VMAT based focused RT as an alternative to Stereotaxy in 1-3 brain mets in Oligometastatic Cancers
PO-1140
Abstract
VMAT based focused RT as an alternative to Stereotaxy in 1-3 brain mets in Oligometastatic Cancers
Authors: ANUPAM DATTA1, SAYAN KUNDU2, JIBAK BHATTACHARYA3, SOUMEN DAS4, AVISHEK PAL5, ALOKE KUMAR5
1Netaji Subhas Chandra Bose Cancer Hospital, Radiation Oncology, Kolkata, India; 2Netaji Subhas Chandra Bose Cancer Hospital, Radiation Oncology, Kolkata, India; 3APOLLO MULTISPECIALITY HOSPITAL, RADIATION ONCOLOGY, KOLKATA, India; 4NETAJI SUBHAS CHANDRA BOSE CANCER HOSPITAL, SURGICAL ONCOLOGY, KOLKATA, India; 5NETAJI SUBHAS CHANDRA BOSE CANCER HOSPITAL, MEDICAL PHYSICS, KOLKATA, India
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Purpose or Objective
To assess the feasibility of VMAT based focused radiotherapy as an alternative of stereotaxy in resource constrained setting.
Material and Methods
31 patients (male – 15, female – 16) of age 32 – 68 years (median– 59 years) with PS 0-2 having Oligometastatic primary (breast, colorectal, NSCLC, melanoma, renal cell carcinoma) with more than 6 months median survival time (MST) calculated by disease specific Graded Prognostic Assessment (GPA) were treated with 30 Gy/5 fractions by Volumetric Arc Therapy (VMAT) from November 2018 to December 2020 in Elekta Synergy linear accelerator. Radiological outcome was assessed by RECIST 1.1 criteria. Toxicities were analyzed by Common Toxicity Criteria for Adverse Effects (CTCAE) v5.0. Neurocognitive evaluation was done by Mini Mental State Examination (MMSE) at completion, 2 weeks and 3 months post Radiotherapy. Time to progression (TTP) of intracranial lesions was calculated from completion of treatment.
Results
3 patients were lost to follow up after completion of treatment. After a median follow up of 9 months (range 5 – 18, mean 9.4) 1 patient (Melanoma) had intra cranial disease progression at completion and expired at 5 months. Remaining patients had excellent radiological outcome. The median duration of TTP was 8 months. On univariate analysis, TTP was significantly associated with primary site of malignancy (p = 0.022) and number of brain metastases (p = 0.004). Age, performance status, tumor volumes (GTV and PTV) had no effect on TTP. 3 patients had grade 2 emesis and 2 patients has grade 2 seizures. There were no grade 3 toxicities. There was no neuro-cognitive deficit in any of the patients.
Conclusion
VMAT offers good intracranial disease control with minimal adverse effects and thus can be used as an alternative to Stereotaxy in 1-3 brain metastases in Oligometastatic disease especially in resource constrained centers.