Category: Clinical Oncology: Outcomes & Complications
Introduction & Objective :
Despite the routine use of the plain chest radiography (CXR) for postoperative pulmonary surveillance, it is a low yield tool for T1 RCC given the low incidence of pulmonary metastasis (PM) in this population to be reported at less than 5%. Current international panel (CUA, EUA, AUA, NCCN) vary in their recommendations for mode, frequency and timing of post-operative pulmonary surveillance but all guidelines recommend surveillance for up to 3 years for T1 disease. However, these guidelines group T1a and T1b into a single entity which adhere to a common surveillance pattern despite a well-established difference in incidence of PM and disease specific survival between T1a and T1b disease.
In this study, we investigate the utility of the routine surveillance CXR in detecting postoperative PM for T1a and T1b RCC after curative treatment with surgical therapy using a large multi-institutional database.
Our primary outcome was the incidence of a asymptomatic pulmonary lesion concerning for PM detected by CXR which required further imaging with CT chest and/or percutaneous pulmonary biopsy. Secondary outcomes include an analysis of high risk pathologic features in predicting pulmonary metastasis. We further compared the rate of pulmonary metastasis between T1a and T1b as well as between PN and TN.
568 patients met criteria for the study of which 384 were T1a and 184 were T1b. Mean duration of follow up for T1a and T1b was 45 and 43 months, respectively. A total of 1,375 CXR’s were reviewed. Patients averaged 2.96 and 2.99 CXRs for T1a and T1b with 46.8% having surveillance beyond 3 years. Indeterminate lesions were found in 5.7% (22/384) of T1a and 5.4% (10/184) in T1b of which 0.01% (2) and 1.1% (2) were confirmed to be PM by Chest CT and subsequent biopsy. The 2 patients with T1a had PM detected beyond 3 years; although one patient had local recurrence and one patient had hemoptysis prompting the CXR. The 2 patients with T1b had asymptomatic PM detected by surveillance CXR within 3 years. High risk pathological features including positive margins, sarcomatoid features, LVI or necrosis were not present in patients with PM. There was no significant difference in the incidence of pulmonary metastases for patients undergoing partial nephrectomy (3/290) or radical nephrectomy (1/278) (p= 0.62).
Our review suggests that the 3 year post-treatment pulmonary surveillanc for the detection of asymptomatic PM should be reserved for T1b RCC and may not be necessary in T1a disease given its low yield and likelihood of false positives on CXR leading to unnecessary radiation and potential biopsies.
Alexander Chow– Resident Physician, Rush University Medical Center, Chicago, Illinois
Alyssa Kahan– Medical Student, Rush University Medical Center, Chicago, Illinois
Thomas Hwang– Medical Student, Rush University Medical Center, Chicago, Illinois
Christopher Coogan– Professor of Urology, Rush University Medical Center, Chicago, Illinois
Kalyan Latchamsetty– Assistant Professor of Urology, Rush University Medical Center, Chicago, Illinois