Pediatric peri-operative fractionated high-dose-rate brachytherapy for recurrent Wilms' tumor using a reconstructed Freiburg flap

A Role of brachytherapy in bilateral Wilms tumors: A long-term follow-up of three highly selected cases and literature review

PURPOSE

To describe experience with partial nephrectomy combined with brachytherapy as part of the local management of bilateral Wilms tumor (WT) including a review of the available literature.

RESULTS (METHODS AND CASE DESCRIPTION)

Between 2011 and 2014, three highly selected patients (age nine months, 16 months, and 4 years) with bilateral WT (two synchronous and one metachronous) underwent enucleation and perioperative brachytherapy to the tumor bed. With a minimum follow-up of 5 years, all three patients are in continuous complete remission with preserved kidney function.

CONCLUSIONS

Although nephron sparing surgery aiming at tumor free-margins remains the gold standard for bilateral WT, tumor enucleation followed by brachytherapy may be considered in carefully selected patients at high risk for end-stage kidney failure. Given the rarity and complexity of the procedure, concentration of care of such patients is mandatory.

Development and dosimetric assessment of a patient-specific elastic skin applicator for high-dose-rate brachytherapy

PURPOSE

The purpose of this study was to develop a patient-specific elastic skin applicator and to evaluate its dosimetric characteristics for high-dose-rate (HDR) brachytherapy.

METHODS AND MATERIALS

We simulated the treatment of a nonmelanoma skin cancer on the nose. An elastic skin applicator was manufactured by pouring the Dragon Skin (Smooth-On Inc., Easton, PA) with a shore hardness of 10A into an applicator mold. The rigid skin applicator was printed using high-impact polystyrene with a shore hardness of 73D. HDR plans were generated using a Freiburg Flap (FF) applicator and patient-specific rigid and elastic applicators. For dosimetric assessment, dose-volumetric parameters for target volume and normal organs were evaluated. Global gamma evaluations were performed, comparing film measurements and treatment planning system calculations with various gamma criteria. The 10% low-dose threshold was applied.

RESULTS

The V_120% values of the target volume were 56.9%, 70.3%, and 70.2% for HDR plans using FF, rigid, and elastic applicators, respectively. The maximum doses of the right eyeball were 21.7 Gy, 20.5 Gy, and 20.5 Gy for the HDR plans using FF, rigid, and elastic applicators, respectively. The average gamma passing rates were 82.5% ± 1.5%, 91.6% ± 0.8%, and 94.8% ± 0.2% for FF, rigid, and elastic applicators, respectively, with 3%/3 mm criterion.

CONCLUSIONS

Patient-specific elastic skin applicator showed better adhesion to irregular or curved body surfaces, resulting in better agreement between planned and delivered dose distributions. The applicator suggested in this study can be effectively implemented clinically.