Twenty patients with confirmed cervical cancer who underwent radiotherapy were selected for this study. All patients had undergone prior conventional photon radiotherapy planning. All patients underwent initial imaging and staging using CT simulation for accurate tumor and OAR delineation, including the bladder, rectum, femoral head and small bowel [5] [6] (as shown in Table 1 ).

Three treatment plans were generated for each patient: conventional photon beam energy (6 MV photon only), conventional photon beam energy (15 MV photon only), and mixed beam energy (6 MV + 15 MV). Mixed beam energy plans were generated using a combination of 6 MV photons and 15 MV photons. Treatment plans were created with the goal of delivering 50.0 Gy to the target planned volume (PTV) over 25 fractions [4] [7] . The Monaco treatment planning system (ELEKTA Medical Systems) was used to create the plans.

Dosimetric parameters such as the mean dose, maximum dose, and dose-volume histograms (DVHs) for the tumor and OARs were analyzed [1] [3] . The primary endpoints included the dose delivered to the planning target volume (PTV) and the dose sparing of OARs such as the bladder, rectum, femoral head and bowel bag (as shown in Table 2 ).

Homogeneity Index (HI): The Homogeneity Index (HI) describes the uniformity of dose within a target volume. The HI is given by,

$\text{HI}=\frac{{\text{D}}_{5\text{\%}}}{{\text{D}}_{95\text{\%}}}$

Here, D_5% is the dose delivered to the hottest 5% of the tissue and D_95% is the minimum dose received by 95% of the tissue.

Conformity Index (CI): The Conformity Index (CI) describes the degree to which the prescribed isodose volume conforms to the shape and size of the target volume. The CI is given by,

$\text{CI}=\frac{{\text{TV}}_{\text{PIV}}^2}{\text{TV}\times \text{PIV}}$

Here, TV_PIV is the portion of the tumor volume that is contained within the prescription isodose volume, TV is the target volume and PIV is the volume enclosed by the prescribed isodose line.

Monaco treatment planning system is utilized for creating and optimizing radiotherapy plans for cervical cancer patients, including mixed beam energy approaches. Here’s a summary of how the process is performed and executed for 6 MV only, 15 MV only, and mixed beam (6 MV & 15 MV) energy plans:

By employing these steps, Monaco planning ensures precise, effective, and safe treatment for cervical cancer using various beam energy configurations. Mixed-energy plans are especially advantageous for complex cases requiring tailored dose distributions.

Mixed beam planning achieved superior tumor coverage compared to single modality plans. The D95, D98, and D100 values were significantly higher in mixed beam plans, indicating better dose distribution within the tumor [3] [7] [11] (refer to Table 3 ).

The dose to rectum is higher in single energy photon plan of 15 MV than single energy photon plan 6 MV and mixed photon energy plan (6 MV and 15 MV mixed) . The mean dose to Rt femoral head is higher in mixed energy plan than individual single photon energy plan but for Lt femoral head the mean dose is higher in 15 MV energy (single photon energy plan) . The mean dose to urinary bladder is higher in 15 MV [6] individual single photon energy plan than individual single photon energy plan 6 MV and mixed photon plan 6MV and 15 MV. Bowel Bag dose at 195cc coverage we get higher dose in mixed energy form (6 MV & 15 MV) than in individual 6 MV & 15 MV photon energy plans [4] . PTV coverage for individual 6 MV photon beam 97.113% = 4607.33 cGy coverage for 15MV individual single photon energy 97.97% = 4669.16 cGy and for mixed photon energy 6 MV and 15 MV 97.38% = 4641.66 cGy (refer to Figures 1-5 ).

The homogeneity index (HI) and conformity index (CI) were improved in mixed beam plans, reflecting a more uniform dose distribution and better conformity to the target volume [1] [3] [11] (as shown in Figure 6 & Figure 7 ).

The findings suggest that mixed beam planning can enhance tumor control while reducing the risk of radiation-induced toxicity in cervical cancer patients. This approach could lead to improved patient outcomes and quality of life.

In summary, mixed beam planning for cervical cancer provides considerable dosimetric benefits by optimizing tumour dose escalation while safeguarding adjacent organs at risk. Additional research and technical innovations are necessary to address planning obstacles and completely incorporate this methodology into standard clinical practice. According to the study’s findings, mixed beam planning provides notable dosimetric benefits for cervical cancer treatment. The enhanced tumor coverage and diminished dose to organs at risk underscore the potential of this method to improve therapeutic results while reducing adverse effects. Subsequent research should concentrate on clinical trials to confirm these dosimetric advantages and investigate the practicality of incorporating mixed beam planning into standard clinical practice.

Mixed beam planning (e.g., combining photon) increases the complexity in dose calculations of treatment, due to the varying physical characteristics of photon and electron beams, leading to potential inaccuracies in treatment planning. requiring advanced computational tools and expertise that may not be widely available, particularly in low-resource settings [8] .

There is no universally accepted protocol for dosimetric evaluation in mixed beam planning, leading to variability in results and treatment outcomes across studies [5] .

Mixed beam planning for cervical cancer is still an emerging area, with limited long-term clinical data on outcomes such as tumor control, survival rates, and toxicity profiles. Limited studies have validated mixed beam techniques with large patient cohorts, making it difficult to generalize findings and ensure safety and efficacy [11] [14] .

Variability in organ motion during treatment can lead to uncertainties in dose delivery, especially for organs at risk. Cervical cancer treatment involves pelvic organs prone to motion, such as the bladder and rectum, which can affect the accuracy of dose delivery and increase the variability in absorbed doses [6] .

Advanced techniques such as mixed beam therapy require significant financial and technical investments, which may be a limitation in many healthcare systems. affecting the consistency and precision of treatment [6] [15] .

Precise dose distribution and avoiding excessive radiation to organs at risk can be challenging due to the complex anatomy of the Pelvic region. Particularly when dealing with heterogeneous tissue densities and complex tumor geometries. Limitations in equipment or software can affect dose accuracy and treatment outcomes [2] [4] .

Establishing standardized protocols for mixed beam planning and dosimetric evaluation to improve consistency and reliability across institutions [5] .

Incorporating advanced imaging techniques (e.g., MRI-guided planning) can improve the accuracy of tumor and OAR delineation for mixed beam planning. Integrating advanced imaging modalities, such as MRI and PET, can improve target delineation and adaptive planning, enhancing dosimetric accuracy [6] [16] .

Developing patient-specific models using artificial intelligence and machine learning can help predict dose distributions and optimize mixed beam parameters [9] .

Innovations in treatment delivery, such as robotic and image-guided radiotherapy systems, can reduce uncertainties in beam targeting and organ motion.

Conducting large-scale clinical trials to validate the efficacy of mixed beam planning in cervical cancer is crucial for establishing standardized protocols.

Developing cost-effective technologies and simplified protocols for mixed beam planning can make advanced techniques accessible in resource-constrained environments.

Incorporating radiobiological models into treatment planning can improve the therapeutic ratio by considering tumor response and normal tissue tolerance [5] .

Adaptive planning during treatment can account for anatomical and dosimetric changes, ensuring consistent dose delivery to the tumor and minimizing OAR exposure.

These directions aim to overcome current challenges and enhance the efficacy, precision, and accessibility of mixed beam planning in cervical cancer treatment [5] [10] .

Development of more precise dosimetry tools and algorithms to better model and verify mixed beam interactions.

Developing affordable and scalable technologies to make mixed beam planning accessible in low- and middle-income countries [6] [15] .

Incorporating advanced imaging modalities, such as MRI-guided radiotherapy, to improve target delineation and dosimetric accuracy.

Conducting long-term studies to gather data on the clinical efficacy, toxicity, and cost-effectiveness of mixed beam planning in cervical cancer treatment [9] [12] [14] .

Leveraging artificial intelligence and machine learning for optimizing mixed beam treatment plans, reducing planning time, and improving dose distribution.

Developing cost-effective solutions and training programs to make mixed beam planning accessible in low-resource settings.

Evaluating not only dosimetric parameters but also patient quality of life and functional outcomes to ensure holistic treatment benefits.

This summary highlights current challenges and provides a roadmap for future advancements in mixed beam dosimetry for cervical cancer.