Interpretation and Prognostic Value of Positron Emission Tomography-Computed Tomography After Induction Chemotherapy With or Without Radiation in IIIA-N2 Non-small Cell Lung Cancer Patients Who Receive Curative Surgery

Abstract

We evaluate the correlation of clinical staging on positron emission tomography-computed tomography (PET-CT) and pathologic staging and the prognostic value of PET-CT after induction chemotherapy in patients with locally advanced nonsmall cell lung cancer (NSCLC).We analyzed 42 cases of clinical stage IIIA-N2 NSCLC who receive 2 to 4 cycles of preoperative chemotherapy with or without radiation followed by curative resection. The maximum standard uptake value (SUVmax) of the suspected lesion on PET-CT was recorded. PET-CT findings after induction chemotherapy were compared with those of initial PET-CT and pathology after surgery.The accuracy of PET-CT in restaging of the primary tumor after induction chemotherapy was 50.0%. Eighteen (42.8%) of 42 patients were underestimated ycT stage, and 3 (7.1%) of 42 patients was overestimated ycT stage by PET-CT scan. The accuracy of PET-CT in restaging of the nodal disease was 71.4%. Six (14.3%) of 42 patients were underestimated ycN stage, and 6 (14.3%) of 42 patients were overestimated ycN stage as compared with pathologic staging. The 2-year overall survival (OS) and relapse-free survival (RFS) rate were 68.5% and 40.9%, respectively. Complete responders (ycT0N0M0) on PET-CT after induction chemotherapy had a significantly longer RFS time than did incomplete responders (28.3 vs 9.1 months, P = 0.021).Complete response on PET-CT after induction chemotherapy with or without radiation was a good prognosticator for RFS in stage IIIA-N2 NSCLC patients who received surgery. However, response evaluation on PET-CT after induction chemotherapy should be interpreted with caution due to its unacceptable accuracy.

KRAS Mutation Status Is Not a Predictor for Tumor Response and Survival in Rectal Cancer Patients Who Received Preoperative Radiotherapy With 5-Fluoropyrimidine Followed by Curative Surgery

“…The median follow-up time of the present study is 34 months, and it is shorter than those of other studies. 4 , 8 , 29 , 30 This may explain the excellent survival outcome regardless of the KRAS oncogene status in our study, and longer follow-up would be helpful to elucidate the value of the KRAS oncogene and its mutation more clearly. 31 …”

A novel [89Zr]-anti-PD-1-PET-CT to assess response to PD-1/PD-L1 blockade in lung cancer

“…A number of clinical studies have shown that alterations in metabolic activity, expressed as changes in SUV during induction therapy or at interim evaluation, are associated with tumor response. In NSCLC, a reduction of SUVmax below 2.5 after 2-4 conventional chemotherapy cycles has been considered a predictor of future response associated with a substantially higher median time to recurrence ( 28 ). Similarly, when the treatment studied is a targeted therapy, such as the EGFR tyrosine-kinase inhibitor erlotinib, a reduction in SUVmax measured by [ 18 F]-FDG-PET is also clearly associated with durable therapeutic responses in NSCLC patients ( 29 ).…”

PET-CT in the UK: current status and future directions

“…Despite this, treatment response in NSCLC is still largely assessed with conventional CT. A recent study from Israel evaluating the use of FDG PET-CT to assess the resectability of patients with stage III NSCLC after neoadjuvant therapy reported a very high sensitivity and negative predictive value for detecting responding nodes, which may guide optimal patient selection for curative resection 107 . Another recent study from Korea evaluating a similar patient cohort reported significantly increased relapse-free and overall survival in patients undergoing surgery who showed CMR within mediastinal nodal disease on FDG PET-CT following neoadjuvant treatment compared to incomplete responders 108 .…”