Biomedical subjects

Gillian Duchesne

Publications and source records attributed to Gillian Duchesne.

8 recordsLinked to original sources

PubMed2006

The psychosocial impact of prostate cancer on patients and their partners.

OBJECTIVE: To assess the psychosocial impact of the diagnosis of either localised or metastatic prostate cancer (PCA) on patients and their female partners. DESIGN: Observational, prospective study at Time 1 and 6 months later at Time 2 of two groups of couples facing PCA. Time 1 was when patients were first diagnosed with histologically confirmed localised (potentially curable) PCA or metastatic (incurable) PCA. MAIN OUTCOME MEASURES: Depression and anxiety disorders according to the Diagnostic and statistical manual of mental disorders 4th edition (DSM-IV); psychological distress; marital satisfaction. RESULTS: At Time 1, partners had rates of DSM-IV major depression and generalised anxiety disorder twice those of women in the Australian community, and considerably higher than the patients' rates. At Time 2, psychological distress in partners had lessened but that in patients had increased. On the other hand, at Time 2, partners' marital satisfaction had deteriorated. CONCLUSIONS: To be fully effective, interventions aimed at reducing the psychosocial morbidity of PCA must involve both patient and partner, rather than the patient alone.

Adaptation, Psychological↗

PubMed2005

Delayed rectal and urinary symptomatology in patients treated for prostate cancer by radiotherapy with or without short term neo-adjuvant androgen deprivation.

BACKGROUND AND PURPOSE: To identify contributing factors to delayed rectal and urinary symptoms in a randomised trial comparing different durations of maximal androgen deprivation (MAD), given prior to radiotherapy, for locally advanced prostate cancer. PATIENTS AND METHODS: Between 1996 and 2000, 818 patients with stages T2b,c, 3 and 4 prostate cancer were entered into a trial comparing 0, 3 and 6 months of MAD prior to and during radiotherapy. Their delayed normal tissue effects were recorded by their treating doctors using standardised scales and by the patients using a self-assessment questionnaire regularly. Time to occurrence and prevalence data were analysed. RESULTS: Rectal and urinary symptom levels were observed to vary markedly over time in at least 80% of patients, with some indicating lasting resolution of symptoms. Prevalence rates were found to be substantially lower than actuarial probability rates. Baseline symptom levels and greatest acute symptom levels were both very powerful predictors. Obstructive lower urinary tract symptoms were noted to improve during the first 4 years after radiotherapy in approximately 60% of cases in each treatment arm. However, the treatment arm itself was not shown to influence these improvements in other univariate or multivariate analyses. MAD was shown to reduce both time to occurrence and prevalence of delayed proctopathic symptoms, but this effect was confirmed statistically in the 3 month treatment arm only. Multivariate models indicated that higher levels of haemoglobin prior to any treatment may in some way protect against delayed proctopathic symptoms. CONCLUSIONS: Prevalence data provide more clinically meaningful estimates of risk of delayed effects in normal tissues where assessment relies substantially on reported symptom levels. In these tissues consideration of the impact of baseline symptom levels and pathologies, and greatest acute symptom levels in analyses of delayed effects appears mandatory. Obstructive lower urinary symptoms improve over several years in the majority of patients treated for locally advanced prostate cancer by radiotherapy. Future research could address whether rectal toxicity is affected by initial haemoglobin levels and declines in it due to MAD.

Age Factors↗

PubMed2005

Short-term androgen deprivation and radiotherapy for locally advanced prostate cancer: results from the Trans-Tasman Radiation Oncology Group 96.01 randomised controlled trial.

BACKGROUND: Androgen deprivation is an established treatment regimen for disseminated prostate cancer; however, its role in patients with localised cancer is less clear. We did a large randomised controlled trial to determine whether 3 months or 6 months of androgen deprivation given before and during radiotherapy improves outcomes for patients with locally advanced prostate cancer. METHODS: 818 men with locally advanced prostate cancer were randomly assigned to: no androgen deprivation (ie, radiotherapy alone: 66 Gy in 33 fractions of 2 Gy per day over 6.5-7.0 weeks to the prostate and seminal vesicles); 3 months' androgen deprivation with 3.6 mg goserelin given subcutaneously every month and 250 mg flutamide given orally three times a day starting 2 months before radiotherapy (same regimen as control group); or 6 months' androgen deprivation, with the same regimen, starting 5 months before radiotherapy (same regimen as control group). Primary endpoints were time to local failure and prostate-cancer-specific survival; secondary endpoints were distant failure, disease-free survival, and freedom from salvage treatment. Analyses were done by intention to treat. FINDINGS: 802 (98%) patients were eligible for analysis. Median follow-up was 5.9 years (range 0.1-8.5). Compared with patients assigned no androgen deprivation, those assigned 3 months' treatment had significantly improved local failure (hazard ratio [HR] 0.56 [95% CI 0.39-0.79], p=0.001), biochemical failure-free survival (0.70 [0.56-0.88], p=0.002), disease-free survival (0.65 [0.52-0.80], p=0.0001), and freedom from salvage treatment (0.73 [0.56-0.96], p=0.025). 6 months' androgen deprivation significantly improved local failure (0.42 [0.28-0.62], p<0.0001), biochemical failure-free survival (0.58 [0.46-0.74], p<0.0001), disease-free survival (0.56 [0.45-0.69], p<0.0001), freedom from salvage treatment (0.53 [0.40-0.71], p<0.0001), distant failure (0.67 [0.45-0.99], p=0.046) and prostate-cancer-specific survival (0.56 [0.32-0.98], p=0.04) compared with no androgen deprivation. INTERPRETATION: 6 months' androgen deprivation given before and during radiotherapy improves the outlook of patients with locally advanced prostate cancer. Further follow-up is needed to estimate precisely the size of survival benefits. Increased radiation doses and additional periods of androgen deprivation might lead to further benefit.

Adenocarcinoma↗

PubMed2004

Prostate implant evaluation using tumour control probability--the effect of input parameters.

In this paper, we examine the effect of treatment parameters in a model used to evaluate permanent prostate implants. The model considers the prostate to be composed of 12 sub-sections, each sub-section is assigned a cell density based on the probability of finding cancer foci in that sub-section. Wasted dose as a result of the dose rate from the implant falling below a level adequate to counteract repopulation was found to vary by 2-16% over the range of radiosensitivity and repopulation rates considered. Within the model, applied to five dose distributions, the uncertainty in the tumour control probability (TCP) values calculated for each sub-section as a result of differences in the model parameters, was found to be less than 12% in most cases for the good quality implants. The difference in TCP values was much larger for the poor quality implant. Substituting a heterogeneous distribution of alpha for a single mean value resulted in generally lower TCP values though introducing a cutoff value with a Gaussian distribution had a profound effect on the calculated values. Despite uncertainties in the parameters, the model was able to identify sub-sections at risk of local recurrence but as a result of these uncertainties, the TCP values can only be considered in the relative rather than absolute sense.

Brachytherapy↗

PubMed2004

Assessment of i-125 prostate implants by tumor bioeffect.

PURPOSE: A method of prostate implant dose distribution assessment using a bioeffect model that incorporates a distribution of tumor cell densities is demonstrated. This method provides both a quantitative method of describing implant quality and spatial information related to the location of underdosed regions of the prostate. This model, unlike any other, takes into account the likelihood of finding cancer cells in the underdosed region. METHODS AND MATERIAL: The prostate volumes of 5 patients were divided into multiple subsections and a unique cell density was assigned to each subsection. The assigned cell density was a function of probability of finding tumor foci in that subsection. The tumor control probability (TCP) for each subsection was then calculated to identify the location of any significantly underdosed part of the prostate. In addition, a single TCP value for the entire prostate was calculated to score the overall quality of the implant. RESULTS: Adequately dosed subsections scored TCP values greater than 0.80. The TCP for underdosed regions fell dramatically particularly in subsections at higher risk of containing tumor cells. CONCLUSIONS: Despite uncertainties in radiobiological parameters used to calculate the TCP and the distribution of cancer foci through the prostate, the bioeffect model was found to be useful in identifying regions of underdosed prostate that may be at risk of local recurrence due to inadequate dose. Unlike the isodose distribution, the model has the potential to demonstrate that small volumes of tissue underdosed in regions most likely to contain higher numbers of tumor cells may be more significant than larger volumes irradiated to a lower dose but with a lower probability of containing cancer cells.

Brachytherapy↗

PubMed2004

A systematic review of brachytherapy. Is it an effective and safe treatment for localised prostate cancer?

BACKGROUND: Brachytherapy is a promising treatment for prostate cancer as it may have reduced rates of impotence and incontinence. OBJECTIVE: General practitioners can influence the treatment patients receive by their referral patterns, so it is important they understand the effectiveness and safety of treatment. We reviewed the primary literature on brachytherapy as sole therapy for localised prostate cancer. DISCUSSION: Although there have been many studies on the safety and effectiveness of brachytherapy, there have been no trials of brachytherapy versus other treatments that would control for factors such as tumour stage, grade, or initial prostate specific antigen levels. Brachytherapy for localised prostate cancer appears to have equivalent survival rates to surgery and lower rates of impotence and urinary incontinence.

Brachytherapy↗

PubMed2003

Acceptability of short term neo-adjuvant androgen deprivation in patients with locally advanced prostate cancer.

PURPOSE: To determine the acceptability of short term neo-adjuvant maximal androgen deprivation (MAD) to patients treated with external beam radiation for locally advanced prostate cancer. METHODS: Between 1996 and 2000, 818 patients with locally advanced, but non-metastatic, prostate cancer were entered into a randomised clinical trial (TROG 96.01), which compared radiation treatment alone with the same radiation treatment and 3 or 6 months neo-adjuvant MAD with goserelin and flutamide. Relevant symptoms, and how troublesome they were to the patient, were scored using a self-assessment questionnaire. This was completed by the patient at registration, and at specified times during and after treatment. Patients taking flutamide had liver function tests checked at regular intervals. RESULTS: All patients have completed at least 12 months follow-up after treatment. Nearly all patients completed planned treatment with goserelin, but 27% of patients in the 6-month MAD treatment arm, and 20% in the 3-month arm, had to stop flutamide early. This was mainly due to altered liver function (up to 17% patients) and bowel side effects (up to 8% patients). However, although flutamide resulted in more bowel symptoms for patients on MAD, there was significant reduction in some urinary symptoms on this treatment. Acute bowel and urinary side effects at the end of radiation treatment were similar in all treatment arms. Side effect severity was unrelated to radiation target volume size, which was reduced by MAD, but symptomatology prior to any treatment was a powerful predictor. Of the 36% of patients who were sexually active before any treatment, the majority became inactive whilst on MAD. However, sexual activity at 12 months after radiation treatment was similar in all treatment arms, indicating that the effects of short term MAD on sexual function are reversible. CONCLUSION: Despite temporary effects on sexual activity, and compliance difficulties with flutamide, short-term neo-adjuvant MAD was not perceived by patients to be a major inconvenience. If neo-adjuvant MAD in the way tested can be demonstrated to lead to improved biochemical control and/or survival, then patients would view these therapeutic gains as worthwhile. Compliance with short-term goserelin was excellent, confirming that LH-RH analogues have a potential role in more long-term adjuvant treatment. However, for more protracted androgen deprivation, survival advantages and deleterious effects need to be assessed in parallel, in order to determine the optimal duration of treatment.

Adult↗

PubMed2002

Measurement of lung tumor volumes using three-dimensional computer planning software.

PURPOSE: To examine the interclinician variation in the definition of gross tumor volume (GTV) in patients undergoing radiotherapy for non-small-cell lung cancer (NSCLC), develop methods to minimize this variation, and test these methods. METHODS AND MATERIALS: The radiotherapy planning computed tomography (CT) scans of 6 consecutive patients with NSCLC in which the radiologist was able to define and outline the GTV were used. Six oncologists independently contoured the tumors with the radiologist's markings as a guide using a three-dimensional treatment planning system. Separate contours were prepared using only mediastinal window settings and using both mediastinal and lung window settings. The volumes were calculated using the planning system software (series 1). Factors that resulted in interclinician variation were determined, and, after a 3-year interval, 5 of the 6 clinicians redefined the GTVs using a revised protocol aimed at minimizing variation (series 2). RESULTS: For series 1, the interclinician variation in the measurement of volumes ranged from 5%, in the most tightly measured tumor, to 42%, in the most variable, but was, on average, 20%. Statistically significant differences were noted among the clinicians (p = 0.002), that is, some clinicians tended to record relatively small and some relatively large volumes. The reasons for the variation among the oncologists included a tendency to include regions with a low probability of containing tumor, as if the oncologist were contouring a target volume; inclusion of adjacent atelectasis (ignoring the radiologist's outline); and variable treatment of spicules. When the exercise was repeated using the revised protocol (series 2), the degree of interclinician variation was reduced, with a range of 7-22% (average 13%). In series 2, the differences among the clinicians were not statistically significant (p = 0.25). CONCLUSION: Despite major radiologic input, significant variation occurred in the delineation of the three-dimensional GTVs of NSCLC among oncologists. Standardization of the approach with guidelines resulted in a reduction in this variation.

Analysis of Variance↗