Metastatic salivary gland carcinoma: A role for stereotactic body radiation therapy? A study of AIRO-Head and Neck working group.

OBJECTIVES: The role of radiotherapy (RT) for oligometastases is currently established in different oncological settings but data on salivary gland cancer (SGC) are lacking. We evaluated the role of RT in oligometastatic SGC patients, focusing on stereotactic body radiation therapy (SBRT). MATERIALS AND METHODS: We performed a retrospective, multicentric study of oligometastatic SGC treated with palliative RT or SBRT. Endpoints included response evaluation and local control (LC). RESULTS: Between 2006 and 2016, 64 patients were collected from 9 Italian Cancer Centers, on behalf of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) Head and Neck Working Group. 37 patients (57.8%) were suffering from adenoid cystic carcinoma (ACC) and 27 patients (42.2%) had non-ACC. Thirty-four patients underwent palliative RT (53,1%), and 30 received SBRT (46,9%). Most common metastatic sites were bone for palliative RT and lung for SBRT. Among patients treated with SBRT, an objective response or a stability was observed in all treated lesions. After a median follow-up of 29.2 months (range 2.3-117.1), LC at 12 months was 57.5% for patients treated with SBRT and was higher in ACC subgroup. CONCLUSION: We confirmed the potential role of SBRT in the management of oligometastatic SGC patients to control limited burden of disease considering the absence of effective systemic therapies.

Radiosurgery and fractionated stereotactic radiotherapy in oligometastatic/oligoprogressive non-small cell lung cancer patients: Results of a multi-institutional series of 198 patients treated with "curative" intent.

OBJECTIVES: stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are a therapeutic option for Oligometastatic/Oligoprogressive (OM/OP) NSCLC. This retrospective multicentre analysis aims to analyse clinical outcomes and treatment related toxicity of patients treated to all sites of know disease with SRS and/or FSRT for OM/OP NSCLC in 8 Italian radiation oncology centres. MATERIALS AND METHODS: From January 2016 to January 2017 198 OM/OP NSCLC patients (pts) were treated in 8 Centres. Inclusion criteria were as follows: 1-5 lesions at onset or after previous systemic treatment; Pts must have all metastatic lesions treated. Endpoints analysed were local progression free survival (LPFS); out-of-field recurrence free survival (OFPS); progression free survival (PFS); overall survival (OS). Time to New systemic Therapy free survival (TNT) and toxicity were also analysed. RESULTS: At the time of radiotherapy, 119 pts (60 %) were treated for a single lesion, 49 (25 %) for 2 lesions, 30 (15 %) for 3-5 metastases. Total number of lesions treated was 333: 204 brain, 68 lung, 24 bone, 16 nodal, 12 adrenal, 8 liver and 1 soft tissue. 83/198 pts (41.8 %) had the primary tumour controlled at the time of the SRT. After a median follow-up of 18 months, median OS and PFS were 29.6 months and 10.6 months, respectively. One year LPFS and OPFS were 90 % and 47 %, respectively. Median TNT was 10 months. At univariate analysis factors associated with better OS were PS 0-1; controlled primary tumour, 1-2 lesions; extracranial metastasis. Multivariate analysis confirmed number of lesions <3 and extracranial metastasis to be related with better survival (Relative Risk 0.4 and 0.41, respectively). Two cases of death possibly related to brain radionecrosis were observed. CONCLUSION: OM/OP NSCLC pts treated with an ablative SRT to all metastatic sites have fair outcomes with acceptable toxicity. Better results might be achieved in case of low disease burden and extracranial possibly when primary tumour is controlled.

Localization accuracy of robotic radiosurgery in 1-view tracking.

PURPOSE: When a lung lesion is detected by only one couple of X-ray tube and image detector integrated with CyberKnife®, the fiducial-less tracking is limited to 1-view (34% of lung treatments at Centro Diagnostico Italiano). The aim of the study was mainly to determine the margin needed to take into account the localization uncertainty along the blind view (out-of-plane direction). METHODS: 36 patients treated in 2-view tracking modality (127 fractions in total) were included in the study. The actual tumor positions were determined retrospectively through logfile analysis and were projected onto 2D image planes. In the same plots the planned target positions based on biphasic breath-hold CT scans were represented preserving the metric with respect to the imaging center. The internal margin necessary to cover in out-of-plane direction the 95% of the target position distribution in the 95% of cases was calculated by home-made software in Matlab®. A validation test was preliminarily performed using XLT Phantom (CIRS) both in 2-view and 1-view scenarios. RESULTS: The validation test proved the reliability of the method, in spite of some intrinsic limitations. Margins were estimated equal to 5 and 6 mm for targets in upper and lower lobe respectively. Biphasic breath-hold CT led to underestimate the target movement in the hypothetical out-of-plane direction. The inter-fractional variability of spine-target distance was an important source of uncertainty for 1-view treatments. CONCLUSION: This graphic comparison method preserving metric could be employed in the clinical workflow of 1-view treatments to get patient-related information for customized margin definition.