The radiobiological effect of using Acuros XB vs anisotropic analytical algorithm on hepatocellular carcinoma stereotactic body radiation therapy.

The purpose of this work was to study the radiobiological effect of using Acuros XB (AXB) vs Analytic Anisotropic Algorithm (AAA) on hepatocellular carcinoma (HCC) stereotactic body radiation therapy (SBRT). Seventy SBRT volumetric modulated arc therapy (VMAT) plans for HCC were calculated using AAA and AXB respectively with the same treatment parameters. Published tumor control probability (TCP) and normal tissue complication probability (NTCP) models were used to quantify the effect of dosimetric difference between AAA and AXB on TCP, NTCP and uncomplicated tumor control probability (UTCP).

3D T1-weighted turbo spin echo contrast-enhanced MRI at 1.5 T for frameless brain metastases radiotherapy.

Purpose: Performance of 3D-T1W-TSE has been proven superior to 3D-MP-GRE at 3 T on brain metastases (BM) contrast-enhanced (CE) MRI. However, its performance at 1.5 T is largely unknown and sparsely reported.

Analysis of Hepatocellular Carcinoma Stereotactic Body Radiation Therapy Dose Prescription Method Using Uncomplicated Tumor Control Probability Model.

Purpose: This work was to establish an uncomplicated tumor control probability (UTCP) model using hepatocellular carcinoma (HCC) stereotactic body radiation therapy (SBRT) clinical data in our institution. The model was then used to analyze the current dose prescription method and to seek the opportunity for improvement.

Methods And Materials: A tumor control probability (TCP) model was generated based on local clinical data using the maximum likelihood method.

Durability of the parotid-sparing effect of intensity-modulated radiotherapy (IMRT) in early stage nasopharyngeal carcinoma: A 15-year follow-up of a randomized prospective study of IMRT versus two-dimensional radiotherapy.

Background: The durability of improved xerostomia with intensity-modulated radiotherapy (IMRT) in patients with early stage nasopharyngeal carcinoma (NPC) is uncertain. We conducted a long-term prospective assessment of participants treated with IMRT or two-dimensional radiotherapy (2DRT) in a prior randomized study.

Methods: Parent study participants (IMRT, n = 28; 2DRT, n = 28) who were free of second malignancy or recurrence were eligible.

Prospective, Multicenter, Phase 2 Trial of Induction Chemotherapy Followed by Bio-Chemoradiotherapy for Locally Advanced Recurrent Nasopharyngeal Carcinoma.

Purpose: To evaluate, in a phase 2 study, whether induction docetaxel, cisplatin, and fluorouracil (TPF) followed by weekly docetaxel and cetuximab in concurrence with intensity modulated radiation therapy can improve the treatment outcome for patients with advanced locally recurrent nasopharyngeal carcinoma (rNPC).

Methods And Materials: Thirty-three patients with rNPC (T3-T4, N0-N1, M0) were recruited. Of these, 19 patients (57.

Prediction of distant metastases from nasopharyngeal carcinoma: Improved diagnostic performance of MRI using nodal volume in N1 and N2 stage disease.

Purpose: To determine if the magnetic resonance imaging (MRI) of the head and neck can predict distant metastases (DM) from nasopharyngeal carcinoma (NPC).

Methods And Materials: MRI examinations of 763 NPC patients were assessed for primary tumour stage (T), nodal stage (N), primary tumour volume (PTV) and total nodal volume (NV). The association between MRI and clinical parameters were examined in DM+ and DM- patients using logistic regression and for distant metastases free survival (DMFS) using cox regression.

Pattern of recurrence and factors associated with cerebrospinal fluid dissemination of glioblastoma in Chinese patients.

Background: Pattern of recurrence of glioblastoma (GBM) seems to have undergone some shifts from distant metastasis as a rarity to a higher proportion, including disease disseminated via cerebrospinal fluid (CSF) pathway. There is still no report on the pattern of recurrence for Chinese population. Here, we evaluated the pattern of recurrence of GBM in Chinese patients along with factors that could affect the distribution of recurrence.

Diffusion-weighted imaging of nasopharyngeal carcinoma to predict distant metastases.

Our study aimed to identify diffusion-weighted imaging (DWI) parameters obtained from primary nasopharyngeal carcinoma (NPC) at initial presentation, that can predict patients at risk of distant metastases. One hundred and sixty-four patients underwent pretreatment magnetic resonance imaging and DWI. The apparent diffusion coefficient (ADC), ADC, and ADC were obtained by histogram analysis.

A new prognostic histopathologic classification of nasopharyngeal carcinoma.

Background: The current World Health Organization (WHO) classification of nasopharyngeal carcinoma (NPC) conveys little prognostic information. This study aimed to propose an NPC histopathologic classification that can potentially be used to predict prognosis and treatment response.

Methods: We initially developed a histopathologic classification based on the morphologic traits and cell differentiation of tumors of 2716 NPC patients who were identified at Sun Yat-sen University Cancer Center (SYSUCC) (training cohort).

Clinical utility of plasma Epstein-Barr virus DNA and ERCC1 single nucleotide polymorphism in nasopharyngeal carcinoma.

Background: Single nucleotide polymorphism (SNP) of the excision repair cross-complementing group 1 (ERCC1) gene has been linked with sensitivity to platinum and radiation. The authors hypothesized that the ERCC1 genotype for the SNPs cytosine-to-thymine substitution at codon 118 (C118T) and cytosine-to-adenine substitution at codon 8092 (C8092A) is prognostic in patients with nasopharyngeal carcinoma (NPC) who receive either radiotherapy (RT) or cisplatin plus RT.

Methods: The authors tested their hypothesis using biomarker screening samples from the Hong Kong NPC Study Group 0502 trial, which was a prospective, multicenter clinical trial that used post-RT plasma Epstein-Bar virus (EBV) DNA (pEBV) levels to screen patients with high-risk NPC for adjuvant chemotherapy.

Non-surgical treatment of lung cancer: personalised stereotactic ablative radiotherapy.

Stereotactic ablative radiotherapy has emerged as a standard treatment for medically inoperable stage I non-small-cell lung cancer and selected cases of lung metastasis. Techniques to freeze or limit tumour movement during treatment and image-guided radiation delivery are integral to a successful stereotactic ablative treatment without overdose of surrounding normal structures. In this article, the practice in a local oncology institution will be used to illustrate the concept of personalised stereotactic ablative radiotherapy.

Current controversies in radiotherapy for nasopharyngeal carcinoma (NPC).

Radiotherapy has a good track record in the treatment of NPC, yet the late toxicity profile and local failure rate for locally advanced disease remain a concern. Modern RT techniques incorporating IMRT and IGRT have widened our potential in treating NPC more effectively, and shall be regarded as the standard of care. Out of the various dose fractionation regimens in IMRT, 70 Gy in 35 fractions or the mini-SIB proves to be safe in combination with chemotherapy, but any further attempt of dose escalation must be tried out with extreme caution to avoid severe toxicities.

Validation of the modified radiosurgery-based arteriovenous malformation score in a linear accelerator radiosurgery experience in Hong Kong.

The modified radiosurgery-based arteriovenous malformation (AVM) score (modified AVM score or Pollock-Flickinger AVM score [PFAS]) is a simplified grading system developed to predict outcome after gamma knife radiosurgery for cerebral AVM. The purpose of this study was to test the PFAS in a cohort of patients managed with linear accelerator (LINAC) radiosurgery. We analyzed 70 consecutive patients with cerebral AVM treated with LINAC radiosurgery in Hong Kong.

Pseudoprogression of malignant glioma in Chinese patients receiving concomitant chemoradiotherapy.

Objectives: To investigate the frequency of pseudoprogression of glioblastoma in Chinese patients receiving concomitant chemoradiotherapy and investigate its association with pseudoprogression and tumour molecular marker O(6)-methylguanine-DNA methyltransferase promoter methylation status.

Design: Case series with internal comparisons.

Setting: University teaching hospital, Hong Kong.

Management outcome of NPC-related and non-NPC-related brain abscess in Hong Kong.

Objectives: (1) To review the patient profile, management outcome and prognostic factors of brain abscess; (2) To compare the neurological outcome of nasopharyngeal carcinoma (NPC)-related brain abscess with non-NPC related brain abscess.

Method: Retrospective review of consecutive patients diagnosed (radiologically and/or microbiologically) with brain abscess in a regional neurosurgical center in Hong Kong over a nine year period.

Results: Fifty-four patients were recruited into this study.

Surgical salvage nasopharyngectomy for recurrent nasopharyngeal carcinoma: a multivariate analysis of prognostic factors.

Background: The purpose of this study was to identify independent prognostic factors that influenced local relapse-free survival (LRFS) and overall survival (OS) of patients who underwent salvage surgery for residual or recurrent nasopharyngeal carcinoma (NPC).

Methods: Ninety-seven patients who had been treated with radiotherapy or chemoradiotherapy for NPC underwent a nasopharyngectomy for a residual or recurrent local tumor between November 1987 and June 2007. The subsequent minimum follow-up was 2 years.

Association of molecular marker O(6)Methylguanine DNA methyltransferase and concomitant chemoradiotherapy with survival in Southern Chinese glioblastoma patients.

Objectives: (1) To compare the survival of concomitant chemotherapy and radiotherapy with radiotherapy alone in Chinese patients with primary glioblastoma. (2) To determine the methylation status of O(6)Methylguanine DNA methyltransferase in Chinese primary glioblastoma, and to assess the prognostic value of O(6)Methylguanine DNA methyltransferase methylation status in such patients.

Design: Retrospective correlative analysis.

Dosimetric comparison of intensity-modulated stereotactic radiotherapy with other stereotactic techniques for locally recurrent nasopharyngeal carcinoma.

Purpose: Locally recurrent nasopharyngeal carcinoma (NPC) patients can be salvaged by reirradiation with a substantial degree of radiation-related complications. Stereotactic radiotherapy (SRT) is widely used in this regard because of its rapid dose falloff and high geometric precision. The aim of this study was to examine whether the newly developed intensity-modulated stereotactic radiotherapy (IMSRT) has any dosimetric advantages over three other stereotactic techniques, including circular arc (CARC), static conformal beam (SmMLC), and dynamic conformal arc (mARC), in treating locally recurrent NPC.

Accelerated fractionation radiotherapy and late intensification with 2 intra-arterial cisplatin infusions for locally advanced head and neck squamous cell carcinoma.

Background: This study was established to determine the maximum tolerated dose of intra-arterial cisplatin (IAC) concurrent with accelerated fractionation radiotherapy for locally advanced head and neck squamous cell carcinoma (HNSCC).

Methods: We conducted a phase I study. Treatment consisted of 70 Gy/35 fractions/5.

Use of Onyx (a patented ethylene-vinyl alcohol copolymer formulation) embolisation of cerebral arteriovenous malformations in Hong Kong: initial experience.

Objective: To review the experience with Onyx embolisation of cerebral arteriovenous malformation.

Design: Prospective study.

Setting: A regional neurosurgical centre in Hong Kong.

Nasopharyngectomy: does the approach to the nasopharynx influence survival?

Objective: To investigate whether the approach used to the nasopharynx to perform a salvage nasopharyngectomy for recurrent or residual nasopharyngeal carcinoma influences survival.

Study Design: A retrospective case series.

Subjects And Methods: Eighty patients underwent a nasopharyngectomy via a transpalatal, maxillary swing, or midfacial degloving approach.

Nasopharyngectomy and surgical margin status: a survival analysis.

Objective: To explore whether the margin status at surgical salvage nasopharyngectomy for local residual or recurrent nasopharyngeal carcinoma affects patient survival.

Design: Retrospective case series review.

Setting: Academic tertiary referral center.

Dosimetric comparison between 2-dimensional radiation therapy and intensity modulated radiation therapy in treatment of advanced T-stage nasopharyngeal carcinoma: to treat less or more in the planning organ-at-risk volume of the brainstem and spinal cord.

The aim of this study is to evaluate the deficiencies in target coverage and organ protection of 2-dimensional radiation therapy (2DRT) in the treatment of advanced T-stage (T3-4) nasopharyngeal carcinoma (NPC), and assess the extent of improvement that could be achieved with intensity modulated radiation therapy (IMRT), with special reference to of the dose to the planning organ-at-risk volume (PRV) of the brainstem and spinal cord. A dosimetric study was performed on 10 patients with advanced T-stage (T3-4 and N0-2) NPC. Computer tomography (CT) images of 2.

Prospective randomized study of intensity-modulated radiotherapy on salivary gland function in early-stage nasopharyngeal carcinoma patients.

Purpose: This randomized trial compared the rates of delayed xerostomia between two-dimensional radiation therapy (2DRT) and intensity-modulated radiation therapy (IMRT) in the treatment of early-stage nasopharyngeal carcinoma (NPC).

Patients And Methods: Between November 2001 and December 2003, 60 patients with T1-2bN0-1M0 NPC were randomly assigned to receive either IMRT or 2DRT. Primary end point was incidence of observer-rated severe xerostomia at 1 year after treatment based on Radiotherapy Oncology Group /European Organisation for the Research and Treatment of Cancer late radiation morbidity scoring criteria.

Nasopharyngeal cancers: which method should be used to measure these irregularly shaped tumors on cross-sectional imaging?

Purpose: To determine whether the standard techniques of measuring tumor size and change in size after treatment could be applied to the measurement of nasopharyngeal cancers, which are often irregular in shape.

Methods And Materials: The standard measurements of bidimensional (BDM) (World Health Organization criteria) and unidimensional (UDM) (Response Evaluation Criteria in Solid Tumors [RECIST] criteria), together with the maximum depth of the tumor perpendicular to the pharyngeal wall (DM), were acquired from axial magnetic resonance images of primary nasopharyngeal carcinoma in 44 patients at diagnosis and in 29 of these patients after treatment. Tumor volume measurements (VM), acquired from the summation of areas from the axial magnetic resonance images, were used as the reference standard.