A Literature review of Rectal Dosimetry in Intracavitary Brachytherapy

Vishnu H Lal; Abhishek Sharma; Kunal Jain; Murali Paramanandan; Rajesh Kumar

Volume : VII, Issue : III, March - 2018

A Literature review of Rectal Dosimetry in Intracavitary Brachytherapy

Vishnu H Lal, Abhishek Sharma, Kunal Jain, Murali Paramanandan, Rajesh Kumar

Abstract :

Rectal dosimetry has fascinated the radiation oncologist ever since the inception of achytherapy in cervix. This is perhaps due to the accessibility of rectum as a region for dosimetry compared to other organ at risks and due to the fact that rectum by all means is a site which delimits the target volume dose

From available literature the first of the study in this regard was by SIEVERT, R. M.et al in the paper Radium– und Ultrastrahlung nebsteinigen Untersuchungen tiber die Anwendbarkeit derselbenin der Physik und der Medizin; But English translation of this study is not available but through metanalysis it is incurred that it was the first of the attempt in this regard carried out at RADIUM–HEMMET . It was pioneering study which came at the following important conclusions on why the measured dose cannot be considered because of the technical difficulties encountered in obtaining them. Sievert points out mainly the following points for this discrepancy (a) the position of the patient at the time of measurement (i.e., lithotomy position, knee–chest position, or supine) ; (b) the position and angle of the probe; (c) pressure applied to the tip of the instrument against the mucosa; (d) the variations of the individual doctor in carrying out the technic; (e) instrument variations (e.g., finite diameter of ionization chamber, method of caliation); and (f) interference caused by the hardware of the radium carriers, requiring that they be moved slightly in order to insert the probe into the bladder. The study though the first of its kind was a landmark study as it paved way for further studies which aimed at overcoming each of these nuances