Comparison of iso-effective and cost-effective high-dose-rate brachytherapy treatment schedules in cervical cancer - regional cancer center experience

Compliance and clinical efficacy of vaginal dilator after radiotherapy for cervical and endometrial malignancies

Objective

To investigate the compliance and clinical efficacy of vaginal dilators (VDs) as an educational intervention in patients receiving pelvic radiation therapy (RT) for endometrial and cervical malignancies.

Material and methods

This is a single institution, retrospective chart review. Patients undergoing pelvic RT for endometrial or cervical cancer at our center were educated about the use of a VD starting 1 month after completion of RT. The patients were assessed after 3 months of prescribing VD. The demographic details and physical examination findings were extracted from medical records.

Results

We identified 54 female patients at our institution during the 6-month duration. The median mean age of patients was 54 ± 9.9 years. Twenty-four (44.4%) had endometrial cancers and 30 (55.6%) were diagnosed with cervical cancers. All patients received external beam RT, 38 (70.4%) received a dose of 45 Gy, and 16 (29.6%) patients received 50.4 Gy. Brachytherapy was also received by all patients, 28 (51.9%) received 5 Gy × 2 fractions, 4 (7.4%) received 7 Gy × 3 fractions and 22 (40.7%) received 8 Gy × 3 fractions. The compliance with VD use was 36 (66.6%) patients. Twenty-two (40.7%) used 2-3 times a week, 8 (14.8%) used <2 times per week and 6 (11.9%) used only once a month, and 18 (33.3%) did not use the VD post-treatment. Per vaginal (PV) examination findings of the patient's vagina with normal mucosa were evaluated in 32 (59.3%) and adhesions were found in 20 (37.0%) and 2 (3.7%) were unable to examine due to dense adhesions. During examination 12 (22.2%) had bleeding PV, however, the majority of the patients, 42 (77.8%) experienced no bleeding PV. Out of the 36 patients who used a VD, it was found to be efficacious in 29 (80.6%) of patients. Upon stratification of efficacy with a frequency of VD, 72.4% (n = 21) efficacy was seen in patients using frequent VD as prescribed 2-3 times per week.

Conclusion

The compliance and efficacy of VD use after radiation to pelvic in cervical and endometrial cancers at 3 months follow-up were found to be 66.6% and 80.6%, respectively. This shows that VD therapy is an effective interventional tool and patients should receive specialist education about vaginal stenosis as toxicity at the outset of treatment.

The impact of different treatment protocols on achieved radiation doses of high-dose-rate brachytherapy for locally advanced cervical cancer: a comparison between 2 fractions in 1 application and separate applications for each fraction

PURPOSE

To compare radiation doses achieved by image-guided brachytherapy for locally advanced cervical carcinoma implemented with two different protocols.

MATERIAL AND METHODS

Medical records of 117 patients with locally advanced cervical carcinoma treated with brachytherapy from 2009 to 2018 at our institution were retrospectively reviewed. All patients had received previous external beam radio/chemotherapy. We performed magnetic resonance image-guided adaptive high-dose-rate brachytherapy delivered by intra-cavitary/interstitial applicators. Dose prescription was 7 Gy for four fractions within two weeks. Original schedule of brachytherapy was two fractions delivered on consecutive days with one applicator insertion; this process was repeated one week later (group 1, 54 patients). From 2015 onwards, another protocol of brachytherapy was mainly used, separately performing applicator insertions for each of the four administered fractions (group 2, 63 patients).

RESULTS

The high-risk clinical target volume (HR-CTV) D90 planning aim (PA) of ≥ 85 Gy (hard constraint) was not achieved in 9 cases out of 54 (17%) in group 1 compared with only 2 out of 63 cases (3%) in group 2 (p = 0.022). A difference between the two groups was also found in the fulfillment of PA 90 Gy (soft constraint) (p = 0.027). We conducted a sub-group analysis of target volume groups and observed that the differences were most pronounced with very large tumors (> 50 cm3). In these patients, PA 85 Gy was only fulfilled in 67% cases when treatment involved two applications, but in all cases with four separate applicator insertions (p = 0.010).

CONCLUSIONS

In our experience, by performing an applicator insertion for each of the fractions, it is possible to correct the non-optimal position of the applicator immediately, and to deliver better doses for consecutive fractions. As a result, the planning aim is more often achieved, especially for large tumors.

Comparative Analysis of 60Co and 192Ir Sources in High Dose Rate Brachytherapy for Cervical Cancer

High-dose-rate (HDR) brachytherapy (BT) is an essential treatment for cervical cancer, one of the most prevalent gynecological malignant tumors. In HDR BT, high radiation doses can be delivered to the tumor target with the minimum radiation doses to organs at risk. Despite the wide use of the small HDR 192Ir source, as the technique has improved, the HDR 60Co source, which has the same miniaturized geometry, has also been produced and put into clinical practice. Compared with 192Ir (74 days), 60Co has a longer half-life (5.3 years), which gives it a great economic advantage for developing nations. The aim of the study was to compare 60Co and 192Ir sources for HDR BT in terms of both dosimetry and clinical treatment. The results of reports published on the use of HDR BT for cervical cancer over the past few years as well as our own research show that this treatment is safe and it is feasible to use 60Co as an alternative source.

Elimination of cervical cancer as a public health problem-how shorter brachytherapy could make a difference during COVID-19

The World Health Organization has called for elimination of cervical cancer as a public health problem and has adopted strategies in this regard. However, the estimates for achieving the goals depend on the ability to provide timely treatment in a certain proportion of cases. The coronavirus disease 2019 pandemic has had a serious impact on healthcare delivery in many low and middle income countries (LMICs) with the highest burden of cervical cancer; funds and infrastructure are being reallocated to deal with the emergency, and cancer care has been seriously affected. In the absence of clear and reliable estimates, the exact extent of disruption remains unclear. It is, therefore, essential that pragmatic approaches are adopted to save lives. There has been considerable debate regarding the use of the 9 Gy × 2 fractions high dose rate brachytherapy schedule for the treatment of locally advanced cervical carcinoma. However, in LMICs with the highest global burden of locally advanced cervical cancer cases, radiation facilities have been using this fractionation schedule in many cases to deal with the overwhelming number of patients, who would have otherwise been denied timely treatment. In view of the current pandemic, and the difficulties in accessing and delivering timely healthcare, mortality owing to delayed treatment cannot be denied in LMICs, which already have underequipped healthcare facilities. Use of the shortest available fractionation schedule to provide timely treatment would serve to save more lives in regions with high incidence and mortality from the disease.