Status of head and neck brachytherapy in Spain in 2022

Purpose Brachytherapy (BT) has been used for many years for disease control in tumours of the head and neck area (H&N). It is currently performed with high dose rate (HDR) or pulsed dose rate (PDR), but its use has been reduced due to the implementation of new non-invasive external beam radiotherapy techniques such as intensity modulation (IMRT) and volumetric modulated arc therapy (VMAT) and the improvement of surgical techniques. Methods The Spanish Brachytherapy Group (GEB) has carried out a survey to find out the number of centres in Spain that continue to use BT in H&N and its indications and expectations for the future. Results The results were presented at the XX GEB Consensus Meeting held on October 21, 2022, in Valencia (Spain) and it was confirmed that, although there are fewer and fewer centres that use BT in H&N, there are still units with extensive experience in this technique that should be positioned as referral centres. Conclusion It is necessary to carry out continuous work with other specialities involved, such as H&N surgeons, and other radiation oncologists, to improve the training of residents, both oncologists and medical physicists (AU)

Status of head and neck brachytherapy in Spain in 2022.

PURPOSE: Brachytherapy (BT) has been used for many years for disease control in tumours of the head and neck area (H&N). It is currently performed with high dose rate (HDR) or pulsed dose rate (PDR), but its use has been reduced due to the implementation of new non-invasive external beam radiotherapy techniques such as intensity modulation (IMRT) and volumetric modulated arc therapy (VMAT) and the improvement of surgical techniques. METHODS: The Spanish Brachytherapy Group (GEB) has carried out a survey to find out the number of centres in Spain that continue to use BT in H&N and its indications and expectations for the future. RESULTS: The results were presented at the XX GEB Consensus Meeting held on October 21, 2022, in Valencia (Spain) and it was confirmed that, although there are fewer and fewer centres that use BT in H&N, there are still units with extensive experience in this technique that should be positioned as referral centres. CONCLUSION: It is necessary to carry out continuous work with other specialities involved, such as H&N surgeons, and other radiation oncologists, to improve the training of residents, both oncologists and medical physicists.

A study comparing baseline and best-corrected visual acuity after iodine-125 episcleral brachytherapy in uveal melanoma.

Purpose: The aim of this study was to analyze the course of visual acuity (VA) in visual outcomes of patients treated with iodine-125 (125I) brachytherapy in our center, based on original VA before treatment. Material and methods: Visual acuity was prospectively assessed using a case series of 305 patients treated with 125I between 1996 and 2022. To examine how VA behaves over time, we divided patient sample into 4 groups: (1) Patients with visual acuity of less than V ≤ 0.1 at baseline; (2) Patients with low to moderate VA, ranging 0.1 < V < 0.4; (3) Patients with moderate-high VA, ranging 0.4 < V < 0.8; (4) Patients with very high VA of V > 0.8. Each of the four groups was studied separately over a 60-month period to determine the percentage of patients with VA improvement, worsening, or with the same VA status. Finally, visual outcomes over time were estimated with 95% confidence interval (CI) using Kaplan-Meier analysis, and VA maintenance rates were reported at 1, 3, 5, 10, 15, and 20 years of follow-up. Results: The median follow-up time was 78.2 months (range, 6-254 months). The cumulative probabilities of survival analysis at 1, 3, 5, and 10 years were 16%, 3%, 2%, and none for the first sub-group; 46%, 20%, 17%, and 14% for the second; 65%, 53%, 29%, and 15% for the third; and 86%, 56%, 48%, and 41% for the fourth sub-group. The median survival in years was 0.30, 0.80, 3.10, and 4.40 for each sub-cohort, respectively. Conclusions: The decrease and maintenance of VA depends on the initial VA of patients. Most patients experience a marked worsening of their VA, regardless of their VA status before treatment with episcleral brachytherapy. Patients with a higher baseline VA retain VA best over time.

Regression of posterior uveal melanoma following iodine-125 plaque radiotherapy based on pre-treatment tumor apical height.

PURPOSE: The aim of this study was to analyze regression rates and local control of uveal melanoma patients treated with iodine-125 ( 125I) brachytherapy based on initial tumor apical height. MATERIAL AND METHODS: Patients treated in a single institution from January 1st, 1996 to 2019 with 125I plaques (ROPES and COMS) for uveal melanoma were included in this study. Patients treated with brachytherapy for iris and those treated with transpupillary thermotherapy prior to brachytherapy were excluded. The sample was classified into 4 categories depending on initial apical tumor height (h0), i.e., h0 ≤ 2.5 (small), 2.5 < h0 ≤ 6.25 (small-medium), 6.25 < h0 ≤ 10 (medium-large), and h0 > 10 mm (large). Percentage of original tumor apical height (Δh) was collected during follow-ups. Patterns of regression were evaluated using linear least squares adjustments. Multivariable Cox regression were performed. RESULTS: In total, 305 patients met the inclusion criteria, and 27, 166, 100, and 13 were considered for small, small-medium, medium-large, and large categories, respectively. Median follow-up was 82.4, 56.8, 76.1, 89.1, and 100.1 months for the entire cohort and each sub-group, respectively. Pattern of decrease when h0 ≤ 2.5 mm was not detectable. For the rest sub-groups, changes in height could be fitted using functional form: Δh (T) = ae-bT + c, R 2 ≥ 0.97. Multivariate Cox analysis factors predictive of local control failure revealed a hazard ratio (HR) of 6.1 (95% CI: 0.7-58.2%, p = 0.05) for patients who remained similar sized after treatment for small-medium tumors. For the rest sub-groups, Cox analysis did not indicate statistical significance in any single variable. CONCLUSIONS: Height changes can be modeled by a negative exponential function for the first 7 years after treatment depending on the initial height, except for those less than 2.5 mm. Non-responding small-medium tumors multiply by 6 the probability of failure in local control.

Treatment planning considerations for 125I eye plaque brachytherapy.

Effective cancer brachytherapy requires a treatment plan that delivers high-dose to tumor, while minimizing the dose to critical normal tissues. Therefore, an accurate knowledge of the sources and magnitude of the techniques is essential for producing robust and well optimized-plans. The purpose of this technical note is to establish general procedures and strategies for optimization and customization of the plaques loaded with radioactive seeds, particularly focusing on the definition of useful tactics to limit high doses to organs at risk and adapt the treatment time to the necessity of institution.