In Vivo Dosimetry for Brachytherapy Study

A dosimeter is a small device that is able to record the dose of radiation received. It can provide an independent check that the dose of radiation delivered matches the dose calculated for patients receiving radiotherapy as part of their cancer treatment.

The purpose of this study is to investigate the clinical use of in vivo dosimeters for brachytherapy. Two types of dosimeters will be used; micro metal oxide field effect transistors (microMOSFETs) and Thermoluminescent detectors (TLDs). These will be placed into the rectum (back passage), urethra (the tube through which urine leave the body from the bladder) and within or near (typically within a few centimetres) to the cancer itself. These devices will record the dose of radiation received at the time of brachytherapy at each of these sites and we will compare that measurement with the expected measurement based on the calculations we made in planning the patient's treatment.

Inclusion criteria

• Patients aged 18 years and above
• Patients receiving HDR brachytherapy using iridium-192 (192Ir) radioactive source either as a monotherapy or in combination with external beam radiotherapy for:

• histologically/radiologically proven primary or locally recurrent prostate cancer
• locally advanced gynaecological malignancy in the primary and recurrent setting

• primary cervix carcinoma (squamous, adenocarcinoma, adenosquamous) FIGO IB2-IVA
• primary vulval FIGO I-IVA
• primary vaginal FIGO I-IVA
• primary endometrial cancer FIGO Stage I-IVA (not suitable for surgery)
• endometrial cancer receiving adjuvant vaginal vault brachytherapy
• recurrent cervix, vulval, vaginal or endometrial cancer suitable for brachytherapy as discussed in a regional gynae-oncology multidisciplinary meeting.
• World Health Organisation (WHO) or Eastern Cooperative Oncology Group (ECOG) performance status 0-2

Exclusion criteria

• Previous brachytherapy exposure to the treatment site
• Patients unable to give informed consent
• Patients unable to have a regional or general anaesthetic
• Patients with the following medical conditions: coagulopathies, history of another primary malignancy, known allergy or sensitivity to study materials; previous or current fistulae
• Not able to understand the implications of participating in the study in English
• Patients with recent (within the last 6 months) or currently participating in interventional research