Objectives: Carcinoma of the cervix is the fourth most frequent cancer in women globally. The uterine cervix has a rich lymphatic supply. Lymph node involvement is one of the negative prognostic factors. Treatment for carcinoma cervix involves a combination of external beam radiation therapy with concurrent chemotherapy, followed by brachytherapy with intracavitary or interstitial technique. While prophylactic nodal irradiation to pelvic nodes is routinely done, a simultaneous integrated boost is given to gross lymph nodes. This study aims to evaluate the dose contribution to the pelvic lymph node regions during brachytherapy. Material and Methods A prospective observational study was conducted at an oncological centre in Hyderabad between March 2024 and April 2025. The study included 23 patients diagnosed with cervical cancer. Eligibility criteria required patients to have an Eastern Cooperative Oncology Group (ECOG) performance status score ranging from 0 to 2 at the time of enrolment. Eligible patients received radical radiation therapy with concurrent chemotherapy followed by three fractions of high dose rate (HDR) intracavitary brachytherapy (7 Gy each to Point A). CT-based planning with modified Fletcher applicators was performed, with pelvic lymph node groups and organs at risk contoured per RTOG/ABS (Radiation Therapy Oncology Group/American Brachytherapy Society) guidelines. Dose–volume histogram (DVH) parameters (D100, D98, D90) for nodal stations were analysed and normalised to the Point A dose. Treatment planning was executed on Oncentra v4.3 and delivered using an Ir-192 source. The study aimed to estimate nodal dose contributions relative to Point A and assess organ-at-risk constraints during brachytherapy. Results: 23 cervical cancer patients (median age 54 years) were enrolled, most presenting in FIGO stage IIIC; 78% had adenocarcinoma. Dose–volume histogram analysis of pelvic nodal groups during HDR intracavitary brachytherapy (7 Gy to Point A) showed wide variation in nodal dose contributions. Against a dose of 7Gy to Point A, the obturator nodes received the highest mean D90 (≈1.5 Gy; ~21.6% of the Point A dose), while the common iliac nodes received the lowest (≈0.17 Gy; ~2.5%). External iliac nodes averaged ~0.55 Gy (≈7.9%), internal iliac ~0.89 Gy (≈12.6%), and presacral nodes ~1 Gy (≈14.3%). Bilateral averages confirmed this gradient, with obturator nodes consistently highest and common iliac lowest. Conclusion: This study demonstrates that pelvic lymph nodes receive measurable dose contributions from standard Fletcher applicator–based HDR brachytherapy in radical cervical cancer treatment. The obturator nodes consistently received the highest relative dose, while the common iliac nodes received the lowest.
Vempati et al. (Mon,) studied this question.