Comparing the meanings of living with advanced breast cancer between women resilient to distress and women with persistent distress: a qualitative study

BACKGROUND

Most women with advanced breast cancer (ABC) show little distress, but about one in ten show persistent distress over time. It remains unclear if meanings ascribed by patients to ABC differentiate these distress trajectories.

STUDY AIMS

This qualitative study (a) compared illness meanings of ABC between women with persistent psychological distress and those with low/transient distress, and (b) examined how illness meanings might influence coping strategies.

METHODS

The sample was drawn from a prior quantitative study exploring psychological distress trajectories following ABC diagnosis. Overall, 42 Cantonese- or Mandarin-speaking Chinese women diagnosed with locally advanced or metastatic ABC were recruited based on their distress trajectory status (low-stable, transient, or persistent distress). Interviews were recorded, transcribed, and analyzed following grounded theory approach using simultaneous analysis.

RESULTS

Women with persistent distress viewed their diagnosis as another blow in life, the illness was global, permeating every aspect of their life. Maladaptive rumination and thought suppression were common responses to illness demands. These women had poor social support. A sense of demoralization stood out in their narratives. In contrast, women with transient/low-stable distress encapsulated the illness, with minimum impacts of their life. They did not evidence dysfunctional repetitive thoughts. Living in a supportive environment, they were able to accept and/or live in the present-moment.

CONCLUSIONS

Rumination, thought suppression, social constraints, and pre-existing exposure to life stress may be potential risks for chronic distress in response to advanced breast cancer. Persistent and transient distress responses to cancer may have different underpinnings. Copyright © 2016 John Wiley & Sons, Ltd.

Is it feasible to discuss an advance directive with a Chinese patient with advanced malignancy? A prospective cohort study

OBJECTIVES

Advance directives have been implemented for years in western countries, but the concept is new to Asian cultures. According to traditional Chinese culture, family members usually play a decisive role in a patient's treatment plan. Thus it may be hard to implement an advance directive despite its importance to the treatment of patients. The objectives of this study were to assess the feasibility of advance directive engagement and to explore significant contributing factors to achieving such a goal.

DESIGN

Prospective cohort study.

SETTING

Palliative Care Unit of Clinical Oncology, Tuen Mun Hospital, Hong Kong.

PATIENTS

The subjects of the investigation were adult patients diagnosed to have advanced malignancy and newly referred to the hospice service from 24 April 2009 to 30 July 2009. Data were collected from nursing assessment forms, locally designed advance directive forms, a checklist completed by oncologists, and details available in the electronic hospital record.

RESULTS

Of the 191 eligible patients, 120 (63%) had the advance directive, whereas 71 (37%) did not. In the Cox regression model, the patient having insight of a poor prognosis was the most significant factor facilitating advance directive engagement (P=0.001). Any family objection in the discussion of advance directives was also an important factor, though it did not reach statistical significance (P=0.082). Other factors like age, gender, education, religion, financial status, living environment, understanding the diagnosis, bereavement experience, type of cancer, nature of illness, courses of chemotherapy or radiotherapy received, main caregiver, in-house supporter, nurse-led clinic attendance, clinical psychologist consultation, and in-patient hospice nurse coordinator interview were all statistically insignificant.

CONCLUSIONS

Our study demonstrated that it was feasible to discuss an advance directive with Chinese patients with advanced malignancy. When patients have insight about their poor prognosis and family members have no objection, it may be appropriate to discuss an advance directive.

Randomized trial of radiotherapy plus concurrent-adjuvant chemotherapy vs radiotherapy alone for regionally advanced nasopharyngeal carcinoma

BACKGROUND

Current practice of adding concurrent-adjuvant chemotherapy to radiotherapy (CRT) for treating advanced nasopharyngeal carcinoma is based on the Intergroup-0099 Study published in 1998. However, the outcome for the radiotherapy-alone (RT) group in that trial was substantially poorer than those in other trials, and there were no data on late toxicities. Verification of the long-term therapeutic index of this regimen is needed.

METHODS

Patients with nonkeratinizing nasopharyngeal carcinoma staged T1-4N2-3M0 were randomly assigned to RT (176 patients) or to CRT (172 patients) using cisplatin (100 mg/m(2)) every 3 weeks for three cycles in concurrence with radiotherapy, followed by cisplatin (80 mg/m(2)) plus fluorouracil (1000 mg per m(2) per day for 4 days) every 4 weeks for three cycles. Primary endpoints included overall failure-free rate (FFR) (the time to first failure at any site) and progression-free survival. Secondary endpoints included overall survival, locoregional FFR, distant FFR, and acute and late toxicity rates. All statistical tests were two-sided.

RESULTS

The two treatment groups were well balanced in all patient characteristics, tumor factors, and radiotherapy parameters. Adding chemotherapy statistically significantly improved the 5-year FFR (CRT vs RT: 67% vs 55%; P = .014) and 5-year progression-free survival (CRT vs RT: 62% vs 53%; P = .035). Cumulative incidence of acute toxicity increased with chemotherapy by 30% (CRT vs RT: 83% vs 53%; P < .001), but the 5-year late toxicity rate did not increase statistically significantly (CRT vs RT: 30% vs 24%; P = .30). Deaths because of disease progression were reduced statistically significantly by 14% (CRT vs RT: 38% vs 24%; P = .008), but 5-year overall survival was similar (CRT vs RT: 68% vs 64%; P = .22; hazard ratio of CRT = 0.81, 95% confidence interval = 0.58 to 1.13) because deaths due to toxicity or incidental causes increased by 7% (CRT vs RT: 1.7% vs 0, and 8.1% vs 3.4%, respectively; P = .015).

CONCLUSIONS

Adding concurrent-adjuvant chemotherapy statistically significantly reduced failure and cancer-specific deaths when compared with radiotherapy alone. Although there was no statistically significant increase in major late toxicity, increase in noncancer deaths narrowed the resultant gain in overall survival.

The implementation of an end-of-life integrated care pathway in a Chinese population

The integrated care pathway is used in end-of-life care to improve quality of care; the Liverpool Care Pathway (LCP) has been used in Europe and North America. Tuen Mun Hospital is a regional hospital in Hong Kong, China. The End-of-life Care Pathway (ECP) based on the concepts used in the Liverpool Care Pathway, was developed, with modification to suit the local condition. Criteria for entry onto the ECP were that the multidisciplinary team agreed the patient was dying, and was at least two of the following: bedbound; semi-comatose; only able to take sips of fluid; no longer able to take tablets. The ECP template replaced all other inpatient documents. The ECP was implemented in the palliative care unit for terminal cancer patients. An audit was performed to review the result. Fifty-one Chinese patients were included in the audit with mean age 64. The median duration of ECP use was 24 hours. All patients had current medication assessed and non-essential drugs were discontinued. The audit result suggested integrated care pathway in end-of-life care could be implemented successfully in an Oriental culture. The acceptance of using the ECP as a standard clinical practice takes time and education. Appropriate template design and supervision are the keys to success.

Intercostal nerve blockade for cancer pain: effectiveness and selection of patients

OBJECTIVES

To review treatment results of intercostal nerve blockade at our centre and those reported in the literature, and to determine which patients benefit most from this procedure.

DESIGN

Retrospective study.

SETTING

Regional palliative care centre in a regional hospital in Hong Kong.

PATIENTS

Oncology patients who had intercostal nerve blockade at Tuen Mun Hospital from 1995 to 2005 were divided into three groups: (1) those who appeared not to tolerate opioids; (2) those deemed to have inadequate pain control, despite high doses of analgesics; and (3) those referred to avoid early use of high-dose opioids and tolerance.

MAIN OUTCOME MEASURES

The effectiveness and complications of intercostal nerve blockade, and the extent of benefit derived from intercostal nerve blockade in different patient groups.

RESULTS

This study found that 80% of the 25 patients noted optimal local pain control and 56% experienced reduction in analgesic use after intercostal nerve blockade. About 32% did not notice recurrence of the targeted pain till the end of their lives. None of the patients developed pneumothorax. Most benefit from intercostal nerve blocks were derived by group 2 patients, 90% of whom obtained optimal local pain control (P=0.23) and enjoyed a significant reduction in analgesics use (P=0.019), and in 40% their target pain was controlled till the end of life. Only about one third of group 3 patients had subsequent reduction in use of analgesics, mainly because they had co-existing pain other than at the target selected for treatment. Half (50%) of group 1 patients achieved optimal pain control.

CONCLUSION

Our treatment results from intercostal nerve blockade are comparable to those reported in the literature. The procedure is safe if closely monitored. Good selection of cases is important for optimising the therapeutic gain. The largest benefit is obtained in patients who have inadequate pain control after high-dose morphine.

A pre-optimised dosimetry system using a rigid applicator for intracavitary treatment of cervical carcinoma

AIMS

Tumour control and complication risk have been major concerns in the treatment of cervical carcinoma. A review of dose distribution for intracavitary treatment of cervical carcinoma revealed that modification of the Manchester dosimetry system is necessary for cases of narrow-sized vagina. A revised dosimetry system was introduced in the present study, with the objective of optimising the dose coverage for the parametrium while minimising the bladder and rectum dosage by restricting the rectal dose so as not to exceed 75% of the brachytherapy prescription dose.

MATERIALS AND METHODS

A suitable-sized applicator was selected according to the patient's anatomy. The revised system is optimised based on the fixed geometry of the applicator. The system was therefore predefined and the distribution of the treatment dose already determined before application. The revised system was applied to 135 cases, involving 540 applications. The clinical outcome in terms of local tumour control and complication rates is reported. The differences between the revised system and the Manchester system in terms of dose coverage for the parametrium and the rectum dose were compared.

RESULTS

The results showed that higher rectal and parametrial dosages were obtained with the Manchester system as compared with the revised system. Our study showed that over 50% of our patients would have received a rectal dose close to 100% of the point A dose if the Manchester system was applied, whereas it was restricted to below 75% using the revised system. Using the revised system, the significance of the parametrial dosage coverage in relation to local control was assessed: the mean dose to the rectum and the bladder as a percentage of point A was 65.7 +/- 5% (range 50-85%) and 66.4 +/- 14% (range 29-116%), respectively. The 5-year actuarial local failure-free survival rates were 90, 92.9, 86.8, 100, 69.7 and 0% for stages IB, IIA, IIB, IIIA, IIIB and IV (P < 0.0001), respectively. The 3-year actuarial complication rates (grade 3/4) for proctitis and cystitis were 1.4 and 0.5%, respectively. The dosage coverage for the parametrium was found to be significant (P = 0.029) in relation to local control for early-stage disease.

CONCLUSIONS

The favourable local tumour control and low complication rates shown by our results indicate that the revised system presents an optimal dose distribution, particularly for the application of small ovoids, whereas morbidity was reduced to a lower level without compromising local control.

Treatment results of endometrial carcinoma with positive peritoneal washing, adnexal involvement and serosal involvement

AIMS

To review the treatment results of patients with endometrial carcinoma having positive peritoneal washing (PPW), adnexal involvement, uterine serosal involvement, or all three.

MATERIALS AND METHODS

The treatment records of patients who had undergone primary surgery for endometrial cancer without distant metastasis during 1990--2001 at the Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong, were reviewed. Thirty-five patients were found to have involvement of positive PPW, adnexal involvement, uterine serosal involvement, or all three. Seven (20%) of them had gross or microscopic lymph-node metastasis. Thirty-three (94.3%) patients received adjuvant radiotherapy (28 whole-pelvic irradiation [WPI]; five abdominal radiotherapy [WART]). Two patients with solitary ovarian metastasis received chemotherapy, and one with isolated PPW also received adjuvant hormonal therapy. The median follow-up was 50.4 months (range 2.4-151.2 months). Multivariate analysis was carried out using the Cox regression proportional hazards model.

RESULTS

Among the 28 patients with clinical or pathological node-negative disease (International Federation of Gynecology and Obstetrics [FIGO] stage IIIA), only two patients with solitary ovarian metastases developed recurrence. The 5-year actuarial disease-free survival (DFS) rates for the whole group and patients without lymph-node involvement were 77.9% and 91.7%, respectively. Five out of the seven patients with lymph-node involvement developed recurrences. Univariate analysis showed that lymph-node involvement (P < 0.0001) and high-grade disease (P = 0.011) were the significant poor prognostic factors. Multivariate analysis showed that lymph-node involvement was the only significant poor prognostic factor to predict poor 5-year DFS (P = 0.0001). Only one patient (3.7%) who had received WART developed grade 4 toxicity.

CONCLUSIONS

This study showed that good treatment results could be obtained from patients with stage IIIA endometrial carcinoma without clinical or pathological lymph-node involvement after adjuvant radiotherapy, with acceptable late side-effects. The relative prognostic importance of individual IIIA involvement and the optimal adjuvant treatment remain to be determined.

Sphenoid sinus mucocoele and cranial nerve palsies in a patient with a history of nasopharyngeal carcinoma: may mimic local recurrence

We report the case history of a patient with a sphenoid sinus mucocoele detected by computed tomography and medical resonance imaging. The patient had a history of nasopharyngeal carcinoma, which was treated by radiotherapy more than 10 years previously. He presented with bilateral twelfth and sixth cranial nerve palsies. Local tumour recurrence was suspected. Further investigations showed that the cranial nerve palsies were caused by radiation damage and the sphenoid sinus mucocoele was an incidental finding. Sphenoid sinus mucocoele is a possible rare late complication of radiotherapy in patients with nasopharyngeal carcinoma.

Salvage radiation therapy for locally recurrent nasopharyngeal carcinoma

PURPOSE

To study the treatment outcome in patients with locally recurrent nasopharyngeal carcinoma (NPC) and to explore whether a combination of high-dose-rate (HDR) intracavitary brachytherapy and external beam radiation therapy (ERT) could improve the therapeutic ratio.

METHODS AND MATERIALS

Ninety-one patients with nonmetastatic locally recurrent NPC who were treated with curative intent during the years 1990-1999 were retrospectively analyzed. Eighty-two patients had histologically proven carcinoma. The remaining 9 had clinical and imaging features suggestive of local recurrence. The Ho's T-stage distribution at recurrence (rT) was as follows: rT1-37, rT2-14, rT3-40. Total equivalent dose (TED) was calculated by the linear-quadratic formula without a time factor correction. For those treated by combined-modality treatment (CMT), the TED was taken as the summation of the equivalent dose by ERT and the absolute dose delivered to floor of the sphenoid by brachytherapy. Eight patients were treated solely with brachytherapy, all receiving 24-45 Gy in 3-10 sessions. Forty-one patients were treated with ERT alone receiving a median TED of 57.3 Gy (range, 49.8-62.5 Gy). Forty-two patients were treated by CMT with a median equivalent dose of 50 Gy (range, 40-60 Gy) given by ERT and 14.8 Gy by brachytherapy (range, 3-29.6 Gy). Multivariate analyses were performed using the Cox regression proportional hazards model.

RESULTS

The 5-year actuarial overall survival rate, disease specific survival rate and local failure-free survival (LFFS) rate for the whole group were 30%, 33. 3% and 37.8%, respectively. The 3-year LFFS rates of rT1, rT2, and rT3 diseases were 64%, 61.5%, and 18.4%, respectively (p = 0.001). Of the 8 patients treated with brachytherapy alone, 4 failed locally. Further analyses were concentrated on the ERT (41 patients) and CMT (42 patients) groups. The 3-year LFFS rates of rT1, rT2, and rT3 diseases were 66.7%, 66.7%, and 18.4%, respectively (p = 0.0008). Better local control for patients who received a TED of 60 Gy or greater was shown. The corresponding 3-year LFFS rates were 29% and 60% (p = 0.0004). Subgroup analysis on the ERT and CMT groups showed a 3-year LFFS rate of 33.5% and 57% (p = 0.003). ERT group had an excess of patients with rT3 disease. Further analysis was performed on the rT1-2 patients showing a trend toward improvement in local control in favor of the CMT group (3-year LFFS rates: CMT, 71.7%; ERT, 54%; p = 0.13). Multivariate analyses showed that rT stage (p = 0.002) and TED (p = 0.01; HR, 0.93; 95% confidence interval, 0.88-0. 98) remained significant. The 5-year major and central nervous system (CNS) complication-free rates were 26.7% and 47.8%. The following factors were found to be significant on univariate analyses for both complications in the ERT and CMT groups: (1) Modality of treatment: more complications with ERT group; and (2) rT stage. Multivariate analyses showed that the rT stage was significant for predicting the occurrence of major (p = 0.004) and CNS complications (p = 0.04).

CONCLUSION

For rT1-2 local recurrences, CMT with at least 60 Gy TED is recommended. The high incidence of major late complications is of serious concern. Ways of improving the local control of Ho's rT3 disease and reducing the risk of late complications should be explored.

Salvage brachytherapy for patients with locally persistent nasopharyngeal carcinoma

PURPOSE

Locally persistent nasopharyngeal carcinoma (NPC) carries an increased risk of local failure if additional treatment is not given. This study was conducted to evaluate the outcomes of patients with locally persistent NPC as treated by high-dose-rate (HDR) intracavitary brachytherapy, and to explore whether routine brachytherapy boost could improve the local control.

METHODS AND MATERIALS

Eighty-seven patients with locally persistent NPC treated during 1990-1998 with HDR intracavitary brachytherapy were retrospectively analyzed. Fibreoptic nasopharyngoscopy was performed 3-6 weeks after completion of the primary external radiation therapy (ERT). Biopsies were only taken from suspicious areas. Those with complete regression of local disease were put on observation. Eighty-seven patients were shown to have persistent viable disease at a median time of 6 weeks post-RT. The distribution according to Ho's staging system at initial diagnosis was as follows: Stage I-8, II-33, III-41, IV-5; T1-19, T2-48, T3-20; N0-32, N1-22, N2-28, N3-5. CT scan for restaging was not performed after the documentation of persistent disease. Our policy was to treat all patients with persistent disease with brachytherapy irrespective of the extent of disease just prior to brachytherapy. They were treated with HDR intracavitary brachytherapy, with either cobalt sources or an iridium source, giving 22.5-24 Gy in 3 weekly sessions in all but 4 patients. This dose was prescribed at a distance of 1.5 cm from the center of the surface as defined by the sources in the first six patients and subsequently reduced to 1 cm for the others. Twelve patients were treated with neoadjuvant chemotherapy. To compare the efficacy of brachytherapy, another 383 consecutive nonmetastatic patients, treated with curative intent by ERT, during the years 1990-1993, were evaluated. Multivariate analysis was performed using the Cox regression proportional hazards model.

RESULTS

The 5-year actuarial local failure-free survival (LFFS) rates and disease-specific survival rates for the brachytherapy group and ERT group were 85% and 76.6% (p = 0.15), and 72% and 67.8% (p = 0.2), respectively. The corresponding 5-year actuarial LFFS rates for T1, T2, and T3 disease were 94.7%, 88.2%, 67.4%, and 84.1%, 79.8%, 62.6%. In assessing the local control, only the T staging was significant on multivariate analysis (p = 0.0004). Other parameters such as age, sex, and persistence of disease (giving brachytherapy) were all nonsignificant. Complications were comparable between the two groups. In the persistent group, the local failure rates of the patients treated with and without neoadjuvant chemotherapy were 17% (2/12) and 13% (10/75) respectively. When analyzed according to different brachytherapy sources, the 5-year LFFS rates of the T1, T2, and T3 patients treated with iridium and cobalt sources were 100% vs. 85.7 (p = 0.19), 93.6% vs. 70% (p = 0.04), and 67.7% vs. 60% (p = 0.72). The difference was statistically significant for the T2 groups. When early T-stage (T1 and T2) patients were grouped together for analysis, the iridium group again showed a statistically significant improvement in 5-year LFFS rate when it was compared with the cobalt group (95.3% vs. 76.5%, p = 0.03) and the ERT alone group (95.3% vs. 81.5%, p = 0.03). The improvement of local control is attributed to a higher nasopharyngeal mucosal dose that is achieved by using small-size flexible applicators with an iridium source. It is interesting to note that the 5-year LFFS rates for the ERT alone group (T1: 84.1%, T2: 79.8%, T3: 62.6%) are comparable to the corresponding rates of the cobalt group. This information supports our speculation that an adequate booster treatment could compensate for inadequate primary treatment. The prognosis of patients with locally recurrent NPC is grave. Maximizing the local control is therefore crucial for the survival of the patients. (ABSTRACT TRUNCATED)

Small cell carcinoma of the cervix complicated by pregnancy

We report the results of treatment in a 26-year old patient with stage IB2 small cell carcinoma of the cervix complicated by pregnancy. A pathological complete remission was achieved following sandwich chemotherapy and radiotherapy. The patient remains in clinical remission 14 months after presentation.

Technical hints for high dose rate interstitial tongue brachytherapy

High dose rate (HDR) interstitial tongue brachytherapy is a new treatment modality. This study describes important technical details required for its successful use. Thirteen patients with carcinoma of the oral tongue were treated solely with interstitial brachytherapy using HDR remote afterloading techniques during the years 1994-1997. The afterloading catheters were positioned by the submandibular approach with the assistance of a template set. Custom-made mandibular lead shields were inserted prior to treatment. Special reusable Tuen Mun Hospital (TMH) lead buttons were made for improved radiation protection. The median dose given was 55 Gy in ten fractions over 6 days. The interfraction interval was 7 hours for the first seven patients treated and was extended to 8 hours for the other six. Shrinking field techniques were employed and the treatment length of the last fraction was reduced by 5 mm. Commencing with the second patient treated with double planar implants, the medial plane was treated with eight fractions while the lateral plane received ten fractions. To reduce further the potential risk of tract seeding, additional coverage to the implantation tracts was given for the last four patients, with the resultant isodose curves resembling a 'comb rake/brush'. The mean and median measured doses on the inner face of the mandibular shields were 113% and 93% of the reference dose respectively (range 77-247). The dose to the corresponding sites on the gingival surface can be reduced by 75% if the 3 mm thick lead shield is placed successfully. With the use of the TMH button, the transmitted dose to the tissue in direct contact can be reduced by one-third. With the 'comb rake/brush' dose distribution, the high dose volume of the single planar implants could be reduced by 44%, compared with the low dose rate technique, if loading to just 5 mm short of the submandibular skin was required. The mean doses for the combination of eight double planar plus two single planar implants, and ten double planar implants, are on average 29% and 37% greater than the reference dose respectively. An 8% reduction in absolute dose in the region between the planes of the catheters would lead to an even greater magnitude of reduction in morbidity to late responding tissue. The prerequisite for the success of HDR interstitial implants is to develop a good technique in positioning the afterloading catheters and protection of the normal tissue. Its importance merits special attention if HDR remote afterloading interstitial tongue brachytherapy is to realize its full potential.

Primary non-Hodgkin's lymphoma of the prostate

We report the results of treating a patient with stage IIBE primary large B-cell non-Hodgkin's lymphoma of the prostate. Complete remission was achieved following aggressive chemotherapy and consolidation radiotherapy. The patient remains in clinical remission 2 years after presentation.

The importance of three-dimensional brachytherapy treatment planning for nasopharyngeal carcinoma

High dose rate (HDR) intracavitary brachytherapy is now more frequently incorporated into treatment programmes for patients with persistent and recurrent nasopharyngeal carcinoma (NPC). However, many centres still employ two-dimensional (2-D) image reconstruction for applicators with a three-dimensional (3-D) orientation. In this study, we introduced the use of a mobile modified Nucletron reconstruction box inside the brachytherapy suite for image reconstruction and quality assurance. Three-dimensional reconstruction of the applicators' configurations proved possible and the dose distributions generated by the 2-D and 3-D image reconstructions could be compared. Thirty-one applications were included in this part of the analysis. The results showed that, based on the 2-D planning method, the reference doses were under-prescribed by 1%-10% in all except one patient, whose dose was over-prescribed by 3%. The evaluated doses to the floor of the sphenoid, which was shown to be significant for subsequent local control, was shown to be underestimated by up to 19% or overestimated by 18%, with an average of 5.9% dose underestimation. With this system, the reliability of the anchoring techniques was verified by posttherapy radiographs. Any catheter displacement of more than 1 mm was counted as a failure. Nine of the 43 verified applications were classified as failures, although six of nine catheter displacements measured < or = 2.5 mm. We recommend the routine use of a modified reconstruction box for 3-D image reconstruction for dose calculation and prescription in the treatment of NPC with HDR intracavitary brachytherapy. Quality assurance programmes should be included as an integral part of any HDR treatment; their importance cannot be overemphasized.

High dose rate intracavitary brachytherapy in the treatment of nasopharyngeal carcinoma

A retrospective study on 61 patients, with local persistent or recurrent nasopharyngeal carcinoma (NPC), treated during 1990-1992 with high dose rate intracavitary brachytherapy alone or combined with external irradiation, is presented. All 39 patients with persistent disease were treated solely with brachytherapy. The actuarial 3-year local failure-free survival (LFFS) rates of the persistent and recurrent groups were 82% and 45% respectively. The corresponding disease specific survival rates were 82% and 62%. Fifteen patients with recurrence received the combined modality treatment and their 3-year LFFS rate was 65%. Three out of 7 patients treated by brachytherapy could be controlled locally. The total dose given to the floor of sphenoid was an important predictor of local control. Of the 23 patients with persistent disease treated with < 17.5 Gy to this area, 6 failed locally as opposed to none of the 16 patients receiving a higher dose (p = 0.031). For those with recurrence treated by the combined modality, none of the 7 patients given >/= 57.5 Gy recurred while 5 local failures were observed among those receiving a smaller dose (p = 0.041). The general implications of these results for the treatment of NPC recurrence are discussed.

Single-exposure dual-energy computed radiography: improved detection and processing

Recent reports have emphasized the potential for dual-energy computed radiographic applications. An improved method for single-exposure material-selective imaging with a photostimulable phosphor computed radiography system was investigated. The essential elements of the technique are (a) prefiltration with gadolinium, which divides the incident broad-beam x-ray spectrum into low-energy and high-energy peaks; (b) a cassette consisting of four photostimulable phosphor plates that record images of increasing mean energies, with a computed energy separation of 23 keV from the front to the rear plate; (c) spatially dependent scatter and beam-hardening corrections; and (d) a noise-reduction algorithm based on noise correlations between bone-selective and soft-tissue-selective dual-energy images. These elements result in improved material cancellation and signal-to-noise ratio throughout the image.