Table 1.
Details of PET-Positive and PET-Negative Patients with CIS Who Developed Invasive Cancer
| Patient | Sex, Age (yr) | Smoking Hi | FEV1/Pred | Time to Develop Ca from Bronchoscopy | PET (SUV Maximum) | Mediastinum (SUV Maximum) | Symptoms |
|---|---|---|---|---|---|---|---|
| PET-positive | |||||||
| 1 | Female, 79 | N | 1.69 (83%) | 18 mo | 3.2 | 1.8 | Nil |
| 2 | Male, 75 | Y | 1.54 (67%) | 6 mo | 3.9 | 1.5 | Nil |
| 3 | Male, 70 | Y | 0.64 (20%) | 6 mo | 3.3 | 2.5 | Hemoptysis |
| 4 | Male, 65 | N | 1.06 (35%) | RT treatment (3 mo after PET) | 3.3 | 2.6 | Hemoptysis |
| 5 | Female, 80 | Y | 1.81 (89% | Stable after 3 yr | 5.9 | 2.1 | Hemoptysis |
| 6 | Male, 75 | N | 2.17 (65%) | 6 mo | 4.2 | 2.3 | Nil |
| 7 | Male, 67 | Y | 2.60 (71%) | 3 yr | 4.7 | 1.8 | Nil |
| 8 | Male, 78 | Y | 1.54 (35%) | 18 mo | 3.5 | 2 | Hemoptysis |
| PET-negative | |||||||
| 1 | Male, 80 | Y | 2.50 (81%) | 2 yr | Negative | 2 | Hemoptysis |
| 2 | Male, 77 | Y | 2.6 (74%) | 3 yr | Negative | 2.1 | Nil |
| 3 | Female, 59 | Y | 1.84 (84%) | 2 yr | Negative | 1.9 | Nil |
| 4 | Male, 75 | Y | 1.95 (73%) | 18 mo | Negative | 2.2 | Nil |
| 5 | Male, 78 | Y | 2.16 (80%) | 2 yr | Negative | 2.3 | Hemoptysis |
| 6 | Female, 79 | Y | 0.9 (50%) | 3 yr | Negative | 2.1 | Nil |
Definition of abbreviations: Ca = cancer; CIS = carcinoma in situ; CT = computed tomography; 18F-FDG = 18fluorodeoxyglucose; Hi = history; PET = positron emission tomography; Pred = predicted; RT = radiotherapy; SUV = standardized uptake value.
18F-FDG-PET/CT scans were analyzed for areas of abnormal 18F-FDG uptake; location and site of 18F-FDG uptake were recorded. In 9 of 29 patients there was increased 18F-FDG uptake at the site of CIS (SUV maximum range, 3.2–5.9; average, 3.5). Seven of the eight patients developed invasive cancer on histological follow-up of the lesion, three after 6 months, two at 18 months, and one at 36 months after 18F-FDG-PET/CT. One patient remained stable with CIS after 3 years. Lesions showing positive uptake were significantly more likely to progress (P = 0.0097; the two-tailed Fisher test was used to assess the association between PET positive/negative findings vs. stable disease/invasive cancer during surveillance; P < 0.05 was taken as significant) to invasive cancer than those with negative 18F-FDG uptake. One patient did not have pathological confirmation of invasive cancer; the diagnosis was made on the basis of increasing bronchial wall thickening on follow-up CT imaging. This patient was treated with external beam radiotherapy with resolution of 18F-FDG avidity on a follow-up scan and resolution of CIS at least histology to normal. In 21 patients, there was no 18F-FDG avidity at sites of CIS. Of these patients, six developed invasive cancer within 3 years of a negative PET. In four patients with negative 18F-FDG scans, CIS lesion histology reverted to normal over 1–3 years follow-up. In the remaining patients, CIS remains stable during follow-up.