Comparison of internal target volume delineation using CT datasets of four-dimensional computed tomography in lung cancer radiotherapy

Abstract

Background: Patients with lung cancer and co-existing interstitial lung disease (ILD) are at increased risk of treatment-related toxicity after both surgery and radiotherapy. A care path was implemented at our institution for patients presenting to the lung tumor board with a possible ILD, and we report on our experience using this structured approach. Methods: Since 2015, patients with possible lung cancer and ILD were referred to the general ILD clinic for assessment. In 2017, a dedicated ILD lung tumor board was established in order to facilitate quick assessment of treatment-related risks. An ethicsapproved institutional database containing details of all these patients was accessed. Results: 24 patients with lung tumors and a co-existing ILD were identified (Table ). The mean interval between referral to, and consultation at our ILD-board was 2 weeks. A prior diagnosis of ILD was available in 9 of 17 (53%) patients, but review led to a reclassification of the ILD subtype in 8 of the former. Treatments for lung cancer included radiotherapy alone (n ¼ 14), surgery (n ¼ 6), sequential chemoradiation (n ¼ 3), and concurrent CRT followed by salvage surgery (n ¼ 1). 6 patients developed progression of ILD after radiation; of these, 2 had received nintedanib during treatment. One patient died because of progressive ILD and in another 3 patients ILD-related deaths could not be excluded. Conclusions: A dedicated care path for ILD patients resulted in a fast evaluation of lung cancer patients. A previous ILD-diagnosis was revised in a majority of patients, a process which can allow for a better understanding of treatment-related risks in different subgroups of ILD patients, and also assess the role of ILD-directed therapies.

Radiation dosimetric influence by different target volume definition in Cyberknife lung cancer and abdomen stereotactic body radiotherapy

“…All these data were normalized to their planned values by comparing the ratios of the dosimetric parameters of the GTVs in each plan. We aimed to investigate that which PTV definition provided the optimum GTV coverage during the treatment plan and reduced the likelihood of potential target leakage (Bushra, 2019).…”