Late Toxicity and Long-Term Local Control in Patients With Ultra-Central Lung Tumours Treated by Intensity-Modulated Radiotherapy-Based Stereotactic Ablative Body Radiotherapy With Homogenous Dose Prescription. Issue 10 (October 2021)

• Record Type: Journal Article
• Authors: Mihai, A.M.; Armstrong, P.J.; Hickey, D.; Milano, M.T.; Dunne, M.; Healy, K.; Thirion, P.; Heron, D.E.; ElBeltagi, N.; Armstrong, J.G.
• Is Part Of: Clinical oncology. Volume 33:Issue 10(2021)
• Page Start: 627
• Page End: 637
• Publication Date: 2021-10
• Subjects: Homogeneous dose distribution -- late toxicity -- SABR; Oncology -- Periodicals; Tumors -- Periodicals; Cancer -- Treatment -- Periodicals; Radiotherapy -- Periodicals; Neoplasms -- Periodicals; Cancer -- Radiotherapy; Cancer -- Treatment; Oncology; Medical radiology; Radiotherapy; Tumors; Electronic journals; Periodicals; 616.994
• DOI: 10.1016/j.clon.2021.05.005
• Languages: English
• ISSNs: 0936-6555

Abstract

Abstract: Aims: To report late toxicity and long-term outcomes of intensity-modulated radiotherapy (IMRT)-based stereotactic ablative body radiotherapy (SABR) in patients with ultra-central lung tumours. Materials and Methods: This is a single-institution retrospective analysis of patients treated with SABR for ultra-central tumours between May 2008 and April 2016. Ultra-central location was defined as tumour (GTV) abutting or involving trachea, main or lobar bronchi. Respiratory motion management and static-field dynamic-IMRT were used, with dose prescribed homogeneously (maximum <120%). Descriptive analysis, Kaplan–Meier method, log-rank test and Cox regression were used to assess outcomes. Results: Sixty-five per cent of patients had inoperable primary non-small cell lung cancer and 35% had lung oligometastases. The median age was 72 (range 34–85) years. The median gross tumour volume and planning target volume (PTV) were 19.6 (range 1.7–203.3) cm 3 and 57.4 (range 7.7–426.6) cm 3, respectively. The most commonly used dose fractionation was 60 Gy in eight fractions ( n = 51, 87.8%). Median BED10 for D98%PTV and D2%PTV were 102.6 Gy and 115.06 Gy, respectively. With a median follow-up of 26.5 (range 3.2–100.5) months, fatal haemoptysis occurred in five patients (8.7%), of which two were directly attributable to SABR. A statistically significant difference was identified between median BED3 for 4 cm 3 of airway, for patients who developed haemoptysis versus those who did not (147.4 versus 47.2 Gy, P = 0.005). At the last known follow-up, 50 patients (87.7%) were without local recurrence. Freedom from local progression at 2 and 4 years was 92 and 79.8%, respectively. The median overall survival was 34.3 (95% confidence interval 6.1–61.6) months. Overall survival at 2 and 4 years was 55.1 and 41.2%, respectively. Conclusion: In patients with high-risk ultra-central lung tumours, IMRT-based SABR with homogenous dose prescription achieves high local control, similar to that reported for peripheral tumours. Although fatal haemoptysis occurred in 8.7% of patients, a direct causality with SABR was evident in only 3%. Larger studies are warranted to ascertain factors associated with outcomes, especially toxicity, and identify patients who would probably benefit from this treatment. Highlights: Use of homogenous dose prescription and respiratory motion management techniques for SABR in patients with ultra-central high-risk tumours results in survival and tumour control outcomes similar to those reported with inhomogeneous dose distribution. Reported outcomes with the abovementioned techniques are comparable to those reported for peripheral tumours. Using the techniques described above, risk of haemoptysis grade 5 was associated with the dose received by 4 cm 3 airways (BED3).