Biomedical subjects

Derrick T Lin

Publications and source records attributed to Derrick T Lin.

8 recordsLinked to original sources

PubMed2006

Proton beam radiation therapy for skull base adenoid cystic carcinoma.

OBJECTIVE: To determine the treatment outcome and prognostic factors in patients with adenoid cystic carcinoma of the skull base treated with proton beam radiation therapy. DESIGN: Retrospective analysis. SETTING: Massachusetts General Hospital, Massachusetts Eye and Ear Infirmary, and Harvard Medical School, Boston. PATIENTS: From 1991 to 2002, 23 patients with newly diagnosed adenoid cystic carcinoma with skull base extension were treated with combined proton and photon radiotherapy. There was tumor involvement of the sphenoid sinus in 61% of patients (14), nasopharynx in 61% (14), clivus in 48% (11), and cavernous sinus in 74% (17). The extent of surgery was biopsy alone in 48% (11), partial resection in 39% (9), and gross total resection with positive margins in 13% (3). The median total dose to the primary site was 75.9 cobalt-gray equivalent. The median follow-up of all surviving patients was 64 months. MAIN OUTCOME MEASURES: Locoregional control and disease-free survival and overall survival rates. RESULTS: Tumors recurred locally in 2 patients at 33 and 68 months, respectively. No patients developed neck recurrence. Eight patients had distant metastasis as the first site of recurrence. The local control rate at 5 years was 93%. The rate of freedom from distant metastasis at 5 years was 62%. The disease-free and overall survival rates at 5 years were 56% and 77%, respectively. In multivariate analysis, significant adverse factors predictive for overall survival were change in vision at presentation (P = .02) and involvement of sphenoid sinus and clivus (P = .01). CONCLUSIONS: High-dose conformal proton beam radiation therapy results in a very encouraging local control rate in patients with adenoid cystic carcinoma of the skull base. Changes in vision at presentation and tumor involvement of the sphenoid sinus and clivus are important prognostic factors.

Adult↗

PubMed2006

Immunohistochemical distinction of intestinal-type sinonasal adenocarcinoma from metastatic adenocarcinoma of intestinal origin.

OBJECTIVES: Distinction of intestinal-type sinonasal adenocarcinoma (ITAC) from adenocarcinoma of intestinal origin metastatic to the sinonasal cavity may be extremely difficult on histologic grounds alone. We studied the role of cytokeratin (CK) and mucin (MUC) expression in differentiating ITAC, metastatic adenocarcinoma of intestinal origin, and non-intestinal-type sinonasal adenocarcinoma (non-ITAC). METHODS: We stained specimens from 5 cases of ITAC and 4 cases of non-ITAC, along with 4 colonic and 3 duodenal adenocarcinoma controls, with CK7 and CK20, MUC2 and MUC5, neuron-specific enolase (NSE), chromogranin (CHR), and carcinoembryonic antigen (CEA) in order to examine the possible combinations of markers that best aid in the diagnosis of these lesions. We also performed a retrospective review of our clinical experience with these rare lesions. RESULTS: CK7 staining was positive in all ITAC and non-ITAC cases, whereas all cases displaying gastrointestinal-type differentiation (ITAC and metastatic intestinal cases) stained positive for both CK20 and MUC2. Staining for MUC5, NSE, CHR, and CEA was variable. CONCLUSIONS: Tumors with the CK7+, CK20+, MUC2+ immunophenotype are likely primary sinonasal lesions, whereas tumors with the CK7-, CK20+, MUC2+ profile warrant further clinical evaluation to exclude metastatic disease from the gastrointestinal tract. Complete surgical resection of ITAC remains the mainstay of therapy.

Adenocarcinoma↗

PubMed2005

Squamous cell carcinoma of the oropharynx and hypopharynx.

Oropharyngeal and hypopharyngeal squamous cell carcinomas require an interdisciplinary approach to manage patients appropriately. Tumor stage and histology, functional outcome, and patient comorbidities are important factors to consider. Various surgical approaches as well as chemotherapy and radiation therapy alone or in combination remain the mainstay of therapy.

Antineoplastic Agents↗

PubMed2004

Tumors of the accessory lobe of the parotid gland: a 10-year experience.

OBJECTIVES/HYPOTHESIS: The differential diagnosis of midcheek masses include pathology arising from normal anatomic structures or from variations of normal accessory parotid gland tissue. Accessory parotid gland tissue has been described as salivary tissue adjacent to Stenson's duct that is separate from the main body of the parotid gland. We report our 10-year experience with the diagnosis and treatment of eight accessory parotid gland neoplasms that have been followed by the senior authors. STUDY DESIGN: This is a retrospective review of our experience with eight accessory parotid gland neoplasms. METHODS: A literature review and retrospective chart review of our experience with accessory parotid gland tumors over the past 10 years. The presentation, evaluation, management, treatment, and outcome were recorded. RESULTS: Eight cases of accessory lobe parotid tumors were identified, which have been followed since the date of initial treatment. All of the patients presented with a slowly growing cheek mass. There was one case of carcinoma expleomorphic adenoma, one case of undifferentiated carcinoma (small cell carcinoma), one case of basal cell adenocarcinoma, one case of benign salivary cyst, two cases of pleomorphic adenoma, and two cases of monomorphic adenoma. A standard facelift approach or modified Blair incision was used to excise these tumors. CONCLUSIONS: Neoplasms of the accessory parotid gland are rare. Management of these tumors include a high index of suspicion, good understanding of the anatomy, and meticulous surgical approach.

Adult↗

PubMed2004

Current concepts in lip reconstruction.

PURPOSE OF REVIEW: Approximately 25% of all oral cavity carcinomas involve the lips, and the primary management of these lesions is complete surgical resection. The management of the resulting lip defect remains a significant reconstructive challenge, requiring meticulous preoperative planning and surgical technique to optimize the functional and cosmetic outcome. Reviewed here are the accepted techniques of lip reconstruction, as well newer techniques that have been reported. RECENT FINDINGS: There have been no major advances in lip reconstruction; rather, continued improvement on accepted techniques. The main goals of reconstruction remain the restoration of oral competence, maintenance of oral opening, and the restoration of normal anatomic relations such that both the active (smile) and passive (form) cosmetic outcome is acceptable. The reconstruction should be tailored to the individual needs of the patient and should take into account the patient's condition, local tissue characteristics, previous treatment(s), and functional needs (eg, denture use), in addition to the size and location of the defect. SUMMARY: The lips play a key role in facial expression, speech, and eating. This requires meticulous attention to preoperative planning and surgical technique to maximize the functional and cosmetic outcome. It is important to assess local tissue characteristics (skin laxity) and previous treatment (surgery and/or irradiation) before the surgical plan is made final. Local tissue should be used whenever possible to provide the least donor site morbidity and the best overall tissue color and texture match. Whenever possible, dynamic reconstruction should be attempted. Careful preoperative assessment and planning will allow the surgeon to reach an acceptable balance between form and function with the reconstruction.

Carcinoma↗

PubMed2004

Use of the anterolateral thigh flap for reconstruction of the head and neck.

PURPOSE OF REVIEW: The anterolateral thigh free flap has achieved recent popularity in North America for the reconstruction of head and neck defects after ablative surgery. The flap is most often based on either the septocutaneous or musculocutaneous perforators of the descending branch of the lateral circumflex femoral artery. Its versatility allows for a subcutaneous, fasciocutaneous, myocutaneous, or adipofascial flap to be obtained. RECENT FINDINGS: Recent publications have described the utility of the anterolateral thigh flap for reconstruction of head and neck defects. It has been used successfully in the reconstruction of the laryngopharynx, oral cavity, oropharynx, external skin, and maxilla. Furthermore, when a thinner flap is needed, a suprafascial anterolateral thigh flap may be raised or the flap may be thinned after it is obtained. SUMMARY: The anterolateral thigh flap is a highly versatile and reliable flap for use in the reconstruction of various soft tissue defects of the head and neck. This flap has gained great popularity in mainland China, Taiwan, and Japan given its versatility, ability for a two-team approach, and minimal donor site morbidity. However, it has not met the same enthusiasm in Europe and North America because of the relative difficulty in perforator dissection, reported variations of the vascular anatomy, and the presumed increased thickness of the anterolateral thigh tissue in the Western population in comparison with the patient population of the Far East. These obstacles may be overcome by increased surgical experience and by the ability to create a thinner suprafascial flap or thinning the flap after it has been obtained.

Head↗

PubMed2002

Cyclooxygenase-2: a novel molecular target for the prevention and treatment of head and neck cancer.

Cyclooxygenase-2 (COX-2), an enzyme that catalyzes the synthesis of prostaglandins, is overexpressed in a variety of premalignant and malignant conditions, including oral leukoplakia and squamous cell carcinoma of the head and neck. Increased levels of COX-2 may contribute to carcinogenesis by modulating xenobiotic metabolism, apoptosis, immune surveillance, and angiogenesis. In experimental models, newly developed selective COX-2 inhibitors suppress the formation of tumors, including tongue cancer. These findings provided a rationale for a number of chemoprevention trials that are underway. Selective COX-2 inhibitors also suppress the growth and metastases of established tumors and enhance the anticancer activity of both radiotherapy and chemotherapy in experimental animals. In this review, evidence is presented that inhibition of COX-2 represents a promising strategy to prevent or possibly treat human head and neck cancers.

Apoptosis↗

PubMed2002

Incidence of inadvertent parathyroid removal during thyroidectomy.

OBJECTIVES: To assess the incidence of unintentional parathyroid removal during routine thyroidectomy and to identify factors that might predict patients at high risk. STUDY DESIGN: Retrospective review of case records. Data analyzed for incidental finding of parathyroid gland(s) in the thyroidectomy specimen and postoperative temporary or permanent hypocalcemia. METHODS: The clinical records of 220 patients undergoing thyroidectomies between January 1997 and October 1999 were reviewed. Pathology reports were screened for information on the presence of parathyroid tissue along with the thyroid specimen. Operative reports were reviewed to exclude the possibility of intentional parathyroid gland removal. Case records were scrutinized to determine whether the patient developed symptomatic hypocalcemia postoperatively. RESULTS: Nine percent of the 220 patients were found to have had inadvertent removal of parathyroid tissue. The majority of patients (95%) had two or less parathyroid glands in their specimens. The size and histological nature of the thyroid lesion were not predictive of inadvertent parathyroid removal. Of the 25 repeat operations for recurrent or persistent malignancy, 5 (20%) were found to have unintentional parathyroid removal compared with 15 (7.71%) of 195 primary thyroidectomy cases (P <.05). Nineteen percent of patients who had tracheoesophageal groove node dissection had an incidental parathyroid in their specimen compared with 7% who did not undergo tracheoesophageal groove node dissection (P = .04). None of the patients with unintentional parathyroid gland removal developed either temporary or permanent postoperative hypocalcemia. CONCLUSIONS: Inadvertent excision of a parathyroid gland(s) occurred in 9% of patients undergoing thyroidectomy in our experience. Reoperative thyroid surgery and tracheoesophageal node dissection were associated with a significantly higher risk of inadvertent parathyroid gland excision. Inadvertent parathyroidectomy did not result in symptomatic temporary or permanent hypocalcemia postoperatively.

Female↗