PET/CT in lung cancer Andrei Šamarin North Estonia Medical Centre 3 rd Baltic Congress of Radiology 08.10.2010
Imaging in lung cancer Why do we need PET/CT? CT is routine imaging modality for staging of the lung cancer Great for visualization of primary tumor/t staging Limited accuracy in mediastinal and distal staging Addition of FDG-PET to conventional work-up Results in changing stage in more than half of the patients 1 Detection of unsuspected distant metastases in 5-29% of patients 2 1.Pieterman et al. NEJM 2000; 343:254-261 2. Schrevens L et al. Oncologist 2004; 9:633 643
PET/CT in lung cancer: indications STAGING Radiation treatment planning Therapy response Solitary pulmonary nodule
PET/CT in lung cancer: staging T stage Mainly based on CT criteria Additional value of PET: N stage Differentiation between tumor and atelectasis Chest wall involvement Metastases in mediastinal and supraclavicular lymph nodes M stage Distant metastases
57-year-old man. Non-small cell lung cancer. FDG-PET/CT for staging
PET/CT in lung cancer: N staging Correct nodal status is crucial for selection of optimal treatment strategy: surgery vs radiochemotherapy FDG-PET is significantly more accurate than CT in the determination of nodal status Gould et al.: meta-analysis of 39 studies 1 Sensitivity Specificity CT 61% 79% FDG PET 85% 90% Toloza et al. : meta-analysis of 43 studies 2 Sensitivity Specificity NPV PPV CT 57% 82% 83% 56% FDG PET 84% 89% 93% 79% Mediastinoscopy 81% 100% 91% 100% 1. Gould et al. Ann Intern Med. 2003 Dec 2;139(11):879-92. 2. Toloza et al. Chest. 2003 Jan;123(1 Suppl):137S-146S
PET/CT in lung cancer: N staging PET negative mediastinum Stage I peripheral non-small cell lung cancer (T1, T2) -> invasive staging can be omitted due to high NPV of FDG-PET 1 PET positive nodes in mediastinum Should be histologically or cytologically confirmed, false-positive rate 13-22% false positives: inflammatory nodes mild bilateral hilar nodal uptake often seen Guidance for targeted biopsy 1. De Leyn P. et al. Eur J Cardiothoracic Surg 2007;32:1-8
77-year-old man. Squamous cell carcinoma of right lung. FDG-PET/CT for staging.
70-year-old man. Squamous cell carcinoma of left lung. FDG-PET/CT for staging.
PET/CT in lung cancer: M staging Lung cancer most commonly spreads to the brain, liver, adrenal glands, bone, and lung. Whole body FDG-PET/CT is excellent method for the detection of extrathoracic metastases sensitivity 94%, specificity 97%, accuracy 96% 1 detects unexpected extrathoracic metastasis in 5-29% of patients 2 changes therapeutic management in 10 to 20% of patients 1. Hellwig D et al. Pneumologie 2001;55; 367-377 2. Schrevens L et al. Oncologist 2004; 9:633 643
PET/CT in lung cancer: M staging Adrenal metastases FDG-PET is superior to CT, best results achieved by PET/CT Low FDG uptake can be seen in adrenal hyperplasia Liver metastases FDG-PET has a higher specificity compared to CT Bone metastases FDG-PET/CT has superior accuracy to bone scintigraphy FDG-PET can detect metastases without visible destruction on CT Brain metastases FDG-PET/CT cannot reliably exclude cerebral metastases Contrast enhanced MRI is recommended Schober O et al. PET-CT Hybrid Imaging. Thieme 2010
70-year-old man. BronchoCa! centr. lobi sup. pulm. sin. FDG-PET/CT for staging.
75-year-old man. BronchoCa! lobi sup. pulm. sin. FDG-PET/CT for staging.
Incorporation of PET/CT in the international guidelines PET/CT is recommended non-invasive modality for staging of non-small cell lung cancer by National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology European Society of Thoracic Surgens (ESTS) guidelines for preoperative lymph node staging for nonsmall cell lung The non-invasive staging of non-small cell lung cancer: the American College of Chest Physicians (ACCP) evidenced-based clinical practice guidelines
Assessment of indeterminate solitary Benign/malignant pulmonary nodule Intense FDG uptake in most histological forms of lung cancer: squamous cell, large cell, small cell, adenocarcinoma Low or absent uptake in bronchoalveolar carcinoma Variable uptake in carcinoid tumors Low uptake due to small size of the tumor FDG uptake in infection and inflammation
Solitary pulmonary nodule FDG-PET/CT provides best results Intermediate pre-test probability of malignancy False negative rate 14% in case of high probability of malignancy Size > 1 cm Lower sensitivity in smaller lesions, especially in basal part of the lungs Solid solitary lesion Ground-glass type lesion on CT -> could represent bronchoalveolar carcinoma Multiple lesions high probability of infection
77-year-old man. Assessment of indeterminate solitary pulmonary nodule. Squamous cell carcinoma
53-year-old man. Assessment of indeterminate solitary pulmonary nodule. Hamartoma
Conclusion FDG-PET/CT is the most accurate modality for the noninvasive staging of lung cancer Beware of false positive findings due to infection and inflammation and false negative findings in BAC, carcinoid Assessment of solitary pulmonary nodule Size > 1 cm Consider pre-test probability of malignancy
Thank you!