Difference in normal tissue complication probability of lower cranial nerves between target volumes recommended by Radiation Therapy Oncology Group and China in intensity-modulated radiotherapy for T1-2 nasopharyngeal carcinoma / 中华放射肿瘤学杂志

Objective To investigate the difference in normal tissue complication probability (NTCP) of lower cranial nerves (LCNs) between target volumes recommended by Radiation Therapy Oncology Group (RTOG) and China in intensity-modulated radiotherapy (IMRT) for T1-2 nasopharyngeal carcinoma (NPC),and to provide the evidence of dose-volume effect for the protection of LCNs in IMRT for NPC.Methods A total of 20 patients with T1-2 NPC who were treated from 2013 to 2015 were enrolled,and LCNs were delineated on CT images.Target volume delineation and treatment plan designing were performed according to the method recommended by RTOG0225 (RTOG target volume delineation method) or the Chinese Working Committee for Clinical Staging of NPC in 2010 (Chinese target volume delineation method),and the differences in the dose to LCNs and NTCP were calculated.Results In the RTOG and Chinese methods for target volume delineation,Dmax to the left and right LCNs was 7 450±273 cGy/7294±309 cGy and 7 361± 160 cGy/7 190±395 cGy,respectively (P=0.018 and 0.042),Dmean was 6735±285 cGy/6 660±333 cGy and 6 446±429 cGy/6 299±467 cGy,respectively (both P=0.000),and the NTCP was 60％±10％/57％±13％ and 51％±15％/45％±17％,respectively (both P=0.000).Conclusions It is feasible to precisely delineate target volume with the LCNs as a routine OAR and predict NTCP in IMRT for T1-2 NPC.The NTCP of the LCNs is closely associated with target volume dose and irradiated volume.The dose to the LCNs and NTCP determined by the Chinese target volume delineation method are significantly lower than those determined by the RTOG method.

Pathological characteristics of loco-regional recurrent nasopharyngeal carcinoma / 临床与实验病理学杂志

Purpose To investigate the pathological characteristics of loco-regional recurrent nasopharyngeal carcinoma ( rNPC ) . Methods Nasopharyngeal biopsy specimens of 46 rNPCs and 63 primary NPCs were collected. HE staining, immunohistochemistry and EBV small RNAs ( EBERs) in-situ hybridization were performed. Results The over-expression rates of both p63 and CK5/6 in rNPC were significantly higher than those of primary NPCs (P=0. 005, P=0. 026), while no statistical significance of Ki-67 over-ex-pression existed between the two groups ( P=0. 387 ) . More necrotic tissues, inflammatory exudates, giant bizarre carcinoma cells, desmoplastic stroma, giant bizarre tumor cells and higher degree of squamous differentiation were found in rNPCs. The carcinoma cells of 5 rNPCs were negative for both EBERs in-situ hybridization and LMP-1 immunohistochemical staining. Conclusion The loco-re-gional rNPC has two peaks of latency interval:2~5 and 9~11 years. The loco-regional rNPC cells have higher degree of squamous differentiation with higher expression of p63 and CK5/6, as well as more invasive ability. In addition, both EBERs in-situ hybridization and LMP-1 immunostaining are negative in 10. 87% (5/46) of loco-regional rNPC.

Differences in delineation of organs at risk lead to dose uncertainties during intensity-modulated radiotherapy for nasopharynx carcinoma / 中华放射肿瘤学杂志

Objective To assess the differences in delineation of organs at risk (OAR) and dosimetry between junior and senior physicians during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) and to evaluate the role of specific training in reducing the differences.Methods Sixteen patients newly diagnosed with NPC were selected in the study.The OAR was delineated separately by three junior physicians and three senior physicians,and the geometric and dosimetric differences were assessed relative to the reference OAR.Delineation was performed again for the two OARs with the biggest difference after specific training in the two groups of physicians,and the differences were evaluated again.The difference was determined by paired t test.Results The maximum dose differences (Dmax) of OAR in the junior and senior physicians were (2.33 ± 12.06) ％ (-48.06％-137.82％) and (0.09 ± 4.72) ％ (-49.54％-42.96％),respectively (P =0.039),and the difference in the optic chiasm was the greatest ((5.85 ± 19.63) ％ ∶ (1.36 ± 4.64) ％,P =0.042).The mean dose differences (Dmean) of OAR in the junior and senior physicians were (3.10 ± 8.07)％ (-46.76％-59.76％) and (-0.93 ± 2.03) ％ (-45.54％-35.69％),respectively (P =0.021),and the difference in the parotid gland was the greatest ((13.23 ± 13.39) ％ ∶ (3.20 ± 6.71) ％,P =0.002).In the secondary delineation after training,the Dmax of the optic chiasm in the junior and senior physicians was (1.68 ± 3.34)％ and (1.50 ± 1.87) ％,respectively (P =0.841),and the difference in junior physicians was reduced significantly compared with before training ((1.68 ± 3.34) ％ ∶ (5.85 ± 19.63) ％,P =0.048) ; the Dmean of the parotid gland in the junior and senior physicians was (2.46 ± 3.06) ％ and (1.35 ± 3.00) ％,respectively (P =0.2 7 4),significantly reduced compared with before training ((2.46 ± 3.0 6) ％ ∶ (13.23 ± 13.39)％,P=0.002; (1.35 ± 3.00)％ ∶ (3.20 ± 6.71) ％,P =0.033).Conclusions The differences in delineation of OAR lead to dose uncertainties during IMRT for NPC,and specific training can improve the accuracy of delineation.

Nasopharyngeal Teratoma in an Adult: A Case Report

Nasopharyngeal teratomas are rare congenital tumors which mainly cause neonatal respiratory difficulty or feeding problems. We report an extremely rare case of nasopharyngeal teratoma in which a 34-year-old woman experienced a foreign body sensation. Simple radiographs and CT scans revealed the presence of an exophytically growing mass with a region of fatty attenuation and a well-formed tooth in the nasopharyngeal wall. The mass was surgically removed, and found at histopathology to be a mature teratoma.

Dural Tail Sign in MR Imaging of Nasopharyngeal Cancer

PURPOSE: To describe the dural tail sign in contrast-enhanced MR images of nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: MR images of 19 consecutive patients, in whom three years previously squamous cell type NPC had been pathologically proven, were reviewed for the presence or absence, location and direction of the dural tail sign and the relationship between this sign and the skull base invasion. Histopathologic specimens obtained in two patients were also described. RESULTS: In ten patients (53%), there was bony invasion of the skull base; in seven of these (37%), dural tails were found. In seven, this tail extended along the floor of the middle cranial fossa; in 5, along the petro-clivus, and in 4, along the tentorium. In all these cases, the adjacent skull base was involved. Histopathologic examination in two patients with dural tails in the middle cranial fossa revealed fibrosis and hyper-vascularity of the dura mater without evidence of tumor cell infiltration. CONCLUSION: The dural tail sign appears to be not infrequent in patients with advanced NPC. The dural tail may be a good indicator of intracranial tumor spread.

Fluoroscopy-Guided Transnasal Biopsy of Nasopharyngeal Carcinoma Using a Flexible Bronchoscopic Biopsy Forcep

PURPOSE: Otolaryngoscopic biopsy of nasopharyngeal carcinoma is a generalized method which may be associatedwith inadequate sampling of tissue and patient discomfort. So, we tried fluoroscopy-guided transnasal biopsy using bronchoscopic biopsy forcep and evaluated its safety and efficacy. MATERIALS AND METHODS: Prospectively weperformed fluoroscopy-guided transnasal biopsy in 11 patients who were radiographically suspected of nasopharyngeal carcinoma. The posterior wall of the nasopharynx was coated with barium sulfate under fluoroscopy. A flexible bronchoscopic biopsy forcep with a steerable guiding catheter which was used in removal of intrahepaticduct stones was inserted through the nare. After localization of the tip of the biopsy forcep at tumor site with fluoroscopy, a tissue specimen was obtained. We also tried CT guided biopsy in initial 2 cases. Each patient hadotolaryngoscopic biopsy to compare the biopsy result and patient discomfort. RESULTS: We could have sufficientamount of tissue for pathological evaluation in 10 of 11 patients by the first pass with the fluoroscopic technique. Contrarily, otolaryngoscopic biopsy was successful in 7 of 11 patients on single passage. Additionally, 2 patients had complaint in our method comparing with 9 patients in otolaryngoscopic biopsy. CONCLUSION: Fluoroscopy-guided transnasal biopsy of nasopharyngeal carcinoma using the bronchoscopic biopsy forcep is safe and accurate. It can be a appropriate method competing otolaryngoscopic biopsy.