ESTRO 2024 - Abstract Book

S959

Clinical - CNS

ESTRO 2024

Material/Methods:

Between September 2018 and July 2023, a total of 22 patients were subjected to stereotactic radiosurgery (SRS) or fractionated SRS for the management of 175 brain metastases. The study population consisted of patients diagnosed with a minimum of four brain metastases, two of whom had previously undergone whole-brain radiotherapy (WBRT). After primary radiosurgery 14 patients underwent additional radiosurgery due to local progression outside of the previously irradiated field (1 to 12 additional sessions). Twenty patients were concurrently receiving systemic therapy while being referred for brain irradiation. The primary tumor sites leading to metastatic dissemination were as follows: cutaneous melanoma (13 patients), non-small cell lung carcinoma (NSCLC) (3 patients), breast carcinoma (4 patients), and colorectal carcinoma (2 patients). For the purposes of planning and contouring, immobilization masks were used in conjunction with brain MRI and CT scans. Treatment parameters were analyzed, which included the conformity index, dose coverage, and the volume of healthy brain tissue affected by radiation. Survival was assessed from the end of the radiotherapy course until the last follow-up or the occurrence of mortality in all patients, with results being compared to the estimated median survival time as per the GPA Index.

Results:

The mean number of metastatic lesions per patient was 8 (ranging from 4 to 20), with the average planning target volume measuring 16.12 cc (ranging from 1.89 to 45.06). The average conformity index was 1.25, with complete gross tumor volume (GTV) coverage of 100% in all patients except for one (99%). The median overall survival time for the study group was 8.1 months, while the median estimated survival time as per GPA Index for the group was 8.3 months.

No reports of Grade 3 (G3) or Grade 4 (G4) toxicities existed. None of the patients discontinued systemic treatment during stereotactic radiotherapy.

Conclusion:

The study provides valuable insights into the effectiveness of CyberKnife for this patient population.

Keywords: Stereotactic radiotherapy, Radionecrosis

2999

Digital Poster

Craniospinal irradiation in Helical Tomotherapy: Dosimetric analysis and acute toxicity evaluation

Siddharth Malukar 1 , Ankita Parikh 1 , Suryanarayana Kunikullaya 1 , Satyajeet Rath 1 , Jayesh Singh 1 , Akash Pandya 1 , Niranjan Dash 1 , Arun T 1 , Maitrik Mehta 1 , Sonal Patel Shah 1 , Vinay Shivhare 1 , Rajan Yadav 2 , Dhara Patel 1 , Krishna Prajapati 1 , Piyush Hadiya 1 , Tushar Bopche 3 , Satish Pelagade 3 , Mitul Kakkad 3 , Jincy C. D. 3 , Anagha Pachat 3