Non-PET Tumor Imaging p2_Gallium

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


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


• 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


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


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


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


• 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


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


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


• Staging

• Monitoring treatment

• Post treatment evaluation

• Restaging-detect tumor recurrence


• 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


• 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


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.


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


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


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.

Health & Medicine

Non-PET Tumor Imaging p2_Gallium