“International Conference on Clinical PET

and Molecular Nuclear Medicine” IAEA - IPET 2007

Bangkok, Thailand 10 to 14 November 2007

EVALUATION OF PULMONARY TUMORS WITH 18F-FDG PET/CT

C. Suarez,C. Suarez, R. Pruzzo, F. Redondo and H. Amaral R. Pruzzo, F. Redondo and H. Amaral

Nuclear Medicine and PET/CT Center, Oncology Clinic, Arturo Lopez Perez Foundation (FALP), Santiago, CHILE.

Introduction:

•Correct caracterization of pulmonary nodules remains a difficult Correct caracterization of pulmonary nodules remains a difficult task for clinicians.task for clinicians.

•Helical CT has 98% sensivity, but only 60% specificity.Helical CT has 98% sensivity, but only 60% specificity.

•PET alone has sensivity 96% (83-100%), specificity 79%(52-100%)PET alone has sensivity 96% (83-100%), specificity 79%(52-100%)

•Sensivity and Specificity are worse in small lesions Sensivity and Specificity are worse in small lesions

•Sensivity is poor in Bronchioloalveolar carcinomaSensivity is poor in Bronchioloalveolar carcinoma

•Many benign conditions may be hipermetabolic and can lead Many benign conditions may be hipermetabolic and can lead to false positive results in PET studiesto false positive results in PET studies

Introduction:

•Multimodality PET/CT tecnology benefits from both the metabolic Multimodality PET/CT tecnology benefits from both the metabolic information of provided by PET and the high anatomic resolution information of provided by PET and the high anatomic resolution of CT, which together improve sensivity and specificity in the of CT, which together improve sensivity and specificity in the caracterization of pulmonary nodulescaracterization of pulmonary nodules

•In this report we describe our experience in the characterization In this report we describe our experience in the characterization of pulmonary tumors in Chilean population with PET/CTof pulmonary tumors in Chilean population with PET/CT

Material and Method:

•158 patients (92 males and 66 females) with S158 patients (92 males and 66 females) with Solitary olitary PPulmonary ulmonary TumorsTumors were prospectively included in the study, mean age 63.1 were prospectively included in the study, mean age 63.1 years (26-96). years (26-96).

•All patients had histopathological study and/or clinical and All patients had histopathological study and/or clinical and complementary imaging follow up longer than 6 months. complementary imaging follow up longer than 6 months.

•68 patients had nodules of less than 30 mm and 90 had masses 68 patients had nodules of less than 30 mm and 90 had masses between 31 and 120 mm.between 31 and 120 mm.

Material and Method:

•All the studies were read simultaneously by both qualified All the studies were read simultaneously by both qualified nuclear medicine physicians and radiologists. nuclear medicine physicians and radiologists.

•Lesions were classified as malignant, benign and indeterminate, Lesions were classified as malignant, benign and indeterminate, based on both radiological appearance and metabolic activity in based on both radiological appearance and metabolic activity in PET/CT, with no SUV Max cutoffPET/CT, with no SUV Max cutoff to distiguish one from another, to distiguish one from another, but an integrated diagnostic criteriabut an integrated diagnostic criteria..

•For this reason, some lesions that were classified as malignant For this reason, some lesions that were classified as malignant could have SUV Max < 2.5 g/ml, and some hypermetabolic lesions could have SUV Max < 2.5 g/ml, and some hypermetabolic lesions with SUV > 2.5 g/ml colud be considered benign.with SUV > 2.5 g/ml colud be considered benign.

115 patients (72.8%) were classified as malignant:115 patients (72.8%) were classified as malignant: Malignancy was demonstrated in 109/115 Malignancy was demonstrated in 109/115 (94.8%(94.8% PPV PPV););

96 non small cell lung cancer (NSCLC)96 non small cell lung cancer (NSCLC), , 6 small cell lung 6 small cell lung cancer (SCLC), and 7 metastases.cancer (SCLC), and 7 metastases.

6 false positive: 4 infectious/inflammatory lesions and 2 typical carcinoid 6 false positive: 4 infectious/inflammatory lesions and 2 typical carcinoid tumors.tumors.

31 (19.6%) as benign 31 (19.6%) as benign 4 were demonstrated malignant by biopsy 4 were demonstrated malignant by biopsy (12.9%(12.9% false false

negativesnegatives),), 2 metastases of colorectal cancer, 1 metastasis of 2 metastases of colorectal cancer, 1 metastasis of thyroid cancer and 1 ofthyroid cancer and 1 of angiosarcoma.angiosarcoma.

12 (7.6%) as indeterminate. 12 (7.6%) as indeterminate. 5 lesions malignant (41.7%), 3 lung cancers, 1 metastasis of 5 lesions malignant (41.7%), 3 lung cancers, 1 metastasis of

kidney cancer and 1 of colorectal cancer. kidney cancer and 1 of colorectal cancer.

RESULTS

Median SUV Max: Median SUV Max:

10.4 g/ml (1.8-35.9) in the malignant group10.4 g/ml (1.8-35.9) in the malignant group 1.0 g/ml (0.3-15.3) in the benign group1.0 g/ml (0.3-15.3) in the benign group 2.2 g/ml (0.6-5.3) in the indeterminate group. 2.2 g/ml (0.6-5.3) in the indeterminate group.

Difference on SUV of malignant and benign lesions Difference on SUV of malignant and benign lesions was highly significant. was highly significant.

RESULTS

Female patient, 67 years old. Evaluated for right SPN, PET/CT demonstrated 15 mm diameter hypermetabolic nodule in the right middle lobe, SUV Max 3.6 g/ml, with no other lesions. Biopsy demonstrated adenocarcinoma, T1N0M0.

Male, 76 years old. Evaluated for left SPN,

PET/CT demonstrated 18 mm diameter hypermetabolic nodule in the left lower lobe, SUV Max 8.2 g/ml, with no other lesions.

Biopsy: adenocarcinoma, T1N0M0. 

Positive Predictive Value for malignancy in the Positive Predictive Value for malignancy in the Malignant Group was 94.8%Malignant Group was 94.8%

False Negatives in the Benign Group was 12.9%False Negatives in the Benign Group was 12.9% Negative Predictive Value 87%Negative Predictive Value 87%

Specificity 0.82Specificity 0.82 Sensivity 0.96Sensivity 0.96 Accuracy 0.93Accuracy 0.93

RESULTS

B M

B TN 27 FN 4 Test - 31 npV 0.87

M FP 6 TP 109 Test + 115 ppV 0.95

Total 146

spec 0.82 sens 0.96 Acc 0.93

RESULTS

Combined PET/CT is a reliable method for study Combined PET/CT is a reliable method for study pulmonary lesions, pulmonary lesions,

with 94,8% positive predictive value for malignancy with 94,8% positive predictive value for malignancy

and 87,1% negative predictive valueand 87,1% negative predictive value

In the indeterminate lesions 41.7% of malignancy was In the indeterminate lesions 41.7% of malignancy was found, and then this patients need a biopsyfound, and then this patients need a biopsy

CONCLUSION

Thanks...