PT - JOURNAL ARTICLE AU - Andrew W Creamer AU - Carolyn Horst AU - Jennifer L Dickson AU - Sophie Tisi AU - Helen Hall AU - Priyam Verghese AU - Ruth Prendecki AU - Amyn Bhamani AU - John McCabe AU - Kylie Gyertson AU - Anne-Marie Mullin AU - Jonathan Teague AU - Laura Farrelly AU - Allan Hackshaw AU - Arjun Nair AU - SUMMIT consortium AU - Anand Devaraj AU - Sam M Janes TI - Growing small solid nodules in lung cancer screening: safety and efficacy of a 200 mm<sup>3</sup> minimum size threshold for multidisciplinary team referral AID - 10.1136/thorax-2022-219403 DP - 2023 Feb 01 TA - Thorax PG - 202--206 VI - 78 IP - 2 4099 - http://thorax.bmj.com/content/78/2/202.short 4100 - http://thorax.bmj.com/content/78/2/202.full SO - Thorax2023 Feb 01; 78 AB - The optimal management of small but growing nodules remains unclear. The SUMMIT study nodule management algorithm uses a specific threshold volume of 200 mm3 before referral of growing solid nodules to the multidisciplinary team for further investigation is advised, with growing nodules below this threshold kept under observation within the screening programme. Malignancy risk of growing solid nodules of size &gt;200 mm3 at initial 3-month interval scan was 58.3% at a per-nodule level, compared with 13.3% in growing nodules of size ≤200 mm3 (relative risk 4.4, 95% CI 2.17 to 8.83). The positive predictive value of a combination of nodule growth (defined as percentage volume change of ≥25%), and size &gt;200 mm3 was 65.9% (29/44) at a cancer-per-nodule basis, or 60.5% (23/38) on a cancer-per-participant basis. False negative rate of the protocol was 1.9% (95% CI 0.33% to 9.94%). These findings support the use of a 200 mm3 minimum volume threshold for referral as effective at reducing unnecessary multidisciplinary team referrals for small growing nodules, while maintaining early-stage lung cancer diagnosis.