ESTRO 2025 - Abstract Book

S1484

Clinical – Mixed sites & palliation

ESTRO 2025

1228

Digital Poster Preliminary results of a CyberKnife SBRT for extracranial sites from a tertiary institute Bhooshan Zade, Vrushab Rao, Raghavendra Holla, Sayli Rakshe Department of CyberKnife Radiosurgery and Radiation Oncology, Ruby Hall Clinic, Pune, India

Purpose/Objective: Isolated lesions, primary or metastatic, are generally asymptomatic and incidentally detected. Treating such lesions with radiotherapy (RT) emphasizes the need for cure/palliation without any adverse events. Cyberknife (CK) has revolutionized targeted RT for small lesions for intracranial as well as extracranial lesions. The accuracy of treatment is ensured by tracking the tumor, fiducials, or other surrogate markers such as the dome of the liver. We report the preliminary results and toxicities of stereotactic body radiotherapy (SBRT) using CyberKnife S7. Material/Methods: Patients treated for extracranial lesions between July 2023 and January 2024 were selected. Maximum tumor size was <5cm. Planning was done on the Precision Planning System. Response to treatment was assessed using imaging 1-3 months after RT either using PET-CT scans or MRI. Toxicities were assessed using the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. Only interval size reduction and toxicity grades of <2 were considered as successful radiosurgeries. Results: 53 SBRT cases treated in 6 months were included. The distribution of cases and the tracking used are listed in the table below.

Indication

Number of cases

Tracking used

Abdominal wall nodule/omental nodule

2

Fiducial tracking

Accelerated partial breast irradiation

6

Tumor bed clip tracking

Adrenal metastases

2

Spine tracking

Bony metastasis

3

Bone tracking

Iliac node

1

Bone tracking

Hepatocellular carcinoma/liver metastases

10

Fiducial tracking

Lung SBRT

9

Respiratory motion tracking

Oral cavity

2

Bone tracking

Para-aortic nodal metastases

5

Spine tracking

Pericardial node

1

Lung tracking

Prostate SBRT

6

Fiducial tracking

Supraclavicular fossa node

1

Spine tracking

TO node

2

Bone tracking

Uterine lesions

3

Fiducial tracking