perfusionsszintigraphie zur diagnostik der lungenembolie

M. Wissmeyer

Department of Nuclear Medicine, University of Berne (Inselspital)

PET/CT in Oncology: PET Tracers PET/CT in Oncology: PET Tracers other than FDGother than FDG

PET – Isotopes and Half LivesPET – Isotopes and Half Lives

15O 2 Minutes

13N 10 Minutes

11C 20 Minutes

18F 110 Minutes

68Ga 68

Minutes

PET - RadiopharmaceuticalsPET - Radiopharmaceuticals

Aminoacids: 11C-Methionine

Proteinsynthesis: 18F-Ethyltyrosine (FET)

Proliferation: 11C-Thymidine, 18F-

Fluorthymidine (FLT)

Hypoxia: 18F-Fluoromisonidazole

Mineralisation (Skeleton): 18F-Fluoride

Cell Membranes: 11C- or 18F-Choline

Fatty Acids: 11C-Acetate

APUD Cell System: 18F-DOPA

Receptor ligands: 68Ga-Petpides (e.g. DOTA-

TOC)

Aminoacids: Aminoacids: 1111C-MethionineC-Methionine

Drawback: Short Halflife => Cyclotron onsite

indispensable

Transporter mediated Uptake

No significant Metabolism in Proteinsynthesis

Well established in Brain Tumours (positive Marker!)


Sensitivity up to 91% for Gliomas (n=23)

Jacobs AH et al., JNM 12/2005


Methionine superior to FDG in Follow up of treated

Gliomas

Sensitivity 89%, Specificity 29%, Accuracy 72% (11%,

100%,

36%, respectively)

Methionine FDG

Pötzi et al., J Neurooncol 2007


Promising in Monitoring Chemotherapy

Galldiks et al., EJNMMI 05/2006


Grosu et al., IJROBP 02/2006

Aminoacids: Aminoacids: 1818F-FETF-FET

Halflife 110 Min. => Cyclotron onsite not required

Transporter mediated Uptake

No significant Metabolism in Proteinsynthesis

Well established in Brain Tumours (positive Marker!)


Gliomas: FET + MRI => Sensitivity 93%, Specificity

94% (n=26)

Variable Uptake in Low Grade Gliomas => No SUV-

Cutoff

1/3 of Astrozytoma Grade II => No FET Uptake (similar

to 11C-

Methionine)

Promising Tool in Detection of Recurrency

Langen KJ et al., NMB 2006


Gliomas: FET => Sensitivity 92%, Specificity 81%,

Accuracy

92% (n=26)

Significantly better than MRI alone in Assessment of

Gliomas

Pauleit D et al., Brain 2005


High Value in Prediction of Prognosis of cerebral

Gliomas

Floeth FW et al., JNM 04/2007


Poor Results in peripheral Tumours

FDG (A) and FET (B) PET in Lymphoma (left) and Head

and

Neck Cancer (right)Pauleit D et al., JNM 2005

Proliferation: Proliferation: 1818F-FLTF-FLT


Nucleosid Analogue (Pyrimidin)

Uptake by passive Diffusion / facilitated Transport

Cellular Trapping after Phosphorylation by

Thymidinkinase


Promising Results cerebral Gliomas: Primary Diagnosis

Saga T et al., Clin Nucl Med 2006


Promising Results cerebral Gliomas: Suspected

Recurrence

Saga T et al., Clin Nucl Med 2006


Early Assessment of Therapy Reponse: Malignant

Lymphoma

Mouse Model

Lymphoma Treated with

Chemotherapy (n=10)

Immunotherapy (CD20 mAB; n=10)

Radioimmunotherapy (90Y-CD20 (Zevalin); n=10)

FLT detects Tumour Response earlier than morphologic

Imaging

Buck AK et al., EJNMMI 2007, in press


Significant Impact on Target Volumes in RT in rectal

Cancer

(Patel DA et al., TCRT 02/2007)

Drawbacks in Lymph Node Imaging in Primary Head

and

Neck Cancer (Troost EGC et al., JNM 2007)

Hypoxia: Hypoxia: 1818F-MisonidazoleF-Misonidazole


Presence of hypoxic Tissue Predicts Outcome of RT

Hypoxia => Increased Tumour Aggressivity =>

Decreased

Response to Therapy => Poor Outcome

Most published Results in Head and Neck Cancer

Impact on Target Volume Definition in RT


Outcome in Head and Neck Cancer: FDG vs. F-MISO

Rajendran JG et al., Clin Cancer Res 09/2006


F-MISO Uptake during RT in Head and Neck Cancer

Eschmann SM et al., Radiotherapy and Oncology 2007; in press


Dose Painting Using F-MISO Information

Thorwarth D et al., IJROBP 2007

Mineralisation: Mineralisation: 1818F-FluorideF-Fluoride


Significantly higher Bone Uptake than 99mTc-

Phosphonates

Blood Clearance faster than 99mTc-Phosphonates

=> Higher Contrast

Planar Scintigraphy more available than PET-Scanners


Bone Scan vs. Fluoride PET

Schirrmeister H et al., JCO 1999


Normal Bone Scan vs. Pathologic Fluoride PET



Pathologic Bone Scan vs. Extensive Metastases in

Fluoride PET


Cell Membranes: Cell Membranes: 1111C- / C- / 1818F-CholineF-Choline

11C-Choline: Halflife 20 Min. => Cyclotron onsite

required

18F-Choline: Halflife 110 Min. => Cyclotron onsite not

required

First Results for a Variety of Tumours

Most Studies in Prostate Cancer

Ongoing multicentric Trial on Choline PET/CT in initial

Staging of

Prostate Cancer


11C-Choline vs. FDG in various Tumours

Tian M et al., EJNMMI 2004


18F-Choline in Prostate Cancer: Diagnosis of Relapse

Cimitan M et al., EJNMMI 2006


18F-Choline in Prostate Cancer: Own Experience

G.G., 62y; mediastinal LN Metastasis

Fatty Acids: Fatty Acids: 1111C-AcetateC-Acetate

Halflife 20 Min. => Cyclotron onsite required

Increased Uptake in slowly growing Tumours

Potential Advantage in FDG negative Tumours

Most Evidence in Prostate Cancer and Myocardial

Imaging

First Studies in Adenocarcinoma of the Lung

Fatty Acids: Fatty Acids: 1111C-AcetateC-Acetate

Acetate PET/CT in recurrent Prostate Cancer

Albrecht S et al., EJNMMI 2007

APUD Cell System: APUD Cell System: 1818F-DOPAF-DOPA


Katecholamine Metabolite Analogue

Active Uptake in APUD Cells

Decarboxylation => No further Metabolism =>

Accumulation

Well established in Neuro-Imaging and 111In-Octreotide

negative neuroendocrine Carcinomas


F-DOPA vs. 111In-Octreotide in GEP Tumours

Ambrosini V et al., Nucl Med Commun 2007


F-DOPA vs. FDG PET/CT in GEP Tumours

Nanni C et al., EJNMMI 2006


F-DOPA vs. FDG PET in Medullary Thyroid Carcinoma

Beuthien-Baumann B et al., EJNMMI 2007


111In-Octreotide vs. 18F-DOPA in typical Carcinoid

B.L., f, 70y; Liver and mesenteric LN Metastases

Receptor Ligands: Receptor Ligands: 6868Ga-PeptidesGa-Peptides

Halflife 68 Min.

Generator Product

Synthesis of Radiopharmaceutical onsite

Peptides: Somatostatin Analogues

Linked to Somatostatin Receptors of Neuroendocrine

Tumours

High Specificity für Somatostatine Receptor Subtypes II

and V

First Results: Sensitivity and Accuracy much higher

than for

111In-Octreotide


Results of a valuable Clinical Trial (n=84)

Gabriel M et al., JNM 2007


Own Experience: 111In-Octreotide vs. DOTATOC PET/CT

W.P., 61y, m, Pancreatic NET, multiple Metastases; Courtesy Dr. M. Hofmann


Own Experience

W.P., 61y, m, Pancreatic NET, multiple Metastases; Courtesy Dr. M. Hofmann

ConclusionsConclusions

Variety of promising PET Tracers besides FDG

Data limited mostly due to small Size of Cohorts

11C labelled Tracers restricted to Centers with

Cyclotron

onsite

Growing Field of 18F labelled Tracers

68Ga as new promising Generator Product in

Neuroendocrine Tumours

perfusionsszintigraphie zur diagnostik der lungenembolie

Health & Medicine