18F-deoxyglucose positron emission tomography (FDG-PET) for the planning of radiotherapy in lung cancer: high impact in patients with atelectasis

PURPOSE

18F-deoxyglucose positron emission tomography (FDG-PET) is increasingly applied in the staging of lung cancer (LC). This study analyzes the potential contribution of PET in radiotherapy planning for LC with special respect to tumor-associated atelectasis.

METHODS AND MATERIALS

Thirty-four patients with histologically confirmed LC, who had been examined by PET during pretreatment staging, were included. All were irradiated after CT-based therapy planning with anterior/posterior (AP) portals encompassing the primary tumor and the mediastinum (CT portals, CP). The result of the PET examination was unknown in treatment planning. In retrospect, a PET portal (PP) was delineated and compared with the CP.

RESULTS

In 12/34 cases, the shape and/or size of the portals were changed, primarily (n = 10) the size of the fields was reduced. The median area of CP was 182 cm2 versus 167 cm2 of PP. Seventeen of 34 patients had dys- or atelectasis caused by a central primary tumor. In these cases, differences between CP and PP were significantly more frequent than in the other patients (8/17 vs. 3/17, p = 0.03).

CONCLUSION

In this retrospective analysis, the information provided by FDG-PET would have contributed to a substantial reduction of the size of radiotherapy portals. This applies particularly for patients with tumor-associated dys- or atelectasis.

Prognostic factors in brain metastases: should patients be selected for aggressive treatment according to recursive partitioning analysis (RPA) classes?

PURPOSE

To determine whether or not Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) derived prognostic classes for patients with brain metastases are generally applicable and can be recommended as rational strategy for patient selection for future clinical trials. Inclusion of time to non-CNS death as additional endpoint besides death from any cause might result in further valuable information, as survival limitation due to uncontrolled extracranial disease can be explored.

METHODS

We performed a retrospective analysis of prognostic factors for survival and time to non-CNS death in 528 patients treated at a single institution with radiotherapy or surgery plus radiotherapy for brain metastases. For this purpose, patients were divided into groups with Karnofsky performance status (KPS) <70% and KPS > or =70%, as proposed by the RTOG.

RESULTS

Median overall survival was 2.9 months (2.0 months for patients with KPS <70% and 3.6 months for patients with KPS > or =70%, p < 0.001). We did not find other variables splitting patients with KPS <70% in different prognostic groups. However, advanced age, multiple brain metastases, presence of extracranial metastases, and uncontrolled primary tumor each predicted shorter survival in patients with KPS > or =70%. When grouped into the original RTOG RPA classes, our data set split into three subgroups with different prognosis and median survival times of 10.5, 3.5, and 2 months, respectively (p < 0.05). Only 3% of patients fell into the most favorable group. Median time to non-CNS death was 4.1 months (12.9 months in RPA class I, 4.9 months in RPA class II, and 3.8 months in RPA class III, respectively, p > 0.05 for RPA class II versus III). However, it was 8.5 months in RPA class II patients with controlled primary tumor, which was found to be the only prognostic factor for time to non-CNS death in patients with KPS > or =70%. In patients with KPS <70%, no statistically significant prognostic factors were identified for this endpoint.

CONCLUSIONS

Despite some differences, this analysis essentially confirmed the value of RPA-derived prognostic classes, as published by the RTOG, when survival was chosen as endpoint. RPA class I patients seem to be most likely to profit from aggressive treatment strategies and should be included in appropriate clinical trials. However, their number appears to be very limited. Considering time to non-CNS death, our results suggest that certain patients in RPA class II also might benefit from increased local control of brain metastases.

A comparison of treatment results for recurrent malignant gliomas

Retreatment of malignant gliomas may be performed with palliative intent after careful consideration of the risks and benefits, and with special regards to iatrogenic neurotoxicity and quality of life (QOL). This review compares studies of several retreatment strategies (published between 1987 and 2000) based on the quality of their evidence. Depending on both established prognostic factors and previous treatment, individually tailored retreatment strategies are possible. In all studies that included a multivariate analysis of prognostic factors, performance status was the most important. So far, predictive factors for response, which might facilitate patient selection, have not been unequivocally defined. In terms of QOL, single-agent chemotherapy (temozolomide, nitrosoureas, platinum and taxane derivatives) may offer a better therapeutic ratio than polychemotherapy. For glioblastoma multiforme, progression-free survival and QOL were more favourable after temozolomide than procarbazine (level 1 evidence). The survival of patients after various radiotherapy techniques is broadly similar. However, considerable toxicity is associated with radiosurgery or brachytherapy. Fractionated stereotactic radiotherapy plus radio-sensitizing cytostatic agents has shown promising initial results in small groups of selected patients and awaits further evaluation. Level 2 evidence derived from non-randomized studies does not suggest a substantial prolongation of survival by re-resection as compared with chemotherapy or radiotherapy alone. Level 1 evidence derived from a randomized trial suggests that application of BCNU polymers significantly improves the outcome after re-resection. However, most studies reported median survival in the range of only 25-35 weeks, thereby emphasizing the need for the development and clinical evaluation of new innovative treatment approaches.

Tissue tolerance to reirradiation

There are increasing requests for delivering a second course of radiation to patients who develop second primary tumors within or close to previous radiotherapy portal or late in-field recurrences. Rational treatment decisions demand rather precise knowledge on long-term recovery of occult radiation injury in various organs. This article summarizes available experimental and clinical data on the effects of reirradiation to the skin, mucosa, gut, lung, spinal cord, brain, heart, bladder, and kidney. The data reveal that, in general, acutely responding tissues recover radiation injury within a few months and, therefore, can tolerate another full course of radiation. For late toxicity endpoints, however, tissues vary considerably in their capacity to recover from occult radiation damage. The heart, bladder, and kidney do not exhibit long-term recovery at all. In contrast, the skin, mucosa, lung, and spinal cord do recover subclinical injury partially to a magnitude dependent on the organ type, size of the initial dose, and, to a lesser extent, the interval between radiation courses. The available clinical data have inspired many radiation oncologists to undertake systematic studies addressing the efficacy and toxicity of reirradiation in various clinical settings. Hopefully, systematic scoring, collection, and analysis of patient outcome will produce quantitative data useful for clinical practice.

Cervical lymph node metastases from occult squamous cell carcinoma: cut down a tree to get an apple?

PURPOSE

To review the value of extended diagnostic work-up procedures and to compare the results of comprehensive or volume-restricted radiotherapy in patients presenting with cervical lymph node metastases from clinically undetectable squamous cell carcinoma.

METHODS AND MATERIALS

A systematic review was undertaken of published papers up to May 2000.

RESULTS

Positron emission tomography (PET) has an overall staging accuracy of 69%, with a positive predictive value of 56% and negative predictive value of 86%. With negative routine clinical examination and computerized tomography (CT) or magnetic resonance imaging (MRI), PET detected primary tumors in 5-25% of patients, whereas ipsilateral tonsillectomy discovered carcinoma in about 25% of patients. Laser-induced fluorescence imaging with panendoscopy and directed biopsies showed some encouraging preliminary results and warrants further study. All together, the reported mucosal carcinoma emergence rates were 2-13% (median, 9.5%) after comprehensive radiotherapy and 5-44% (median, 8%) after unilateral neck irradiation. The corresponding nodal relapse rates were 8-45% (median, 19%) and 31-63% (median, 51.5%), and 5-year survival rates were 34-63% (median, 50%) and 22-41% (median, 36.5%), respectively. Retrospective single-institution comparisons between comprehensive and unilateral neck radiotherapy did not show apparent differences in outcome. Prognostic determinants for survival are the N stage, number of nodes, extracapsular extension, and histologic grade. No data were found to support the benefit of chemotherapy in this disease.

CONCLUSION

Physical examination, CT or MRI, and panendoscopy with biopsies remain the standard work-up for these patients. Routine use of PET or laser-induced fluorescence imaging cannot be firmly advocated based on presently available data. Although combination of nodal dissection with comprehensive radiotherapy yielded most favorable results, its impact on the quality of life should be recognized, and the confounding effects of patient selection for various treatment modalities on therapeutic outcome cannot be ruled out. A randomized trial comparing the therapeutic value of comprehensive vs. volume-limited radiotherapy is being considered.

Rapid course radiation therapy vs. more standard treatment: a randomized trial for bone metastases

PURPOSE

In a prospective randomized trial we examined whether radiotherapy of painful bone metastases can be shortened using larger single doses without impairing effectivity.

METHODS AND MATERIALS

One hundred patients with painful bone metastases having no prior surgical intervention or treatment with x-ray therapy and had a median follow-up of 12 months were analyzed. The primary tumor was located in the breast in 43%, in the lung in 24%, and in the prostate in 14%. The most frequent sites of metastases were the pelvis (31%), the vertebral column (30%), and the ribs (20%). Further percentages of sites were: lower extremity 11%, upper extremity 6%, and skull 2%. Fifty-one patients received a short course radiotherapy with a total dose of 20 Gy in 1 week (daily dose 4 Gy), and 49 patients received 30 Gy in 3 weeks (daily dose 2 Gy).

RESULTS

There were no significant differences in frequency, duration of pain relief, improvement of mobility, recalcification, frequency of pathologic fractures nor survival. There was a light trend favoring 30 Gy in frequency of pain relief and recalcification. Survival was mostly influenced by primary tumor site, Karnofsky performance status, and possibly by the response to radiotherapy (pain relief).

CONCLUSIONS

Because of the very short life expectancy of patients with metastatic bone disease, we now use 20 Gy in 1 week as our standard to reduce hospital stay.

A palliative accelerated irradiation regimen for advanced non-small-cell lung cancer vs. conventionally fractionated 60 GY: results of a randomized equivalence study

PURPOSE

Radiation oncologists are often faced with patients with advanced non-small-cell lung cancer (NSCLC), who are not suitable candidates for state-of-the-art radical treatment, but who also are not judged to have a very short life expectancy. Some physicians treat these patients palliatively, whereas others advocate more intensive treatment. To find out if there is a substantial difference in outcome between these approaches, we performed a randomized prospective study.

METHODS AND MATERIALS

Between 1994 and 1998, 152 eligible patients with advanced NSCLC Stage III (n = 121) or minimal Stage IV (n = 31) were randomized to receive conventionally fractionated (cf; A: 60 Gy, 6 weeks, n = 79) or short-term treatment (PAIR; B: 32 Gy, 2 Gy b.i.d.; n = 73) of tumor and mediastinum.

RESULTS

One-year survival rate for all patients was 37% with no significant difference between the two treatment arms (A: 36%; B: 38%; p = 0.76). As far as can be judged from limited data available, palliation was adequate and similar for the two treatment arms. Apart from expected differences in the time course of esophagitis, acute side effects were moderate and equally distributed. No severe late effects were observed.

CONCLUSIONS

In the present randomized trial, survival and available data on palliation were not different after cf to 60 Gy compared to the palliative PAIR regimen. Therefore, for patients who are not suitable for radical treatment approaches, the prescription of a palliative short-term irradiation appears preferable compared to cf over several weeks.

Tumor-related prognostic factors for remission of brain metastases after radiotherapy

PURPOSE

To study CT determined response to external beam radiotherapy as well as influence of tumor-related factors, especially of tumor volume, on remission and to evaluate whether particular subgroups of metastases are controlled by low-dose radiotherapy.

METHODS AND MATERIALS

Contrast-enhanced CT scans before and after radiotherapy were analyzed.

INCLUSION CRITERIA

brain metastases treated with whole-brain radiotherapy (10 fractions of 3 Gy over 2 weeks) since 1983; no additional treatment, for example, surgery or chemotherapy; at least one follow-up CT. Three hundred thirty-six metastases from 108 patients were evaluated with regard to their volume, extent of necrosis, histology of primary tumor, and interval between radiotherapy and follow-up CT. All parameters were correlated with best local result and progression-free survival by uni- and multivariate tests. Volume-response curves were calculated.

RESULTS

In univariate analysis local result was significantly influenced by each of the four parameters mentioned above. Complete remission was observed in 37% of metastases from small-cell carcinoma, 35% of those from breast cancer, 25% of those from squamous-cell carcinoma, and 14% of those from nonbreast adenocarcinoma. The rate was 52% for metastases <0.5 cm3 and 0% for those >10 cm3. In multivariate analysis, small volume and no necrosis were the most important prognostic factors for complete remission. Progression-free survival was influenced by best local result.

CONCLUSION

With radiotherapy to a total dose of 30 Gy even small metastases had a complete remission rate of 52% only. Therefore, patients should be treated with locally more effective dose and fractionation schedules when local control is the aim. However, partial remission rate was remarkable even for large and necrotic metastases. This should be considered when palliation is the aim of treatment.

Late radiation toxicity after whole brain radiotherapy: the influence of antiepileptic drugs

This retrospective study had the following aims: (a) calculation of actuarial rate of late radiation toxicity after whole-brain radiotherapy (WBRT), (b) correlation of clinical symptoms with changes of computed tomography (CT) scans, and (c) analysis of potentially predictive factors with special regard to concomitant treatment with antiepileptic drugs. We analyzed 49 adult patients, selected from a preexisting data base. Inclusion criteria were as follows: no previous brain irradiation; WBRT without boost; CT, clinical, and neurologic examination before and more than 3 months after completion of WBRT. Uni- and multivariate tests of various patient- and treatment-related parameters as possible predictive factors for clinical symptoms of late radiation toxicity (scored according to the RTOG/EORTC system) as well as cerebral atrophy and white matter abnormalities were performed. Median age was 54 years. Patients were treated for brain metastases (n = 37), primary cerebral lymphoma (n = 2), primary brain tumors (n = 7), or with prophylactic intention (n = 3). Carbamazepine was given to 15 patients, phenytoin to 12, and barbiturate to 7, respectively; 42 patients also received corticosteroids. The median dose of WBRT was 30 Gy (range 27-66 Gy). Median fraction size was 3 Gy (1-3 Gy). Nine patients received two fractions per day. The biologically effective dose (BED) according to the linear-quadratic model ranged between 90 and 141 Gy (median, 120 Gy; alpha/beta value, 1 Gy). Median follow-up was 10 months (range, 4-130 months). In 16 cases, symptoms of late radiation toxicity grade I-III appeared. Actuarial rates were 32% after 1 year, 49% after 2 years, and 83% after 5 years. Actuarial rates of cerebral atrophy were 50% after 1 year and 84% after 2 years (white matter abnormalities: 25% and 85%, respectively). There was a significant correlation between atrophy and white matter abnormalities, but not between CT changes and clinical symptoms. CT changes were dependent on BED, absence of barbiturate use, and preexisting cerebral atrophy. Clinical symptoms usually were dependent on BED too, but treatment with carbamazepine was more important in the multivariate model. Neither other drugs nor other factors influenced late radiation toxicity. A detailed analysis showed that most carbamazepine-treated symptomatic patients took the drug during WBRT as well as during follow-up. Actuarial rates of grade I-III symptoms were 18% versus 50% after 1 year with or without carbamazepine. Even after exclusion of carbamazepine-treated patients, CT changes and clinical symptoms did not correlate. In conclusion, a BED <120 Gy was associated with a lower rate of late radiation toxicity after WBRT. The anticonvulsant drug carbamazepine showed a surprisingly clear influence on clinical symptoms of late radiation toxicity; that might be explained by the fact that the side effects of long-term drug treatment are indistinguishable from mild or moderate true radiation sequelae, rather than that it has a role in the pathogenesis of radiation-induced changes.

The results of colorectal cancer treatment by p53 status: treatment-specific overview

PURPOSE

Both negative and positive influences of mutant p53 on treatment outcome have been reported, and we present here a meta-analysis of published studies where outcome was reported for defined treatment groups.

METHODS

We identified articles on the effect of p53 status by treatment modality, excluding those not stratified by method of treatment. A common hazard ratio was estimated from studies that reported a multivariate analysis. We also estimated the numbers of patients expressing the endpoint at the mean or median follow-up time and calculated a pooled odds ratio.

RESULTS

Twenty-eight articles were evaluable (23 using immunohistochemistry to detect overexpression of p53 and 8 using DNA sequencing), for a total of 4,416 patients. For patients treated with surgery only, the immunohistochemistry studies showed a significant influence of p53 status on disease-free survival and a marginally significant influence on overall survival. In the studies using DNA sequencing, by contrast, there was a significant influence of p53 mutations on overall survival, but not disease-free survival. For patients treated with surgery and radiotherapy, the influence of p53 status on disease-free survival was either insignificant or marginally significant, depending on test used; there was no influence on overall survival.

CONCLUSIONS

Although this pooled analysis of published studies where treatment was accounted for shows that there is a borderline significant hazard associated with p53 overexpression or mutation vs. p53 wild-type, it is unlikely that p53 can be applied in a routine clinical setting alongside factors such as T stage, nodal status, and residual tumor, whose prognostic value is much stronger.

The challenge of p53 as prognostic and predictive factor in gliomas

In recent years, increasing interest in genetic abnormalities and biologic factors such as the tumour suppressor gene p53 as possible predictive and prognostic factor in gliomas has emerged. Inactivation of p53 can result in resistance to apoptosis, one of the mechanisms thought to explain the failure to respond to DNA-damaging agents. Thus, inactivation of p53 might be associated with a worse prognosis. Considering the inconsistent results of several recent studies, it has remained controversial whether p53 actually can be related to response to treatment and patients' prognosis. Therefore, a systematic review of the literature was performed, which included 28 publications. Techniques for assessing the inactivation of p53 varied widely. Overall, approximately 50% or more of astrocytoma specimens evaluated by immunohistochemistry stained positively for p53, regardless of histologic grade. Eight studies were restricted to comparably treated patients within a single histologic group. In most instances, non-restrictive inclusion criteria and use of statistical methods, which were not sufficient to correct the possible bias, make it difficult to reach unequivocal conclusions. However, it appears that the prognostic information of p53 is at best marginal, especially when compared to established parameters such as grading, age, etc. Its predictive value, which most likely is rather limited too, can hardly be judged without prospective studies also evaluating other biological factors as well as end-points other than time to radiological progression.

Risk factors and dose-effect relationship for osteoradionecrosis after hyperfractionated and conventionally fractionated radiotherapy for oral cancer

A high frequency of osteoradionecrosis after hyperfractionated radiotherapy (RT) of head and neck tumours led to a detailed analysis of risk factors in the dental, surgical, and radiotherapeutic areas. 168 patients with oral cancer were analysed retrospectively. 19% of them had been irradiated primarily and 81% postoperatively. 116 patients received a total dose mostly ranging from 60 Gy to 70 Gy to the ICRU 29 reference point (daily single dose 2 Gy). 52 patients were treated hyperfractionally with two daily fractions of 1.2 Gy per day, 4 h minimum apart and a total dose 82.8 Gy. Dental findings could be evaluated in 126 patients. Factors were checked for prognostic significance for osteoradionecrosis (ORN). Dose dependency was computed using a PROBIT analysis. Dental status before radiotherapy was generally poor (mean 11/32 teeth present, of these 1 was dead, 2.4 carious, 2.4 loose, 0.3 destroyed). On average, six teeth (range 0-27 teeth) had to be extracted. In one-third of the patients bone surgery was necessary. ORN occurred in 8.6% of the patients treated conventionally but in 22.9% of those treated hyperfractionally (p = 0.029). Biologically effective dose (p = 0.032) and deep paradontitis (p = 0.034) proved to be significant risk factors for ORN. PROBIT analysis showed a steadily rising dose dependency of the ORN frequency after conventional radiotherapy. Using total doses up to 70 Gy the frequency of ORN was 8.6%. Dose escalation using hyperfractionation led to an intolerable ORN frequency (22.9%) where a short interfraction interval was a significant factor. The use of this dose fractionation was therefore discontinued in 1992.

Patterns of relapse and late toxicity after resection and whole-brain radiotherapy for solitary brain metastases

BACKGROUND

This retrospective analysis was performed in order to evaluate the pattern of relapse and the risk of late toxicity for solitary brain metastases treated with surgery and whole-brain radiotherapy and to correlate the results with those from radiosurgical trials.

PATIENTS AND METHODS

From a total of 66 patients, 52 received 10 x 3 Gy and 10 were treated with 20 x 2 Gy whole-brain radiotherapy after resection of their brain metastases.

RESULTS

The actuarial probability of relapse was 27% and 55% after 1 and 2 year(s), respectively. The local relapse rate (at the original site of resected brain metastases) was rather high for melanoma, non-breast adenocarcinoma, and squamous-cell carcinoma. No local relapse occurred in breast cancer and small-cell carcinoma. Failure elsewhere in the brain seemed to be influenced by extracranial disease activity. Size of brain metastases and total dose showed no correlation with relapse rate. Occurrence of brain relapse was not associated with a reduced survival time, because 10/15 patients who developed a relapse received salvage therapy. Of the patients, 11 had symptoms of late radiation toxicity (the actuarial probability was 42% after 2 years).

CONCLUSIONS

Most results of surgical and radiosurgical studies are comparable to ours. Several randomized trials investigate surgical resection versus radiosurgery, as well as the effects of additional whole-brain radiotherapy in order to define the treatment of choice. Some data support the adjuvant application of 10 x 3 Gy over 2 weeks as a reasonable compromise when local control, toxicity, and treatment time have to be considered.

Relation between local result and total dose of radiotherapy for brain metastases

PURPOSE

Some studies published recently focused on the improvement of the treatment results of patients with brain metastases who underwent radiation therapy. They evaluated survival as a measure for the expected improvement, but failed to demonstrate a significant benefit from an increased total dose of radiotherapy. This study was targeted to investigate the effect of dose escalation with a different endpoint, the local response.

METHODS AND MATERIALS

As a first step, a retrospective analysis of 164 patients treated with a standard regimen of 10 x 3 Gy was performed to find factors correlating with the local result. All patients were systematically followed and underwent regular computed tomography (CT) examinations of the brain after irradiation. The second step was to compare, with respect to local control and survival, 39 patients treated with a total dose of 40-60 Gy with 39 patients treated with the standard regimen selected by means of a matched cohort pairs method.

RESULTS

The retrospective analysis showed a dependence of the local result after irradiation on three parameters: diameter of brain metastases, primary tumor, and tumor histology. Small-cell and adenocarcinoma were found to be more radiosensitive than squamous-cell carcinoma. The highest radiosensitivity was found in breast cancer metastases. The matching procedure was performed with respect to those parameters and also the number of brain metastases and total cerebral tumor volume. The resulting groups were absolutely equivalent and differed only with regard to the total dose applied. The local response (complete or partial remission) was 48-52% after 30 Gy vs. 77% after 40-60 Gy (p < or = 0.05). Survival was not significantly different. A further analysis of the dose-response relationships showed the tendency of control probability to increase with total dose.

CONCLUSION

This study suggests that there is a rationale for dose escalation in the treatment of brain metastases with radiotherapy, when local control is the aim. However, it seems questionable whether an improvement in survival results.

Prognostic models predicting survival of patients with brain metastases: integration of lactate dehydrogenase, albumin and extracranial organ involvement

AIMS

To explore the role of expanded assessment of metastatic extracranial organ involvement, as well as albumin and lactate dehydrogenase (LDH), i.e. surrogates of disease extent, in survival prediction models for patients with brain metastases.

MATERIALS AND METHODS

A retrospective analysis of 189 patients treated with whole brain radiotherapy was carried out. Uni- and multivariate analyses included recursive partitioning analysis classes, basic score for brain metastases and diagnosis-specific graded prognostic assessment (DS-GPA).

RESULTS

Elevated LDH correlated significantly with extracranial organ involvement, low albumin with primary tumour type and primary tumour control. Elevated LDH, low albumin and a combination of both correlated significantly with overall survival. LDH, albumin and the number of extracranial organs involved (none, one, two or more harbouring metastases) were independent prognostic factors in multivariate analyses (if added to the three established scores mentioned above and also if added to individual parameters such as age, performance status, etc.). A combination of these three new prognostic factors predicted very short survival (median 0.7 months if all three were present).

CONCLUSION

We have previously defined patient groups in whom foregoing radiotherapy was unlikely to compromise survival. These were patients with a DS-GPA score of 0-1.5 points and age ≥75 years or Karnofsky performance status ≤50 or uncontrolled primary tumour with extracranial metastases to at least two organs. Patients with a combination of three new adverse features (elevated LDH plus low albumin plus extracranial metastases to at least two organs) might also be considered for best supportive care. Furthermore, it appears warranted to study whether scores such as DS-GPA can be optimised by integrating information on these three parameters.

Prediction of short survival in patients with brain metastases based on three different scores: a role for 'triple-negative' status?

AIMS

To evaluate models predicting short survival in patients with brain metastases treated with whole-brain radiotherapy (WBRT).

MATERIALS AND METHODS

This was a retrospective analysis of 312 patients. Each patient was assigned to three different four-tiered prognostic scores: the Basic Score for Brain Metastases (BSBM), the Graded Prognostic Assessment (GPA) and the score developed by Rades et al. In addition, a 'triple-negative' cohort was evaluated (all three scores predicted unfavourable prognosis, n=30).

RESULTS

No statistically significant survival differences were found between the most unfavourable BSBM, GPA, Rades et al. and 'triple-negative' groups. The BSBM best predicted short survival: patients classified in the unfavourable group (Karnofsky performance status <80, uncontrolled primary tumour and presence of extracranial metastases) had a 12.5% survival at 4 months and a 0% 1-year survival. Patients in this group who survived for 4 months or more had simultaneously detected cancer and brain metastases, were treatment naive, and received systemic therapy in addition to WBRT. Excluding this type of patient from the analysis resulted in survival figures that were indistinguishable from those obtained with best supportive care without WBRT in other studies.

CONCLUSIONS

Although continuous research is necessary to identify patients who can be managed safely and palliated without WBRT, we feel that a model of the BSBM unfavourable group (Karnofsky performance status <80, uncontrolled primary tumour and presence of extracranial metastases) and no intent to treat systemically might form a basis for validation in other large databases. The triple-negativity criterion was not superior for predicting poor prognosis.

Dose-escalated simultaneous integrated-boost treatment of prostate cancer patients via helical tomotherapy

PURPOSE

The goal of this work was to assess the feasibility of moderately hypofractionated simultaneous integrated-boost intensity-modulated radiotherapy (SIB-IMRT) with helical tomotherapy in patients with localized prostate cancer regarding acute side effects and dose-volume histogram data (DVH data).

METHODS

Acute side effects and DVH data were evaluated of the first 40 intermediate risk prostate cancer patients treated with a definitive daily image-guided SIB-IMRT protocol via helical tomotherapy in our department. The planning target volume including the prostate and the base of the seminal vesicles with safety margins was treated with 70 Gy in 35 fractions. The boost volume containing the prostate and 3 mm safety margins (5 mm craniocaudal) was treated as SIB to a total dose of 76 Gy (2.17 Gy per fraction). Planning constraints for the anterior rectal wall were set in order not to exceed the dose of 76 Gy prescribed to the boost volume. Acute toxicity was evaluated prospectively using a modified CTCAE (Common Terminology Criteria for Adverse Events) score.

RESULTS

SIB-IMRT allowed good rectal sparing, although the full boost dose was permitted to the anterior rectal wall. Median rectum dose was 38 Gy in all patients and the median volumes receiving at least 65 Gy (V65), 70 Gy (V70), and 75 Gy (V75) were 13.5%, 9%, and 3%, respectively. No grade 4 toxicity was observed. Acute grade 3 toxicity was observed in 20% of patients involving nocturia only. Grade 2 acute intestinal and urological side effects occurred in 25% and 57.5%, respectively. No correlation was found between acute toxicity and the DVH data.

CONCLUSION

This institutional SIB-IMRT protocol using daily image guidance as a precondition for smaller safety margins allows dose escalation to the prostate without increasing acute toxicity.

Dose/effect relationships for brain metastases

PURPOSE

Only in selected patients with brain metastases, e.g. those with controlled or absent extracranial tumour, may application of higher total doses of radiotherapy improve survival. However, local control is the prerequisite for long-term survival. This study aimed to answer the question whether or not local control can be improved by dose escalation.

METHODS

Computed tomography scans of 322 patients were analysed in order to evaluate the best local result after radiotherapy and the time to local progression. Total doses of 25-60 Gy were administered (single doses 1.8-5 Gy). The biologically effective dose (BED10) was calculated for statistical evaluation according to the linear-quadratic model assuming an alpha/beta-value of Gy. It ranged between 37.5 Gy and 72 Gy.

RESULTS

The best local result was dependent on the number of brain metastases, BED and the histology of the primary tumour (small-cell and breast carcinoma had higher remission rates than squamous-cell carcinoma, non-breast adenocarcinoma and others). Partial remission rates significantly increased with BED, whereas complete remission rates did not improve. Histology was the only significant factor in multivariate tests. The 1-year-failure rate improved with increased BED from 44% to 31% (P > 0.05). Overall survival (median 3 months) was not dependent on total dose.

CONCLUSIONS

Previous studies suggested that a prolongation of survival can be achieved through better local management (e.g. surgery plus radiotherapy, radiosurgery). However, it is still uncertain whether conventional external-beam radiotherapy with higher total doses leads to comparable results. The optimum dose level still has to be established. For squamous-cell carcinoma and adenocarcinoma a BED of at least 72 Gy seems to be necessary, for small-cell and breast carcinoma, doses between 48 Gy and 60 Gy might be sufficient. The important influence of tumour histology on local remission and progression-free survival should be considered when planning future clinical trials.

Use of the Graded Prognostic Assessment (GPA) score in patients with brain metastases from primary tumours not represented in the diagnosis-specific GPA studies

BACKGROUND AND PURPOSE

Assessment of prognostic factors might influence treatment decisions in patients with brain metastases. Based on large studies, the diagnosis-specific graded prognostic assessment (GPA) score is a useful tool. However, patients with unknown or rare primary tumours are not represented in this model. A pragmatic approach might be use of the first GPA version which is not limited to specific primary tumours.

PATIENTS AND METHODS

This retrospective analysis examines for the first time whether the GPA is a valid score in patients not eligible for the diagnosis-specific GPA. It includes 71 patients with unknown primary tumour, bladder cancer, ovarian cancer, thyroid cancer or other uncommon primaries. Survival was evaluated in uni- and multivariate tests.

RESULTS

The GPA significantly predicted survival. Moreover, improved survival was seen in patients treated with surgical resection or radiosurgery (SRS) for brain metastases. The older recursive partitioning analysis (RPA) score was significant in univariate analysis. However, the multivariate model with RPA, GPA and surgery or SRS versus none showed that only GPA and type of treatment were independent predictors of survival.

CONCLUSION

Ideally, cooperative research efforts would lead to development of diagnosis-specific scores also for patients with rare or unknown primary tumours. In the meantime, a pragmatic approach of using the general GPA score appears reasonable.

Hyperfractionated and accelerated-hyperfractionated radiotherapy for glioblastoma multiforme

Because of promising radiobiological advantages allowing dose escalation and/or reduction of treatment time, hyperfractionated and accelerated-hyperfractionated radiotherapy (hf-rt, ahf-rt) were introduced as part of treatment of glioblastoma multiforme (gbm). In December 1988 we started a prospective study of hf-rt (total dose 78 Gy, two daily fractions of 1.3 Gy, interval between daily fractions 6 hr, treatment time 6 weeks, n = 34 patients). The results were compared with our previous regimen of conventionally fractionated radiotherapy (cf-rt: total dose 60 Gy, single dose 2 Gy, treatment time 6 weeks, n = 32 patients). In June 1990, the protocol was modified in order to reduce treatment time (ahf-rt: total dose 60 Gy, two daily fractions of 1.5 Gy, interval 6 hr, treatment time 4 weeks, n = 92 patients until December 1996). No chemotherapy was given. Entry criteria were: age > or = 17 years, pathological diagnosis of supratentorial gbm, and no previous treatment other than surgery. The ahf-rt group included significantly more patients with previous surgical resection instead of biopsy only. Compared with the cf-rt group, both the hf-rt and the ahf-rt group included significantly more patients with frontal tumor location. We found no significant survival difference between the groups (median survival 7-10 months, 1-year survival rate 19%-29%). Progression-free survival, clinical course, and toxicity were also not significantly different. Karnofsky performance status, age, and corticosteroid dose during radiotherapy were the most important prognostic factors. The results of this trial are in large agreement with most previous publications. It demonstrated no improved survival. However, it showed that treatment time can be reduced by ahf-rt without loss of survival benefit or intolerable toxicity. A short radiotherapy course might be appropriate for many patients with gbm who are not suitable for rather aggressive investigational therapies.

Influence of differing radiotherapy strategies on treatment results in diffuse large-cell lymphoma: a review

In the absence of evidence from randomised trials, radiation treatment of diffuse large-cell lymphoma of B-cell type represents an area of controversy with considerable differences in patterns of practice. The present literature survey aims at clarification of the role of radiotherapy in combined modality settings by identification of dose-response relationships, predictive factors for local control, and potential pitfalls in the interpretation of retrospective studies. Radiotherapy might increase local control in initially involved areas and is usually delivered to these sites (involved-field treatment). Combined modality treatment is currently recommended for patients in stage I or II if they are not treated in the context of prospective studies. Whether involved-field consolidation radiotherapy after systemic treatment in patients with bulky, stage III-IV lymphomas should be routinely recommended is presently unclear. Definition of bulky disease is arbitrary and varied between 6 and 10cm, reflecting a considerable difference in the number of clonogenic tumour cells. Several retrospective and one prospective randomised study suggest improved disease-free and overall survival by radiotherapy in advanced stages. The 5-year local control by radiotherapy was 93-98%. Currently, we recommend the following minimum doses for involved-field radiotherapy derived from this literature survey. Lymphomas with initial size <3.5 cm (possibly <6 cm) can be treated with 30 or 30.6Gy when a complete remission (CR) has been achieved by chemotherapy. The next group might be sufficiently controlled by 36Gy, but it remains unclear whether the cut-off should be 6cm or higher. Forty Gy appears to control tumours in the range of 7-10cm. Most likely, 45Gy does not have to be exceeded for larger lesions. Data on those with less than CR are contradictory. Judging the amount of viable tumour in these patients is problematic, but crucial to determine the intensity of further treatment. The value of positron emission tomography is still under investigation. Because the difference between doses of 30 and 40Gy might actually make a difference for the long-term toxicity of radiotherapy in some of the normal tissues and organs at risk (salivary glands, orbital structures, lung, heart, etc.), it appears prudent to resolve the open questions in prospective trials with careful documentation of side effects.

Ten years disease-free survival after solitary brain metastasis from breast cancer

The unique case of a 51-year-old woman who developed a solitary brain metastasis as the first site of systemic disease 11 months after a total mastectomy for an undifferentiated infiltrating ductal carcinoma of her right breast is described. After surgery for the pT2pN0 carcinoma, the patient received radiotherapy of the internal mammary and supraclavicular lymph nodes. The brain metastasis was treated with surgery and adjuvant whole-brain radiotherapy to a total dose of 30 Gy in December 1984 and January 1985. Afterwards a hormonal treatment with tamoxifen was initiated, which still continues. Since then no further distant or lymph node metastases have developed. The patient is under regular after-care and undergoes various apparative examinations every 6 months. She is generally well and suffers only from a postoperatively persistent hemianopsia. This is the first case in which a disease-free survival for more than 10 years after brain metastases from breast cancer has been reported. It illustrates the specific biological behaviour of this tumour type and the chance of achieving long-term survival in very selected cases.

Accelerated radiotherapy for brain metastases

BACKGROUND AND PURPOSE

Two novel fractionation schedules for whole-brain irradiation were applied to patients with brain metastases. Both schedules were aimed at reduction of treatment time, whereby tumour control should be increasing with the application of a higher total dose (schedule 2).

MATERIALS AND METHODS

We applied 2 x 2.5 Gy/day to a total dose of 30 Gy (schedule 1) or 2 x 1.8 Gy/day to a total dose of 50.4 Gy (schedule 2). The interval between daily fractions was 6 h. Treatment was interrupted on weekends. The 30 Gy schedule was also used in adjuvant treatment for resected brain metastases. We compared the results of 15 patients who underwent the 50.4 Gy schedule and 47 patients who were treated up to 30 Gy with those of a historical patient group, treated with one daily fraction of 3 Gy up to 30 Gy (n = 283).

RESULTS

Local result, clinical course and survival were similar for the 30 Gy groups, whereby prognostic factors were equally distributed. Despite a favourable patient selection no therapeutic gain was seen for the 50.4 Gy group. Patients treated with the accelerated 30 Gy schedule had a significantly worse progression-free survival and a higher rate of late radiation toxicity than the historical group. In contrast, no severe acute toxicity was observed.

CONCLUSIONS

Considering progression-free survival and late toxicity, the accelerated 30 Gy schedule can not be recommended without hesitation. Radiotherapy with a higher total dose (50.4 Gy) showed no advantage.

The challenge of p53 as prognostic and predictive factor in Hodgkin's or non-Hodgkin's lymphoma

The results of individual studies examining the role of p53 as a predictive and prognostic factor in lymphoid malignancies have varied considerably. In order to summarize the available data on the overexpression or mutation of p53 in Hodgkin's and non-Hodgkin's lymphoma, a systematic literature review was performed. Twenty-four studies met the eligibility criteria. With respect to non-Hodgkin's lymphoma, most studies seem to support the hypothesis that patients whose tumors contain wild-type p53 respond better to treatment and have increased survival rates. If true, the implication may be that patients with p53 mutated tumors could be selected for non-standard treatment. With respect to Hodgkin's lymphoma, comparable associations were rarely reported. However, techniques for assessing the inactivation of p53 varied widely. Furthermore, in most instances, the study design and/or statistical methods did not allow sufficient analyses of the influence of confounding factors such as histologic type, stage, first-line and salvage treatment, etc. Therefore, it remains unclear whether the apparent influence of p53 status on outcome in non-Hodgkin's lymphoma is independent of established parameters such as stage, performance status, etc. Further studies involving large numbers of specimens derived from patients treated in clinical trials with identical regimens, follow-up and salvage strategies are needed. These studies should also be stratified according to histologic subtypes.

Radiation myelopathy: new perspective on an old problem

This article discusses recent advances in basic research that alter the view of the pathogenesis of radiation myelopathy and summarizes the available data from developmental neurobiology and preclinical studies on demyelinating diseases. These studies have produced interesting insights into oligodendrocyte development, intercellular signaling pathways, and myelination processes. Current findings suggest that administration of cytokines as platelet-derived growth factor and basic fibroblast growth factor could increase proliferation of oligodendrocyte progenitors, enhance their differentiation, up-regulate synthesis of myelin constituents, and promote myelin regeneration in the adult central nervous system (CNS). Other compounds might also be able to modulate the progression of pathogenic processes that lead to myelopathy. In addition, several possible biological prevention or treatment strategies, for example stimulation of endogenous cellular regeneration and glial cell transplantation, are discussed. Rationally designed animal experiments pursuing such strategies could further elucidate the pathogenesis of radiation-induced CNS damage.