Undetected lymph node metastases in presumed early stage NSCLC SABR patients.
BACKGROUND
Stereotactic body radiation therapy (SBRT, also called stereotactic ablative body radiation SABR) is the treatment of choice for many patients with early-stage non-small cell lung cancer (NSCLC), including those who are unfit for surgery or refuse surgery.


METHODS
In an effort to develop optimal staging for the evaluation of SBRT candidates, we review the performance of available lymph node staging methods, as well as risk factors for lymph node involvement. Pubmed was searched to identify relevant literature. Current staging methods for NSCLC, including Positron Emission Tomography/Computed Tomography(PET/CT) and endobronchial ultra sound (EBUS), have limited sensitivities. Expert commentary: There are several factors, including primary tumor location, tumor size, and histology that are possibly associated with the sensitivity of PET/CT to detect mediastinal lymph node metastasis. Small lymph node metastases typically remain undetected by PET/CT. Therefore invasive nodal staging procedures are indicated for most presumed early-stage NSCLC patients, but these also have limited sensitivity. Occult lymph node metastasis is associated with adverse outcome in NSCLC. Moreover, there is overwhelming evidence that certain patients who have lymph node metastases detected at the time of surgery derive an overall survival benefit from adjuvant therapies. It remains to be determined if improved detection of lymph node metastases in SABR candidates can indeed improve prognosis.
a Department of Radiation Oncology , Indiana University School of Medicine , Indianapolis , IN , USA.
Alberto
A
Cerra-Franco
b Department of Pulmonary Medicine , Indiana University School of Medicine , Indianapolis , IN , USA.
Khalil
K
Diab
a Department of Radiation Oncology , Indiana University School of Medicine , Indianapolis , IN , USA.
Tim
T
Lautenschlaeger
D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods; D011379:Prognosis; D016634:Radiosurgery / Q000379:methods*; D015996:Survival Rate
CT; EBUS; EUS; PET; SABR; SBRT; SBRT lymph node metastases; non-small cell lung cancer; occult metastases; staging