Dosimetric comparison of cobalt-60 and iridium-192 source based high dose rate brachytherapy for treating carcinoma of the uterine cervix

Document Type : Original Paper


1 Department of Radiation Oncology, Mahatma Gandhi Memorial Medical College, Government Cancer Hospital, Indore Pin Code; 452001

2 Government Cancer Hospital, MGM Medical College, Indore

3 Department of Obstetrics and Gynecology Government Multispeciality Hospital Sector-16 Chandigarh

4 Association with: 1) Amity University, Madhya Pradesh & 2) Shalby Hospital, Indore



Background: Iridium-192 (Ir-192) based high dose rate brachytherapy(HDR-BT) has been used in locally advanced carcinoma uterine cervix (LACUC) for the last many years. Cobalt-60 (Co-60) based HDR-BT has also been used since last more than a decade. Since not enough research data is available to compare both HDR-BT applications, it is rational to compare plans by both HDR-BT techniques.

Methods and materials: Twenty patients diagnosed with LACUC were randomly selected in two arms with ten patients in each arm who were treated with 50 Gray (Gy) in 25 fractions (#) by external beam radiotherapy following the remaining dose by Intracavitary radiation therapy. In arm-1 patients were treated with Ir-192 HDR while in arm-2 with Co-60 HDR-BT. Target volume and normal organs were delineated as per American Brachytherapy Society (ABS) guidelines. 21Gy in 3#@7Gy/# with a weekly plan and delivered to all patients. The dosimetric parameters of both arms were analyzed and compared.

Result: Mean dose to 90% of HR-CTV was 100.62% {standard deviation (SD): 2.78} in arm-1 while 102.05% (SD: 3.07) in arm-2. The mean dose to 2cc of the bladder, rectum, and sigmoid was 16.06 Gy (SD: 2.54), 11.66 Gy (SD: 2.31), and 3.98 Gy (SD: 1.74) respectively in arm-1 while 15.9 Gy (SD: 0.58), 11.5 Gy (SD: 0.91) and 4.1 Gy (SD: 1.52) respectively in arm-2.

Conclusion: No significant difference in dosimetric data was found in plans done for Co-60 and Ir-192-based HDR-BT in LACUC, so the Co-60-based HDR-BT unit seeing economical, regulatory, and administrative matters is a better choice.


Main Subjects

Articles in Press, Accepted Manuscript
Available Online from 12 February 2024
  • Receive Date: 23 July 2023
  • Revise Date: 10 September 2023
  • Accept Date: 12 February 2024