Reducing dose to rectum by placement of a rectum-emptying tube in cervical cancer patients treated with brachytherapy

Marjorie Ferré; Leonel Varela Cagetti; Christophe Zemmour; Marguerite Tyran; Pierre Fau; Cyrus Chargari; Agnès Tallet; Laurence Gonzague; Pierre Annede

doi:10.1016/j.brachy.2021.03.008

Reducing dose to rectum by placement of a rectum-emptying tube in cervical cancer patients treated with brachytherapy

Brachytherapy. 2021 Jul-Aug;20(4):748-754. doi: 10.1016/j.brachy.2021.03.008. Epub 2021 Apr 18.

Authors

Marjorie Ferré¹, Leonel Varela Cagetti¹, Christophe Zemmour², Marguerite Tyran¹, Pierre Fau¹, Cyrus Chargari³, Agnès Tallet¹, Laurence Gonzague¹, Pierre Annede⁴

Affiliations

¹ Department of Radiotherapy, Paoli Calmettes Institute, Marseille, France.
² Department of Clinical Research and Innovation, Biostatistics and Methodology Unit, Paoli Calmettes Institute, Marseille, France.
³ Department of Radiation Oncology, Gustave Roussy Comprehensive Cancer Center, Villejuif, France.
⁴ Department of Radiotherapy, Paoli Calmettes Institute, Marseille, France. Electronic address: pierreannede@gmail.com.

PMID: 33883092
DOI: 10.1016/j.brachy.2021.03.008

Abstract

Purpose: Only scarce data are available on the possibility to reduce rectal dose by controlling rectum filling before HDR (high dose rate) IGABT (image-guided adaptive brachytherapy) in LACC (locally advanced cervical carcinoma) patients. We compared dosimetric outcomes before and after the evacuation of gasses using a rectum emptying tube.

Methods and material: Sixty CT (computed tomography) scans from 30 consecutive patients with cancer of the cervix undergoing HDR IGABT after EBRT were reviewed. Patients who underwent at least one gas evacuation were included in the analysis. The three-dimensional dosimetric data of the dosimetric plan performed before and after gas evacuation were compared. Primary endpoint was the difference between D2cc of the rectum before and after the procedure. Expected probability of grade 2-4 overall rectum morbidity was assessed using a probit model from the prospective multicenter EMBRACE study.

Results: Thirty five (58.3%) CT scans from 23 patients (76.7%) requiring gas evacuation were analysed. The mean rectum volume, before and after gas evacuation, was 123.1 cc (sd, ± 60.4) and 66.4 cc (sd, ± 34.8), respectively. For each patient, the volume of the rectum after gas evacuation was lower than before. No major complication occurred during and after the procedure. After gas evacuation, a significant reduction in rectal dose per fraction was observed, on average -4.3 Gy (-38.4%, p < 0.001) for D0.1cc and -1.9 Gy (-30.6%, p < 0.001) for D2cc. Estimated mean probability to develop a grade 2-4 rectum morbidity was significantly lower after gas evacuation, 6.9% (sd,± 1.94) versus 9.5% (sd,± 3.17), p < 0.001.

Conclusion: Gas evacuation using a rectal emptying tube in selected LACC patients treated with HDR BT after chemoradiotherapy, allowed a substantial reduction in the dose to the rectum. Such procedure could be of particular interest when a dose escalation strategy is being considered.

Keywords: Brachytherapy; Cervical cancer; Rectum; Toxicity.

Publication types

Multicenter Study

MeSH terms

Brachytherapy* / methods
Female
Humans
Prospective Studies
Radiotherapy Dosage
Rectum / diagnostic imaging
Uterine Cervical Neoplasms* / diagnostic imaging
Uterine Cervical Neoplasms* / radiotherapy