Cervical cancer remains one of the most common malignancies affecting women worldwide and represents a significant public health burden, particularly in developing countries such as India. According to the World Health Organization and the International Agency for Research on Cancer, cervical cancer is among the leading causes of cancer-related mortality in women, with a substantial proportion of patients presenting at locally advanced stages requiring definitive chemoradiotherapy. Concurrent chemoradiotherapy (CCRT), which combines external beam radiotherapy with cisplatin-based chemotherapy followed by brachytherapy, has become the standard of care for locally advanced cervical cancer due to improved local control and survival outcomes1. Despite its therapeutic benefits, pelvic radiotherapy is associated with several acute and late toxicities affecting surrounding normal tissues. One of the most common gastrointestinal complications is radiation enteritis, which results from radiation-induced injury to the small intestine and manifests as diarrhea, abdominal pain, malabsorption, and occasionally severe complications such as strictures or perforation. The incidence of acute radiation enteritis during pelvic irradiation ranges from 30–70%, depending on treatment technique, radiation dose, and the volume of bowel irradiated2. During pelvic radiotherapy for cervical cancer, the position of pelvic organs varies considerably depending on bladder filling. A distended bladder can displace small bowel loops superiorly and anteriorly, thereby reducing the volume of small intestine exposed to radiation within the treatment field3. Conversely, an empty bladder allows small bowel loops to descend into the pelvis, increasing radiation exposure and the likelihood of gastrointestinal toxicity.³ Therefore, implementing a standardized bladder filling protocol during radiotherapy has been proposed as a simple and effective strategy to minimize small bowel irradiation and reduce radiation-induced enteritis. Several dosimetric and clinical studies have demonstrated that maintaining a consistently full bladder during pelvic radiotherapy can significantly reduce the irradiated volume of bowel and potentially decrease gastrointestinal toxicity. However, patient compliance with bladder protocols, variations in bladder filling, and lack of uniform institutional guidelines may influence treatment reproducibility and toxicity outcomes4. In the era of image-guided and conformal radiotherapy techniques, organ motion and volume variation remain important considerations for treatment planning and delivery. Evaluating the clinical impact of bladder filling protocols on radiation enteritis is therefore essential for optimizing treatment strategies, improving patient tolerance to therapy, and enhancing overall treatment outcomes in cervical cancer patients receiving concurrent chemoradiotherapy5. Justification of the Study Radiation enteritis remains a significant cause of morbidity in patients undergoing pelvic radiotherapy for cervical cancer. Although bladder filling protocols are routinely recommended to displace bowel loops away from high-dose radiation fields, there is limited clinical data evaluating their direct impact on the incidence and severity of radiation enteritis, particularly in resource-limited settings. A systematic assessment of bladder filling protocols may help establish standardized treatment preparation guidelines, reduce gastrointestinal toxicity, and improve patient quality of life during concurrent chemoradiotherapy. Therefore, this study aims to evaluate the impact of a bladder filling protocol on the occurrence and severity of radiation enteritis in patients with cervical cancer undergoing concurrent chemoradiotherapy. Aim To evaluate the impact of a bladder filling protocol on the incidence and severity of radiation enteritis in patients with cervical cancer undergoing concurrent chemoradiotherapy. Objectives 1. To assess the incidence of radiation enteritis in cervical cancer patients receiving concurrent chemoradiotherapy. 2. To evaluate the effect of a standardized bladder filling protocol on the severity of radiation enteritis. 3. To analyze the relationship between bladder volume during radiotherapy and gastrointestinal toxicity. 4. To determine whether adherence to a bladder protocol reduces treatment-related small bowel irradiation and associated complications.

Study Design and Setting This prospective observational study was conducted in the Department of Radiotherapy at a tertiary care teaching hospital. The study aimed to evaluate the impact of a bladder filling protocol on the incidence and severity of radiation enteritis in patients with cervical cancer undergoing concurrent chemoradiotherapy. Duration of Study The duration of the study was 18 months, during which eligible patients diagnosed with cervical cancer and planned for definitive concurrent chemoradiotherapy were recruited and followed up during the course of treatment. Study Population Patients diagnosed with histopathologically confirmed carcinoma of the cervix who were planned for definitive concurrent chemoradiotherapy were included in the study. Sample Size A total of 60 patients fulfilling the inclusion criteria were enrolled in the study during the study period. Inclusion Criteria 1. Patients aged 18–70 years with histologically confirmed carcinoma cervix. 2. Patients with locally advanced cervical cancer (FIGO stage IIB–IVA) planned for concurrent chemoradiotherapy. 3. Patients with ECOG performance status 0–2. 4. Patients who provided written informed consent for participation in the study. Exclusion Criteria 1. Patients with previous pelvic radiotherapy. 2. Patients with prior abdominal or pelvic malignancy. 3. Patients with inflammatory bowel disease or chronic gastrointestinal disorders. 4. Patients with metastatic disease or those planned for palliative treatment. 5. Patients unable to comply with the bladder filling protocol. Bladder Filling Protocol All patients were instructed to follow a standardized bladder filling protocol during simulation and throughout external beam radiotherapy. Patients were asked to: • Empty their bladder 45–60 minutes before treatment. • Drink approximately 500–700 ml of water after voiding. • Maintain the bladder in a comfortably full state during CT simulation and daily radiotherapy sessions. Compliance with the bladder protocol was assessed before treatment delivery through patient reporting and clinical verification. Radiotherapy Technique All patients underwent CT simulation in the supine position with immobilization devices. Treatment planning was performed using a three-dimensional conformal radiotherapy (3D-CRT) technique or intensity-modulated radiotherapy (IMRT) as per institutional protocol. External beam radiotherapy (EBRT) was delivered to the pelvis to a total dose of 45–50.4 Gy in 25–28 fractions, five fractions per week over 5–6 weeks. Following EBRT, patients received intracavitary brachytherapy according to institutional guidelines to achieve the recommended cumulative dose to point A. Chemotherapy Protocol All patients received concurrent chemotherapy with weekly cisplatin (40 mg/m²) during external beam radiotherapy, provided there were no contraindications. Assessment of Radiation Enteritis Patients were evaluated weekly during treatment for symptoms of gastrointestinal toxicity including: • Diarrhea • Abdominal pain • Nausea • Tenesmus • Frequency of bowel movements Radiation enteritis was graded according to the Radiation Therapy Oncology Group (RTOG) acute radiation morbidity scoring criteria. Data Collection The following parameters were recorded: • Patient demographics (age, performance status) • Tumor stage and histopathology • Bladder filling compliance • Treatment details (radiotherapy dose and chemotherapy cycles) • Incidence and grade of radiation enteritis Statistical Analysis Data were entered into Microsoft Excel and analyzed using Statistical Package for Social Sciences (SPSS) software version 22.0. Descriptive statistics such as mean, standard deviation, and percentages were used to summarize patient characteristics. The association between bladder filling protocol adherence and the incidence of radiation enteritis was analyzed using the Chi-square test, with a p value of <0.05 considered statistically significant.

A total of 60 patients with Histopathologically confirmed carcinoma cervix undergoing concurrent chemoradiotherapy were included in the study. All patients were evaluated for compliance with the bladder filling protocol and the occurrence of radiation enteritis during treatment. The mean age of patients was 52.4 ± 9.6 years, with the majority of patients belonging to the 41–60 years age group. Most patients presented with FIGO stage IIB and IIIB disease. Compliance with the bladder filling protocol was observed in the majority of patients during the treatment period. Radiation enteritis was assessed weekly during treatment using RTOG acute radiation morbidity criteria. The incidence and severity of radiation enteritis were compared between patients who maintained good bladder filling compliance and those with poor compliance. Table 1: Distribution of Patients According to Bladder Filling Protocol Compliance (n = 60) Bladder Protocol Compliance Number of Patients Percentage (%) Good Compliance 38 63.3 Poor Compliance 22 36.7 Total 60 100 Interpretation: Out of 60 patients, 38 (63.3%) maintained good compliance with the bladder filling protocol during radiotherapy, whereas 22 (36.7%) showed poor compliance. Table 2: Incidence of Radiation Enteritis According to Bladder Filling Compliance Bladder Protocol Grade 0–1 Enteritis Grade 2 Enteritis Grade 3 Enteritis Total Good Compliance (n=38) 28 8 2 38 Poor Compliance (n=22) 8 9 5 22 Total (n=60) 36 17 7 60 Patients with good bladder filling compliance had a lower incidence of moderate to severe radiation enteritis compared to those with poor compliance. Grade 2–3 enteritis occurred in 10 patients (26.3%) in the compliant group compared with 14 patients (63.6%) in the poorly compliant group, suggesting that maintaining a bladder filling protocol may reduce gastrointestinal toxicity during pelvic radiotherapy.

Radiation enteritis is one of the most common acute toxicities observed in patients receiving pelvic radiotherapy for cervical cancer. Damage to the intestinal mucosa occurs due to radiation-induced inflammation, epithelial cell loss, and vascular injury, resulting in symptoms such as diarrhea, abdominal cramps, and malabsorption. Strategies that reduce the radiation dose to the small bowel are therefore essential to minimize treatment-related morbidity and improve patient tolerance to concurrent chemoradiotherapy. In the present study, the majority of patients (63.3%) were able to maintain good compliance with the bladder filling protocol during radiotherapy. Patients who adhered to the bladder protocol demonstrated a significantly lower incidence of moderate to severe radiation enteritis compared to those with poor compliance. These findings suggest that maintaining a distended bladder during treatment helps displace the small bowel away from the radiation field, thereby reducing radiation exposure and associated gastrointestinal toxicity. Several previous studies have reported similar observations regarding the protective effect of bladder filling during pelvic irradiation. McBain et al. demonstrated that a full bladder during pelvic radiotherapy significantly reduces the volume of small bowel within the radiation field, thereby decreasing the risk of radiation-induced bowel toxicity.⁸ Andreyev highlighted that radiation enteritis remains a significant clinical problem during pelvic radiotherapy and emphasized the importance of treatment planning strategies that limit bowel irradiation. Approaches such as bladder distension, patient positioning, and conformal radiotherapy techniques have been shown to reduce gastrointestinal complications.⁹ A prospective study by Jhingran et al. evaluating acute gastrointestinal toxicity in cervical cancer patients receiving pelvic radiotherapy found that higher radiation dose to the small bowel was associated with an increased risk of diarrhea and enteritis. Their study suggested that measures that reduce bowel dose may improve treatment tolerance and patient quality of life.¹⁰ Similarly, Pinkawa et al. reported that bladder filling plays an important role in organ motion and dose distribution during pelvic radiotherapy. A consistently full bladder helps push bowel loops out of the pelvis and improves treatment reproducibility.¹¹ Modern radiotherapy techniques such as intensity-modulated radiotherapy (IMRT) have further improved the ability to spare organs at risk; however, patient-related factors such as bladder filling remain important determinants of bowel dose. Kidd et al. demonstrated that appropriate bladder and bowel preparation can reduce radiation exposure to surrounding normal tissues and decrease treatment-related toxicity.¹² The findings of the present study are consistent with these observations and reinforce the importance of maintaining a standardized bladder filling protocol during concurrent chemoradiotherapy for cervical cancer. Such protocols are simple, non-invasive, and cost-effective methods that can be implemented even in resource-limited settings to reduce gastrointestinal toxicity. However, the present study has certain limitations. The sample size was relatively small, and bladder volume was assessed primarily based on patient compliance rather than objective imaging measurements. Future studies with larger sample sizes and image-guided assessment of bladder volume may provide more precise evaluation of the relationship between bladder filling and bowel dose.

The present study demonstrates that adherence to a bladder filling protocol during concurrent chemoradiotherapy for cervical cancer significantly reduces the incidence and severity of radiation enteritis. Patients who maintained adequate bladder filling experienced lower rates of moderate to severe gastrointestinal toxicity compared to those with poor compliance. Implementation of a standardized bladder preparation protocol during pelvic radiotherapy is a simple and effective strategy to minimize small bowel irradiation and improve treatment tolerance. Incorporating such protocols into routine clinical practice may enhance patient outcomes and quality of life during radiotherapy for cervical cancer.

1.Rose PG, Bundy BN, Watkins EB, et al. Concurrent cisplatin-based radiotherapy and chemotherapy for locally advanced cervical cancer. N Engl J Med. 1999;340:1144-1153. 2.Hauer-Jensen M, Denham JW, Andreyev HJN. Radiation enteropathy—pathogenesis, treatment and prevention. Nat Rev Gastroenterol Hepatol. 2014;11:470-479. 3.McBain CA, Henry AM, Sykes JR, et al. The influence of bladder filling on small bowel dose during pelvic radiotherapy. Radiother Oncol. 2006;79:63-67. 4.Pinkawa M, Fischedick K, Asadpour B, et al. Prostate position variability and dose exposure of surrounding organs depending on bladder filling. Radiother Oncol. 2006;79:69-75. 5.Jhingran A, Winter K, Portelance L, et al. A prospective study of acute gastrointestinal toxicity during pelvic radiotherapy for cervical carcinoma. Int J Radiat Oncol Biol Phys. 2012;82:e1-e7. 6.Andreyev HJN. Gastrointestinal complications of pelvic radiotherapy. Lancet Oncol. 2007;8:1007-1017. 7.Kidd EA, Siegel BA, Dehdashti F, Grigsby PW. Clinical outcomes of bladder and bowel management during pelvic radiotherapy. Int J Radiat Oncol Biol Phys. 2010;76:135-141. 8.Bandanatham S, Gururajachar JM, Somashekar MK. Compliance with bladder protocol during concurrent chemoradiation for cancer of the cervix and its impact on enteritis: A prospective observational study. Rep Pract Oncol Radiother. 2018;23(2):69-74. 9.Chen VE, Gillespie EF, Manger RP, et al. The impact of daily bladder filling on small bowel dose for intensity modulated radiation therapy for cervical cancer. Med Dosim. 2019;44(2):102-106. 10.Ma S, Zhang T, Jiang L, et al. Impact of bladder volume on treatment planning and clinical outcomes of radiotherapy for patients with cervical cancer. Cancer Manag Res. 2019;11:7171-7181. 11.Chopra S, et al. Late Toxicity After Adjuvant Conventional Radiation Versus Image-Guided Intensity-Modulated Radiotherapy for Cervical Cancer (PARCER): A Randomized Controlled Trial. J Clin Oncol. 2021;39(33):3682-3692. 12.Lee J, et al. Impact of reduced margin pelvic radiotherapy on gastrointestinal toxicity and outcome in gynecological cancer. Clin Transl Radiat Oncol. 2023;43:100671.