Treatment volume from total reference air kerma (TRAK) in intracavitory applications and its comparison with ICRU reference volume.
OBJECTIVE
A systematic dosimetry study conforming to International Commission on Radiation Units and Measurements Report Number 38, was carried out for, cancer of Cervix Stage I and II cases at Tata Memorial Hospital.


METHODS
The reference Volume dimension were noted for each applicator. Also 3-D dosimetry was performed for selected cases, and actual geometric volume enclosed by various isodose surfaces were obtained. A relation was derived, which gave the volume enclosed by any isodose surface as a function of total reference air kerma of the sources in the applicator. The volume enclosed by reference isodose surface was compared with the product of its dimensions height, width, and thickness.


RESULTS
The volume enclosed by any isodose surface of an intracavitary application can be easily derived from total reference air kerma of the sources within the applicator.


CONCLUSIONS
Ratio of the volume enclosed by reference isodose surface with the product of its dimensions (HWT) could be a predictive parameter for clinical outcome, besides the reference volume specified by the report.
Deshpande
D D
DD
Department of Medical Physics, Tata Memorial Hospital, Parel, Bombay, India.
Shrivastava
S K
SK
Nehru
R M
RM
Viswanathan
P S
PS
Dinshaw
K A
KA
D001918:Brachytherapy / Q000592:standards*; D005260:Female; D006801:Humans; D011879:Radiotherapy Dosage; D001743:Urinary Bladder / Q000528:radiation effects; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*