The normal tissue objective (NTO) is a tool used in inverse-planned intensity-modulated radiation therapy (IMRT) to minimize dose dispersion to surrounding tissues. The current study focuses on the NTO’s impact on RapidArc treatment plans for cervical cancer patients or its role in reducing doses to healthy surrounding tissues.

This study included 11 cervical cancer patients who underwent RapidArc treatment. We assessed plans both with and without the NTO objective by evaluating parameters such as homogeneity, conformity, gradient index (GI), IMRT factor, integral dose and the volume of normal tissues receiving low doses of 40, 30, 20 and 10 Gy. Further, differences between automatic NTO and manual NTO were evaluated using Wilcoxon signed-rank test.

There were no significant differences in the conformity index, homogeneity index, IMRT factor and integral dose between plans with automatic NTO and those with manual NTO RapidArc plans. However, we did observe a clear advantage in using manual NTO for controlling low-dose exposure to normal tissues. The comparisons between automatic and manual NTO resulted in a GI of 3·1 ± 0·3 versus 2·7 ± 0·68 (p = 0·008). Furthermore, we noticed a significant reduction in the volumes receiving low doses (V10, V20, V30 and V40) with the manual NTO settings.

The NTO plays a crucial role in optimizing RapidArc plans for treating cervical cancer. Based on the findings of this study, manual NTO settings of distance from PTV border xstart = 0·5 mm, start dose f0 = 105%, end dose f∞ = an average of 40%, dose fall-off 0·2 mm–1 were optimal. Further research involving a larger sample size and exploration of various NTO parameters is necessary to validate our results.

To determine and summarise the literature on prostatic seed stability by investigating seed marker migration and loss in prostate cancer patients. In addition, documenting the implications of significant seed migration and loss in clinical practise.

PubMed and Sciencedirect databases were used to locate papers on the stability of gold seed markers in prostate patients treated with external beam radiation therapy. The search found 3,238 articles and ten articles were selected and reviewed based on inclusion and exclusion criteria for the scope of this literature review.

Minimal migration and loss of seeds was observed in the literature reviewed, with the majority of authors reporting <2·0 mm migration within the prostate; however, there were individual cases reported outside of the 2·0 mm threshold. It was also found that significant migration had an impact on image matching, as well as, planning treatment volume margins.

Seed stability within the prostate has been proven, with most authors reporting minimal migration within a 2·0 mm threshold and minimal loss of seeds. Although individual cases can have significant migration and loss, if marker migration exceeds the 2·0 mm threshold, a protocol is required to deal with both non-significant and significant migration.