Serosurveillance of SARS-CoV-2 in companion animals in Sarawak, Malaysia

SARS-CoV-2 is a zoonotic betacoronavirus that was first reported at the dawn of 2019 in Wuhan, China and has since spread globally, causing an ongoing pandemic. Anthroponotic transmission was reported early, with confirmed infections reported in 26 species to date, including dogs and cats. However, there is a paucity of reports on the transmission of SARS-CoV-2 to companion animals, and thus, we aimed to estimate the seroprevalence of SARS-CoV-2 in dogs and cats in Sarawak, Malaysia. From August 2022 to 2023, we screened plasma samples of 172 companion animals in Sarawak, Malaysia, using a species-independent surrogate virus neutralization test. Our findings revealed the presence of neutralizing antibodies of SARS-CoV-2 in 24.5% (27/110) of dogs and 24.2% (15/62) of cats. To the best of our knowledge, this is the first report of the seroprevalence of SARS-CoV-2 in companion animals in Malaysia. Our findings emphasize the need for pet owners to distance themselves from their pets when unwell, and a strategy must be in place to monitor SARS-CoV-2 in companion animals to assess the potential impact of the virus on companion animals.

[Outcomes of laryngotracheal reconstruction with anterior and posterior costal cartilage grafts in severe pediatric subglottic stenosis or laryngeal web]

Objective: To investigate outcomes of laryngotracheal reconstruction (LTR)with anterior and posterior costal cartilage grafts in severe pediatric subglottic stenosis (SGS) or laryngeal web (LW). Methods: A review of patients with severe subglottic stenosis or laryngeal web between January 2020 and January 2022 was performed. Demographic features including gender, age at diagnosis, age at surgery, etiology, airway support, and other comorbidities were collected preoperatively. Patients were evaluated in surgical site, breathing, swallowing, phonation and complications postoperatively.Descriptive analysis was used in this research. Results: Eight patients were included: six with grade Ⅲ SGS following Cotton-Myer grading scale, and two with type Ⅲ LW following Cohen's classification. All patients underwent LTR with anterior and posterior costal cartilage grafts. Five patients underwent single-stage LTR (ssLTR), and three patients underwent double-stage LTR (dsLTR). Seven out of eight patients were able to successfully extubate or decannulate with normal swallowing function; four patients had mild hoarseness, and three had moderate hoarseness. One patient failed in extubation, and underwent tracheotomy. Conclusions: LTR with anterior and posterior costal cartilage grafts is an effective and safe treatment for severe SGS or LW. Careful preoperative assessment of disease severity and overall medical status will help selection between ssLTR and dsLTR, thereby maximizing patient outcomes for both modalities.

[Ⅲ ]

Objective: Our aim of this study is to describe the outcomes of a series of patients who underwent cleft repair and posterior cartilage grafts laryngotracheoplasty (LTP) from anterior midline cervical approach for type Ⅲ laryngotracheoesophageal clefts (LETC). Methods: A review of patients with type Ⅲ LETC between May 2017 and December 2021 was performed. Demographic features including gender, age at surgery, weight, airway support, feeding status, and airway and other comorbidities were collected preoperatively. Patients were evaluated in breathing, swallowing and phonation postoperatively. The developmental status and morbidities were recorded. Results: Five patients who underwent cleft repair and posterior cartilage grafts LTP from anterior midline cervical approach were included. All patients survived and thrived postoperatively. At last follow-up, 3 patients were able to successfully extubate with acceptable voice, and 2 patients were tracheostomied. Four patients were able to be fed orally without aspiration, and one patient needed to be fed by thick food. Conclusion: The combination of cleft repair and posterior cartilage grafts LTP from anterior midline cervical approach is an effective and safe treatment for type Ⅲ LETC.

Impact of transitioning to an online course - A report from the ESTRO gyn teaching course

Introduction

In 2020, the ESTRO course on image-guided radiotherapy and chemotherapy in gynaecological cancer was converted into an online version due to the COVID-19 pandemic. This paper describes the change process and evaluates the impact on participants compared with previous live courses.

Methods and materials

The 2019 live course contained 41 h of educational content, comprising 33 h of synchronous activities (lectures, interactive activities, videos) and 8 h of homework (contouring, dose planning). For the online course, the lectures were provided as pre-course material (11 mandatory, 22 optional). Contouring/dose planning homework was unchanged. The synchronous sessions were reconfigured as six 2-hour webinars (total educational content ~38 h).Participant numbers/characteristics, engagement and satisfaction for six live courses and the online course were compared.

Results

Participant numbers for the online and live courses were similar (90 vs. mean 96). There were more participants from outside Europe (28% vs. mean 18%) and more non-doctors (47% vs. mean 33%). Proportion of participants responding to the pre-course questionnaire was similar (77% vs. mean 78%) but post-course questionnaire response was lower (62% vs. mean 92%).43% participants viewed ≥75% of mandatory lectures before the webinars. 86% viewed the optional lectures. Submissions of contouring and dose planning homework was higher (contouring 77%-90% vs. 56%-69%, dose planning 74%-89% vs. 29%-57%).96% (47/49) participants rated the online course as Excellent (43%) or Good (53%). Overall satisfaction was similar (4.4 vs. mean 4.6).

Conclusion

Participant satisfaction and engagement with the online course remained high despite less contact time with faculty.

Clinical and imaging findings in cervical cancer and their impact on FIGO and TNM staging - An analysis from the EMBRACE study

OBJECTIVE

To investigate differences in local tumour staging between clinical examination and MRI and differences between FIGO 2009, FIGO 2018 and TNM in patients with primary cervical cancer undergoing definitive radio-chemotherapy.

METHODS

Patients from the prospective observational multi-centre study "EMBRACE" were considered for analysis. All patients had gynaecological examination and pelvic MRI before treatment. Nodal status was assessed by MRI, CT, PET-CT or lymphadenectomy. For this analysis, patients were restaged according to the FIGO 2009, FIGO 2018 and TNM staging system. The local tumour stage was evaluated for MRI and clinical examination separately. Descriptive statistics were used to compare local tumour stages and different staging systems.

RESULTS

Data was available from 1338 patients. For local tumour staging, differences between MRI and clinical examination were found in 364 patients (27.2%). Affected lymph nodes were detected in 52%. The two most frequent stages with FIGO 2009 are IIB (54%) and IIIB (16%), with FIGO 2018 IIIC1 (43%) and IIB (27%) and with TNM T2b N0 M0 (27%) and T2b N1 M0 (23%) in this cohort.

CONCLUSIONS

MRI and clinical examination resulted in a different local tumour staging in approximately one quarter of patients. Comprehensive knowledge of the differential value of clinical examination and MRI is necessary to define one final local stage, especially when a decision about treatment options is to be taken. The use of FIGO 2009, FIGO 2018 and TNM staging system leads to differences in stage distributions complicating comparability of treatment results. TNM provides the most differentiated stage allocation.

A case of recurrent hepatic haemangioendothelioma

Hepatic haemangioendothelioma is a rare (1:1,000,000) mesenchymal tumour of the liver of vascular origin. Metastatic malignancies, other primary liver tumours and cholangiocarcinomas all have significantly worse prognoses and may mimic hepatic haemangioendothelioma. Hence, careful pathological assessment with appropriate tumour markers and immunohistochemistry are essential. We present a rare case of recurrence of hepatic haemangioendothelioma after 10 years post-hemihepatectomy. Surgical approaches include liver resection, liver transplantation and ablative techniques with chemotherapy and radiotherapy reserved for patients where a surgical approach is not possible. Hepatic haemangioendothelioma has an unpredictable course that is generally indolent and it is associated with a significantly better long-term survival. Consequently, it is important that these tumours are recognised and the approach to the diagnosis should be methodical. Owing to the protracted course of the disease, a prolonged duration of surveillance and an aggressive approach towards disease recurrence are essential for long-term survival.

An unusual cause of acute abdomen and acute renal failure: Djenkolism

The djenkol bean (Archidendron pauciflorum) is a native delicacy in Southeast Asia, though consumption can sometimes lead to djenkolism. Clinical features of djenkolism include acute abdominal pain, hematuria, urinary retention, and acute kidney injury (AKI). The pain can be severe, which often leads to a misdiagnosis of acute abdomen. In this paper, we report the case of an Indonesian migrant with djenkolism. Due to the short history and severity of the abdominal pain, medical professionals suspected acute abdomen and proceeded with a negative exploratory laparotomy. However, djenkolism was suspected once relatives informed the professionals that the patient had consumed djenkol beans hours earlier. The patient recovered through aggressive hydration and urine alkalinization with bicarbonate infusion. We highlight the importance of being aware of this rare cause of AKI, especially in Southeast Asia, in order to provide early diagnoses and prompt treatments.

Symptoms, Sites, and Significance of Mycoplasma genitalium in Men Who Have Sex with Men

During 2016-2017, we tested asymptomatic men who have sex with men (MSM) in Melbourne, Australia, for Mycoplasma genitalium and macrolide resistance mutations in urine and anorectal swab specimens by using PCR. We compared M. genitalium detection rates for those asymptomatic men to those for MSM with proctitis and nongonococcal urethritis (NGU) over the same period. Of 1,001 asymptomatic MSM, 95 had M. genitalium; 84.2% were macrolide resistant, and 17% were co-infected with Neisseria gonorrhoeae or Chlamydia trachomatis. Rectal positivity for M. genitalium was 7.0% and urine positivity was 2.7%. M. genitalium was not more commonly detected in the rectums of MSM (n = 355, 5.6%) with symptoms of proctitis over the same period but was more commonly detected in MSM (n = 1,019, 8.1%) with NGU. M. genitalium is common and predominantly macrolide-resistant in asymptomatic MSM. M. genitalium is not associated with proctitis in this population.

[Evaluation and treatment of children's laryngeal clefts]

Objectives: To provide the experience about the diagnostic process and following management, and to discuss the outcome and predictors in children with laryngeal cleft (LC). Methods: A retrospective case study was conducted at an academic children's hospital. Thirty children were diagnosed as laryngeal cleft between January 2016 and April 2017.Airway evaluations were performed using both flexible and rigid endoscopy, and swallowing evaluations were performed using fiberoptic endoscopic examination of swallowing or modified barium swallow. Results: Of 30 cases, 18 were male and 12 were female, ranging in age from birth to 8 years. Two cases were diagnosed as type 0 LC, and they were offered thickened liquid without medication. Throughout follow-up, they remained asymptomatic and showed no respiratory complications. Nineteen children were diagnosed as type Ⅰ LC. Six of them were significantly improved by anti-reflux therapy and feeding instructions. Four children were concomitant with swallowing dysfunction and/or neuromuscular disorders, and they were given a tracheotomy and routine management. Another 4 children were submitted surgical repair when routine treatment failed, and their symptoms were relieved. Five children were concomitant with larygomalacia, and their symptoms were totally ameliorated by supraglottoplasty. Three children were diagnosed as type Ⅱ LC. Two of them received surgical repair and clinically improved, and the rest one was treated by anti-reflux therapy and still under follow-up. Three children were diagnosed as type Ⅲ LC. One of them was underwent surgical repair and clinically improved. Two children were tracheotomized and treated by anti-reflux therapy. Three cases were diagnosed as type Ⅳ LC at birth and no one survived. Conclusions: Laryngeal cleft is a rare congenital anomaly manifesting with a variety of symptoms, including swallowing disorder, aspirations, dyspnea, stridor and hoarseness. Diagnosis and treatment of laryngeal clefts is a challenge. The best way to evaluate the LC is FEES by laryngeal endoscopy combined with MLB. Cases with type 0-Ⅰ mostly were significantly improved by anti-reflux therapy and feeding instructions. When routine treatment failed, surgical repair is needed. All the cases with LC type Ⅱ-Ⅲ need surgical repair as soon as possible. For type Ⅳ cases, early diagnosis, appropriate treatment and management help to reduce mortality and morbidity.

Alterations in classical and nonclassical HLA expression in recurrent and progressive HPV-induced usual vulvar intraepithelial neoplasia and implications for immunotherapy

Immunotherapy of usual vulvar intraepithelial neoplasia (uVIN) is promising; however, many patients still fail to show clinical responses, which could be explained by an immune escape through alterations in human leukocyte antigen (HLA) expression. Therefore, we analyzed a cohort of patients with a primary (n = 43) and subsequent recurrent uVIN lesion (n = 20), vaccine-treated uVIN patients (n = 12), patients with human papillomavirus (HPV)-induced vulvar carcinoma (n = 21) and healthy controls (n = 26) for the expression of classical HLA-class I/II and nonclassical HLA-E/-G and MHC class I chain-related molecule A (MICA). HLA-class I was downregulated in 70% of uVIN patients, including patients with a clinical response to immunotherapy. Downregulation of HLA-class I is probably reversible, as only 15% of the uVIN cases displayed loss of heterozygosity (LOH) and HLA-class I could be upregulated in uVIN keratinocyte cultures by interferon γ. HLA-class I downregulation is more frequently associated with LOH in vulvar carcinomas (25-55.5%). HLA-class II was found to be focally expressed in 65% of uVIN patients. Of the nonclassical molecules, MICA was downregulated in 80% of uVIN whereas HLA-E and -G were expressed in a minority of cases. Their expression was more prominent in vulvar carcinoma. No differences were found between the alterations observed in paired primary and recurrent uVIN. Importantly, downregulation of HLA-B/C in primary uVIN lesions was associated with the development of recurrences and progression to cancer. We conclude that downregulation of HLA is frequently observed in premalignant HPV-induced lesions, including clinical responders to immunotherapy, and is associated with worse clinical outcome. However, in the majority of cases downregulation may still be reversible.

Implementation of image-guided brachytherapy for cervix cancer in the UK: progress update

AIMS

Image-guided brachytherapy (IGBT) is the new gold standard for cervix cancer brachytherapy. In 2009, the Royal College of Radiologists (RCR) published a guidance document to facilitate the implementation of IGBT for cervix cancer in the UK. This paper reports the progress since the publication of the RCR document.

MATERIALS AND METHODS

Questionnaires were sent to 45 UK centres known to offer brachytherapy for cervix cancer in 2011. Replies were received from 43 (96%) centres. Details collected included brachytherapy machine, imaging technique for brachytherapy planning, applicator design and total dose to point A from external beam radiotherapy and brachytherapy. The results were compared with the 2008 survey reported in the RCR document.

RESULTS

The number of centres offering computed tomography (CT) or magnetic resonance imaging (MRI)-based IGBT for cervix cancer has increased to 32 (71%) in 2011 compared with 12 (26%) in 2008. Although the most common applicator design in 2011 remains the tandem-ovoid applicator (71%), more respondents are using the tandem-ring applicator (29% versus 9% in 2008). Only seven (16%) centres are routinely prescribing < 70Gy(10) to point A in 2011 compared with 10 (22%) in 2008.

CONCLUSION

Considerable progress with implementing IGBT for cervix cancer has been made in the UK since the publication of the RCR guidance document.

Comparison of RIPASA and Alvarado scores for the diagnosis of acute appendicitis

INTRODUCTION

The accuracy of the Alvarado score in diagnosing acute appendicitis in an Asian population has been disappointingly low. We prospectively compared the RIPASA score with the Alvarado score for the diagnosis of acute appendicitis.

METHODS

200 consecutive patients who presented to the Accident and Emergency Department with right iliac fossa pain were recruited in the study. Both the RIPASA and Alvarado scores were derived, but decisions for appendicectomy were based on clinical judgement. Receiver operating curve (ROC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for both scoring systems were calculated.

RESULTS

Only 192 out of the 200 patients who satisfied the inclusion and exclusion criteria were included in the analysis. At the optimal cut-off threshold score of 7.5 derived from the ROC, the sensitivity, specificity, PPV, NPV and diagnostic accuracy of the RIPASA score were 98.0 percent, 81.3 percent, 85.3 percent, 97.4 percent and 91.8 percent, respectively. At the cut-off threshold score of 7.0 for the Alvarado score, the sensitivity, specificity, PPV, NPV and diagnostic accuracy were 68.3 percent, 87.9 percent, 86.3 percent, 71.4 percent and 86.5 percent, respectively. The RIPASA score correctly classified 98 percent of all patients confirmed with histological acute appendicitis to the high-probability group (RIPASA score greater than 7.5) compared with 68.3 percent with the Alvarado score (Alvarado score greater than 7.0; p-value less than 0.0001).

CONCLUSION

The RIPASA score at a cut-off threshold total score of 7.5 is a better diagnostic scoring system than the Alvarado score for the diagnosis of acute appendicitis in our local setting.

Uncomplicated diverticular disease is not a common cause of colonic symptoms

BACKGROUND

Colonic diverticular disease is common among older individuals whereas colonic symptoms, such as those of irritable bowel syndrome, are frequent in the general population.

AIM

To determine among patients in secondary care, if uncomplicated diverticular disease is a common cause of colonic symptoms.

METHODS

Patients aged ≥50 years attending gastroenterology out-patient clinics or scheduled for colonoscopy or barium enema in a secondary care hospital were invited to take part. Those with structural gastrointestinal diseases were excluded. Participants completed a locally validated Rome II questionnaire on colonic symptoms. Patients with diverticular disease were compared with those without.

RESULTS

Seven hundred and eighty four patients with no structural pathology other than diverticular disease or benign colonic polyps completed the study. A total of 744 patients underwent colonoscopy, 40 barium enema. Of these, 281 patients had diverticular disease. Among patients with and without diverticular disease, the frequency of abdominal pain, diarrhoea, constipation and irritable bowel syndrome were 123 (44%) and 226 (46%), 44 (16%) and 80 (17%), 38 (14%) and 80 (17%) and 66 (25%) and 119 (25%), respectively (N.S.).

CONCLUSION

Uncomplicated colonic diverticular disease is not a common cause of colonic symptoms among patients in secondary care.

A novel algorithm for the morphometric assessment of radiotherapy treatment planning volumes

Quantitative assessment of target volume contouring in radiotherapy treatment planning is an important aspect of quality assessment and educational exercises. The Conformity Index (CI) is a volume-based statistic frequently used for this purpose. Although the CI is relatively simple to understand and can be calculated using most treatment planning systems, it does not provide any information on the differences in shape between the two volumes. We present a new morphometric (shape-based) statistic known as the "mean distance to conformity" (MDC). For a specific volume that is being evaluated against a reference volume, the MDC represents the average distance that all outlying points in the volume must be moved in order to achieve perfect conformity with the reference volume. The MDC comprises a component related to under-contouring (where the evaluation volume is smaller than the reference volume) and a component related to over-contouring (where the evaluation extends beyond the reference volume). Furthermore, voxel-by-voxel information on conformity errors can also be displayed using a volume-error histogram. Calculation of MDC statistics is achieved using a three-dimensional grid search algorithm. By using a range of scenarios comprising both theoretical and actual clinical volumes, we demonstrate the increased utility of the MDC for the detection of contouring errors.

Clinical impact of computed tomography-based image-guided brachytherapy for cervix cancer using the tandem-ring applicator - the Addenbrooke's experience

AIMS

We report our initial 3-year experience of chemoradiotherapy for cervical cancer with computed tomography-based image-guided high dose rate (HDR) brachytherapy using the tandem-ring applicator.

MATERIALS AND METHODS

Twenty-eight patients were treated between February 2005 and December 2007. All patients received initial external beam radiotherapy (EBRT) followed by HDR brachytherapy (planned dose 21 Gy to point A in three fractions over 8 days). For each insertion, a computed tomography scan was obtained with the brachytherapy applicator in situ. The cervix, uterus and organs at risk (OAR) were contoured on the computed tomography images to create an individualised dosimetry plan. The D(90) (the dose delivered to 90% of the tumour target), V(100) (the percentage of tumour target volume receiving 100% of the prescribed dose) and the minimum dose in the most exposed 2 cm(3) volume (D(2 cc)) of rectum, bladder and bowel were recorded. The equivalent dose in 2 Gy fractions delivered by EBRT and brachytherapy was calculated.

RESULTS

The 3-year cancer-specific survival was 81%, with a pelvic control rate of 96%. In 24 patients, a D(90)>or=74 Gy (alpha/beta10) was achieved. The only patient with local recurrence had a D(90) of 63.8 Gy(alpha/beta10). The overall actuarial risk of serious late morbidity was 14%. Seventeen patients had satisfactory OAR doses using the standard loading pattern. Seven patients had modifications to reduce the risk of toxicity, whereas two had modifications to improve the tumour dose. Comparison with a previous cohort of patients treated with chemoradiotherapy and a conventionally planned low dose rate triple source brachytherapy technique showed an improvement in local pelvic control of 20% (P=0.04).

CONCLUSIONS

The implementation of a computed tomography-based tandem-ring HDR brachytherapy technique in conjunction with individual dose adaptation has resulted in a significant improvement in local control at Addenbrooke's without increasing the risk of serious toxicity, and with little effect on radiotherapy resources.

Concurrent weekly cisplatin chemotherapy and radiotherapy in a haemodialysis patient with locally advanced cervix cancer

AIMS

Concurrent cisplatin chemo-radiotherapy improves outcome in cervical carcinoma. In haemodialysis patients, cisplatin is potentially hazardous. We report the treatment of a haemodialysis patient with cervix cancer using cisplatin-based chemo-radiation. Mathematical modelling using toxicity data from a range of cisplatin dosages and schedules reported in published studies was undertaken.

MATERIALS AND METHODS

The patient was treated using weekly cisplatin chemotherapy 25mg/m(2). The serum platinum levels were measured. Correlations between reported toxicity and platinum levels for a variety of cisplatin schedules in published studies were evaluated.

RESULTS

Treatment was completed with no interruptions and minimum acute toxicity. The platinum levels rose progressively. The elimination half-life was prolonged at 6.6-7.5 days. The percentage extraction varied between 7.7 and 41.0%. The cumulative cisplatin dose correlated with neurotoxicity (P=0.002). Myelotoxicity correlated with the peak cisplatin level in the first 15 days of treatment (P=0.01). With an elimination half-life of 7.5 days, 35 mg/m(2) weekly is predicted to have the same risk of myelotoxicity and neurotoxicity as 40 mg/m(2) weekly in a patient with normal renal function.

CONCLUSIONS

Weekly cisplatin chemotherapy 25mg/m(2) can be delivered safely in a haemodialysis patient. Dialysis is effective in eliminating platinum even if carried out more than 3h after infusion, but it should commence as soon as possible after cisplatin infusion, as the incidence of myelotoxicity is related to the peak platinum level.

Acute toxicity of chemo-radiotherapy for cervical cancer: the Addenbrooke's experience

AIMS

An audit of acute treatment-related toxicity during chemo-radiotherapy for cervical cancer was carried out to assess its tolerance outside research settings.

MATERIALS AND METHODS

Between May 1999 and April 2003, 74 patients with carcinoma of the cervix were treated with radical radiotherapy given concurrently with weekly cisplatin chemotherapy. Fifty-nine (79.7%) patients received chemo-radiotherapy as primary radical treatment, 10 (13.5%) patients were treated adjuvantly for poor-prognosis features after radical surgery, and the remaining five (6.8%) were given chemo-radiotherapy for pelvic recurrences after previous surgery. Acute treatment-related toxicity was graded prospectively at weekly intervals during chemo-radiotherapy using the National Cancer Institute Common Toxicity Criteria.

RESULTS

The most common adverse effects were diarrhoea (80.6%), malaise (66.7%) and nausea (62.5%). The most common haematological toxicity was anaemia, with 41.7% patients developing grade 1 or 2 toxicity. Only three (4.2%) patients had grade 3 or 4 toxicity. One patient had grade 3 thrombocytopenia, another had grade 4 neutropenia and the third patient had grade 3 diarrhoea. A statistically significant correlation was found between maximum treatment-related toxicity, larger treatment volumes (P = 0.006) and disease stage (P = 0.04). A total of 97.3% of patients completed external beam radiotherapy without any interruptions for treatment-related toxicity. Only two patients (3.4%) experienced a delay in brachytherapy for treatment-related toxicity. Two patients died during external beam radiotherapy, and one patient suffered a fatal pulmonary embolism 1 week after completing brachytherapy treatment. A total of 70.2% patients completed the planned number of chemotherapy cycles, with a further 20.3% receiving at least three cycles. The most common reason for failure to complete chemotherapy as planned was gastrointestinal toxicity. There was no correlation between failure to complete planned chemotherapy and patient age, disease stage, radiotherapy treatment volumes or postoperative treatment.

CONCLUSION

Our study has shown that cisplatin-based chemo-radiotherapy for carcinoma of the cervix is well tolerated when given to a largely unselected population of patients outside research settings. The effectiveness of the treatment should therefore mirror the efficacy obtained in clinical trials.

Brachiocephalic-superior vena cava metallic stenting in malignant superior vena cava obstruction

INTRODUCTION

We studied the effectiveness of unilateral brachiocephalic (BC)-superior vena cava (SVC) metallic stent therapy in malignant SVC obstruction.

MATERIALS AND METHODS

From November 1998 to February 2002, SVC stenting was performed in 11 patients with symptomatic malignant SVC obstruction. There were 10 males and 1 female, with a mean age of 64.2 years (range, 37 to 78 years). The computed tomography (CT) scan and superior vena cavogram findings of all patients showed malignant SVC obstruction. Both internal jugular veins were patent in all patients by ultrasound. SVC stenting was performed with Wallstent (Boston Scientific, Minneapolis, MN, USA) in 10 patients and Memotherm stent (Bard angiomed, Wachhausstrasse, Germany) in 1 patient. Pressure gradient, duration of the procedure, peri-procedural morbidity and mortality and the general well-being of the patients were reviewed.

RESULTS

SVC stenting was performed at a mean duration of 9.6 days (range, 3 to 30 days) after presentation. All were technically successful with 10 across the right BC-SVC and 1 across the left BC-SVC. There was no peri-procedural morbidity or mortality. The entire procedure was completed at a mean duration of 115 minutes (range, 75 to 225 minutes) with good angiographic and pressure results. Immediate symptomatic relief of SVC syndrome was achieved in 10 patients who had received prompt work-up and stenting 3 to 18 days after presentation. The remaining patient, who received work-up and stenting 30 days after presentation, remained dyspnoeic and died of pneumonia 7 days after the procedure.

CONCLUSION

Unilateral BC-SVC metallic stenting is an effective measure in malignant SVC obstruction. Prompt pre-stenting work-up and stenting are recommended to achieve a longer symptomatic relief period.

An audit of delays before and during radical radiotherapy for cervical cancer--effect on tumour cure probability

AIM

To evaluate the potential impact of time delay before and during radical radiotherapy for cervical carcinoma at Addenbrooke's Hospital.

MATERIALS AND METHODS

An audit was undertaken which recorded the number of gaps during external beam radiotherapy (EBRT), overall treatment time, and delay between first oncology consultation to start of radiotherapy, for patients receiving primary radical radiotherapy for cervical cancer in 1996, 1998 and 2001. Radiobiological modelling was used to calculate the tumour control probability (TCP). A questionnaire survey of 62 oncology departments in the U.K. was carried out for comparison.

RESULTS

The percentage of patients completing EBRT without any interruptions was 22, 67 and 94% in 1996, 1998, and 2001, respectively (P = 0.0009). The median overall treatment time was 49, 42 and 39 days in 1996, 1998 and 2001, respectively (P = 0.001). However, the median waiting time to start of radiotherapy increased from 14 days in 1996 to 18 days in 1998 and 35 days in 2001 (P = 0.007).

CONCLUSION

The results from the national survey showed that this pattern of improved overall treatment times accompanied by deterioration in waiting times was also seen in most other U.K. centres. Radiobiological modelling showed that any potential gain in TCP resulting from shorter overall treatment times could be offset entirely by the adverse effect of increasing waiting times. The calculations suggest that the tumours most likely to be adversely affected by long waiting times are those with shorter volume doubling times or a medium chance of tumour control at the outset of treatment. A system of patient triage, and prioritization of patients deemed most likely to benefit from a reduced waiting time, may be necessary in the current climate of limited radiotherapy resources.

Treatment of localized carcinoma of the penis: a survey of current practice in the UK

Consensus opinion from published reports on the management of localized carcinoma of the penis recommends that patients with small, distal, non-poorly differentiated lesions should be offered penis-conserving treatment, while those with larger or more advanced lesions should be considered for amputative surgery. A questionnaire survey was sent to 289 urologists and 237 oncologists in the UK to assess their practice for the treatment of localized carcinoma of the penis. Consultants were asked to choose between penis-conserving surgery, amputation or radiotherapy as their preferred treatment for four examples of localized disease. Oncologists were also asked to indicate their preferred radiation modality (external beam radiotherapy or brachytherapy). For treating a small lesion situated distally on the glans penis, 56.7% of urologists and 94.5% of oncologists preferred penis-conserving methods; 28.8% of urologists and one oncologist preferred partial or total amputation. In total, 43.2% of urologists would consider amputative surgery for this lesion compared with only 5.5% of oncologists. Only 23.3% of oncologists considered using brachytherapy. For a 4 cm lesion situated distally, the majority of urologists surveyed (82.0%) preferred amputative surgery, while the majority of oncologists (68.5%) preferred conservative treatment. For a 1.5 cm lesion extending on to the penile shaft, 68.5% of urologists preferred amputative surgery while 85.0% of oncologists preferred penis-conserving options. For a 4 cm lesion extending on to the shaft, the vast majority of urologists (86.5%) preferred amputation as treatment compared with only 36.9% of oncologists. The results of the survey suggested that clinicians tended to favour the treatment modality of which they have most experience. As such, urologists tended to prefer surgery while clinical oncologists tended to prefer radiotherapy, irrespective of the size and position of the primary tumour or consensus opinion. These results emphasize the importance of multidisciplinary clinics and site specialization, so that both clinicians and patients can make informed choices about optimal treatment, based on the knowledge of all available treatment options.

An audit of clinic consultation times in a cancer centre: implications for national manpower planning

A departmental audit was conducted to assess the frequency, extent and causes of late completion of oncology clinics. Data were collected prospectively from clinical, medical, haematological and multidisciplinary oncology clinics. The data recorded included: clinic start and finish times, number of patients seen, type of consultation, number of doctors in each clinic, time spent by the doctor with the patient, and other factors that may have contributed to the late completion of clinics. A total of 848 patient consultations were recorded in 81 clinics. Of 67 clinics in which the finish time was recorded, 19 (28%) were completed on time, while 48 (72%) were late by a mean time of 49 minutes. The mean time spent by consultants with new, follow-up and chemotherapy patients was 37, 21 and 22 minutes respectively. This did not include time spent reviewing notes, dictating or ordering investigations. There was no significant difference in the time spent by specialist registrars compared with consultants, or clinical oncologists compared with medical oncologists and haematologists. The incidence of unforeseen problems such as difficult consultations, missing information, unplanned interruptions, late starts and overbooking of patients were not significantly different in those clinics that finished late compared with those that finished on time. The mean overrun of multidisciplinary clinics was longer than for non-multidisciplinary clinics (59 and 31 minutes respectively), despite a higher ratio of doctors to patients in the former (1:5.4 and 1:7 respectively). This audit showed that the main cause of late finishes in clinics in our department was the longer than anticipated time spent by doctors with patients. Consultations are taking longer because of the increasing complexity of non-surgical cancer treatments and the greater emphasis placed on patient information and informed consent. The Royal College of Radiologists (RCR) has calculated that, if a consultant oncologist sees a maximum of 315 new patients per year, the time available for each follow-up consultation would be 10 minutes. Our audit showed that follow-up consultations took an average of 21 minutes. These results suggest that the RCR recommendations for consultant expansion substantially underestimates the true number of consultants required for the treatment of cancer patients in the UK.

Radiation-induced malignant melanoma of the cervix

We report the occurrence of a malignant melanoma of the uterine cervix in a patient previously irradiated for a squamous cell carcinoma of the cervix. The management of malignant melanoma of the cervix is reviewed. The risk of second cancers in general, malignant melanoma in particular, after radiotherapy for cervical cancer is also discussed.

Hermitamides A and B, toxic malyngamide-type natural products from the marine cyanobacterium Lyngbya majuscula

A Papua New Guinea collection of the marine cyanobacterium Lyngbya majuscula yielded two new and toxic natural products, hermitamides A (1) and B (2). The hermitamides were isolated using a brine shrimp (Artemia salina) toxicity assay. Planar chemical structures of 1 and 2 were established through 1D and 2D NMR, as well as FABMS data. Semisyntheses of hermitamides A (1) and B (2) were achieved by coupling the acid chloride derivative of 7(S)-methoxytetradec-4(E)-enoic acid (4), obtained from the same cyanobacterium collection, and the respective free amines, phenethylamine and tryptamine. Hermitamides A (1) and B (2) exhibited LD(50) values of 5 microM and 18 microM in the brine shrimp bioassay, and an IC(50) values of 2.2 microM and 5.5 microM to Neuro-2a neuroblastoma cells in tissue culture, respectively. Hermitamide A was mildly ichthyotoxic to goldfish, with an LD(50) value of 19 microM, while hermitamide B was inactive at 25 microM.

Philadelphia positive acute lymphoblastic leukaemia (ALL): clinico-haematologic characteristics, molecular analyses and 3-year follow up--a single institution study

INTRODUCTION

The Philadelphia chromosome is one of the commonest chromosomal aberration in adult acute lymphoblastic leukaemia (ALL) patients. We present the results of a 3-year prospective study to look at the clinico-haematologic, immunophenotypic, cytogenetic and molecular profile of 13 adult patients with Philadelphia (Ph) positive ALL out of 35 newly diagnosed ALL seen at our institution over the past 3 years.

MATERIALS AND METHODS

Thirty-five adult ALL patients seen between 1996 and 1998 comprised the study group. Marrow samples were obtained for immunophenotyping and karyotypic analysis at diagnosis. Samples were also obtained simultaneously for molecular testing for Ph chromosome.

RESULTS

Thirteen patients were found to be Ph positive by molecular analysis while cytogenetic studies identified the chromosomal abnormality in 9 of these patients. The median age of our Ph positive patients was similar to those without Ph chromosome. Pre-B phenotype appears to be common in this group of patients. In concordance with other studies, Ph positive ALL was associated with a poor prognosis in our patients.

CONCLUSION

Identification of Ph chromosome is important in the management of patients with ALL as it is an important prognostic marker.

cis,cis- and trans,trans-ceratospongamide, new bioactive cyclic heptapeptides from the Indonesian red alga Ceratodictyon spongiosum and symbiotic sponge Sigmadocia symbiotica

Chemical investigation of the marine red alga (Rhodophyta) Ceratodictyon spongiosum containing the symbiotic sponge Sigmadocia symbiotica collected from Biaro Island, Indonesia, yielded two isomers of a new and bioactive thiazole-containing cyclic heptapeptide, cis,cis-ceratospongamide (1) and trans, trans-ceratospongamide (2). Isolation of these peptides was assisted by bioassay-guided fractionation using a brine shrimp toxicity assay (Artemia salina). The structures of the ceratospongamides, which each consist of two L-phenylalanine residues, one (L-isoleucine)-L-methyloxazoline residue, one L-proline residue, and one (L-proline)thiazole residue, were established through extensive NMR spectroscopy, including (1)H-(13)C HMQC-TOCSY, and (1)H-(15)N HMBC experiments, as well as chemical degradation and chiral analysis. cis,cis- and trans,trans-ceratospongamide are stable conformational isomers of the two proline amide bonds. Molecular modeling of these two ceratospongamide isomers showed the trans, trans isomer to be quite planar, whereas the cis,cis isomer has a more puckered overall conformation. trans,trans-Ceratospongamide exhibits potent inhibition of sPLA(2) expression in a cell-based model for antiinflammation (ED(50) 32 nM), whereas the cis,cis isomer is inactive. trans,trans-Ceratospongamide was also shown to inhibit the expression of a human-sPLA(2) promoter-based reporter by 90%.

Molecular and phenotypic spectrum of de novo Philadelphia positive acute leukemia

The Philadelphia chromosome is present in a heterogeneous group of leukemias. It is most commonly associated with chronic myelogenous leukemia (CML) and B-lineage acute lymphoblastic leukemia (ALL) being found in more than 95% and 15-25% of cases respectively. We undertook a study to determine the morphologic, phenotypic and molecular diversity of Philadelphia positive de novo acute leukemia patients seen at our institution over the past 3 1/2 years. Twenty-one patients with de novo acute leukemia were found to have the Philadelphia chromosome by cytogenetic studies. They consisted of 3 patients with acute myelogenous leukemia (AML), 1 biphenotypic leukemia and 17 ALL patients. Of the patients with ALL, 16 were of B-lineage while 1 had a T-cell phenotype. Ten patients expressed the p210 BCR-ABL transcript alone and 10 expressed only the p190 BCR-ABL transcript. One patient had co-expression of p190 and p210 b3a2 BCR-ABL transcripts. Thus the Philadelphia chromosome can be found in a diverse cohort of morphologic and immunologic subtypes of de novo acute leukemia reflecting the heterogeneity of lineage involvement in this disease.

Contrast enhanced dynamic MRI of cervical carcinoma during radiotherapy: early prediction of tumour regression rate

This prospective study investigated the relationship between changes in the MRI dynamic enhancement of cervical carcinoma early during radiotherapy, and tumour regression rate throughout radiotherapy. A total of 36 MRI examinations was performed in seven patients with cervical carcinoma, including a T2 weighted sequence weekly during radiotherapy and also a multislice dynamic Gd-DTPA enhanced sequence before and after the first 2 weeks of radiotherapy. Tumour enhancement was determined on dynamic images using a region of interest and signal-to-noise ratio method. Serial tumour volumes over time on T2 weighted images were estimated using the Cavalieri method of modern design-based stereology to obtain tumour regression rate. It was found that peak and mean enhancement prior to radiotherapy ranged from 3.0 to 13.3, and from 1.9 to 12.2, respectively. After 2 weeks of radiotherapy, peak and mean enhancement ranged from 7.5 to 13.0, and from 6.3 to 10.6, respectively. The change in peak and mean tumour enhancement between dynamic scans ranged, respectively, from -2.0 to 8.4 and from -4.5 to 8.5. Tumour volume decreased exponentially with time (p < 0.01). Tumour regression rates ranged from 2.0% to 15.2% per day, and correlated positively with changes of both peak and mean tumour enhancement (p < 0.01). It is concluded that MRI dynamic enhancement during the first 2 weeks of radiotherapy may provide early prediction of tumour regression rate, and therefore be of value in designing treatment schedules for cervical carcinoma.

Two patients with novel BCR/ABL fusion transcripts (e8/a2 and e13/a2) resulting from translocation breakpoints within BCR exons

We have identified novel BCR-ABL mRNA fusions by RT-PCR in two patients with Philadelphia (Ph) chromosome positive leukaemia. Sequencing revealed in-frame fusions consisting of part of BCR exon e8 spliced to ABL exon a2 in one patient and part of BCR exon e13 spliced to ABL exon a2 in the other. The breaks within BCR exons e8 and e13 did not conform to consensus splice sites, suggesting that the aberrant fusion mRNAs may have arisen as a result of translocation breakpoints at these sites. This was confirmed by genomic DNA bubble PCR for the second patient. These data show that BCR-ABL translocation breakpoints can occasionally occur within coding exons.

Determination of tumour regression rates during radiotherapy for cervical carcinoma by serial MRI: comparison of two measurement techniques and examination of intraobserver and interobserver variability

Tumour regression rates of 11 patients with cervical carcinoma were estimated during external beam radiotherapy (EBRT) using serial MRI (average time interval 7 days; range 3-15 days). An average of five investigations (range 4-8) was performed per subject. Tumour volume was measured by two observers using the Cavalieri method of modern design stereology in combination with (a) planimetry and (b) point counting. The mean precision of all the volume estimates obtained by manually tracing the outline of the tumour was 6.6%. The mean precision obtained by counting an average of 176 points per investigation on the same transects was 6.7%. The intraobserver repeatability of planimetry, interobserver reproducibility of planimetry and point counting were excellent with no significant difference between the volume estimates obtained using either technique. Based on the planimetry measurements, initial tumour volumes ranged from 6.5 to 222 cm3 (mean 63 cm3, median 44 cm3). Based on the point counting measurements, initial tumour volumes ranged from 7.2 to 235 cm3 (mean 68 cm3, median 46 cm3). Tumour regression began within a few days of commencing EBRT and showed an exponential relationship with time (p < 0.01). There was good agreement between the regression rates obtained by planimetry and those obtained by point counting. No significant correlation was found between initial tumour volume and tumour regression rate for either planimetry or point counting. Planimetry measurements were, on average, obtained in about half the time taken for point counting (i.e. 30 min and 50 min, respectively). Although point counting is generally likely to be the more efficient approach, planimetry may be the preferred approach for estimating tumour volume when a purpose built track ball is available and the tumour morphology is relatively simple. Volume measurement should be obtained using the Cavalieri method to ensure that the estimates are unbiased and that their precision can be predicted. The measured tumour regression rates may have important implications for improving local tumour control, optimum timing of brachytherapy and minimizing the risk of radiation damage.

An audit of the treatment of carcinoma of the uterine cervix using external beam radiotherapy and a single line source brachytherapy technique

A single line source brachytherapy (BT) technique has been developed at Clatterbridge to boost the dose to the primary tumour after whole pelvis external beam radiotherapy (EBRT) for the radical treatment of carcinoma of the cervix. 226 patients with invasive carcinoma of the uterine cervix were treated with radiotherapy alone using this technique (median age 57 years; range 25-87 years). 49 patients had Stage IB disease, 97 had Stage II, 73 had Stage III and seven patients had biopsy confirmed Stage IVA disease. Patients with low bulk disease were given 40-42.5 Gy in 20 fractions while those with bulky disease received 45 Gy in 20 fractions or 50 Gy in 25 fractions. On completion of EBRT, 186 patients (82.3%) proceeded to intracavitary BT using a linear arrangement of sources with the Selectron (Nucletron) remote afterloading unit. Most of the patients (137/226, 60.6%) received a single insertion of 20 Gy to point "A", at a preferred dose rate within the range 0.95-1.05 Gy h-1. In another 30 patients (13.3%), BT was possible at a later date after further tumour regression. Only 10 patients (4.4%) did not receive BT as part of their treatment. The 5 year actuarial cause-specific survival rate was 79% in Stage I disease, 61% in Stage II, 31% in Stage III and 71% in the small number of patients with Stage IVA disease. The 5 year pelvic control rates were 88% for Stage I, 69% for Stage II, 45% for Stage III and 71% for Stage IVA. Significant prognostic variables for survival and local pelvic control on univariate analysis included disease stage, patient age, tumour bulk, nodal status, anaemia, renal failure and overall treatment time. Tumour grade was a significant prognostic variable for survival but not for local tumour control. The extent of parametrial involvement was a significant prognostic variable for survival and local control for Stage IIB but not for Stage IIIB. There was a statistically significant decrease in survival and local tumour control for patients receiving > or = 70 Gy to point "A", or > or = 55 Gy to point "B". On multivariate analysis, the independent prognostic variables for survival and local control were disease stage, overall treatment time and renal failure. Patient age was also an independent prognostic variable for survival while nodal status was an independent prognostic variable for local control. A high proportion of the patients had adverse prognostic features resulting in a very high actuarial risk of distant metastases of 38.1% at 5 years (68.8% for Stage III patients). The overall treatment time was significantly longer in Stage III patients compared with Stage I and Stage II patients. The actuarial rate of Grade 2 late radiation morbidity was 2.7% and 4.3% for the urinary tract and bowel respectively while that of Grade 3 morbidity was only 0.6% and 1.4%, respectively. Good local control can be achieved for patients with nonbulky tumours using relatively low biological doses while minimizing the risk of late treatment related toxicity. Several changes in treatment policy have been made in an attempt to improve local tumour control and possibly survival, particularly for Stage III patients and patients with bulky disease.

Radical radiotherapy for carcinoma of the uterine cervix using external beam radiotherapy and a single line source brachytherapy technique: the Clatterbridge technique

At the Clatterbridge Centre for Oncology, a single line source brachytherapy technique using the Selectron (Nucletron) low dose rate remote afterloading equipment has been developed for use in conjunction with homogenous whole pelvis external beam radiotherapy in the radical treatment of carcinoma of the cervix. The technique incorporates several modifications aimed at reducing treatment related morbidity while maintaining satisfactory local tumour control and cure rates. A flexible dose prescription system has been devised to allow individualization of the brachytherapy isodose distribution according to the clinical findings and the estimated normal tissue doses. Modifications of source loading distributions are carried out to limit the point "A" dose rate to a narrow range to take into account the dose rate effect on the risk of complications. Source loading distributions are also modified according to the estimated normal tissue doses in order to respect normal tissue tolerance. This paper describes the technique and its underlying principles.

Early experience with surgically inaccessible wide-necked intracranial aneurysm embolised with Guglielmi Electrically Detachable coils and electrothrombosis

We describe our early successful experience with Guglielmi Electrically Detachable Coils (GDC) and electrothrombosis in treating a surgically inaccessible wide-necked intracranial aneurysm in a Chinese patient. The precautions taken to prevent unnecessary complications while performing this technique was also described. It provides a serious alternative to other less ideal types of embolising agents and direct surgery in treating patients with these difficult-to-treat aneurysms.

Bladder dose estimation during intracavitary brachytherapy for carcinoma of the cervix using a single line source system

The estimation of maximum bladder doses from orthogonal radiographs is unreliable when triple source systems are used for intracavitary brachytherapy (BT) for gynaecological cancers. For single line source systems, the estimation of maximum bladder doses from radiographs should be more reliable due to the radial symmetry of the isodose distribution. A pilot study has been carried out to compare the estimated maximum bladder doses from standard radiographs with data obtained from CT for single line source BT treatments. 12 patients undergoing treatment for carcinoma of the cervix were selected for CT assessment of their bladder doses. For each patient, the dose rates at the International Commission of Radiation Units and Measurements (ICRU) bladder reference point B1 and a second reference point B2 2.5 cm cranially were computed from orthogonal radiographs and were compared with the maximum bladder dose rate as determined by CT scanning. Dose rates were computed for two different source loading patterns: (1) a 6 cm line source with uniformly distributed linear activity along its length; (2) a 6 cm line source with increased activity in the central 2 cm segment. The mean ratio of the maximum CT bladder dose rate to the dose rate at the ICRU reference point B1 on orthogonal radiographs for the line source with uniform linear activity was 1.32 (range 0.62-2.43, SD = 0.54). When the dose rates at both reference points B1 and B2 were considered, the mean ratio of the maximum CT dose rate to the maximum dose rate from radiographs was only 1.05 (range 0.72-1.72, SD = 0.24). For the line source with increased activity in the central segment, the mean ratio of the maximum CT bladder dose rate to the dose rate at B1 was 1.38 (range 0.60-2.63, SD = 0.64). When both B1 and B2 were considered, the variation in the ratio of the maximum CT dose rate to the maximum dose rate from radiographs was considerably smaller (mean ratio = 1.07, range 0.69-1.76, SD = 0.26). For single line source systems, single point dose estimation using the ICRU reference point on orthogonal radiographs will underestimate the maximum bladder dose although the discrepancy is less than for triple source systems. If the ICRU reference point is used in conjunction with a second reference point 2.5 cm cranially, then underestimation of the maximum bladder dose is unlikely to occur as at least one of the points is likely to be a reasonable estimate of the maximum bladder dose.

The influence of air cavities on the optic chiasm dose during pituitary radiotherapy for acromegaly

The treatment planning of acromegalic patients can be complicated by the presence of abnormally large frontal air sinuses which allow increased anterior beam transmission causing increased dose to the optic nerve and chiasm which, if excessive, can result in blindness. This potential problem has been investigated by computer treatment planning exercises which have allowed for a variable thickness (1-3 cm) of air cavity beneath the frontal field and for different weightings of the lateral opposed fields relative to the anterior field. The resultant overdosage can be greater than 5% of the intended dose. The increased biological effect from errors of this magnitude is sufficient to increase the risk of optic nerve damage since neural tissue is very sensitive to small increments in fraction size. Even when the reduced attenuation is allowed for in the computer plan, the thickness of the air sinuses varies across the field so that irradiation through the frontal enlarged frontal air sinuses causes inhomogeneous dose distributions in the target volume. Acromegalic patients should therefore be treated with a more superior beam which would avoid the air sinuses altogether.

Treatment of carcinomas of the uterine cervix which remain bulky after initial external beam radiotherapy: a pilot study using integrated cytotoxic chemotherapy prior to brachytherapy

The use of cytotoxic chemotherapy (CT) between external beam radiotherapy (EBRT) and intracavitary brachytherapy (BT) in patients with bulky carcinomas of the uterine cervix which regress poorly after initial EBRT has been evaluated in a pilot study. The aim of CT was to limit tumour clonogen repopulation while awaiting further tumour regression in order to improve the BT dose distribution. Between 1989 and 1992, 22 patients with FIGO Stage IIA, IIB and IIIB cervical carcinomas were given two to three cycles of cisplatin-based CT between EBRT and intracavitary BT. Patients were selected for CT if there was bulky residual tumour extending beyond the range of point "A" after completion of EBRT. The median survival of patients with Stage IIA/B and Stage IIIB disease was 24 months and 13 months, respectively. The 5 year actuarial survival rate for patients with Stage IIA/B disease was 42%. There were no long-term survivors among patients with Stage IIIB disease. Survival difference between Stage IIA/B patients and Stage IIIB patients was statistically significant (p < 0.04). 5 year actuarial pelvic control rates were 38% and 0% for Stage IIA/B and Stage IIIB patients, respectively. There were no serious late radiation complications in the entire study group. Bulky carcinomas of the cervix which respond poorly to initial EBRT have a particularly poor prognosis. For Stage IB-IIB patients with persistent bulky disease after EBRT, published reports suggest that a 5 year actuarial survival rate of around 40% can be obtained using higher doses of radiation alone, but the risk of serious late morbidity is considerable. The results of our study suggest that in Stage IIA/B carcinomas of the cervix which remain bulky after initial EBRT, the use of integrated cytotoxic chemotherapy prior to intracavitary BT can give similar 5 year survival rates but with minimal treatment related morbidity.

Case report: low dose rate and high dose rate intracavitary brachytherapy in a patient with carcinoma of the cervix

The role of low dose rate (LDR) intracavitary radiotherapy in the management of carcinoma of the uterine cervix is well established. However, there are selected groups of patients in whom high dose rate (HDR) intracavitary radiotherapy may have particular advantages. A case report of a patient with carcinoma of the cervix who received both LDR and HDR intracavitary radiotherapy is presented. A comparison of the normal tissue doses produced by the two forms of brachytherapy is made. The choice of dose for the HDR treatment was calculated using standard linear quadratic isoeffect equations. The relative clinical merits of LDR and HDR treatments in gynaecological cancer are discussed.

National Patient Master Index in Singapore

It has been the practice of hospitals and medical institutions to keep their patients' medical records. Access to such valuable information will be confined within the respective health institutions if there is no proper infrastructure to facilitate sharing of the information. On the other hand, it has been the wish of medical professionals, as well as patients who frequent hospitals and medical institutions that patients' medical records, especially essential medical conditions, are readily available, whenever required, regardless of the health institution by which the patient is being attended to. In response, the National Patient Master Index (NPMI) system was conceived and implemented by the Singapore Ministry of Health in 1994. The NPMI system aims at providing a patient database at national level that allows authorised users faster access to a patient's essential medical data thereby facilitating patient management. This paper describes the implementation of the NPMI system, its data elements, system functionality and access control to address data confidentiality and privacy.

The achievement of isoeffective bronchial mucosal dose during endobronchial brachytherapy

PURPOSE

The use of endobronchial brachytherapy in the treatment of lung cancer is increasing due to the more widespread availability of high dose rate afterloading equipment. The complications include small airway (segmental and small lobar bronchi) fibrosis, stenosis, and obstructive complications in addition to hemorrhage. A progressive reduction in the diameter of the bronchial lumen occurs at each division of the bronchial tree. If uniform dwell times along a bronchial catheter treatment length are used, this will result in higher doses being given to the bronchial mucosa in the distal part of the treatment volume where the brachytherapy source mucosa distances are smaller, and underdosage proximally, where the source mucosa distances are larger.

METHODS AND MATERIALS

The known mathematical relationships of the sequential reductions in the diameter of the bronchial lumen have been incorporated into two methods of optimization, which have been compared to uniform dwell times along a treatment length from trachea to segmental bronchus.

RESULTS

The resulting isodose plots are presented, and demonstrate the extent of the overdosage distally, and the underdosage proximally when using uniform dwell times, and the achievement of isoeffective mucosal doses when using differential dwell times.

CONCLUSION

This refinement in brachytherapy technique offers the potential for reduced normal tissue complications and possibly improved tumor control by reducing overdosage and underdosage, respectively.

Derivation of the optimum dose per fraction from the linear quadratic model

The linear quadratic equation for fractionated radiotherapy has already been adapted to include a time factor for tumour repopulation: loge cell kill (E) is given as a function of dose per fraction (d), number of fractions (n), overall treatment time (T) and the clonogen doubling time (Tp). By incorporating a normal tissue isoeffect and replacing the relationship between T and n by a function f, the equation for E can be rewritten as a more complex function of d. In this form, E and d are continuous variables so that the dose per fraction (d') required to produce maximum values of E for isoeffective late normal tissue effects can be found by differential calculus. The derived equation takes the form (beta kTp-alpha Tp)d2 + 1.386fd + 0.693fk = 0 and when solved for d provides a direct estimation of the optimum dose per fraction. Where normal tissue sparing is possible and the tumour dose z is related to the normal tissue dose d, the optimum dose per fraction z' can be found by solving the equation (beta kTp-alpha gTp)z2 + 1.386fgz + 0.693fk = 0 The results show that a critical minimum dose per fraction is required to counteract rapid tumour clonogen repopulation in both conventional and accelerated radiotherapy. The calculus method is reasonably accurate for larger fraction numbers, when clonogen doubling times are 3.5 days or longer and for conventional radiotherapy given 5 days per week. The model is even more accurate for accelerated hyperfractionated radiotherapy providing that there is complete repair between successive fractions. Where greater normal tissue sparing is possible, as with focal teletherapy methods and brachytherapy, higher tumour doses per fraction can be used to increase further the tumour cell kill without exceeding normal tissue tolerance. These predicted doses per fraction are consistent with clinical experience when the given constraints in terms of frequency of treatment are considered. The model described can be used for tumours in which repopulation occurs at a constant rate throughout treatment. For tumours in which accelerated repopulation occurs, the optimum dose per fraction can be separately calculated for the initial phase of slow repopulation (for which very small doses per fraction are optimal) and also for the second phase of rapid repopulation (for which either accelerated hyperfractionated treatments or hypofractionated focal methods of treatment would be appropriate). The limitations of the model are fully discussed including the need for accurate radiobiological predictive assays. In the future such assays of pre-treatment doubling times and tumour cell radiosensitivities could be used to determine reasonable ranges for the optimum dose per fraction in experimental tumours and subsequently in clinical trails. This approach could produce major improvements in the therapeutic potential of radiotherapy.

Non-uniform dwell times in line source high dose rate brachytherapy: physical and radiobiological considerations

The ability to vary source dwell times in high dose rate (HDR) brachytherapy allows for the use of non-uniform dwell times along a line source. This may have advantages in the radical treatment of tumours depending on individual tumour geometry. This study investigates the potential improvements in local tumour control relative to adjacent normal tissue isoeffects when intratumour source dwell times are increased along the central portion of a line source (technique A) in radiotherapy schedules which include a relatively small component of HDR brachytherapy. Such a technique is predicted to increase the local control for tumours of diameters ranging between 2 cm and 4 cm by up to 11% compared with a technique in which there are uniform dwell times along the line source (technique B). There is no difference in the local control rates for the two techniques when used to treat smaller tumours. Normal tissue doses are also modified by the technique used. Technique A produces higher normal tissue doses at points perpendicular to the centre of the line source and lower doses at points nearer the ends of the line source if the prescription point is not in the central plane of the line source. Alternatively, if the dose is prescribed at a point in the central plane of the line source, the dose at all the normal tissue points are lower when technique A is used.

Results of a questionnaire regarding the practice of radiotherapy for carcinoma of the cervix in the UK

A questionnaire was sent to 50 departments of clinical oncology in the UK in September 1991. The aim was to determine the range of external beam and brachytherapy techniques employed at that time in the radical treatment of carcinoma of the cervix. Replies were received from 35 centres. This paper summarizes the preliminary findings of the study. Low dose rate (LDR) brachytherapy techniques predominated (34/35 = 97%) but 41% of departments (13/32) had future plans for the use of high dose rate (HDR) equipment. For low bulk (Stage I-II) carcinoma of the cervix, there was no detectable association between the total brachytherapy dose prescribed and the brachytherapy dose rate. In bulky (Stage I-II) carcinoma of the cervix treated by initial open teletherapy (without shielding), there was a statistically significant reduction in the prescribed brachytherapy dose with increasing dose rate. There was considerable variation between centres in the measurement or estimation of normal tissue doses during brachytherapy. The range of techniques used and the variation in expected complication rates should be closely monitored via medical audit and a further follow-up questionnaire may reveal important changes.