcinoma, Hodgkins and
  non-Hodgkins lymphoma, and in primary hepatomas.
  
• Concentration of gallium may be found in other
  tumor types but with low sensitivity and
  specificity.

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Ga67 Tumor, Planar

• Indications
• Staging and post therapy imaging in
• 1. Lung carcinoma
• 2. Hodgkins disease
• 3. Non-Hodgkins lymphoma
• 4. Hepatocellular carcinoma
• 5. Melanoma
• 6. Leukemia

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Ga67 Tumor, Planar

• Ga67 needs a medium energy large field of view
  collimator for the 184 and 296 keV energes.
• Dosage range 5-10 mCi

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Ga67 Tumor, Planar

• Patient Prep
• 5-10 mCi (10 mCi in Shackett) of Ga67 citrate is
  given intravenously.
• Imaging begins 72 hours post injection
• If the area of interest is in the abdomen, the
  patient should have cleansing enemas the day
  before and the morning of the examination
• Patient should be instructed to void on return to
  the department

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Ga67 Tumor, Planar

• Contraindications
• Patients cannot have other nuclear medicine
  studies during the time period for the gallium
  scan
• Patients cannot have contrast studies during the
  time period needed for the gallium scan

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Ga67 Tumor, Planar

• Equipment
• Collimator- medium to high energy, parallel hole
• Statistics peak for gallium, with windows at
  25, 1000 Kcounts per image
• Whole body 10cm/min. Head to mid-femur

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Ga67 Tumor, Planar

• Abnormal results
• Large hematomas present as cold spots
• Can show neoplasia associated with Hodgkins
  disease, hepatomas from aloholic cirrhosis, and
  malignant melanomas of bone, brain and lung.

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Ga67 Tumor, SPECT

• Malignant tissue has an affinity for Ga67, so
  small lymph nodes involved with malignancy can be
  visualized. These can be visualized on whole
  body images but show up better on SPECT.
• CT scans usually reports lymph nodes larger than
  1 cm are abnormal. But Ga67 scans can visualize
  lymph nodes less than 1 cm that are involved with
  malignancy.

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Ga67 Tumor, SPECT

• Patient Prep, indications contraindications are
  the same as the whole body scan but dosage may be
  increased for statistics
• Protocol circular or non-circular, 360o, 64
  stops, 20-25 sec/stop

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Monoclonal Antibody Imaging

• Monoclonal antibodies are frequently referred to
  as the magic bullet
• Monoclonal antibodies are used to either image
  the cancer or other diseases or treat the cancer

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Monoclonal Antibody Imaging

• The most studied tumor-associated antigen is the
  onco-fetal antigen carcinoembryonic antigen
  (CEA). CEA antigen is present is the majority of
  colorectal carcinomas

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Monoclonal Antibody Imaging

• Clinical imaging studies
• Colon cancer In-111 CYT 103 (OncoScint)
• Melanoma In-111 labeled antimelanoma antibody
  cocktail (225.28S and 763.24T) administered
  subcutaneously
• Ovarian carcinoma In-111 OncoScint
• Neuroblastomas In-111 OctreoScan
• Lymphoma (non-Hodgkins) Bexxar or Zevalin
• For complete list, look in Sodee (685 691)

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Monoclonal Antibody Imaging

• OnocScint
• Detection of colorectal or ovarian carcinomas
• Detection of breast, non-small cell lung,
  pancreatic, gastric and esophageal cancers
• Evaluation of elevated serum CEA

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Monoclonal Antibody Imaging

• OncoScint
• In-111 chloride satumomab pendetide (4-6 mCi)
• Contraindications Patients with human anti-mouse
  antibody (HAMA) titer gt100 ng/ml
• Collimator medium energy, general purpose or
  all purpose

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Monoclonal Antibody Imaging

• OncoScint
• Set for Indium peaks (173 and 247) with 15-20
  windows
• Statics 600 seconds or more perview (gt 1000
  Kcounts)
• Whole body 10cm/min or slower
• SPECT 360o, 60 projections, 40 sec/frame

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Monoclonal Antibody Imaging

• OncoScint
• Procedure
• Administer with IV butterfly for 5 minutes and
  flush.
• Physician or nurse should be available for
  possible allergic reaction (1 mg epinephrine
  available)
• Follow vital signs, baseline, and 5, 15, 30, 60
  minutes after injection

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Monoclonal Antibody Imaging

• OncoScint
• Procedure
• Image at 72, 96 and 120 hours post injection.
• Patient should void before imaging
• Statics 10 minutes per view. Ant-post views of
  thorax, abdomen and pelvis.
• SPECT may be done at 72 hours if planar appears
  normal

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Monoclonal Antibody Imaging

• OncoScint
• Normal Results
• Activity in the liver, spleen, bone marrow and
  blood pool
• Bowel activity may be present because of
  radiotracer in stool
• Activity in kidneys, bladder, male genitalia and
  female nipples

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Monoclonal Antibody Imaging

• OncoScint
• Abnormal Results
• Increased extrahepatic uptake (equal to liver) in
  tumors
• Persistent and stationary over time with delayed
  scans, particularly over lymph nodes or organ of
  interest
• If trying to isolate hepatic tumors a background
  subtraction technique with Tc99m Sulfur Colloid
  (1mCi) can be used
• Background vascularity will decrease on 96 and
  120 hour images except for liver, which shows
  lesions then as less activity than normal tissue

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Monoclonal Antibody Imaging

• There are tons of other studies that deal with
  monoclonal antibodies. Going through all of them
  would be painfully boring to everyone here.
• Other studies include OctreoScan, Bexxar and
  Zevalin to name a few.
• OctreoScan can be found in Shackett p 188

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Peptide Imaging

• The advantages of peptide imaging are
• it rarely produces an allergic-type reaction,
• has a low radiation associated with its use,
• and is much less expensive than the comparable
  monoclonal antibody techniques
• The first Tc99m peptide introduced was AccuTect
  which detected venous thrombosis.

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Peptide Imaging

• There are other peptides, but in the interest of
  time Ill discuss one.
• NeoTect used to tell if a pulmonary nodule is
  benign or malignant
• NeoTect binds with somatostatin receptors that
  are present on many malignant tumors

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Peptide Imaging

• NeoTect
• Like the monoclonal antibodies, NeoTect may
  induce anaphylactic shock, so a nurse epinephrine
  should be present at injection.
• Patients should drink at least 8 o.z. of water
  before administration
• Images are acquired 2-4 hours after injection.
  SPECT images are required for optimal images of
  the chest.

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Breast Imaging

• Thallium-201 localized in malignant breast tissue
  and in metastatic breast carcinomatous sites.
  Tc99m Sestamibi has been shown to show up in the
  same spots.
• Images can be found in Sodee 814-816

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Breast Imaging

• For Breast metastases
• No patient prep
• Administer 3 mCi Tl-201 or 25 mCi Tc99m sestamibi
  intravenously
• Begin imaging 20 minutes post injection.
• Set camera for Tl-201 (80 keV) or Tc99m (140 keV)
• Statics should be over 1000K
• Whole body should be 20 to 25 minutes

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Breast Imaging

• For Static Breast Imaging
• Same prep and dosage as metastatic imaging
• Place patient in supine position and inject in
  the opposite are of the affected breast
• With triple-head camera place one camera head in
  the anterior position and the other two heads in
  the obliques
• Inject 3 mCi Tl-201 or 25 mCi Tc99m sestamibi

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Breast Imaging

• For Static Breast Imaging
• The arms should be over the patients head.
  Include the axillae and the breast in the field
  of view. Begin imaging 2 minutes post-dose and
  take 2 to 10 minute acquisitions
• Perform RAO and LAO views of the affected breast
  and axilla. Repeat views for 2 minutes each with
  marker on suspected mass and nipple

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Breast Imaging

• For Static Breast Imaging
• If needed, tape the breast to avoid
  superimposition on liver or heart
• Thallium-201 in breast carcinoma imaging has a
  96 sensitivity and no false positive results
  were obtained in preliminary tests
• Tl-201 and Tc99m sestamibi can find malignant
  brain tumors with metabolically active remnants
  following radiation therapy. CT and MRI have
  been unable to differentiate viable tumor from
  radiation effects in brain tissue

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Lymphoscintigraphy / SLN node

• Is performed for evaluation of
• Spread of cancers, (e.g. lymphatic leukemia,
  reticulum cell carcinoma, Hodgkins disease and
  melanoma
• Lymphatic kinetics, particularly for cancers
• And detection of metatstatic inavasion of the
  lymph nodes

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Lymphoscintigraphy / SLN node

• Patient prep
• Wipe area with alocohol pad, shave if necessary
  clean area with Betadine
• For breast, patient is to bring mammograms and
  any related studies with her or make previous
  studies available
• For breast, patient is instructed to massage area
  of injection after injections and between imaging
  sessions

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Lymphoscintigraphy / SLN node

• Radiopharamceutical Tc99m Sulfur Colloid. 200
  uCi to 2 mCi.
• Method of administration
• For melanoma, 2-6 subcutaneous and/or
  intradermal, producing a wheal, placed around
  cancer site, surgery or region of interest.
  Volume should not exceed .25 mL per injection
  site.

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Lymphoscintigraphy / SLN node

• Method of administration (cont.)
• For breast, four placed in tissue surrounding
  lesion, as much as 4 mL per syringe at 3, 6, 9
  and 12-oclock positions around tumor site.
  Lidocane or sedation may be given to reduce pain
  of injections.
• Flow 30-60sec/frame, 10-15 minutes
• Statics every 5 minutes for up to 30 minutes,
  300 second counts.

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Lymphoscintigraphy / SLN node

• Normal results
• Radiotracer enters the lymphatic system through
  normal channels and proceeds through the system
  into the major lymphatic beds
• Visualization of the sentinel node or nodes is
  normal within the first 30 minutes
• Biopsy of these nodes will yield the results

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Lymphoscintigraphy / SLN node

• Abnormal results
• None or only some of the expected nodes
  visualizing indicates malignant blockage.
  Surgical or trauma scars can block the normal
  progression of the lymph
• Continuity of chain interrupted
• Enlargement of chain width because of lymphoma,
  congestion or lyphadenitis
• Displacement of expected location by metastasis
  or collateral circulation

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Tumor PET

• Indications
• Evaluation of grade of glioma and true extent of
  brain tumor
• Differentiation of recurrent tumor from scar and
  radiation necrosis
• Evaluation of chemotherapy effect on metabolism
• Contraindications
• Patient too agitated, uncooperative or
  claustrophobic to remain still for acquisition
• Specific consideration of drug and food
  ingestion, or lack thereof for each study

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Tumor PET

• Radiopharmaceutical F-18-FDG, the most widely
  used. 5-15 mCi (Shackett)
• Method of administration IV injection, done
  quickly because of radiation exposure

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Tumor PET

• Patient Prep
• Patient is NPO after midnight
• No caffeine or tobacco 12 hours before exam
• Discontinue all meds on morning of exam
• Diabetic patients half their dosage
• Patient should be fully hydrated
• Patient must remain calm with no movement during
  imaging

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Tumor PET

• Procedure
• Patient is placed in a reclining chair or bed for
  10 minutes and asked to relax and refrain from
  talking. Room should be quiet and dark.
• Inject the F-18-FDG, followed by 20 to 30 mL
  saline flush
• Patient should continue to rest for 45 to 90 more
  minutes

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Tumor PET

• Procedure (cont)
• Patient is placed supine on the imaging table and
  reminded to stay still
• Image per protocols at facility.

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Oncology

• Sources I stole from
• Nuclear Medicine and PET. Christian, Bernier,
  Langan.
• Nuclear Medicine Technology. Shackett.
• Principles and Practice of Nuclear Medicine.
  Early and Sodee.
• The package insert for NeoTect.

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Oncology
Good Luck on the Boards!