title: Treatment planning methods in high dose rate interstitial brachytherapy of carcinoma cervix: a dosimetric and radiobiological analysis.
abstract: Treatment planning is a trial and error process that determines optimal dwell times, dose distribution, and loading pattern for high dose rate brachytherapy. Planning systems offer a number of dose calculation methods to either normalize or optimize the radiation dose. Each method has its own characteristics for achieving therapeutic dose to mitigate cancer growth without harming contiguous normal tissues. Our aim is to propose the best suited method for planning interstitial brachytherapy. 40 cervical cancer patients were randomly selected and 5 planning methods were iterated. Graphical optimization was compared with implant geometry and dose point normalization/optimization techniques using dosimetrical and radiobiological plan quality indices retrospectively. Mean tumor control probability was similar in all the methods with no statistical significance. Mean normal tissue complication probability for bladder and rectum is 0.3252 and 0.3126 (P = 0.0001), respectively, in graphical optimized plans compared to other methods. There was no significant correlation found between Conformity Index and tumor control probability when the plans were ranked according to Pearson product moment method (r = -0.120). Graphical optimization can result in maximum sparing of normal tissues.
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Surega
authors.initials: S
authors.lastname: Anbumani
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Pichandi
authors.initials: P
authors.lastname: Anchineyan
authors.affiliation: Photonics, Nuclear and Medical Physics Division, VIT University, Vellore 632014, India.
authors.forename: Arunainambiraj
authors.initials: A
authors.lastname: Narayanasamy
authors.affiliation: Department of Radiation Oncology, Kidwai Memorial Institute of Oncology, Hosur Road, Bangalore 560029, India.
authors.forename: Siddanna R
authors.initials: SR
authors.lastname: Palled
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Sajitha
authors.initials: S
authors.lastname: Sathisan
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Punitha
authors.initials: P
authors.lastname: Jayaraman
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Muthu
authors.initials: M
authors.lastname: Selvi
authors.affiliation: Department of Radiation Oncology, HCG Bangalore Institute of Oncology, RRMR Extension KH Road, Bangalore 560027, India.
authors.forename: Ramesh S
authors.initials: RS
authors.lastname: Bilimagga