A comparison between revised Manchester Point A and ICRU-89-recommended Point A definition absorbed-dose reporting using CT images in intracavitary brachytherapy for patients with cervical carcinoma

Ankur Mourya; Sunil Choudhary; Uday Pratap Shahi; Neeraj Sharma; Himani Gautam; Ganeshkumar Patel; Satyajit Pradhan; Lalit Mohan Aggarwal

doi:10.1016/j.brachy.2020.07.009

A comparison between revised Manchester Point A and ICRU-89-recommended Point A definition absorbed-dose reporting using CT images in intracavitary brachytherapy for patients with cervical carcinoma

Brachytherapy. 2021 Jan-Feb;20(1):118-127. doi: 10.1016/j.brachy.2020.07.009. Epub 2020 Aug 16.

Authors

Ankur Mourya¹, Sunil Choudhary¹, Uday Pratap Shahi¹, Neeraj Sharma², Himani Gautam³, Ganeshkumar Patel¹, Satyajit Pradhan⁴, Lalit Mohan Aggarwal⁵

Affiliations

¹ Department of Radiotherapy & Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
² School of Biomedical Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
³ Department of Radiation Oncology, Mahatma Gandhi Medical College & Hospital, Jaipur, Rajasthan, India.
⁴ Mahamana Pandit Madan Mohan Malaviya Cancer Centre, Homi Bhabha Cancer Hospital, Varanasi, Uttar Pradesh, India.
⁵ Department of Radiotherapy & Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India. Electronic address: lalitm@bhu.ac.in.

PMID: 32811759
DOI: 10.1016/j.brachy.2020.07.009

Abstract

Purpose: This study is a comparison between revised Manchester Point A and International Commission on Radiation Units and measurements (ICRU) 89 report-recommended Point A absorbed-dose reporting in intracavitary brachytherapy for patients with cervical carcinoma.

Methods and materials: The retrospective dosimetric study is based on the data of 32 patients with cervical carcinoma treated with high-dose-rate brachytherapy. Patients received 21 Gy in three fractions (7.0 Gy X three fractions) to Point A (A_flange, revised Manchester definition). All the patients were replanned with a new Point A (A_icru89) defined on CT images as per the American Brachytherapy Society/ICRU-89. The data collected were compared with the data obtained from Point A (A_flange).

Results: When using the A_flange plan normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 820.79 ± 207.47 cGy, 654.66 ± 152.69 cGy, and 588.91 ± 136.35 cGy, respectively. Likewise, when using the ICRU-89 Point A_icru89 normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 869.30 ± 224.67 cGy, 693.24 ± 166.20 cGy, and 616.61 ± 150.32 cGy, respectively. For the rectum, Point A_flange normalization plans, the mean dose of 0.1 cc, 1 cc, and 2 cc volumes was 589.37 ± 163.26 cGy, 487.51 ± 126.03 cGy, and 442.70 ± 111.43 cGy, respectively. Likewise, using the A_icru89 plan, the mean 0.1 cc, 1 cc, and 2 cc rectum volume was 625.07 ± 171.31 cGy, 517.50 ± 131.05 cGy, 464.94 ± 121.81 cGy, respectively. The statistical mean difference of Total Reference Air Kerma rate, V₁₀₀ (cc), bladder, rectum and sigmoid, was found significant.

Conclusions: It has been found that the position of revised Manchester (A_flange) and ICRU-89 Point A does not match on CT images/radiograph, which resulted in variation in doses to the tumor, V₁₀₀ (cc), organ at risk, and Total Reference Air Kerma.

Keywords: American Brachytherapy Society; Cervix carcinoma; High-dose-rate brachytherapy; ICRU; Intracavitary brachytherapy; Point A.

MeSH terms

Brachytherapy* / methods
Carcinoma*
Female
Humans
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted
Rectum / diagnostic imaging
Retrospective Studies
Tomography, X-Ray Computed
Uterine Cervical Neoplasms* / diagnostic imaging
Uterine Cervical Neoplasms* / radiotherapy