Q1) False about role of PET scan in Ca esophagus
a) Upstages disease in 15% cases
b) Used to assess response to pre op chemo radiation
c) Used for selecting patients for surgery after neoadjuvant chemo Rt
d) Assessment of response is seen after 2 weeks of pre op chemo RT
PET/CT provides additional information in 18.5% and altered management in 17% with 11% upstaged and 7.5% downstaged compared with conventional imaging.
FDG-PET appears to be the best method for identifying responders in oesophageal cancer. Weber et al.assessed early response to therapy within 14 days of commencement of chemoradiotherapy for adenocarcinoma and found that a decrease in SUV of greater than 35% indicated a major pathological response with a 3-year survival of 70%, compared with a 3-year survival of only 35% in the non-responders.
PET/CT is superior to PET alone and is also better than CT for distant metastases.
A meta-analysis of the use of FDG-PET found that a higher SUV indicated a worse prognosis and was associated with a higher risk of recurrence. A higher SUV was also associated with longer tumours, higher T-stage status, positive N-stage status and squamous cell histology
Endoscopic ultrasound remains the best modality for the assessment of the T stage with a high pooled sensitivity for tumour invasion (81–90%), especially for T4 disease (92.4%), and the specificity is 99%.