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M Brada

Publications and source records attributed to M Brada.

At least 37 records · Page 2Linked to original sources
PubMed2000

A medical research council randomized trial in patients with primary cerebral non-Hodgkin lymphoma: cerebral radiotherapy with and without cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy.

BACKGROUND: The role of chemotherapy in the treatment of patients with primary central nervous system lymphoma (PCL) remains unclear, with no randomized trials available to aid in the interpretation of the current data. The Medical Research Council therefore conducted the current randomized trial to assess the impact on survival of postradiotherapy chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in nonimmunocompromised adult patients with pathologically proven PCL. METHODS: After surgery, patients were randomized at a ratio of 1:2 to radiotherapy alone (RT: 40 grays [Gy] in 20 fractions to the whole brain followed by a 14-Gy boost to the tumor plus a 2-cm tumor margin) or to the same radiotherapy followed by six cycles of CHOP chemotherapy given at 3-week intervals (RT-CHOP). The target sample size was 90 patients, which allowed 90% power to detect a doubling of the median survival time. RESULTS: Between 1988 and 1995, 53 patients were randomized: Fifteen patients were randomized to RT, and 38 patients were randomized to RT-CHOP. The trial closed earlier than planned through poor accrual. The median patient age was 57 years, 57% of the patients were male, and 75% of the patients had unifocal disease. The median number of chemotherapy cycles received was 6 (mean, 4 cycles). Forty-three patients have died, and the median follow-up of survivors is 5 years (range, 1-9 years). There was no evidence of a benefit from RT-CHOP with respect to overall survival (hazard ratio [HR], 1.19; 95% confidence interval, 0.51-2.76) after adjustment for prognostic factors (patient age and neurologic performance status) in an analysis in which HR > 1 favored the control (RT) group. CONCLUSIONS: CHOP has no clear role in the postradiotherapy treatment of patients with PCL. Chemotherapy is poorly tolerated and largely palliative in older, less fit patients. In younger patients, initial chemotherapy designed to penetrate the blood-brain barrier warrants further investigation.

Adult↗
PubMed2000

A Comparison of clinical target volumes determined by CT and MRI for the radiotherapy planning of base of skull meningiomas.

PURPOSE: To assess the utility of image registration and to compare the localization of clinical target volumes (CTV) using CT and MRI for patients with base of skull meningiomas undergoing radiotherapy. METHODS AND MATERIALS: Seven patients were imaged using CT and a T1-weighted MR volumetric sequence. Following image registration using a chamfer-matching algorithm, transaxial MR slices were reconstructed to match the planning CT slices. The accuracy of the image fusion was assessed in a preliminary study with matching accuracy better than 1.5 mm. The CTV in each patient was separately segmented by two independent observers for both CT and reconstructed MR image sets. Scalar and vector assessments were made of the difference in radial extent between the two outlines on each transaxial plane for all patients. A positive vector value corresponded to a greater extension of the tumor on MR compared to CT and vice versa. Scalar measurements compared the modulus of the differences between MR and CT, regardless of which volume was more extensive. Qualitative comparisons were also performed. RESULTS: Interobserver difference was small with a mean (+/- 1SD) volume difference of 1.5 +/- 1.5 cm(3) for CT and 0.5 +/- 1.0 cm(3) for MRI. The mean CT- and MR- CTVs were 17.6 +/-10.8 and 19.6 +/-14.2 cm(3) respectively. The mean overlap and composite volumes were 13.8 +/-10. 1 and 23.3 +/-14.8 cm(3) respectively. Average scalar differences in the left, right, anterior, and posterior directions were 6.0 +/- 7.0, 3.3 +/- 2.5, 4.9 +/- 3.9, and 4.5 +/- 5.0 mm respectively. The average vector differences were 3.3 +/- 8.5, -0.3 +/- 3.8, 1.1 +/- 5. 8, 1.5 +/- 6.4 mm (for left, right, anterior, and posterior directions respectively). Qualitatively, MR appeared to discern more tumor involvement in soft tissue regions adjacent to the skull base whereas CT appeared to provide larger target volumes within bony regions. CONCLUSIONS: MRI appeared to define CTVs that were larger but not inclusive of CT-defined CTVs. Although the average vector differences were small, the differences on individual borders could be large. In some instances, the CT or MR volumes were vastly different, each providing separate information. Therefore, the use of MRI and CT is complementary. Until accurate histological confirmation of disease extent is available, it is prudent to consider composite CT/MR volumes for the radiotherapy planning of base of skull meningiomas.

Adult↗
PubMed2000

Cerebral haemangiopericytoma treated with conservative surgery and radiotherapy.

Cerebral haemangiopericytomas are rare tumours that resemble meningiomas but behave more aggressively, with a tendency to metastasize. We report two patients with haemangiopericytoma who had limited surgical resections owing to perioperative blood loss but who had massive tumour shrinkage after a course of radical radiotherapy. We suggest a more conservative surgical approach to the management of these tumours.

Adult↗
PubMed2000

Advice on hair and scalp care during cranial radiotherapy: a prospective randomized trial.

BACKGROUND: The advice on hair washing during brain irradiation is aimed at minimizing radiation induced skin toxicity. We performed a prospective randomized trial to assess the effect of advice on scalp care on the local skin reaction in patients undergoing cranial radiotherapy. METHODS: One hundred and nine patients undergoing cranial radiotherapy were randomized into two groups. Patients in group 1 were advised not to wash hair during treatment and patients in group 2 to maintain normal pattern of hair washing. They were assessed weekly over a period of 10 weeks from the start of treatment. Symptoms of pain and itching were recorded using a modified RTOG/EORTC acute skin reaction scoring system and skin reaction was assessed clinically using erythema/desquamation score. The frequency of hair washing and the distress of changing the practice of normal hygiene were recorded on a diary card. Skin reaction scores were compared as a summary measure using area under the curve per week (AUC/week) and median scores, and the differences between groups were assessed by means of the t-test. RESULTS: One hundred and nine patients commencing cranial radiotherapy according to standard protocol were randomized into the trial (group 1, 55 patients; group 2, 54 patients). Patients asked to restrict hair washing, washed at a lower average frequency. There were no significant differences between scores of skin reaction in the two groups for each of the variables measured. CONCLUSIONS: The practice of normal hair washing is not associated with increased severity of adverse skin reaction. As a request to change the pattern of normal hygiene may cause distress, the current advice should be to maintain normal hair washing during cranial radiotherapy.

Adolescent↗
PubMed2000

Health-related quality of life in patients with anaplastic astrocytoma during treatment with temozolomide.

One of the objectives of this phase II study was to determine whether temozolomide (TMZ) improved the health-related quality of life (HRQL) of patients with recurrent anaplastic astrocytoma (AA). HRQL was assessed at baseline (pretreatment) and every 4 weeks at each treatment cycle using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) (version 2.0) and the Brain Cancer Module (BCM20). Changes from baseline in the scores of seven preselected HRQL domains (role and social functioning, global QL, visual disorder, motor dysfunction, communication deficit and drowsiness) were determined at 6 months as well as prior to, and at the time of, disease progression. The significance of the changes was assessed by calculating statistical significance, effect sizes and the proportions of patients with improvement in their HRQL scores (changes of >/=10 points). After 6 months of treatment, patients who were free of progression of disease reported either an improvement or maintenance of all the preselected HRQL domains scores. Patients with disease progression by 6 months usually experienced improvement in HRQL before progression, but there was a sharp decline in most of the preselected domains at progression. We conclude that treatment of recurrent AA with temozolomide is associated with significant HRQL benefits.

Adult↗
PubMed2000

Evaluation of a nurse-led telephone clinic in the follow-up of patients with malignant glioma.

The aim of this study was to evaluate nurse-led telephone follow-up (NTF) for patients with high-grade glioma as an alternative to conventional clinic follow-up (CCF) and to assess patient satisfaction with this approach. Patients who were completing primary therapy for high-grade glioma and were suitable for CCF were offered the alternative of nurse-led telephone follow-up. NTF was arranged by the nurse at mutually agreed times. Assessment was by open discussion and a semistructured questionnaire, together with the Barthel Activities of Daily Living Index. Formal medical assessment in the clinic was arranged at 4-month intervals or earlier if indicated. Twenty-two patients were asked to complete a satisfaction questionnaire. Between February 1996 and October 1997, 43 patients with high-grade glioma, one with primitive neuroectodermal tumour and one with oligoastrocytoma agreed to be monitored by NTF. Their median survival from diagnosis was 16 months (95% confidence interval 13-23 months). At the time of analysis, the median time of follow-up by the telephone clinic was 6 months (range 2-21), with symptomatic progressive disease the reason for discontinuation of NTF in all patients. Two-hundred and fifty-four telephone calls were made, of which 234 were routine and 20 non-routine, being initiated by the patients or their carers. NTF was considered as a sufficient replacement for CCF during the stable phase of the disease. There were 41 unscheduled clinic visits, of which 31 were at the time of progression and usually initiated at NTF. The majority of unplanned visits were due to a change in symptoms and would not have been avoided with CCF carried out at the same time intervals. Patient satisfaction was high, with a median satisfaction score of 9, (range 3.6-10 ) on a scale of 0-10. NTF provides an alternative approach to conventional hospital attendance and moves the emphasis away from cancer surveillance to a more patient centred supportive model. It can be carried out without apparent detriment to the patient and is associated with high satisfaction rating.

Adult↗
PubMed2000

A phase II study of temozolomide vs. procarbazine in patients with glioblastoma multiforme at first relapse.

A randomized, multicentre, open-label, phase II study compared temozolomide (TMZ), an oral second-generation alkylating agent, and procarbazine (PCB) in 225 patients with glioblastoma multiforme at first relapse. Primary objectives were to determine progression-free survival (PFS) at 6 months and safety for TMZ and PCB in adult patients who failed conventional treatment. Secondary objectives were to assess overall survival and health-related quality of life (HRQL). TMZ was given orally at 200 mg/m(2)/day or 150 mg/m(2)/day (prior chemotherapy) for 5 days, repeated every 28 days. PCB was given orally at 150 mg/m(2)/day or 125 mg/m(2)/day (prior chemotherapy) for 28 days, repeated every 56 days. HRQL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 [+3]) and the Brain Cancer Module 20 (BCM20). The 6-month PFS rate for patients who received TMZ was 21%, which met the protocol objective. The 6-month PFS rate for those who received PCB was 8% (P = 0.008, for the comparison). Overall PFS significantly improved with TMZ, with a median PFS of 12.4 weeks in the TMZ group and 8.32 weeks in the PCB group (P = 0.0063). The 6-month overall survival rate for TMZ patients was 60% vs. 44% for PCB patients (P = 0.019). Freedom from disease progression was associated with maintenance of HRQL, regardless of treatment received. TMZ had an acceptable safety profile; most adverse events were mild or moderate in severity.

Adult↗
PubMed2000

Effect of disease burden on health-related quality of life in patients with malignant gliomas.

The burden imposed by disease recurrence in patients with high-grade gliomas is not well documented. We studied the frequency of self-report symptoms and the effects on health-related quality of life in patients who had recurrent glioblastoma multiforme or anaplastic astrocytoma and who had a Karnofsky performance score > or = 70. Patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 Items (QLQ-C30) and the Brain Cancer Module (BCM20) before initiation of treatment for first recurrence of disease. Six symptoms (fatigue, uncertainty about the future, motor difficulties, drowsiness, communication difficulties, and headache) were reported with a frequency > 50% by both groups of patients. An additional two symptoms (visual problems and pain) were also reported with frequencies of > 50% by patients with recurrent glioblastoma multiforme. Most of the symptoms were likely due to recurrence, but previous radiation therapy and on-going corticosteroid treatment may have also been casual factors for fatigue, whereas uncertainty about the future and pain were probably nonspecific for brain cancer. Problems with motor functioning, vision, leg strength, and pain were reported more frequently by patients with recurrent glioblastoma multiforme than by those with recurrent anaplastic astrocytoma. Scores on health-related quality-of-life functioning scales were similar in the two groups. Finally, the scores for patients who had recurrent high-grade gliomas and a Karnofsky performance score > or = 70 were compared with the reported health-related quality of life scores of patients with other cancers. Their scores were similar to those of patients with metastatic cancers and worse than those of patients with localized cancers.

Adult↗
PubMed2000

Health-related quality of life in patients treated with temozolomide versus procarbazine for recurrent glioblastoma multiforme.

PURPOSE: To determine whether chemotherapy with temozolomide (TMZ) versus procarbazine (PCB) for recurrent glioblastoma multiforme (GBM) was associated with improvement in health-related quality of life (HRQOL). PATIENTS AND METHODS: HRQOL was assessed at baseline and during treatment using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and a Brain Cancer Module (BCM20) in two clinical trials that enrolled a total of 366 patients. Two hundred eighty-eight patients provided HRQOL data that could be used for analysis; 109 patients received TMZ in a phase II study, whereas 89 patients received TMZ and 90 received PCB in a randomized phase III study. Changes from baseline in the scores of seven preselected HRQOL domains (role and social functioning, global quality of life [QOL], visual disorders, motor dysfunction, communication deficit, and drowsiness) were calculated for all groups. Statistical significance, effect sizes, and proportions of patients with improved HRQOL scores (changes of > or = 10 points) were calculated. RESULTS: Before disease progression, patients treated with TMZ were found to have an improvement in most of the preselected HRQOL domain scores compared with their baseline (pretreatment) scores. Those who were progression-free on TMZ at 6 months had improvement in all the preselected HRQOL domains. Conversely, patients treated with PCB reported deterioration in HRQOL that was independent of whether or not the disease had progressed by 6 months. Patients with disease progression, regardless of treatment, experienced a sharp decline in all domains at the time of progression. CONCLUSION: Treatment with TMZ was associated with improvement in HRQOL scores compared with treatment with PCB. The deterioration reported by PCB-treated patients was likely because of toxicity. Delaying disease progression by treatment with TMZ is beneficial to the HRQOL status of patients with recurrent GBM.

Adult↗
PubMed2000

Growth hormone treatment of children with brain tumors and risk of tumor recurrence.

GH is increasingly used for treatment of children and adults. It is mitogenic, however, and there is therefore concern about its safety, especially when used to treat cancer patients who have become GH deficient after cranial radiotherapy. We followed 180 children with brain tumors attending three large hospitals in the United Kingdom and treated with GH during 1965-1996, and 891 children with brain tumors at these hospitals who received radiotherapy but not GH. Thirty-five first recurrences occurred in the GH-treated children and 434 in the untreated children. The relative risk of first recurrence in GH-treated compared with untreated patients, adjusted for potentially confounding prognostic variables, was decreased (0. 6; 95% confidence interval, 0.4-0.9) as was the relative risk of mortality (0.5; 95% confidence interval, 0.3-0.8). There was no significant trend in relative risk of recurrence with cumulative time for which GH treatment had been given or with time elapsed since this treatment started. The relative risk of mortality increased significantly with time since first GH treatment. The results, based on much larger numbers than previous studies, suggest that GH does not increase the risk of recurrence of childhood brain tumors, although the rising trend in mortality relative risks with longer follow-up indicates the need for continued surveillance.

Adolescent↗
PubMed2000

The treatment of malignant cerebral tumours.

Malignant cerebral tumours are uncommon. While a large proportion are resistant to conventional therapies there are a significant number of curable malignant brain tumours that require recognition and appropriate therapy.

Adolescent↗
PubMed2000

Stereotactic conformal radiotherapy for pituitary adenomas: technique and preliminary experience.

OBJECTIVE: Stereotactic conformal radiotherapy (SCRT) is a high precision technique of fractionated radiotherapy which ensures accurate delivery of radiation with reduction in the volume of normal tissue irradiated as compared to conventional external beam radiotherapy. We describe the technique and preliminary experience of SCRT in patients with residual and recurrent pituitary adenomas. PATIENTS AND METHODS: Between February 1995 and March 1999, 22 patients (mean age: 45.3, range: 20-67 years) with residual or recurrent pituitary adenomas (13 nonfunctioning, nine secretory) were treated with SCRT. All were immobilized in a relocatable Gill-Thomas-Cosman (GTC) frame and tumour was localized on a postcontrast planning computerized tomography (CT) and MRI scan. The gross tumour volume (GTV) and the critical structures were outlined on contiguous 2-3 mm separated slices. A margin of 5 mm (12 patients) to 10 mm (10 patients) was grown around GTV in three-dimensions (3-D) to generate the planning target volume (PTV). The treatment was delivered by three (five patients) and four (17 patients) maximally separated conformal fixed fields with each field conformed to the shape of the tumour using customized lead alloy blocks (19 patients) or multileaf collimator (three patients). The patients were treated on a 6-MV linear accelerator to a dose of 45 Gy in 25 fractions (18 patients) and 50 Gy in 30 fractions (four patients). RESULTS: The technique of SCRT has become a part of the routine work of the radiotherapy department. The treatment was well tolerated with minimal acute toxicity. One patient developed transient quadrantanopia 2 weeks after treatment with full recovery after a short course of corticosteroids. One patient had a transient visual deterioration 7 months after treatment due to cystic degeneration of the tumour which fully recovered following surgical decompression. Nine of the 15 patients presenting with visual impairment had improvement after treatment and the visual status remained stable in all others. One patient with acromegaly and one with a prolactinoma achieved normalization of elevated hormonal abnormality four and 10 months after SCRT, respectively. The remaining seven patients with a secretory adenoma had declining hormone levels at last follow-up. Newly initiated hormone replacement therapy was required in five patients. At a median follow-up of 9 months (range 1-44 months), the 1 and 2 year actuarial progression free and overall survival were 100%. CONCLUSION: Stereotactic conformal radiotherapy is a high precision technique suitable for the treatment of pituitary adenomas requiring radiotherapy. Preliminary results suggest effective tumour control and low toxicity within the range expected for conventional external beam radiotherapy. While the technique is of potential benefit in reducing the volume of normal brain irradiated, the advantages in terms of sustained tumour control and reduced toxicity over conventional radiotherapy need to be demonstrated in long-term prospective studies.

Adenoma↗
PubMed2000

Clinical trial end points in malignant glioma: need for effective trial design strategy.

Although oncologists have devised a number of measures of therapeutic efficacy, the design and evaluation of clinical trials of therapy for malignant gliomas present special difficulties. These include comparability of study design, patient stratification, classification of tumor type, and outcome response measures. In addition, these tumors and their treatment have profound effects on patients' quality of life. Consequently, considerations of quality of life are an important factor in study design. These issues are addressed to facilitate the interpretation of current and future studies of emerging treatment options in patients with malignant gliomas.

Brain Neoplasms↗
PubMed1999

The incidence of cerebrovascular accidents in patients with pituitary adenoma.

BACKGROUND AND PURPOSE: Patients with pituitary adenomas are effectively treated with a combination of surgery, radiotherapy, and medical therapy. Nevertheless, long-term studies suggest increased mortality that is independent of tumor control, with cerebrovascular accidents (CVA) as the major contributing cause. The purpose of this study was to define the frequency of CVAs in a cohort of patients with pituitary adenoma and identify potential predisposing factors. PATIENTS AND METHODS: A cohort of 331 United Kingdom (UK) residents with pituitary adenoma treated at the Royal Marsden Hospital (RMH) between 1962 and 1986 was studied. The frequency of CVA was assessed from RMH and referring hospital records and clinicians, by postal questionnaire of referring hospitals and general practitioners, and by examination of all death certificates. The data were analyzed by actuarial methods, and risk factors were assessed by multivariate analysis. The data were compared to the incidence of CVA in the general population using a published UK population cohort. RESULTS: Sixty-four of 331 patients developed CVA after primary treatment of pituitary adenoma. The actuarial incidence of CVA was 4% (95% CI: 2-7%) at 5 years, 11% (95% CI: 8-14%) at 10 years, and 21% (95% CI: 16-28%) at 20 years measured from the date of radiotherapy. The relative risk of CVA compared to the general population in the UK was 4.1. Age was an independent predictive factor for CVA. However, the relative risk in comparison to the general population was independent of age. The relative risk of developing CVA was higher in women compared to men, in patients undergoing debulking surgery compared to less radical procedures, and in patients diagnosed and treated in the 1980s compared to previous decades. The dose of radiotherapy was an additional independent prognostic factor on multivariate analysis. CONCLUSION: Patients with pituitary adenoma treated with surgery and radiotherapy have a significantly increased risk of CVA compared to the general population. The factors which may contribute to the increased risk include the presence of pituitary adenoma and consequent endocrine disturbances and the treatment, particularly the extent of surgery and the dose of radiotherapy. When assessing the value of treatment strategies, it is therefore important to include not only intermediate endpoints of tumor and hormonal control, but also late toxicity, including the incidence of CVA and overall survival as the primary endpoint. The potential predisposing factors for CVA need further elucidation to develop treatment strategies with lower risk and consequently, reduced mortality.

Adenoma↗
PubMed1999

Optimization of stereotactically-guided conformal treatment planning of sellar and parasellar tumors, based on normal brain dose volume histograms.

PURPOSE: To investigate the optimal treatment plan for stereotactically-guided conformal radiotherapy (SCRT) of sellar and parasellar lesions, with respect to sparing normal brain tissue, in the context of routine treatment delivery, based on dose volume histogram analysis. METHODS AND MATERIALS: Computed tomography (CT) data sets for 8 patients with sellar- and parasellar-based tumors (6 pituitary adenomas and 2 meningiomas) have been used in this study. Treatment plans were prepared for 3-coplanar and 3-, 4-, 6-, and 30-noncoplanar-field arrangements to obtain 95% isodose coverage of the planning target volume (PTV) for each plan. Conformal shaping was achieved by customized blocks generated with the beams eye view (BEV) facility. Dose volume histograms (DVH) were calculated for the normal brain (excluding the PTV), and comparisons made for normal tissue sparing for all treatment plans at > or =80%, > or =60%, and > or =40% of the prescribed dose. RESULTS: The mean volume of normal brain receiving > or =80% and > or =60% of the prescribed dose decreased by 22.3% (range 14.8-35.1%, standard deviation sigma = 7.5%) and 47.6% (range 25.8-69.1%, sigma = 13.2%), respectively, with a 4-field noncoplanar technique when compared with a conventional 3-field coplanar technique. Adding 2 further fields, from 4-noncoplanar to 6-noncoplanar fields reduced the mean normal brain volume receiving > or =80% of the prescribed dose by a further 4.1% (range -6.5-11.8%, sigma = 6.4%), and the volume receiving > or =60% by 3.3% (range -5.5-12.2%, sigma = 5.4%), neither of which were statistically significant. Each case must be considered individually however, as a wide range is seen in the volume spared when increasing the number of fields from 4 to 6. Comparing the 4- and 6-field noncoplanar techniques to a 30-field conformal field approach (simulating a dynamic arc plan) revealed near-equivalent normal tissue sparing. CONCLUSION: Four to six widely spaced, fixed-conformal fields provide the optimum class solution for the treatment of sellar and parasellar lesions, both in terms of normal brain tissue sparing and providing a relatively straightforward patient setup. Increasing the number of fields did not result in further significant sparing, with no clear benefit from techniques approaching dynamic conformal radiotherapy in the cases examined.

Brain↗
PubMed1999

Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors.

PURPOSE: Intensity-modulated radiotherapy (IMRT) offers the potential to more closely conform dose distributions to the target, and spare organs at risk (OAR). Its clinical value is still being defined. The present study aims to compare IMRT with stereotactically guided conformal radiotherapy (SCRT) for patients with medium size convex-shaped brain tumors. METHODS AND MATERIALS: Five patients planned with SCRT were replanned with the IMRT-tomotherapy method using the Peacock system (Nomos Corporation). The planning target volume (PTV) and relevant OAR were assessed, and compared relative to SCRT plans using dose statistics, dose-volume histograms (DVH), and the Radiation Therapy Oncology Group (RTOG) stereotactic radiosurgery criteria. RESULTS: The median and mean PTV were 78 cm3 and 85 cm3 respectively (range 62-119 cm3). The differences in PTV doses for the whole group (Peacock-SCRT +/-1 SD) were 2%+/-1.8 (minimum PTV), and 0.1%+/-1.9 (maximum PTV). The PTV homogeneity achieved by Peacock was 12.1%+/-1.7 compared to 13.9%+/-1.3 with SCRT. Using RTOG guidelines, Peacock plans provided acceptable PTV coverage for all 5/5 plans compared to minor coverage deviations in 4/5 SCRT plans; acceptable homogeneity index for both plans (Peacock = 1.1 vs. SCRT = 1.2); and comparable conformity index (1.4 each). As a consequence of the transaxial method of arc delivery, the optic nerves received mean and maximum doses that were 11.1 to 11.6%, and 10.3 to 15.2% higher respectively with Peacock plan. The maximum optic lens, and brainstem dose were 3.1 to 4.8% higher, and 0.6% lower respectively with Peacock plan. However, all doses remained below the tolerance threshold (5 Gy for lens, and 50 Gy for optic nerves) and were clinically acceptable. CONCLUSIONS: The Peacock method provided improved PTV coverage, albeit small, in this group of convex tumors. Although the OAR doses were higher using the Peacock plans, all doses remained within the clinically defined threshold and were clinically acceptable. Further improvements may be expected using other methods of IMRT planning that do not limit the treatment delivery to transaxial arcs. Each IMRT system needs to be individually assessed as the paradigm utilized may provide different outcomes.

Algorithms↗
PubMed1999

Radiosurgery for pituitary adenoma.

The role of irradiation in the management of pituitary adenomas is not well defined. Nevertheless, patients with residual or recurrent tumours have been treated with conventional external-beam radiotherapy and more recently with high-precision stereotactic techniques of stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). We review some of the recently published articles on the efficacy and toxicity of SRS in the light of the current literature describing the results of conventional radiotherapy. While the general perception is that single-fraction SRS is more effective and less toxic than fractionated radiotherapy and in hormone-secreting tumours may produce a faster decline in elevated hormone levels, the available evidence suggests higher toxicity than seen with fractionated treatment without the reassurance of long-term tumour control. There is also no convincing evidence for more rapid reduction of elevated hormones. For the treatment of larger non-spherical pituitary adenomas, it may be appropriate to explore a potentially safer high-precision technique of fractionated conformal stereotactic radiotherapy (SCRT). In conclusion, there is currently little justification for the routine use of single-fraction SRS for the treatment of the majority of patients with benign pituitary adenomas.

Journal Article↗