Treatment planning systems dosimetry auditing project in Portugal.

BACKGROUND AND PURPOSE: The Medical Physics Division of the Portuguese Physics Society (DFM_SPF) in collaboration with the IAEA, carried out a national auditing project in radiotherapy, between September 2011 and April 2012. The objective of this audit was to ensure the optimal usage of treatment planning systems. The national results are presented in this paper. MATERIAL AND METHODS: The audit methodology simulated all steps of external beam radiotherapy workflow, from image acquisition to treatment planning and dose delivery. A thorax CIRS phantom lend by IAEA was used in 8 planning test-cases for photon beams corresponding to 15 measuring points (33 point dose results, including individual fields in multi-field test cases and 5 sum results) in different phantom materials covering a set of typical clinical delivery techniques in 3D Conformal Radiotherapy. RESULTS: All 24 radiotherapy centers in Portugal have participated. 50 photon beams with energies 4-18 MV have been audited using 25 linear accelerators and 32 calculation algorithms. In general a very good consistency was observed for the same type of algorithm in all centres and for each beam quality. CONCLUSIONS: The overall results confirmed that the national status of TPS calculations and dose delivery for 3D conformal radiotherapy is generally acceptable with no major causes for concern. This project contributed to the strengthening of the cooperation between the centres and professionals, paving the way to further national collaborations.

Necrotizing sialometaplasia of palate: a case report.

Background. Necrotizing sialometaplasia (NS) is an uncommon benign reactive necrotizing inflammatory process involving minor salivary gland that often mimics malignancy both clinically and histopathologically. Case Report. We report the case of a healthy 26-year-old man with a painless swelling in the hard palate near the middle raphe, asymptomatic, well limited, and raised edges. The patient was submitted to incisional biopsy and histopathological examination. The histological diagnosis was necrotizing sialometaplasia. Discussion. The clinical and histological similarity between this entity and a malignant lesion implies a risk of unnecessary or mistreatment. Therefore, clinicians and pathologists should be aware of this lesion as to avoid errors in the diagnosis and treatment of this benign pathologic condition.

Eosinophils may predict occult lymph node metastasis in early oral cancer.

OBJECTIVE: The aim of this study was to investigate whether tumor-associated tissue eosinophilia (TATE) in early oral squamous cell carcinoma (OSCC) would aid in predicting occult lymph node metastasis. PATIENTS AND METHODS: Seventy-one patients undergoing elective neck dissection for T1 and T2 OSCC were evaluated for clinical features, prognosis, and TATE. The degree of TATE in OSCC was statistically analyzed in relation to the clinicopathological features, tumor invasion, occult lymph node metastasis, and survival using χ(2) test and Kaplan-Meier method. RESULTS: Statistical analysis revealed that intense TATE was a significant feature (p = 0.004) to predict occult lymph node metastasis in patients with early OSCC. All regional recurrences of the OSCC occurred in patients showing intense TATE. CONCLUSIONS: These results suggest that intense TATE can be clinically used as a predictive factor for occult lymph node metastasis. CLINICAL RELEVANCE: The presence of intense TATE is an adjunctive histopathological marker to reinforce the indication of elective neck dissection of the patients with early OSCC.

Recurrent peripheral odontogenic keratocyst: a case report.

A case of peripheral odontogenic keratocyst arising in a 57-year-old white female patient involving the posterior mandibular gingiva that recurred after 12 months of follow-up is presented. This reported case reinforces that patients presenting peripheral odontogenic keratocyst should be carefully followed up after conservative surgical treatment.

Expression of vascular endothelial growth factor-C does not predict occult lymph-node metastasis in early oral squamous cell carcinoma.

Strong vascular endothelial growth factor-C (VEGF-C) expression has been correlated to occurrence of lymph-node metastases in patients with oral squamous cell carcinoma (OSCC). The incidence of occult lymph-node metastasis remains a decisive factor in the prognosis of patients with early OSCC. The aim of this study was to evaluate VEGF-C expression as a predictor of occult lymph-node metastasis in OSCC. Eighty-seven patients with primary OSCC arising in the tongue or floor of mouth, clinically T1N0M0 or T2N0M0, with (pN+) and without (pN0) occult lymph-node metastases were analyzed for VEGF-C expression by malignant cells. Occult lymph-node metastases (pN+) were detected in 22% of the 64 patients who were submitted to elective neck dissection. No statistically significant difference was found between OSCC with and without occult lymph-node metastasis in regard to VEGF-C immunoexpression by malignant cells and clinicopathologic features. Independently of VEGF-C expression, lymph-node metastasis (pN+) was the most significant prognostic factor for overall survival of patients with OSCC (p=0.030). These findings indicate that isolated VEGF-C expression by malignant cells is not of predictive value for occult lymph-node metastasis in the early stages of OSCC.