A multicenter LArge retrospectIve daTabase on the personalization of Stereotactic ABlative Radiotherapy use in lung metastases from colon-rectal cancer: the LaIT-SABR study

INTRODUCTION

stereotactic ablative radiotherapy (SABR) has been shown to increase survival in oligometastatic disease, but local control of colorectal metastases remains poor. We aimed to identify potential predictive factors of SBRT response through a multicenter large retrospective database and to investigate the progression to the polymetastatic disease (PMD).

MATERIAL AND METHODS

the study involved 23 centers, and was approved by the Ethical Committee (Prot. Negrar 2019-ZT). 1033 lung metastases were reported. Clinical and biological parameters were evaluated as predictive for local progression-free survival (FLP). Secondary end-point was the time to the polymetastatic conversion (tPMC).

RESULTS

Two-year FLP was 75.4%. Two-year FLP for lesions treated with a BED <100 Gy, 100-124 Gy, and ≥125 Gy was 76.1%, 70.6%, and 94% (p=0.000). Two-year FLP for lesion measuring ≤10 mm, 10-20 mm, and >20 mm was 79.7%, 77.1%, and 66.6% (p=0.027). At the multivariate analysis a BED ≥125 Gy significantly reduced the risk of local progression (HR 0.24, 95%CI 0.11-0.51; p=0.000). Median tPMC was 26.8 months. Lesions treated with BED ≥125 Gy reported a significantly longer tPMC as compared to lower BED. The median tPMC for patients treated to 1, 2-3 or 4-5 simultaneous oligometastases was 28.5, 25.4, and 9.8 months (p=0.035).

CONCLUSION

The present is the largest series of lung colorectal metastases treated with SABR. The results support the use of SBRT in lung oligometastatic colorectal cancer patients as it might delay the transition to PMD or offer relatively long disease-free period in selected cases. Predictive factors were identified for treatment personalization.

[Pulmonary hypertension in patients with left ventricular dysfunction studied with contrast-enhanced Doppler echocardiography: relations with diastolic parameters and prognostic implications]

In patients with left ventricular dysfunction, the prognostic value of both pulmonary hypertension and mitral flow patterns has been recognized. However, the effect of the association of different degrees of pulmonary hypertension on prognosis and the corresponding left ventricular diastolic dysfunction is not clear. Accordingly, we considered the impact on survival of a categorization based on the relationship between pulmonary artery pressure and left ventricular diastolic dysfunction, as assessed by mitral and pulmonary venous flow analyses. Transthoracic Doppler echocardiography was carried out in 92 patients with ejection fraction < 45%, pulmonary artery systolic pressure > 25 mmHg and sinus rhythm. Tricuspid regurgitant velocity and Doppler parameters derived from transmitral and pulmonary venous flows were evaluated. In the case of inadequate baseline tracings, weak or poor Doppler signals were enhanced by intravenous injection of a galactose-based contrast agent (Levovist 8 ml suspension at a concentration of 400 mg/ml). To select those whose pulmonary hypertension was either proportional or unproportional to left side filling pressures, patients were divided as follows: Group 1 (n = 69) with low discrepancies and Group 2 (n = 23) with marked discrepancies between Doppler estimates of pulmonary artery systolic pressure and left side filling abnormalities. The patients of each group were also classified according to their mitral flow pattern: abnormal relaxation, pseudonormal and restrictive. Mean pulmonary artery systolic pressure was 49 +/- 16 mmHg in the total population, 43 +/- 11 mmHg in Group 1 and 68 +/- 14 mmHg in Group 2 (p < 0.0001). Several mitral and pulmonary venous flow variables significantly correlated with pulmonary artery systolic pressure in the total population and in the study groups. The best correlations were observed in Group 1 as regards the ratio of reverse-to-forward atrial wave duration (r = 0.83), E wave deceleration rate (r = 0.81), E wave deceleration time (r = -0.81) and the systolic fraction of pulmonary venous flow peak velocities (r = -0.75). In Group 1, the lower heart failure-free survival rate at 10 months was observed in patients with restrictive pattern (68%) as opposed to those with pseudonormal (94%) and abnormal relaxation patterns (97%). The overall heart failure-free survival rate in Group 2 was 86%. In conclusion, the classification according to the relationship between pulmonary hypertension and the alterations of left chamber filling may contribute to the prognostic stratification of patients with left ventricular dysfunction. The patients with pulmonary hypertension proportional to the increase in left chamber filling pressures and restrictive pattern exhibited the worst prognosis.