To transfer the preplan for the head and neck brachytherapy to the clinical implantation procedure, a preplan-based 3D-printed individual template for needle insertion guidance had previously been designed and used. The accuracy of needle insertion using this kind template was assessed in vivo. In the study, 25 patients with head and neck tumors were implanted with 125I radioactive seeds under the guidance of the 3D-printed individual template. Patients were divided into four groups based on the site of needle insertion: the parotid and masseter region group (nine patients); the maxillary and paranasal region group (eight patients); the submandibular and upper neck area group (five patients); and the retromandibular region group (six patients). The distance and angular deviations between the preplanned and placed needles were compared, and the complications and time required for needle insertion were assessed. The mean entrance point distance deviation for all 619 needles was 1.18 ± 0.81 mm, varying from 0.857 ± 0.545 to 1.930 ± 0.843 mm at different sites. The mean angular deviation was 2.08 ± 1.07 degrees, varying from 1.85 ± 0.93 to 2.73 ± 1.18 degrees at different sites. All needles were manually inserted to their preplanned positions in a single attempt, and the mean time to insert one needle was 7.5 s. No anatomical complications related to inaccurately placed implants were observed. Using the 3D-printed individual template for the implantation of 125I radioactive seeds in the head and neck region can accurately transfer a CT-based preplan to the brachytherapy needle insertion procedure. Moreover, the addition of individual template guidance can reduce the time required for implantation and minimize the damage to normal tissues.

A molecular container for a single water molecule was obtained by chemical transformation of a [60]fullerene cage. A phosphate moiety acts as an effective “stopper” in the orifice (see picture).

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Background This study aimed to determine the effectiveness and safety of surgery combined with postoperative 125I seed brachytherapy for treatment of primary mucoepidermoid carcinoma (MEC) of the parotid gland. Methods Retrospective analysis of data of patients with MEC (n = 108) treated with surgery plus postoperative 125I seed brachytherapy between 2004 and 2016. Overall survival (OS), disease‐free survival (DFS), local control rate (LCR), distant metastasis, and radiation‐associated toxicities were analyzed, and factors affecting outcomes were evaluated. Results The 5‐ and 10‐year OS were 98.8% and 95.8%, respectively. The DFS and LCR at 5 and 10 years were all 91.4%. Age ≥ 60 years (hazard ratio [HR] = 6.86, 95% confidence interval [CI]: 1.54‐30.55) and T4 disease (HR = 7.15, 95% CI: 1.40‐36.52) were poor prognostic factors. Acute radiation‐associated toxicities were minor. Conclusion Surgery plus 125I seed brachytherapy appears to be an effective treatment for parotid gland MEC, capable of providing satisfactory outcomes with few complications.