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ABSTRACT: Factors which can predict an increased risk of axillary metastases in cases of T1 breast cancer could help to identify those patients most likely to benefit from axillary surgery. This pragmatic study aimed to examine the ability of commonly reported tumour pathological features to predict axillary metastases. All cases of T1 infiltrating ductal carcinoma excised with ipsilateral axillary nodes over a 7 year period were reviewed retrospectively. Of the 639 cases, 197 (30.8%) had positive nodes. Axillary metastases were found with 66.3% of tumours showing vascular invasion but only 16.0% of those without vascular invasion. Following multivariate analysis, vascular invasion and tumour size were found to be independent predictors of positive nodes but tumour grade was not. The decision to perform axillary dissection in T1 breast cancer could be based on the presence of vascular invasion and the size of the primary tumour.
The Breast 05/2001; 10(2):155-9. · 2.49 Impact Factor
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ABSTRACT: A method that uses electronic portal imaging to design intensity-modulated beams for compensation in breast radiotherapy was implemented using multiple static fields in a planning study. We present the results of the study to verify the algorithm, and to assess improvements to the dosimetry.
Fourteen patients were imaged with computed tomography (CT) and on a treatment unit using an electronic portal imager. The portal imaging data were used to design intensity-modulated beams to give an ideal dose distribution in the breast. These beams were implemented as multiple static fields added to standard wedged tangential fields. Planning of these treatments was performed on a commercial treatment planning system (Target 2, IGE Medical Systems, Slough, U.K.) using the CT data for each patient. Dose-volume histogram (DVH) analysis of the plans with and without multileaf collimator (MLC) compensation was carried out. This work has been used as the basis for a randomized clinical trial investigating whether improvements in dosimetry are correlated with the reduction of long-term side effects from breast radiotherapy.
The planning analysis showed a mean increase in target volume receiving 95-105% of prescribed dose of 7.5% (range -0.8% to 15.9%) when additional MLC compensation was applied. There was no change to the minimum dose for all 14 patient data sets. The change in the volume of breast tissue receiving over 105% of prescribed dose, when applying MLC compensation, was between -1.4% and 11.9%, with positive numbers indicating an improvement. These effects showed a correlation with breast size; the larger the breast the greater the amount of improvement.
The method for designing compensation for breast treatments using an electronic portal imager has been verified using planning on CT data for 14 patients. An improvement was seen in planning when applying MLC compensation and this effect was greater the larger the breast size.
International Journal of Radiation OncologyBiologyPhysics 03/2000; 46(3):671-9. · 4.11 Impact Factor
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ABSTRACT: Inadequate surgical excision with residual involvement of resection margins by tumour after breast conservation results in increased local recurrence rates. To reduce this risk positive margins are, therefore, usually excised. Systemic treatment with tamoxifen or chemotherapy reduces local recurrence, along with radiotherapy. However, no studies to date have examined the correlation between chemoendocrine treatment, together with radiotherapy, and local relapse in patients with unexcised involved resection margins, having had breast conservation treatment.
The histopathology reports were reviewed of 184 patients who were treated from June 1991 to August 1995 within our randomised study of neoadjuvant versus adjuvant chemoendocrine therapy with mitozantrone and methotrexate (2M) +/- mitomycin-C (3M) and tamoxifen, used concurrently with radiation following conservation surgical treatment. Histological resection margin was considered positive if ductal carcinoma in situ (DCIS) or invasive carcinoma was present microscopically less than 1 mm from the excision margin.
Although 38% of patients had unexcised microscopically involved margins, local relapse rate as first site of relapse was only 1.9% after a median follow up of 57 months. There was no difference in distant relapse (P = 0.2) and survival (P = 0.5) between the positive and negative margins groups.
The presence of positive unexcised margins does not have a significant effect on outcome in patients who are treated with chemoendocrine therapy together with radiotherapy. Further clinical trials are required.
Annals of Oncology 01/2000; 10(12):1451-5. · 6.43 Impact Factor
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ABSTRACT: A treatment plan optimisation algorithm has been applied to 12 patients with early prostate cancer in order to determine the optimum beam-weights and wedge angles for a standard conformal three-field treatment technique. The optimisation algorithm was based on fast-stimulated-annealing using a cost function designed to achieve a uniform dose in the planning-target-volume (PTV) and to minimise the integral doses to the organs-at-risk. The algorithm has been applied to standard conformal three-field plans created by an experienced human planner, and run in three PLAN MODES: (1) where the wedge angles were fixed by the human planner and only the beam-weights were optimised; (2) where both the wedge angles and beam-weights were optimised; and (3) where both the wedge angles and beam-weights were optimised and a non-uniform dose was prescribed to the PTV. In the latter PLAN MODE, a uniform 100% dose was prescribed to all of the PTV except for that region that overlaps with the rectum where a lower (e.g., 90%) dose was prescribed. The resulting optimised plans have been compared with those of the human planner who found beam-weights by conventional forward planning techniques. Plans were compared on the basis of dose statistics, normal-tissue-complication-probability (NTCP) and tumour-control-probability (TCP). The results of the comparison showed that all three PLAN MODES produced plans with slightly higher TCP for the same rectal NTCP, than the human planner. The best results were observed for PLAN MODE 3, where an average increase in TCP of 0.73% (+/- 0.20, 95% confidence interval) was predicted by the biological models. This increase arises from a beneficial dose gradient which is produced across the tumour. Although the TCP gain is small it comes with no increase in treatment complexity, and could translate into increased cures given the large numbers of patients being referred. A study of the beam-weights and wedge angles chosen by the optimisation algorithm revealed significant inter-patient variability the implications of which are examined. Probably the most significant benefit of the algorithm is the time saved (about a factor of 10) in computing optimised beam-weights and wedge angles for this simple plan.
Radiotherapy and Oncology 01/1996; 37(3):209-20. · 5.58 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the central lung distance (CLD) as a surrogate for the volume of lung irradiated during tangential breast radiotherapy. 20 women underwent a planning computed tomography (CT) scan and three-dimensional (3D) treatment planning for both breasts. The field size was perturbed in a systematic manner to give a number of plans with the CLD increasing from 0 to 30 mm. The volume of lung irradiated was determined directly using dose-volume histograms of the lung and correlated with the known CLD. The results indicate that absolute and percentage lung volumes increase with increasing CLD according to a quadratic relationship which is different for both left and right lungs. It is concluded that while there is no substitute for a 3D plan and a lung dose-volume histogram calculation, CLD may be used as a guide to the volume of lung included within the tangential fields used for breast radiotherapy.
British Journal of Radiology 10/1995; 68(813):1004-8. · 1.31 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the relative merits of the coplanar field arrangements most frequently used for conformal radiotherapy of the prostate using dose-volume histograms and normal tissue complication probabilities (NTCPs). Twelve patients with early prostate cancer underwent a planning CT scan of the pelvis. Isocentric plans for each patient were devised using three, four, six and eight conformal fields and beam-weights optimised using fast simulated annealing to give a dose homogeneity across the planning target volume of +/- 5% or better while minimising irradiation of the relevant organs at risk. The plans were then evaluated using dose-volume histograms of the organs at risk (bladder, rectum and both femoral heads) and the Lyman model of normal tissue complication probability for the rectum. Analysis of dose-volume histogram data averaged over the 12 patients indicates an advantage for six (p = 0.002) and eight (p = 0.0001) fields with respect to the percentage volume of the femoral heads receiving > 50% of the prescribed dose compared with three fields. There was a similar advantage for six (p = 0.0007) and eight (p = 0.0001) fields compared with four fields. Ranking of the treatment techniques indicates that the four-field technique is the worst with respect to femoral head irradiation but the best with respect to reducing rectal irradiation. A higher dose can be prescribed to the isocentre with the four-field technique for a 5% rectal NTCP. The six-field technique led to sparing of the bladder when the different treatment techniques were ranked using bladder dose-volume histogram data. We conclude that none of the techniques studied consistently proved to be superior when applied to this sample of patients with prostate cancer with respect to sparing all the organs at risk. The absolute differences between techniques are small and would be very difficult to detect with respect to clinically relevant endpoints.
Radiotherapy and Oncology 10/1995; 37(1):29-34. · 5.58 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the effect of breast size on dose heterogeneity. Twenty women underwent a planning CT scan of the thorax. A three-dimensional treatment plan was devised for each patient using a standard technique of isocentric medial and lateral wedged tangential fields. Three-dimensional dose distributions were derived using an equivalent path length (EPL) inhomogeneity correction and cumulative dose-volume histogram (DVH) data calculated for the breast. Analysis of the DVHs for each patient reveals that 0.2-23.8% of the breast received an absorbed dose outside the desired 95-105% of that prescribed at the isocentre. The degree of dose heterogeneity was most strongly correlated with breast volume (r = 0.70, 95% confidence interval (C.I.) 0.37-0.87). There was also a positive correlation for breast dose heterogeneity versus brassière (bra) cup size (Spearman rank correlation rho = 0.62), breast area (r = 0.39, 95% C.I. -0.06-0.71) and chest wall separation (r = 0.31, 95% C.I. -0.15-0.66). We conclude that breast size is an important determinant of dose heterogeneity within the breast.
Radiotherapy and Oncology 04/1995; 34(3):210-8. · 5.58 Impact Factor
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ABSTRACT: In recent years there have been great advances and innovations in all technical aspects of radiotherapy, including three dimensional (3D) computer planning, patient immobilization, radiation delivery and treatment verification. Despite this progress, the technique of tangential breast irradiation has changed little over this period and has not exploited these advances. There is increasing evidence that dose inhomogeneity within the breast is greater than at other anatomical sites, especially in women with large breasts. This paper is a review of the factors contributing to poor dosimetry in the breast, the clinical consequences of an inhomogeneous dose distribution, and how breast dosimetry could be improved by considering each of the stages from planning to accurate treatment delivery. It also highlights the particular problem of women with large breasts who may be more likely to have a poorer cosmetic outcome after a fractionated course of radiotherapy than women with small/medium-sized breasts, and supports the clinical impression that such women are also more likely to have greater dose inhomogeneity when 3D treatment plans are examined. Preliminary data from our current computed tomography (CT) planning study are presented to support these observations.
British Journal of Radiology 01/1995; 67(804):1149-54. · 1.31 Impact Factor
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ABSTRACT: A clinical evaluation of a computer segmentation algorithm was performed to determine whether the incorporation of such an algorithm into a radiotherapy treatment planning computer would increase the speed of segmentation and therefore increase user productivity. Six pelvic computed tomography (CT) data cubes were manually segmented akin to current radiotherapy practice on three occasions and the mean times for each data cube recorded to provide baseline measurements. The same images were then segmented using the new region growing algorithm, backed up by manual segmentation and contour editing tools where necessary, and the times compared with the baseline for each data cube. The results confirm that this algorithm can decrease segmentation times by a factor of 2.4 without compromising the quality of the final plan (p < 0.0001). Most of this time gain is from a rapid segmentation of the pelvic bones and external contour rather than the soft tissues of the pelvis. We conclude that such algorithms will be of value for segmenting large pelvic CT data cubes for radiotherapy planning by making the procedure less labour intensive.
British Journal of Radiology 05/1994; 67(796):392-5. · 1.31 Impact Factor
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ABSTRACT: This paper is a retrospective review of the treatment of carcinoma of the penis with radiotherapy alone over a 30-year period from 1960-1990 at The Royal London Hospital. During that time, 44 patients aged 31-85 years (mean 63) underwent treatment in our department, all of whom had histologically proven squamous carcinoma. Patients initially treated by surgery and those treated with combined surgery and radiotherapy were excluded from analysis. Twenty-four patients were treated by an iridium mould, and 20 by external beam irradiation. There were 67% complete responses; 79% for the patients treated by an iridium mould, 53% for those treated by external beam irradiation, although this difference between the two treatment groups was due to a more favourable stage distribution in the iridium group. Actuarial 2-, 5- and 10-year overall survivals were 87.9%, 85.1% and 72.3% respectively, with no significant difference between the iridium and external beam groups. For Stage I patients, the response rates and actuarial penile disease free survivals were comparable for the iridium and external beam groups. Urethral stricture was recorded in 10% of those treated by external beam irradiation and 13% of those treated by iridium mould. These results confirm that conservative treatment of carcinoma of the penis with radical radiotherapy allows preservation of a functioning penis with acceptable morbidity and a high proportion of long term survivors when surgery is used for salvage of locoregional relapse.(ABSTRACT TRUNCATED AT 250 WORDS)
Clinical Oncology 02/1993; 5(4):207-10. · 2.07 Impact Factor
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ABSTRACT: A retrospective study was performed to determine whether the long-term (5 years or more) administration of tamoxifen is detrimental to bone mineral density (BMD). 19 patients taking adjuvant tamoxifen for breast cancer were paired with 19 controls comparable in age, time since menopause and performance status. BMD was measured at the femoral neck, lumbar spine and total body by dual energy X-ray absorptiometry (DEXA). There was no detrimental effect on BMD at any site. There was a trend towards an increase in BMD at the femoral neck. There were minor decreases in the serum calcium, phosphate and alkaline phosphatase.
European Journal of Cancer 02/1993; 29A(14):1971-3. · 5.54 Impact Factor
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Clinical Oncology 02/1993; 5(5):309-12. · 2.07 Impact Factor
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ABSTRACT: The results of pre-operative radical radiotherapy and subsequent maxillary resection are reported in 54 consecutive patients with carcinoma of the maxillary antrum treated at The Royal London Hospital from 1965 to 1989. The actuarial two and five year survivals were 50.3 per cent and 38.5 per cent respectively. Patients with adenocarcinomas fared better when compared with squamous and undifferentiated carcinomas (log rank p = < 0.01). Undifferentiated carcinoma and involved regional lymph nodes were both very poor prognostic factors. In those patients who were either unfit for or refused maxillary resection, radical radiotherapy alone was still an effective treatment, with only a slight disadvantage in terms of local control and survival.
The Journal of Laryngology & Otology 12/1992; 106(12):1063-6. · 0.60 Impact Factor
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ABSTRACT: A pterygium is a benign, usually progressive fibrovascular overgrowth of the conjunctiva usually arising at the inner canthus of the eye which may cause local symptoms, particularly if large and impinging on the cornea. The treatment of choice for symptomatic pterygia is surgical excision, but early proliferation of fibroblasts and vascular buds leads to recurrence in a large proportion of cases. We review the published results of adjuvant postoperative beta irradiation using an ophthalmic applicator containing strontium-90 which is effective at reducing recurrence to an acceptable level. This treatment is well tolerated in the short term, and although a number of late sequelae are recognized, these are extremely uncommon in everyday clinical practice.
Clinical Oncology 04/1991; 3(2):105-9. · 2.07 Impact Factor
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ABSTRACT: A pterygium is a benign, usually progressive fibrovascular overgrowth of the conjunctiva usually arising at the inner canthus of the eye which may cause local symptoms, particularly if large and impinging on the cornea. The treatment of choice for symptomatic pterygia is surgical excision, but early proliferation of fibroblasts and vascular buds leads to recurrence in a large proportion of cases. We review the published results of adjuvant postoperative beta irradiation using an ophthalmic applicator containing strontium-90 which is effective at reducing recurrence to an acceptable level. This treatment is well tolerated in the short term, and although a number of late sequelae are recognized, these are extremely uncommon in everyday clinical practice.
Clinical Oncology.
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ABSTRACT: This paper is a retrospective review of the treatment of carcinoma of the penis with radiotherapy alone over a 30-year period from 1960–1990 at The Royal London Hospital. During that time, 44 patients aged 31–85 years (mean 63) underwent treatment in our department, all of whom had histologically proven squamous carcinoma. Patients initially treated by surgery and those treated with combined surgery and radiotherapy were excluded from analysis. Twenty-four patients were treated by an iridium mould, and 20 by external beam irradiation. There were 67% complete responses; 79% for the patients treated by an iridium mould, 53% for those treated by external beam irradiation, although this difference between the two treatment groups was due to a more favourable stage distribution in the iridium group. Actuarial 2-, 5- and 10-year overall survivals were 87.9%, 85.1% and 72.3% respectively, with no significant difference between the iridium and external beam groups. For Stage I patients, the response rates and actuarial penile disease free survivals were comparable for the iridium and external beam groups. Urethral stricture was recorded in 10% of those treated by external beam irradiation and 13% of those treated by iridium mould. These results confirm that conservative treatment of carcinoma of the penis with radical radiotherapy allows preservation of a functioning penis with acceptable morbidity and a high proportion of long term survivors when surgery is used for salvage of locoregional relapse. There were no significant differences between the two treatment techniques used.
Clinical Oncology.
