Intracavitary brachytherapy (ICBT) is essential in managing locally advanced cervical cancer. Brachytherapy as a modality has the advantage of a higher dose to the tumour with a dose fall off at the periphery as per the inverse square law. The dose per fraction is much higher than external beam radiotherapy. So proper application and dosimetry are of paramount importance to reduce late toxicity.

A retrospective analysis of 69 patients who underwent three ICBT applications of 7 Gray in each fraction was done. The factors under consideration were the type of pain management (spinal anaesthesia (SA) versus conscious sedation (CS)), the initial size of the disease (bulky and non-bulky) and subsequent fractions (first fraction versus third fraction). The dosimetric parameters analysed were the doses received by points A, B and P and that of the critical organs (bladder, rectum and sigmoid colon).

The dose received by critical organs was comparable concerning all the factors under consideration. The dose to point P on the left side was significantly lower in the CS group than in the SA group (p-value = 0·031). Also, the dose to point P on the right side was significantly lower in the third fraction compared with the first fraction (p-value = 0·016).

ICBT under spinal anaesthesia resulted in a higher dose to the pelvic wall. The initial size of the tumour or the subsequent fractions does not significantly affect the dose received by critical organs.

To analyse the dosimetric benefit of the hybrid inverse planning optimisation (HIPO) planning method over the graphical optimisation (GrO) planning method for 3D volume-based intravaginal brachytherapy (IVBT) in a mono-centre patient cohort.

Twenty-five patients surgically staged with endometrial cancer were considered for the study. All the patients had received adjuvant IVBT for three fractions with one-time computed tomography image-based planning. The data on the patient, tumour, plan, and treatment characteristics were retrieved from the database. All the plans were re-optimised with GrO and HIPO techniques for this comparison study. The different dosimetric parameters were compared between the two methods, and the collected data were tabulated and shown graphically. The statistical evaluation was performed with IBM SPSS version 26, and Origin Pro 8.5 was employed for plots.

HIPO plans show similar target coverage in terms of D 90(%), V 95(%) and conformity index with no significant statistical difference from the GrO plans with an acceptable increase in homogeneity index (0·087 ± 0·062%). It succeeds in achieving a statistically significant reduction of dose to organs at risk such as D0·1 cc, D1·0 cc and D2·0 cc for the bladder (11·59%, 4·8% and 3·99%), rectum (41·33%, 16·9% and 16·05%) and sigmoid (20·97%, 13·53% and 11·21%), respectively, in comparison with GrO optimisation.

Considering the dosimetric outcome of 3D-based IVBT, it is suggested to adopt inverse optimisation techniques like HIPO over GrO to achieve higher quality treatment plan in terms of adequate target dose and lesser dose to OARs.

In this study we compared radiation dose received by organs at risk (OARs) after breast conservation surgery(BCS) and mastectomy in patients with left breast cancer.

Total 30 patients, 15 each of BCS and mastectomy were included in this study. Planning Computerised Tomography (CT) was done for each patient. Chest wall, whole breast, heart, lungs, LAD, proximal and distal LAD, and contra lateral breast was contoured for each patient. Radiotherapy plans were made by standard tangent field. Dose prescribed was 40Gy/16#/3 weeks. Mean heart dose, LAD, proximal and distal LAD, mean and V5 of right lung, and mean, V5, V10 and V20 of left lung, mean dose and V2 of contra lateral breast were calculated for each patient and compared between BCS and mastectomy patients using student’s T test.

Mean doses to the heart, LAD, proximal LAD and distal LAD were 3.364Gy, 16.06Gy, 2.7Gy, 27.5Gy; and 4.219Gy, 14.653Gy, 4.306Gy, 24.6Gy, respectively for mastectomy and BCS patients. Left lung mean dose, V5, V10 and V20 were 5.96Gy, 16%, 14%, 12.4%; and 7.69Gy, 21%, 18% and 16% in mastectomy and BCS patients, respectively. There was no statistical significant difference in the doses to the heart and left lung between mastectomy and BCS. Mean dose to the right lung was significantly less in mastectomy as compared to BCS, 0.29Gy vs. 0.51Gy, respectively (p = 0.007). Mean dose to the opposite breast was significantly lower in patients with mastectomy than BCS (0.54Gy Vs 0.37Gy, p = 0.007). The dose to the distal LAD was significantly higher than proximal LAD both in BCS (24.6Gy Vs 4.3Gy, p = <0.0001) and mastectomy (27.5Gy Vs 2.7Gy, p = <0.0001) patients.

There was no difference in doses received by heart and left lung between BCS and mastectomy patients. Mean doses to the right lung and breast were significantly less in mastectomy patients.