The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy. Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients. Eight patients with head and neck cancers were involved in this study. For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy. A total of 147,232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis, representing 3,460 species level operational taxonomic units (OTUs) and 140 genus level taxa. Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics. Moreover, the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves. This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.
Actinomyces ; classification ; radiation effects ; Actinomycetaceae ; classification ; radiation effects ; Alcaligenaceae ; classification ; radiation effects ; Bacteria ; classification ; radiation effects ; Capnocytophaga ; classification ; radiation effects ; Carnobacteriaceae ; classification ; radiation effects ; Computational Biology ; Dental Plaque ; microbiology ; Follow-Up Studies ; Gemella ; classification ; radiation effects ; Head and Neck Neoplasms ; radiotherapy ; High-Throughput Nucleotide Sequencing ; Humans ; Middle Aged ; Neisseria ; classification ; radiation effects ; Prevotella ; classification ; radiation effects ; Propionibacteriaceae ; classification ; radiation effects ; RNA, Bacterial ; analysis ; RNA, Ribosomal, 16S ; analysis ; Streptococcus ; classification ; radiation effects ; Veillonella ; classification ; radiation effects

It is well recognized that radiation can be carcinogenic for a wide variety of tumors, especially, in breast, thyroid, and bone marrow which appear to be radiosensitive. The criteria for establishing the dignosis of radiation- induced malignancy are the knowledge of prior irradiation and the appearance of a malignancy in the irradiated area. We report a case of carcinoma of the thyroid and esophagus following prior neck irradiation for thyroid mass.
Carcinoma, Squamous Cell/*etiology ; Esophageal Neoplasms/*etiology ; Female ; Humans ; Middle Aged ; Neck/*radiation effects ; *Neoplasms, Radiation-Induced ; Thyroid Neoplasms/*etiology

OBJECTIVETo study the impact of different planning target volume (PTV) margin settings on surface and superficial dose distribution and explore the resolution of high superficial dose when the target area is close to the surface during head and neck intensity-modulated radiotherapy (IMRT).

METHODSA typical superficial target volume was designed in an circular neck phantom. Two experimental inverse IMRT plans were conducted with 8MV X ray, and in plan A, the superficial side of PTV margin ranged from 0 to 5 mm, while other side margins were 5 mm; in plan B, an suppositional machine dosimetry data for IMRT optimization was established in which the build-up dose was eliminated, and this machine data was used to optimize the inverse IMRT plan followed by recalculation of the planned dose distribution with the actual clinical machine dosimetry data. The variation of the surface and superficial dose resulting from set-up error and the dose distribution to CTV were compared. The adequate PTV margin was analyzed when the CTV approached the surface.

RESULTSIn plan A, the high dose greater than the prescribed dose was found in the surface and superficial region when the superficial sparing distance was between the surface and PTV d<3 mm, and the 3 mm set-up margin increased this superficial dose remarkably. Reducing the superficial side of PTV margin lowered the high superficial dose effectively and allowed maintenance of the prescribed dose to the CTV. To avoid reduction of the dose to the CTV to below 95% of the prescribed dose, the superficial side of PTV margin should be greater than 1 mm. Plan B effectively lowered the surface doses and maintained the prescribed dose to the CTV.

CONCLUSIONSWith appropriate techniques for optimizing inverse IMRT, more homogeneous superficial dose can be achieved.

Computer Simulation ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Radiation Injuries ; prevention & control ; Radiation Protection ; methods ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Intensity-Modulated ; methods ; standards ; Skin ; radiation effects

OBJECTIVETo study the radiosensitizing effect of resveratrol on human hypo pharyngeal squamous cell carcinoma (FaDu) cells in nude mice.

METHODSForty-three nude mice bearing FaDu cell xenografts were randomized into control group, radiotherapy (12 Gy) group, resveratrol treatment (50 mg/kg) group, and radiotherapy plus resveratrol treatment group. After corresponding treatments, the tumor volume in the mice was measured every 3 days, and the microvessel density (MVD) in the tumor was evaluated with CD31 immunofluorescence histochemical staining.

RESULTSThe tumor volume and weight were the smallest in mice receiving radiotherapy plus resveratrol treatment (P<0.05) but comparable between those having resveratrol treatment alone and the control mice. Radiotherapy plus resveratrol treatment resulted in a tumor inhibition rate of 76.64% and a significantly decreased MVD in the tumor compared with the other 3 groups.

CONCLUSIONResveratrol can produce a radiosensitizing effect on human hypopharyngeal carcinoma in nude mice.

Animals ; Carcinoma, Squamous Cell ; drug therapy ; radiotherapy ; Cell Line, Tumor ; radiation effects ; Head and Neck Neoplasms ; drug therapy ; radiotherapy ; Humans ; Hypopharyngeal Neoplasms ; drug therapy ; radiotherapy ; Mice ; Mice, Nude ; Radiation Tolerance ; Radiation-Sensitizing Agents ; pharmacology ; Stilbenes ; pharmacology ; Transplantation, Heterologous ; Tumor Burden

Amifostine ; therapeutic use ; Animals ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Oral Health ; Radiation Injuries ; etiology ; prevention & control ; therapy ; Radiation-Protective Agents ; therapeutic use ; Radiotherapy ; adverse effects ; Radiotherapy, Conformal ; Salivary Glands ; radiation effects ; Salivation ; radiation effects ; Submandibular Gland ; surgery ; transplantation ; Xerostomia ; etiology ; prevention & control ; therapy

To evaluate radiation effect on the hematopoietic system, we analyzed 44 patients who were treated with conventionally fractionated radiation therapy (RT) at Chonbuk National University Hospital. According to the treatment sites, we classified them into three groups: group I as head and neck, group II as thorax, and group III as pelvis. White blood cell, lymphocyte, platelet and hemoglobin were checked before and during RT The results were as follow; 1. White blood cell (WBC) and lymphocyte count were declined from the first week of RT to the third week, and then slightly recovered after the third or fourth week. There was prominent decrease in lymphocyte counts than WBC. 2. Platelet counts were declined until the second week of the RT, showed slight recovery at fourth week in all groups. Hemoglobin values were slightly decreased in the first week and then recovered the level of pretreatment value, gradually. 3. Lymphocyte count were declined significantly on group III(p<0.01), WBC and platelet counts were decreased on group II but statistically not significant.
Blood Cells* ; Blood Platelets ; Head ; Hematopoietic System ; Humans ; Jeollabuk-do ; Leukocytes ; Lymphocyte Count ; Lymphocytes ; Neck ; Pelvis ; Platelet Count ; Radiation Effects* ; Thorax

Malignant tumors of the head and neck frequently require treatment with both radiotherapy and surgery. Reconstruction of the defect in previously irradiated field is a challenge to surgeon, who must produce both a functional and an esthetic result. Hyperbaric oxygen therapy(HBO) has been used in an attempt to reduce the deleterious effects of radiation. But the issue of whether prior irradiation and HBO of the recipient site of a free flap affects the result of reconstruction continues to generate controversy. So, the effects of irradiation and hypergbaric oxygen therapy on microvascular anastomosis was evaluated in an experimental study in femoral vessels of rats. The experimental groups were divided into 3 groups, contorol group, irradiation group, and irradiation and HBO group. Preoperative irradiation was delivered in the left groin field with single dose corresponding 2,000cGy and total 48 hours of HBO was given 100% oxygen at 2.4 atmosphere for 4 weeks. The femoral vessels of 60 rats were anastomosed after irradiation and HBO treatment. Three days, 1 week, 2 weeks and 4 weeks after surgery, the femoral vessels were evaluated for patency and histopathologic changes. There was no notable effect of irradiation on patency of femoral vessels in rats and the radiation effects were obvious on histological examination which showed the sloughing of the endothelial cells, subintimal hyperplasia and fibrosis on the media and adventitia of femoral arteries. The histologic changes of the femoral veins were mild and not typical. But the effects of hyperbaric oxygen therapy after irradiation was seen not marked difference in irradiation group.
Adventitia ; Animals ; Atmosphere ; Endothelial Cells ; Femoral Artery ; Femoral Vein ; Fibrosis ; Free Tissue Flaps ; Groin ; Head ; Hyperbaric Oxygenation* ; Hyperplasia ; Neck ; Oxygen ; Radiation Effects ; Radiotherapy ; Rats

BACKGROUNDElective radiation of lower neck is controversial for nasopharyngeal carcinoma (NPC) without lymph node metastasis (N0 disease). Tumor volume is an important prognostic indicator. The objective of this study is to explore the potential impact of tumor volume on the indication of the lower neck irradiation for N0-NPC, by a qualitative evaluation of the relationship between tumor volume and nodal metastasis.

METHODSMagnetic resonance (MR) images of 99 consecutive patients with NPC who underwent treatment were retrospectively reviewed. Primary tumor volumes of NPC were semi-automatically measured, nodal metastases were N-classified and neck level involvements were examined. Distributions of tumor volumes among N-category-based groups and distributions of N-categories among tumor volume-based groups were analyzed, respectively.

RESULTSThe numbers of patients with N0 to N3 disease were 12, 39, 32, and 16, respectively. The volumes of primary tumor were from 3.3 to 89.6 ml, with a median of 17.1 ml. For patients with nodal metastasis, tumor volume did not increase significantly with the advancing of N-category (P > 0.05). No significant difference was found for the distribution of N1, N2, and N3 categories among tumor volume-based groups (P > 0.05). Nevertheless patients with nodal metastasis had significantly larger tumor volumes than those without metastasis (P < 0.05). Patients with larger tumor volumes were associated with an increased incidence of nodal metastasis.

CONCLUSIONSCertain positive correlations existed between tumor volume and the presence of nodal metastasis. The tumor volume (>10 ml) is a potential indicator for the lower neck irradiation for N0-NPC.

Adolescent ; Adult ; Aged ; Carcinoma ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; pathology ; radiotherapy ; Neck ; radiation effects ; Retrospective Studies ; Tumor Burden

OBJECTIVETo study the radiosensitizing effect of resveratrol on hypopharyngeal carcinoma cell line FADU in vitro.

METHODSHypopharyngeal carcinoma cell line FADU was cultured in in vitro DMEM. Its inhibition on cell proliferation was detected using cytotoxicity test (MTT assay). The cell survival curve was drawn using clone formation to obtain sensitive enhancement ratio (SER). Changes of the cell cycle and cell apoptosis were analyzed using flow cytometry (FCM).

RESULTSResults of MTT showed the inhibition of resveratrol on FADU cells increased along with its concentrations (P < 0.05). Results of clone formation indicated the surviving fraction at 2 Gy (SF2) was 0.717 ± 0.062 in the irradiation group, and 0.426 ± 0.035 in the resveratrol plus irradiation group (with SER ranged 1.684 ± 0.178) with statistical difference (P = 0.007). Results of FCM showed that after radiation of 4 Gy radiation, cells at G2/M phase arrest increased, but cells at G1 decreased. After radiation of resveratrol for 24 h, cells at G1 decreased, but cells at G2/M phase and S phase arrest increased. When 4 Gy radiation combined resveratrol was used, cells at G2/M phase arrest significantly increased, but cells at G1 significantly decreased. The apoptosis rate was 1.94% ± 1.65% in the control group, 4.56% ± 0.92% in the irradiation group, 2.03% ± 1.46% in the resveratrol group, and 23.11% ± 7.22% in the resveratrol plus irradiation group. There was statistical difference between the resveratrol plus irradiation group and the rest 3 groups (P < 0.05).

CONCLUSIONResveratrol could enhance the radiosensitivity of hypopharyngeal carcinoma FADU cells in vitro possibly by inducing cell apoptosis and causing changes in the cell cycle distribution.

Apoptosis ; Carcinoma, Squamous Cell ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; Cell Survival ; Head and Neck Neoplasms ; Humans ; Hypopharyngeal Neoplasms ; drug therapy ; Radiation Tolerance ; Radiation-Sensitizing Agents ; therapeutic use ; Stilbenes ; therapeutic use

Differentiated thyroid cancer can be effectively treated with high-dose 131I and the other head and neck cancer can also be effectively treated with extra-radiotherapy, but these treatments often result in a reduction in salivary gland function, causing xerostomia. Collectively, these effects can lead to severe secondary complications, including difficulty in speaking and swallowing, decreasing appetite even affecting nutrition and sleep. Amifostine, an analog of cysteamine, is a phosphorlyated aminothiol prodrug and its active metabolite, WR-1065 etc, can selectively protect normal tissues from the cytotoxic effects of drugs and/or radiation while preserve antitumor effects. Many studies have demonstrated that amifostine protects normal tissues from both acute and late extra-radiation damage without protecting the tumor. It has been approved by FDA to be used for protecting the salivary gland from xerostomia caused by radiotherapy. It has also show protecting effects on intra-radiotherapy, but there are many problems waiting for study.
Amifostine ; adverse effects ; therapeutic use ; Animals ; Clinical Trials as Topic ; Clinical Trials, Phase II as Topic ; Clinical Trials, Phase III as Topic ; Cytoprotection ; Head and Neck Neoplasms ; drug therapy ; radiotherapy ; Humans ; Rabbits ; Radiation Injuries ; prevention & control ; Radiation-Protective Agents ; pharmacology