PALZ Case 1

Parametric images of the transport rate k1, the phosphorylation rate k3 and the distribution volume VB have been calculated using the pixelwise model calculation of a 2-tissue compartment model. A support vector machine algorithm as well as VOI-based kinetic data of a DKFZ database of oncological patients have been used for that purpose.


1. Upper image: transversal FDG-uptake image (SUV-image) demostrating the tumor clearly hypermetabolic. Lower image: transversal image ( same slice as upper image). Parametric image of the transport rate K1 demonstrating the tremendous enhanced K1 prior treatment.		2. Same patient. Upper image: transversal FDG-uptake image (SUV-image). Lower image: transversal image ( same slice as upper image). Parametric image of the phosphorylation rate k3 demonstrating the clearly enhanced k3 prior treatment.


3. SUV, VB prior therapy. Same patient. Upper image: transversal FDG-uptake image (SUV-image). Lower image: transversal image ( same slice as upper image). Parametric image of the distribution volume VB demonstrating a high VB prior treatment, which is indicative for a high tumor perfusion.		4. Follow-up images after two cycles of a preoperative chemotherapy with EIA (etoposide/Ifosfamide/adriamycin) Upper image: transversal FDG-uptake image (SUV-image) Lower image: transversal image ( same slice as upper image). Parametric image of the transport rate K1 demonstrating a decreased but still enhanced K1 after treatment.


5. Same patient. Upper image: transversal FDG-uptake image (SUV-image) after 2 chemotherapeutic cycles Lower image: transversal image ( same slice as upper image). Parametric image of the phosphorylation rate k3 demonstrating a clearly decrease in k3 after treatment.		6. Same patient. Upper image: transversal FDG-uptake image (SUV-image) after therapy Lower image: transversal image ( same slice as upper image). Parametric image of the distribution volume VB demonstrating a clear decrease in VB after two cycles of treatment, which is indicative for a low tumor perfusion and low angiogenesis.

VB
(vessel density)

k1
(transport)

K3
(phosphorylation)

FDG prior EIA

FDG after EIA

Comparison of the parametric images of VB, k1 and K3 prior and after two cycles of chemotherapy with EIA. The parametric images demonstrate primarily a decrease in the distribution volume VB and in the phosphorylation rate k3 after two adriamycin-based chemotherapeutic cycles. Transport of FDG is still enhanced as given by K1.

The advantage of parametric imaging here is the specific information oft he therapeutic effect, not only concerning the change in global FDG-uptake (which is related to tumor viability), but also on the tumor perfusion, transport and phosphorylation of FDG. A decrease of VB reflects a response regarding an antiangiogenetic effect. A decrease in phosphorylation (k3) is associated with an antiproliferative effect of a drug.Therefore, in this case the decrease of the SUV from 12.7 to 3.3 is mainly related to an antiangiogenetic and antiproliferative effect of treatment. The residual uptake is mainly due to the decreased but still enhanced FDG transport (K1).Theoretically, the consequence should be to use a specific treatment now directed against K1, the transport of FDG (or glucose). This is unfortunately not available now. However, those results help to understand the effect of current treatment protocols and may direct to the development of new, more specific drugs.