Internal Radiation (Interstitial Brachytherapy) for Simultaneous Treatment of Synchronous Carcinoma of Cervix and Vulva: A Rare Case Report

Introduction

Synchronous carcinoma of the cervix and vulva represents a rare and challenging clinical scenario requiring a multidisciplinary approach for diagnosis and treatment. The treatment strategy often includes a combination of surgery, radiation therapy, and chemotherapy tailored to the individual patient's condition and disease stage. For advanced stages, radiotherapy is the only radical treatment available for these patients.^1,2

A specialized form of radiation therapy, interstitial brachytherapy (I-BT) is used to treat localized cancers by placing radioactive sources directly within or close to the tumour through thin, flexible catheters or needles. It allows for precise dose delivery to each tumour site, minimizing exposure to surrounding healthy tissues. This approach is particularly valuable when dealing with complex cases where different malignancies might be located in challenging anatomical areas or require tailored radiation doses.

Therefore, I-BT for synchronous malignancies represents a promising strategy in their management, combining precision and adaptability to improve patient outcomes.

Case report

A 79-year-old post-menopausal female with hypertension, diabetes and coronary artery disease presented with complaints of bleeding per vaginum for 1 month. She had a history of recurrent urinary tract infections. Local examination revealed a leukoplakia patch and a 3x3x4cm mass lesion involving the left vulva and anterior vagina. On per speculum and per vaginum examination, another irregular proliferative lesion was visible on cervix which bled on touch. The patient underwent magnetic resonance imaging (MRI) of the pelvis (Figure 1) in October, 2023 which showed a large (~50 x 16x 44 mm) irregular mass lesion in the vulvar region abutting the adjacent urethra with partial loss of intervening fat planes. Additionally, a second large mass lesion (25 x 28x 30 mm) with ill-defined heterogeneous altered signal intensity was seen involving the cervix, upper third of the vagina and lower third of the uterine body. Short Tau Inversion Recovery (STIR) imaging revealed hyperintense signals with fat stranding in the bilateral parametrium, suggestive of parametrial invasion. There were multiple lymph nodes seen on both sides of the pelvis. To rule out metastasis, she then underwent Positron Emission Tomography – Contrast Enhanced Computed Tomography (PET- CECT) which showed the same loco-regional disease and no metastatic deposit elsewhere in the body. Histology via punch biopsy confirmed squamous cell carcinoma of the cervix (Federation of Gynecology and Obstetrics [FIGO]-2018 stage IIIC1) and vulva (FIGO-2021 stage IIIB).

(SORBO) applicator in situ. This scan was used to assess the vaginal length, evaluate the gross disease and determine the extent of lateral needle insertion and needle length for the procedure. The central tandem and vaginal cylinder were utilized to treat the cervical lesion by insertion through the lower inlet of the MUPIT, along with interstitial needles placed in the vicinity. Circular inserts were affixed to the upper and middle MUPIT inlets, and the interstitial needles were inserted to treat the vulvar lesion (Figure 2). Dosages of 25Gy in 5 fractions and 21Gy in 5 fractions were delivered to the vulvar and cervical lesions, respectively

Discussion

Synchronous malignancies are rare and only a few case reports have been published in literature for synchronous carcinoma in cervix and vulva. Most of these were early stage and amenable to surgery. However, our case was unresectable and received radical radiotherapy as treatment for individualised sites. Planning for interstitial brachytherapy boost to deliver curative doses of radiation, poses a challenge to treating oncologists. As per an old report, there are around 323 brachytherapy (232 high dose rate [HDR] and 91 low dose rate [LDR]) installations, but less than one third of the institutions practise interstitial treatment (cervix, endometrium, and oesophagus).³ Another survey in India, demonstrated that

93% of radiation oncologists thought lack of training as a hurdle in practising brachytherapy.⁴ Therefore, expertise is required in this field to execute complicated treatment plans. Following EBRT, I-BT provided a focused radiation boost to the cervical and vulvar lesions. The use of MUPIT allowed for accurate placement of the radioactive sources and delivery of high doses of radiation to the targeted areas. The post-treatment MRI demonstrated a significant response, with a near-complete resolution of the cervical tumour and marked reduction in the vulvar lesion. The literature is sparse and there is a lack of guidelines for such cases, therefore the treatment for such patients needs to be individualised.