Palliative Chemotherapy and Targeted Therapy for Recurrent and Metastatic Nasopharyngeal Carcinoma: Reminiscences and the Future

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Inverse planning in three-dimensional conformal and intensity-modulated radiotherapy of mid-thoracic oesophageal cancer

The aim of this study is to demonstrate the use of inverse planning in three-dimensional conformal radiation therapy (3DCRT) of oesophageal cancer patients and to evaluate its dosimetric results by comparing them with forward planning of 3DCRT and inverse planning of intensity-modulated radiotherapy (IMRT). For each of the 15 oesophageal cancer patients in this study, the forward 3DCRT, inverse 3DCRT and inverse IMRT plans were produced using the FOCUS treatment planning system. The dosimetric results and the planner's time associated with each of the treatment plans were recorded for comparison. The inverse 3DCRT plans showed similar dosimetric results to the forward plans in the planning target volume (PTV) and organs at risk (OARs). However, they were inferior to that of the IMRT plans in terms of tumour control probability and target dose conformity. Furthermore, the inverse 3DCRT plans were less effective in reducing the percentage lung volume receiving a dose below 25 Gy when compared with the IMRT plans. The inverse 3DCRT plans delivered a similar heart dose as in the forward plans, but higher dose than the IMRT plans. The inverse 3DCRT plans significantly reduced the operator's time by 2.5 fold relative to the forward plans. In conclusion, inverse planning for 3DCRT is a reasonable alternative to the forward planning for oesophageal cancer patients with reduction of the operator's time. However, IMRT has the better potential to allow further dose escalation and improvement of tumour control. © 2004 The British Institute of Radiology.link_to_OA_fulltex

Five-year update on a randomized factorial study on concurrent and adjuvant chemotherapy for advanced nasopharyngeal carcinoma

PURPOSE/OBJECTIVE(s): To update the results of a randomized factorial trial studying the role of concurrent chemoradiation (CRT) and adjuvant chemotherapy (AC) for advanced nasopharygngeal carcinoma (NPC) …published_or_final_versio

Evaluation of radiation-induced changes to parotid glands following conventional radiotherapy in patients with nasopharygneal carcinoma

Objectives: Xerostomia is a common post-radiotherapy (post-RT) complication in nasopharyngeal carcinoma (NPC) patients. This study evaluated the relation of post-RT parotid gland changes with the dose received. Methods: Data from 18 NPC patients treated by radiotherapy between 1997 and 2001 were collected. Parotid gland volumes were measured and compared between their pre-RT and post-RT CT images; both sets of CT were conducted with the same scanning protocol. Doppler ultrasound was used to assess the haemodynamic condition of the glands after radiotherapy. Doppler ultrasound results were compared against 18 agematched normal participants. A questionnaire was used to evaluate the patients'comments of xerostomia condition. Radiotherapy treatment plans of the participants were retrieved from the Eclipse treatment planning system from which the radiation doses delivered to the parotid glands were estimated. The correlations of parotid gland doses and the post-RT changes were evaluated. Results: The post-RT parotid glands were significantly smaller (p<0.001) than the pre-RT ones. They also demonstrated lower vascular velocity, resistive and pulsatility indices (p<0.05) than normal participants. The degree of volume shrinkage and subjective severity of xerostomia demonstrated dose dependence, but such dependence was not definite in the haemodynamic changes. Conclusion: It was possible to predict the gland volume change and subjective severity of xerostomia based on the dose to the parotid glands for NPC patients. However, such prediction was not effective for the vascular changes. The damage to the gland was long lasting and had significant effects on the patients' quality of life. © 2011 The British Institute of Radiology.link_to_subscribed_fulltex

Association of XRCC1 and XRCC3 gene haplotypes with the development of radiation-induced fibrosis in patients with nasopharyngeal carcinoma

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Clinical Correlates of Health Preference and Generic Health-related Quality of Life in Patients with Colorectal Neoplasms

Background: The aims of the study were to assess the health preference and health-related quality of life (HRQOL) in patients with colorectal neoplasms (CRN), and to determine the clinical correlates that significantly influence the HRQOL of patients. Methods: Five hundred and fifty-four CRN patients, inclusive of colorectal polyp or cancer, who attended the colorectal specialist outpatient clinic at Queen Mary Hospital in Hong Kong between October 2009 and July 2010, were included. Patients were interviewed with questionnaires on socio-demographic characteristics, and generic and health preference measures of HRQOL using the SF-12 and SF-6D Health Surveys, respectively. Clinical information on stage of disease at diagnosis, time since diagnosis, primary tumour site was extracted from electronic case record. Mean HRQOL and health preference scores of CRN patients were compared with age-sex matched controls from the Chinese general population using independent t-test. Multiple linear regression analyses were conducted to explore the associations of clinical characteristics with HRQOL measures with the adjustment of socio-demographic characteristics. Results: Cross-sectional data of 515 eligible patients responded to the whole questionnaires were included in outcome analysis. In comparison with age-sex matched normative values, CRN patients reported comparable physical-related HRQOL but better mental-related HRQOL. Amongst CRN patients, time since diagnosis was positively associated with health preference score whilst patients with rectal neoplasms had lower health preference and physical-related HRQOL scores than those with sigmoid neoplasms. Health preference and HRQOL scores were significantly lower in patients with stage IV colorectal cancer than those with other less severe stages, indicating that progressive decline from low-risk polyp to stage IV colorectal cancer was observed in HRQOL scores. Conclusion: In CRN patients, a more advanced stage of disease was associated with worse HRQOL scores. Despite potentially adverse effect of disease on physical-related HRQOL, the mental-related HRQOL of CRN patients were better than that of Chinese general population. © 2013 Wong et al.published_or_final_versio

Salivary Anionic Changes after Radiotherapy for Nasopharyngeal Carcinoma: A 1-Year Prospective Study

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Radiation recall after capecitabine in a patient with recurrent nasopharyngeal carcinoma: a case report

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Evaluation of radiation dose and image quality for the Varian cone beam computed tomography system

Purpose: To compare the image quality and dosimetry on the Varian cone beam computed tomography (CBCT) system between software Version 1.4.13 and Version 1.4.11 (referred to as "new" and "old" protocols, respectively, in the following text). This study investigated organ absorbed dose, total effective dose, and image quality of the CBCT system for the head-and-neck and pelvic regions. Methods and Materials: A calibrated Farmer chamber and two standard cylindrical Perspex CT dosimetry phantoms with diameter of 16 cm (head phantom) and 32 cm (body phantom) were used to measure the weighted cone-beam computed tomography dose index (CBCTDIw) of the Varian CBCT system. The absorbed dose of different organs was measured in a female anthropomorphic phantom with thermoluminescent dosimeters (TLD) and the total effective dose was estimated according to International Commission on Radiological Protection (ICRP) Publication 103. The dose measurement and image quality were studied for head-and-neck and pelvic regions, and comparison was made between the new and old protocols. Results: The values of the new CBCTDIw head-and-neck and pelvic protocols were 36.6 and 29.4 mGy, respectively. The total effective doses from the new head-and-neck and pelvic protocols were 1.7 and 8.2 mSv, respectively. The absorbed doses of lens for the new 200° and old 360° head-and-neck protocols were 3.8 and 59.4 mGy, respectively. The additional secondary cancer risk from daily CBCT might be up to 2.8%. Conclusions: The new Varian CBCT provided volumetric information for image guidance with acceptable image quality and lower radiation dose. This imaging tool gave a better standard for patient daily setup verification. © 2011 Elsevier Inc.postprin