The Watch the Spot Trial (WTS)

The Watch the Spot Trial: A Pragmatic Trial of More Versus Less Intensive Strategies for Active Surveillance of Patients With Small Pulmonary Nodules

Patient-Centered Outcomes Research Institute, University of California, Davis, University of California, San Francisco

This study will compare two clinically accepted protocols for surveillance imaging in individuals who are found to have a small pulmonary nodule on chest computed tomography (CT) scans.

The investigators will conduct an unblinded, prospective, pragmatic, cluster-randomized, comparative effectiveness trial of more intensive versus less intensive CT surveillance of patients found to have small pulmonary nodules in diverse health care settings. The goal of this pragmatic clinical trial is to identify the surveillance strategy that will maximize early diagnosis for individuals with cancerous nodules, while minimizing unnecessary surveillance of patients without cancer that can result in emotional stress, exposure to harmful ionizing radiation, and the discovery of incidental findings that may lead to unnecessary treatment.

Chest CT scans to be repeated at 3, 6, 12 and/or 24 months, depending on patient risk factors and nodule size and attenuation (density)

Chest CT scans to be repeated at 3, 6, 12 and/or 24 months, depending on patient risk factors and nodule size and attenuation (density). Overall, participants in the less frequent arm are expected to undergo 30% fewer surveillance imaging tests.

Chest CT scans to be repeated at 3, 6, 12 and/or 24 months, depending on patient risk factors and nodule size and attenuation (density)

Chest CT scans to be repeated at 3, 6, 12 and/or 24 months, depending on patient risk factors and nodule size and attenuation (density). Overall, participants in the less frequent arm are expected to undergo 30% fewer surveillance imaging tests.

Proportion of cancerous nodules with tumor (T) stage greater than T1a disease by the AJCC staging system, 7th edition

Among individuals with small pulmonary nodules identified either incidentally or by screening, compare more versus less intensive surveillance to determine the number of cancerous nodules that progress beyond T stage T1a.

Numbers of imaging tests, biopsy tests and surgical procedures, measured by review of electronic health records

Measured from date of nodule identification until date of cancer diagnosis or completion of 24 months of follow-up

Exposure to ionizing radiation, using the computed tomography dose index (CTDIvol), measured in mGy (milliGray)

Measured from date of nodule identification to date of cancer diagnosis or completion of 24 months of follow-up

Measured from date of nodule identification to date of cancer diagnosis or completion of 24 months of follow-up

Numbers of CT scans recommended by the assigned protocol that were not ordered by the ordering provider, and/or not completed by the patient

Compare adherence to the recommended protocols for CT surveillance, and adherence to use of low radiation dose techniques.

Measured from date of nodule identification to date of cancer diagnosis or completion of 24 months of follow-up

Inclusion Criteria: The target population includes adults with small lung nodules that may represent a new diagnosis of lung cancer, who typically would be managed by CT surveillance in usual clinical practice. Thus, we will enroll all patients: aged ≥35 years at least one nodule measuring ≤15 mm in average diameter on chest CT. Exclusion Criteria: Pregnant Women Age <35 years Known diagnosis of cancer (except non-melanoma skin cancer) within 5 years

We plan to share de-identified IPD for all study variables with other researchers on request as long as there is an acceptable justification

De-identified IPD will be made available within 6-12 months following study completion, to allow time for the primary study team to complete manuscripts that report on each of the 4 study aims.

Interested researchers will be required to submit a formal request with justification and aims to the study Data Coordinating Center. Requests will be reviewed and approved by the study Executive Committee. Relevant data use or data transfer agreements will need to be completed.

MacMahon H, Austin JH, Gamsu G, Herold CJ, Jett JR, Naidich DP, Patz EF Jr, Swensen SJ; Fleischner Society. Guidelines for management of small pulmonary nodules detected on CT scans: a statement from the Fleischner Society. Radiology. 2005 Nov;237(2):395-400. doi: 10.1148/radiol.2372041887.

Naidich DP, Bankier AA, MacMahon H, Schaefer-Prokop CM, Pistolesi M, Goo JM, Macchiarini P, Crapo JD, Herold CJ, Austin JH, Travis WD. Recommendations for the management of subsolid pulmonary nodules detected at CT: a statement from the Fleischner Society. Radiology. 2013 Jan;266(1):304-17. doi: 10.1148/radiol.12120628. Epub 2012 Oct 15.

Gould MK, Donington J, Lynch WR, Mazzone PJ, Midthun DE, Naidich DP, Wiener RS. Evaluation of individuals with pulmonary nodules: when is it lung cancer? Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013 May;143(5 Suppl):e93S-e120S. doi: 10.1378/chest.12-2351.

Berrington de Gonzalez A, Mahesh M, Kim KP, Bhargavan M, Lewis R, Mettler F, Land C. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009 Dec 14;169(22):2071-7. doi: 10.1001/archinternmed.2009.440.

Smith-Bindman R. Is computed tomography safe? N Engl J Med. 2010 Jul 1;363(1):1-4. doi: 10.1056/NEJMp1002530. Epub 2010 Jun 23. No abstract available.

Smith-Bindman R, Miglioretti DL, Johnson E, Lee C, Feigelson HS, Flynn M, Greenlee RT, Kruger RL, Hornbrook MC, Roblin D, Solberg LI, Vanneman N, Weinmann S, Williams AE. Use of diagnostic imaging studies and associated radiation exposure for patients enrolled in large integrated health care systems, 1996-2010. JAMA. 2012 Jun 13;307(22):2400-9. doi: 10.1001/jama.2012.5960.

Gould MK, Tang T, Liu IL, Lee J, Zheng C, Danforth KN, Kosco AE, Di Fiore JL, Suh DE. Recent Trends in the Identification of Incidental Pulmonary Nodules. Am J Respir Crit Care Med. 2015 Nov 15;192(10):1208-14. doi: 10.1164/rccm.201505-0990OC.

Wiener RS, Gould MK, Slatore CG, Fincke BG, Schwartz LM, Woloshin S. Resource use and guideline concordance in evaluation of pulmonary nodules for cancer: too much and too little care. JAMA Intern Med. 2014 Jun;174(6):871-80. doi: 10.1001/jamainternmed.2014.561.

Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med. 2007 Nov 29;357(22):2277-84. doi: 10.1056/NEJMra072149. No abstract available.

Ost D, Fein AM, Feinsilver SH. Clinical practice. The solitary pulmonary nodule. N Engl J Med. 2003 Jun 19;348(25):2535-42. doi: 10.1056/NEJMcp012290. No abstract available.