AU - Neelakandan, Vijayaprabhu AU - Christy, S AU - Mukherji, Ashutosh AU - Reddy, K TI - Craniospinal irradiation by rapid Arc® technique in supine position: A dosimetric and clinical analysis PT - ORIG DP - 2018 Jan 1 TA - Journal of Current Oncology PG - 16-22 VI - 1 IP - 1 4099- http://www.https://journalofcurrentoncology.org//article.asp?issn=2589-8892;year=2018;volume=1;issue=1;spage=16;epage=22;aulast=Neelakandan;type=0 4100- http://www.https://journalofcurrentoncology.org//article.asp?issn=2589-8892;year=2018;volume=1;issue=1;spage=16;epage=22;aulast=Neelakandan AB - Introduction: In craniospinal irradiation (CSI), prone position has been commonly used but, in some patients, especially pediatric cases where anesthesia is needed prone position may not help. In planning CSI by supine technique, beam geometry and field matching have to be considered, and immobilization is essential to ensure reproducibility of treatment. Materials and Methods: Data of four patients (3 with medulloblastoma and 1 with lymphoma) treated between March 2012 and October 2013 were included in this retrospective dosimetric study and analyzed. Patients were evaluated for dose coverage, organs at risks (OARs) sparing, number of monitor units, and daily table position shifts. Results: All patients underwent CSI by volumetric-modulated arc therapy (VMAT) technique in supine position. All four cases developed Grade 1 skin changes, and only one case developed a Grade 2 change at the end of radiotherapy; also both pediatric cases developed Grades 2 and 3 anemia and leukopenia toward their 4th week of treatment onward. The Rapid Arc®-CSI plans were able to generate dose distributions with high planning target volume (PTV) conformity and homogeneity and with sparing of OAR. The cumulative conformity index for all patients was 0.986, and homogeneity index was 0.1007. The mean PTV doses were within 108% with V110% of <12%, and V107% was 20%. On the evaluation of patient setup errors, a maximal shift of 3 mm in longitudinal direction was noted. At 3 years, all medulloblastoma cases except 1 were in remission. One adult patient with medulloblastoma had multiple spinal metastases at 1 year. Conclusions: Treatment of patients in supine position is reproducible and easily maintained with minimal acute reactions. VMAT technique helps avoid junctions, field-matching, and benefits with image guidance for precise dose delivery, conformity, and OAR sparing.