non-pet tumor imaging p2_gallium
TRANSCRIPT
Jiraporn Sriprapaporn, M.D.
Nuclear Medicine
Siriraj Hospital September 2015
Non-PET Oncologic Imaging_Jiraporn
Radiopharmaceuticals for Non-PET Oncologic Applications
Nonspecific
• Ga-67 citrate:
– Lymphoma
• Tl-201 chloride:
– Bone sarcomas
– Brain tumors
– Thyroid cancer
• Tc-99m sestamibi:
– Breast cancer
– Parathyroid adenomas
– Thyroid cancer
• Tc-99m tetrofosmin: Similar to sestamibi
Tumor-Type Specific
• I-131: Diff thyroid cancer (PTC, FTC)
• I-131 MIBG: Neural crest tumors (adrenal medullary imaging)
• Radiolabeled peptides: Somatostatin receptors (SSTR)
– In-111 pentetreotide (OctreoScan): Neuroendocrine tumors [NETs]
– Tc-99m HYNIC-TOC: NETs
– Tc-99m depreotide*: Lung cancer
• Radiolabeled monoclonal antibodies:
– Tc-99m arcitumomab (CEA-Scan)*: Colorectal cancer
– In-111 capromab pendetide (ProstaScint): Prostate cancer
– In-111 ibritumomab tiuxetan (Zevalin): Lymphoma
– I-131 tositumomab (Bexxar): Lymphoma
REF : modified from The Requisites
Non-PET Oncologic Imaging_Jiraporn
Physical Characteristics of Common Radionuclides Used for Tumor Imaging Agents
Radiotracer Physical T1/2 (hr)
Decay
Photopeaks
Injected dose mCi (MBq)
Organ receiving
highest dose rad/ mCi
(mGy/MBq)
Effective dose
rem/mCi (mSv/MBq)
keV Abundance
(%)
Ga-67* 78 EC
93 185 300 394
41 23 18 4
10 (370) Colon
0.74 (0.2) 0.44 (0.12)
Tl-201* 73 EC 69-83 94 3 (111) Kidneys
1.7 (0.46) 0.85 (0.23)
In-111* 67 EC 171 245
90 94
6 (222) Spleen
2.1 (0.57) 0.20 (0.054)
Tc-99m sestamibi
6 IT 140 88 20 (740) Gallbladder 0.14 (0.039)
0.033 (0.009)
modified from The Requisites, 4th Ed. SNM Guidelines
* Cyclotron-produced
Non-PET Oncologic Imaging_Jiraporn
• 67Ga has been used for imaging a variety of solid
tumours since 1969.
• Ga-67 is cyclotron-produced radionuclide
imported**
• Ga-67 citrate is the first widely used tumor
imaging agent.
• Mech: bind to iron transport proteins eg.
transferrin, lactoferrin
• Dose: 10 mCi IV.
• Imaging time: WB imaging at 24-72 hrs. pi.
• Applications:
– Tumors: Lymphoma (Hodgkin's lymphoma*), Bronchogenic carcinoma, Malignant
melanoma, Hepatoma
– Infection & Inflammation Anterior Posterior
Non-PET Oncologic Imaging_Jiraporn
Ga-67 Scan: Precautions
• Pregnancy
• Breast feeding (breastfeeding should be
discontinued)
• Children aged <14 years due to the high
radiation exposure, except when there is clear
evidence of malignancy.
2003 EANM Guideline
Non-PET Oncologic Imaging_Jiraporn
Ga-67 Scan: Patient Preparation
• Food and liquid restrictions are not mandatory.
• Bowel preparation is optional to decrease the bowel
activity.
– In this case Laxatives should be given on the day
before 67Ga scintigraphy (at least 18 hours prior to
scanning).
• Gallium scan should be avoided within 24 hr after blood
transfusion or gadolinium-enhanced MRI scanning,
which may interfere with Ga-67 biodistribution.
• Also it is advisable to wait 3-4 weeks after chemotherapy
for following-up imaging.
2003 EANM Guideline
Non-PET Oncologic Imaging_Jiraporn
Ga-67 Image Acquisition
• The gamma camera for whole body imaging should
be a large-field-of-view (LFOF) gamma camera
preferably equipped with a medium-energy
collimator.
• Energy windows: should cover 3 windows
photopeak (93, 185 and 300 keV).
• Whole-body imaging at 24-48 (72hrs)
• SPECT/CT imaging of the affected regions if
available.
2003 EANM Guideline
Non-PET Oncologic Imaging_Jiraporn
• Nasopharynx, salivary & lacrimal glands
• Thymus
• Liver: greatest uptake
• Spleen
• Bone marrow & skeleton:
– Ga is incorporated into the Ca hydroxyapatite crystal as a Ca analog.
– Marrow activity occurs because of its behavior as an iron analog.
• Bowel: primarily colonic activity (after 24 hrs)
• Breasts: esp. lactating breasts-breast milk
• Renal cortex: first 24 hours
• External genitalia
• Excretion: kidneys (upto 25% in the first 24 hrs) & subsequently via large bowel 4-yo boy
Anterior Posterior
Non-PET Oncologic Imaging_Jiraporn
Interpretation Pitfalls
• False positive:
– Infection, inflammation including granulomatous disease such as
TB, sarcoidosis
– Thymic hyperplasia
– Sites of physiological uptake,
– Recent surgery, wound healing
– Healing fractures
– Recent administration of antibiotics (clindamycin)
– Administration of CSGF BM uptake
– External superficial contamination,
– Renal failure
– Chemo/radiotherapy-induced uptakes (within 3-4 weeks)
2003 EANM Guideline Essentials NM AuntMinnie.com
Non-PET Oncologic Imaging_Jiraporn
Interpretation Pitfalls
• False negative:
– Some types of tumors-low or no Ga-67 avidity
– Small tumor lesions
– Location of tumors; abdomen interfered by
physiologic bowel activity. (improved with SPECT/CT)
– Recent iron or gadolinium administration (within 24
hrs)
– Post chemotherapy
– Post radiotherapy
– Steroid administration
Need to confirm Ga-67 avidity prior to Rx to be used for F/U.
2003 EANM Guideline
Non-PET Oncologic Imaging_Jiraporn
• Staging
• Monitoring treatment
• Post treatment evaluation
• Restaging-detect tumor recurrence
Non-PET Oncologic Imaging_Jiraporn
• Ga-67 sensitivity depend on size, location and
histology of tumors. (more difficult in abdomen &
pelvis due to bowel excretion)
• Sensitivity of untreated HL is > 85% to 90%.
• Sensitivity of NHL is < that in HL, // histologic
subtypes.[60% for lymphocytic-90% for histiocytic]
• Sensitivity: high-grade > low-grade
Essentials NM
Non-PET Oncologic Imaging_Jiraporn
• Hodgkin’s lymphoma
• Cervical and
mediastinal
lymphadenopathies
Anterior Posterior
HL with right paratracheal lymphadenopathy
Planar Images SPECT Images
The Requisites, 3rd Ed.
Pre-treatment Ga-67 scan Post-treatment Ga-67 scan
Non-PET Oncologic Imaging_Jiraporn
Ga-67 scan in a Pt with stage II mediastinal NHL s/p first line CMT
• The coronal chest images, CT (left), Ga-67 (middle), and fusion (right),
demonstrate that there is intense accumulation of the radiotracer in the
bilateral hilar and subcarinal regions, consistent with residual viable
lymphoma.
• The patient subsequently progressed and required second line therapy.
Non-PET Oncologic Imaging_Jiraporn
Ga-67 Scan vs F-18 FDG PET Images
• Ga-67 higher
background activity
• Ga-67 lower image
resolution
• Ga-67 less sensitivity
Mody RJ 2007
Nowadays Ga-67 scan has
mainly been replaced by F-18 FDG PET/CT scan !
Ga-67 Scan
F-18 FDG PET Scan
Non-PET Oncologic Imaging_Jiraporn
Ga-67 vs PET
• DLBCL, posterior
mediastinal and left
inguinal disease
(arrow) are evident on
PET (a), but cannot
be distinguished from
marrow activity on
gallium scanning
planar (b) or SPECT
(c).
Wirth A, 2002 http://www.sciencedirect.com/science/article/pii/S0002934301011172
Non-PET Oncologic Imaging_Jiraporn
Tsukamoto N, Kojima M, Hasegawa M, Oriuchi N, Matsushima T, Yokohama A, et al. The usefulness of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) and a comparison of (18)F-FDG-pet with (67)gallium scintigraphy in the evaluation of lymphoma: relation to histologic subtypes based on the World Health Organization classification. Cancer. 2007 Aug 1;110(3):652-9. PubMed PMID: 17582800.
METHOD:
• 255 patients with lymphoma had their disease staged using F-18 FDG-PET, and 191 of those
patients also were assessed using Ga-67 scintigraphy.
• Disease sites were identified on a site-by-site basis using CT scans and/or MRI imaging.
• The results of these conventional imaging modalities were compared with the results from F-18
FDG-PET and Ga-67, and correlations between the imaging results and pathologic diagnoses
were evaluated by using the WHO classification system.
RESULTS:
• Of 913 disease sites in 255 patients, F-18 FDG-PET identified >97% of disease sites of HL and
aggressive and highly aggressive NHL.
• For indolent lymphoma, the detection rate of F-18 FDG-PET was 91% for follicular lymphoma (FL);
82% for extranodal MALT lymphoma; and approximately 50% for small lymphocytic lymphoma
(SLL) and splenic marginal zone lymphoma (SMZL).
• The results from Ga-67 were similar to those from F-18 FDG-PET for most histologic subtypes.
However, the sensitivity of Ga-67 was unexpectedly poor for FL, for mantle cell lymphoma (MCL),
and for the nasal type of natural killer/T-cell lymphoma (NK/T-nasal), ranging from 30% to 38%.
CONCLUSIONS:
• F-18 FDG-PET was useful for all histologic subtypes of lymphoma other than SLL and SMZL.
• Compared with Ga-67, the authors strongly recommend the use of (18)F-FDG-PET in patients with
FL, MCL, and NK-nasal.