Solid Indeterminate Pulmonary Nodules of Less Than 300 mm3: Application of Different Volume Doubling Time Cut-offs in Clinical Practice

Abstract

In the British Thoracic Society guidelines for incidental pulmonary nodules, volumetric analysis has become the recommended method for growth assessment in solid indeterminate pulmonary nodules (SIPNs) <300 mm3. In these guidelines, two different volume doubling time (VDT) cut-offs, 400 and 600 days, were proposed to differentiate benign from malignant nodules. The present study aims to evaluate the performance of these VDT cut-offs in a group of SIPNs <300 mm3 which were incidentally detected in a routine clinical setting. During a 7-year period, we retrospectively selected 60 patients with a single SIPN <300 mm3. For each SIPN, the volume and VDT were calculated using semiautomatic software throughout the follow-up period, and the performance of the 400- and 600-day VDT cut-offs was compared. In the selected sample, there were 38 benign and 22 malignant nodules. In this group of nodules, the sensitivity, negative predictive value and accuracy of the 600-day VDT cut-off were higher than those of the 400-day VDT cut-off. Therefore, in the management of SIPNs <300 mm3 which were incidentally detected in a clinical setting, the 600-day VDT cut-off was better at differentiating benign from malignant nodules than the 400-day VDT cut-off, by reducing the number of false negatives.

What’s New on Quantitative CT Analysis as a Tool to Predict Growth in Persistent Pulmonary Subsolid Nodules? A Literature Review

“…Among quantitative CT methods, those related to thoracic imaging are the most studied [20,22,23,[31][32][33][34][35][36][37][38][39][40][41][42][43]. In particular, the applications related to the classification and management of lung nodules are the most well-known and are used in both clinical practice and lung cancer screening programs [20,22,23,[31][32][33][34].…”

“…Among the radiological diagnostic methods applied in the thoracic field, CT is the most widely used for quantitative analysis [21]. While the effectiveness of quantitative CT applications for predicting malignancy in solid nodules is well established and widely described in the literature [22,23], those related to SSN growth prediction are much more recent and, therefore, less well-known.…”

Quantitative CT Analysis for Predicting the Behavior of Part-Solid Nodules with Solid Components Less than 6 mm: Size, Density and Shape Descriptors

“…Methods for the quantitative analysis of medical CT images are constantly expanding, and the applications of such methods in the thoracic field are increasing [4,5,9,14,[17][18][19][20][21][22]28,[30][31][32][33][34].…”

“…Lung nodules represent a common finding on chest computed tomography (CT), and their incidence is steadily increasing [1][2][3]. With improvements in temporal and spatial resolution, multidetector CT (MDCT) scanners are now able to detect a larger number of nodules, especially small nodules and subsolid nodules (SSNs) [1, [3][4][5].…”

Nódulo pulmonar solitario: ¿Es la medición del tiempo de duplicación volumétrica realmente útil para diferenciar lesiones benignas de malignas?

“…Al comparar ambas formas de calcular el volumen, los métodos tridimensionales parecen ser más consistentes con el resultado histopatológico, dado el crecimiento asimétrico y no siempre redondeado de algunos nódulos 5,7,9 . Esto es especialmente válido para NP pequeños 10,11 , y cobra relativa importancia tomando en cuenta que actualmente los nódulos pulmonares incidentales más frecuentes de en-contrar en TC, son menores a 10 mm 9 , donde los métodos en dos dimensiones pierden exactitud, en especial si el crecimiento es lento y/o los intervalos entre controles son muy cortos. En estos casos se ha observado que la variabilidad interobservador aumenta con respecto a los métodos tridimensionales, posiblemente por crecimientos submilimétricos difíciles de medir manualmente 9,10,12 .…”