Imaging Questions in Ovarian Cancer

Susanna I. Lee, MD, PhD

Emerging Technologies

• PET-CT

• Perfusion imaging– Dynamic contrast enhanced CT (DCE-CT)

– Dynamic contrast enhanced MRI (DCE MRI)

• Nodal imaging– Ultrasmall superparamagnetic iron oxide (USPIO) MRI

– Diffusion weighted imaging (DWI) MRI

• Percutaneous tumor ablation

• 22,975 studies from 1,178 centers over 1 year

• 15% patients with gynecologic cancers– 2,096 ovarian

– 1,198 uterine corpus

– 434 cervix

• Query referring physician on intended patient management before and after PET-CT

PET Impact on Management

Hillner BE et al. J Clin Oncol 2008. 26:2155

PET-CT in Recurrence

no treatment treatment

PET-CT in Recurrence

surgery chemotherapy

PET-CT in Recurrence

CT alone PET-CT

Sensitivity 92% 97%

Specificity 60% 80%

Kappa 0.29 0.63

Sebastian S et al. Abdom Imaging 2008. 33:112

• 53 patients with epithelial ovarian cancer

• Concurrent diagnostic CT and PET-CT scans

Emerging Technologies

• PET-CT

• Perfusion imaging– Dynamic contrast enhanced CT (DCE-CT)

– Dynamic contrast enhanced MRI (DCE MRI)

• Nodal imaging– Ultrasmall superparamagnetic iron oxide (USPIO) MRI

– Diffusion weighted imaging (DWI) MRI

• Percutaneous tumor ablation

DCE MRI Tracer Kinetic Model

Ktrans

ep= Ktrans/e

e=

Volume transfer constant

Flux rate constant

Tofts PS et al. J Magn Reson Imaging 1999. 10:223

DCE MRI As a Biomarker

• Correlate with pathologic prognostic indicators– Tumor grade, microvessel density, VEGF expression

• Predict clinical response to therapy– Anti-VEGF antibody, tyrosine kinase inhibitor

• Prospectively acquired DCE MRI databases with corresponding clinical outcome– ACRIN 6657/CALGB 150007 – neoadjuvant breast cancer– ACRIN 6677/RTOG0265 – recurrent glioblastoma

Neoadjuvant Breast Cancer

Hylton N. J Clin Oncol 2006. 24:3293

DCE MRI

SER map

pre post 1 cycle post chemo

Emerging Technologies

• PET-CT

• Perfusion imaging– Dynamic contrast enhanced CT (DCE-CT)

– Dynamic contrast enhanced MRI (DCE MRI)

• Nodal imaging– Ultrasmall superparamagnetic iron oxide (USPIO) MRI

– Diffusion weighted imaging (DWI) MRI

• Percutaneous tumor ablation

USPIO MRI

• Paramagnetic core in dextran

• Half life ~25-30 h

• Nanoparticles dark on T2*

• Macrophage accumulation– Normal nodes = dark

– Tumor replaced nodes = bright

Harisinghani MG et. al. N Eng J Med 2003. 348: 2491

USPIO MRI Endometrial Cancer

benign

malignant

USPIO MRI for Nodal Metastases• 631 patients, 3004 nodes with histology

• Summary ROC for per lymph node data

AUC = 0.96AUC = 0.84

Will O et al. Lancet Oncol 2005. 7:52

What About the Small Nodes?

Any size <10 mm

Unenhanced MRI 63% NA

USPIO MRI 88% 70%

PET-CT (cervical ca)* 72% 37%

PET-CT (endometrial ca)^ 53% 40%

*Sironi S et al. Radiology 2006. 238:272^ Kitajima K et al. Am J Roentgenol 2008. 190:1652

USPIO and Small NodesEndometrial ca with 5 mm node

USPIO PET

Percutaneous Tumor Ablation

• Thermal – frictional heating– Radiofrequency (460 kHz)

– Microwave (900-2450 MHz)

• Cryo – freeze thaw cycles

• High intensity focused ultrasound (HIFU)– Acoustic lens to focus ultrasound for power deposition

– Thermonecrosis

– No applicator tract

Radiofrequency Ablation

• Radiofrequency generator 60-250 W

• Coagulation necrosis 55-100oC

GroundingPad

Power Source

Radiofrequency Ablation• Indications– Medically inoperable patients or bridge to transplant

– Liver – hepatocellular carcinoma, colon cancer

– Kidney – renal cell ca

– Lung – NSCLC, metastases

• Lesion selection criteria– Percutaneous approach available

– < 5.5 cm

– Adjacent structures

– Heat sink effect

Clear Cell Ovary Recurrence

Radiofrequency Ablation

hydrodissection ablation

Followup PET-CT1 month 1 year

High Grade Muellerian AblationPre-RF RF

Three Year Followup3 months 3 years