Simple fabrication technique of personalized endocavitary brachytherapy applicator for maxillary alveolar cancer.

Purpose: We report on methods and outcomes of post-operative endocavitary brachytherapy after prior irradiation and salvage surgery in a patient with maxillary alveolar squamous cell carcinoma (SCC). Material and methods: A 67-year-old male with right maxillary alveolar SCC was referred for brachytherapy after prior definitive chemoradiotherapy and salvage posterior maxillectomy. A personalized endocavitary applicator was fabricated using dental impression plastic tray, vinyl polysiloxane paste, and four flexible catheters to deliver fourteen 3.5 Gy high-dose-rate fractions. High-risk and intermediate-risk clinical target volumes were treated to 3.7 Gy (D90) and 2.4 Gy (D98), with mandibular dose limited to 2.3 Gy (D2cc) per fraction. These corresponded to total 2 Gy equivalent doses (EQD2) of 72.8 Gy, 40.5 Gy, and 34 Gy, respectively. Results: The patient developed grade 2 mucositis and was disease-free for six months. He had biopsy-confirmed local recurrence at 8 months. He refused further treatment and expired within a month. Conclusions: This simple approach to a personalized endocavitary applicator is feasible and allows for lower costs and less treatment delays, while ensuring patient comfort and convenience.

Risk factors for recurrent papillary thyroid carcinoma

OBJECTIVE: To identify risk factors associated with disease recurrence among Filipinos with papillary thyroid carcinoma (PTC).METHODS:Design: Retrospective Cohort StudySetting: Tertiary National University HospitalParticipants: 76 patients diagnosed with papillary thyroid carcinoma, classified as low and low-to-intermediate risk (2015 ATA classification) that underwent total thyroidectomy with or without neck dissection from 2010-2014 and were followed up from 10 months to 5 years. Log rank and Cox regression analyses were used to determine significant risk factors for recurrence.RESULTS: 29 (38.15%) had recurrence. On univariate analysis, age, tumor size, multifocality, extrathyroidal extension, presence of lateral neck nodes and RAI therapy were statistically associated with recurrence. However, on multivariate analysis, no clinicopathologic factor was statistically associated with recurrence.CONCLUSION: Age of >45 years, female sex, tumor size of >2 cm, multifocality, presence of microscopic extrathyroidal extension and lymph node metastasis might contribute to the recurrence of papillary thyroid cancer while post-operative radioactive ablation may have some protective effect. However, this study suggests that other factors must be included in the model to better understand the relationship between these factors and recurrence.

Genetic polymorphisms in CYP1A1, GSTM1, GSTP1, GSTT1, NAT1 and NAT2 and oral cavity cancer risk among Filipinos

Polymorphisms in metabolic genes have been shown to modulate susceptibility to oral cavity cancer. Cases (n=176) and controls (n=317) from the Filipino population were genotyped for selected polymorphisms in CYP1A1, GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subjects. The CYP1A1m1/m1 genotype is protective against oral cancer, while being homozygous for the GSTP1 c.313G genotype and heterozygous for the NAT1*10 homozygotes and non-homozygotes for the CYP1A1 m1 allele. The risk from heterozygosity for the NAT1*10 allele was limited to subjects who were not homozygous for the GSTP1 c.313G genotype remained a significant oral cancer risk modifier, together with environmental variables, the homozygous GSTP1 c.313G genotype remained a significant oral cancer risk modifier, together with environmental risk factors, such as smoking, passive smoking, inverted smoking and tobacco chewing, and environmental protective factors, i.e. moderate consumption of fish sauce (patis) and shrimp paste (bagoong). The GSTP1 c.313G polymorphism increases susceptibility for oral cavity cancer in the Filipino population.