Prognostic factors for acute and late skin reactions in radiotherapy patients

Chromosomal aberrations induced by chemotherapy and radiotherapy in lymphocytes from patients with breast carcinoma

PURPOSE

Stable chromosomal aberrations (SCAs) have been found in circulating lymphocytes from patients treated for breast carcinoma. Therefore, we tried to define their incidence in such patients, to determine an in vitro dose-effect relationship, and to correlate these data with clinical parameters.

METHODS AND MATERIALS

This prospective study included 25 patients who, after surgery, underwent either radiotherapy (RT) alone (n = 15) or RT combined with chemotherapy (n = 10). SCAs were scored using the fluorescent in situ hybridization technique before RT and 4 and 12 months after RT. Dose-effect curves were established by in vitro irradiation of blood samples with 2 and 4 Gy, before and after treatment.

RESULTS

In all patients, the rate of SCAs increased significantly after external irradiation. No significant decrease in SCAs was observed during the first year after RT. RT and chemotherapy had no effect on the lymphocyte in vitro dose-effect relationship. No relationship was found in the distribution of patients between the yield of SCAs scored after external irradiation and after in vitro irradiation. SCAs after RT or in vitro irradiation did not correlate with family history of breast carcinoma or acute toxicity of treatment. More significantly, the yield of SCA after external irradiation was strongly related to the irradiation of the internal mammary chain and the supraclavicular lymph node area, suggesting that the volume of irradiated blood vessels was an essential parameter in determining the rate of SCAs.

CONCLUSION

A high and stable yield of SCAs persisted at least 1 year after external irradiation. The nature of the volume irradiated containing large blood vessels was the major determinant of the observed biologic dose.

Relationship between residual radiation-induced DNA double-strand breaks in cultured fibroblasts and late radiation reactions: a comparison of training and validation cohorts of breast cancer patients

BACKGROUND AND PURPOSE

Using pulsed field gel electrophoresis (PFGE) a significant correlation was demonstrated between residual DNA double-strand breaks (dsbs) and the development of late radiation fibrosis in a group of 39 breast cancer patients studied retrospectively. This group formed a training cohort generating a hypothesis that there is a relationship between residual radiation-induced DNA dsbs in cultured fibroblasts and late radiotherapy reactions in breast cancer patients. The aim of this study was to retest and validate the hypothesis.

MATERIALS AND METHODS

The study was retrospective. Skin biopsies were taken from a validation cohort of 50 breast cancer patients and PFGE was used to examine residual radiation-induced dsbs in cultured fibroblasts. Late morbidity was measured clinically as fibrosis and using the late effects on normal tissues scales that incorporate subjective, objective management and analytic data (LENT SOMA).

RESULTS

PFGE data were obtained for 49 biopsies. In the 49 patients there was no correlation between residual DNA damage and either fibrosis (r=-0.027, P=0.85) or LENT SOMA (r=-0.10, P=0.48) scores. There was no significant relationship between residual damage and fibrosis for the combined training and validation cohorts of 88 patients (r=0.20, P=0.063).

CONCLUSIONS

This study did not validate the hypothesis that there is a relationship between fibroblast residual DNA damage and late morbidity in breast cancer patients. The PFGE assay on fibroblasts is not a suitable test of the degree of late radiation-induced fibrosis in the breast.

Studies on radiosensitivity from an epidemiological point of view - overview of methods and results

BACKGROUND AND PURPOSE

The establishment of a predictive in vitro assay for radiosensitivity has been a goal in radiotherapy research. To date, no single assay has proven to be effective for this purpose. A review of the epidemiologic methods used in the studies has been undertaken to evaluate limitations associated with specific design options and to develop recommendations for future research.

MATERIALS AND METHODS

We focused on studies attempting to establish the usefulness of an assay in breast cancer patients undergoing radiotherapy using skin reactions as indicators for radiosensitivity. The 25 published studies included were evaluated with respect to criteria for good epidemiological studies: (a) study design, (b) study population, (c) assessment of radiation reaction, and (d) treatment of confounding factors.

RESULTS

Limitations in study design were often found among the studies reviewed. Possible sources of bias are, among others, misclassification due to non-standardized assessment of side effects, selection bias due to drawing convenience patient groups instead of representative patient groups, and confounding due to analysis not adjusted for important factors influencing the severity of side effects.

CONCLUSIONS

Further studies should make use of good epidemiological practice so that valid conclusions can be drawn with respect to the usefulness of an in vitro assay to distinguish between patients with different degrees of radiosensitivity in clinical practice.

[Reversibility of radiation-induced fibroatrophy]

PURPOSE

The radiation-induced fibro-atrophic process described in numerous tissues and organs is a localized and irreversible late effect of high-dose radiation therapy. Our purpose is to show that this process is today reversible.

CURRENT KNOWLEDGE AND KEY POINTS

This review describes a synthesis of various clinical, paraclinical and histopathological aspects of radiation-induced fibro-atrophic process, and of cellular and molecular process regulation. Schematically, there exists a prefibrotic aspecific inflammatory phase, then a constituted and cellular phase, then a matricial densification and remodeling phase, associated in some cases with a tissular terminal necrosis. The respective parts and their evolution during time of the main protagonists as myofibroblast, extracellular matrix and growth factor TGF beta 1 are clarified. From the pathophysiological mechanisms described, curative therapeutic attitudes are proposed for the different progressive phases. Especially, superoxide dismutase (not available) and the pentoxifylline-tocopherol combination seem to allow reduction and reversibility of the fibro-atrophic radiation-induced established process, in clinics as in animal experiments.

FUTURE PROSPECTS AND PROJECTS

Some phase II trials try to assess the therapeutic interest of combined pentoxifylline-tocopherol in various radiation-induced sequelae, as in osteo-radionecrosis. A clinical randomized trial phase III has just been achieved and could support the results of these experimental and retrospective clinical trials.

Deterministic rather than stochastic factors explain most of the variation in the expression of skin telangiectasia after radiotherapy

BACKGROUND

The large patient-to-patient variability in the grade of normal tissue injury after a standard course of radiotherapy is well established clinically. A better understanding of this individual variation may provide valuable insights into the pathogenesis of radiation damage and the prospects of predicting the outcome.

PURPOSE

To estimate the relative importance of the stochastic vs. patient-related components of variability in the expression of radiation-induced normal tissue damage.

METHODS AND MATERIALS

The study data were selected from the dose fractionation studies of Turesson in Gothenburg. Patients treated with bilateral internal mammary fields, who completed at least 10 years of follow-up, were included. The material included 22 different fractionation schedules (11 on each side). Telangiectasia was graded on an arbitrary 6-point scale using clinical photographs of the irradiated fields. For each field, in each patient, a curve showing the grade of telangiectasia as a function of time was constructed. A measure of radioresponsiveness was obtained from the difference between the area under the curve (AUC) for a specific field in an individual patient minus the mean AUC of fields receiving the same dose fractionation schedule. As a confirmatory procedure, the same analysis was repeated with a weighted area under the curve (WAUC) approach, in which the time spent at or above each of the 5 nonzero grades was calculated for each field in each patient. These times were used as explanatory variables in a linear regression analysis of biological equivalent dose to establish statistically the weight of each grade providing the optimal relationship between dose and effect. Using these regression coefficients, the weighted area under the grade-time curve (WAUC) was estimated.

RESULTS

The AUC was significantly correlated with the isoeffective dose in 2-Gy fractions (ID2). An analysis of variance components, using the maximum likelihood method, showed that 90% (with 95% confidence limits 65% and 100%) of the variance in radioresponsiveness in the right-sided field was explained by the radioresponsiveness on the left-sided field. Through the linear regression analysis between the AUC and the ID2, it was estimated that patients with a reaction that is 1 SD from the population mean would require a dose modification of approximately 23 Gy (from the group mean of 56 Gy) to give them a level of reaction similar to the group average. Similarly, the WAUC was significantly correlated with the ID2, and 81% (with 95% confidence limits 49% and 100%) of the variance in radioresponsiveness in the right-sided field was explained by the radioresponsiveness on the left-sided field. Patients with a reaction that is 1 SD from the population mean would require a dose modification of approximately 21 Gy (from the group mean of 56 Gy) to give them a level of reaction similar to the group average.

CONCLUSION

For a given fractionation schedule, patient-related factors explain 81-90% of the patient-to-patient variation in telangiectasia level seen after radiotherapy. The remaining 10-19% are explained by stochastic effects. This observation encourages further research into genetic or phenotypic assays of normal tissue radioresponsiveness.

The impact of skin washing with water and soap during breast irradiation: a randomized study

BACKGROUND

The effect of washing the irradiated skin during radiotherapy for breast cancer is uncertain. The purpose of this study was to evaluate the impact of washing the breast skin with water and soap during radiotherapy on the intensity of acute skin toxicity.

MATERIALS AND METHODS

Ninety-nine patients treated for breast cancer were prospectively randomized prior to receiving radiotherapy to the breast into two groups: (1), no washing was allowed during radiotherapy (49 patients); and (2), washing was allowed with water and soap (50 patients). Acute toxicity was recorded according to the Radiation Therapy Oncology Group (RTOG) acute skin toxicity scale for each patient every week during radiotherapy and 1 month after the end of radiotherapy. Symptoms related to skin toxicity were scored by visual analogue scales at the same time intervals. Other data collected included sociodemographic data, characteristics related to the tumor and previous treatments, radiation technique, necessity for a second simulation due to loss of skin marks and treatment interruptions.

RESULTS

In the non-washing group, the following maximum acute toxicity scores were observed: grade 0, 2%; grade 1, 41%; grade 2, 57%; grades 3 and 4, 0%. For the washing group, the scores were: grade 0, 0%; grade 1, 64%; grade 2, 34%; grade 3, 2%; and grade 4, 0%. Moist desquamation was seen in 33% of non-washing patients, but in only 14% of washing patients. The median scores of pain, itching and burning of the treated skin were higher in the non-washing group, although this was not statistically significant. In a multivariate analysis using logistic regression, acute skin toxicity was associated with the patient's weight, concomitant radiochemotherapy and hot spots on dosimetry, and there was a trend toward more acute skin toxicity in the non-washing group.

CONCLUSION

Washing the irradiated skin during the course of radiotherapy for breast cancer is not associated with increased skin toxicity and should not be discouraged.

[Radiation-induced superficial fibrosis and TGF-alpha 1]

Radiation-induced fibrosis is a late sequela of both therapeutic and accidental irradiations, which has been described in various tissues, including the lung, liver, kidney and skin. This review presents different aspects of superficial radiation-induced fibrosis, such as clinical observations, histological changes, cellular and molecular regulations, and medical management. Recent evidence on the critical role played by TGF-beta 1 in the initiation, development and persistence of fibrosis are discussed, as well as the possibility that this cytokine may constitute a specific target for antifibrotic agents.

Relationship between in vitro chromosomal radiosensitivity of peripheral blood lymphocytes and the expression of normal tissue damage following radiotherapy for breast cancer

BACKGROUND AND PURPOSE

There is a need for rapid and reliable tests for the prediction of normal tissue responses to radiotherapy, as this could lead to individualization of patient radiotherapy schedules and thus improvements in the therapeutic ratio. Because the use of cultured fibroblasts is too slow to be practicable in a clinical setting, we evaluated the predictive role of assays of lymphocyte chromosomal radiosensitivity in patients having radiotherapy for breast cancer.

MATERIALS AND METHODS

Radiosensitivity was assessed using a micronucleus (MN) assay at high dose rate (HDR) and low dose rate (LDR) on lymphocytes irradiated in the G(0) phase of the cell cycle (Scott D, Barber JB, Levine EL, Burril W, Roberts SA. Radiation-induced micronucleus induction in lymphocytes identifies a frequency of radiosensitive cases among breast cancer patients: a test for predispostion? Br. J. Cancer 1998;77;614-620) and an assay of G(2) phase chromatid radiosensitivity ('G(2) assay') (Scott D, Spreadborough A, Levine E, Roberts SA. Genetic predisposition in breast cancer. Lancet 1994; 344: 1444). In a study of acute reactions, blood samples were taken from breast cancer patients before the start of radiotherapy, and the skin reaction documented. 116 patients were tested with the HDR MN assay, 73 with the LDR MN assay and 123 with the G(2) assay. In a study of late reactions, samples were taken from a series of breast cancer patients 8-14 years after radiotherapy and the patients assessed for the severity of late effects according to the'LENT SOMA' scales. 47 were tested with the HDR assay, 26 with the LDR assay and 19 with the G(2) assay. For each clinical endpoint, patients were classified as being normal reactors or 'highly radiosensitive patients' (HR patients (Burnet NG. Johansen J, Turesson I, Nyman J. Describing patients' normal tissue reactions: Concerning the possiblity of individualising radiotherapy dose presciptions based on potential predictive assays of normal tissue radiosensitivity. Int. J. Cancer 1998;79:606-613)).

RESULTS

The HR patients could be identified in some of the assays. For example, for acute skin reactions, 9/123 patients were judged as HR; they had significantly higher G(2) scores than normal reactors (P=0.004). For the late reactions, the mean HDR MN scores were higher for the 4/47 patients who had severe telangiectasia (P=0.042) and the 8/47 patients had severe fibrosis (P=0.055). However, there were no trends towards increased chromosomal radiosensitivity with the micronucleus scores at HDR or LDR, or with G(2) chromosomal radiosensitivity.

CONCLUSIONS

While these results support the concept of using lymphocytes to detect elevated sensitivity to radiotherapy (as an alternative to fibroblasts), these assays are unlikely to be of assistance for the prediction of normal tissue effects in the clinic in their present form.

Cellular radiosensitivity and complication risk after curative radiotherapy

PURPOSE

To test for an association between in vitro fibroblast radiosensitivity and complication risk in a case-control study of breast cancer patients treated under standard conditions in a clinical trial of radiotherapy dose fractionation.

PATIENTS AND METHODS

A cohort of patients participating in a randomised clinical trial of radiotherapy dose fractionation was selected on the basis of treatment-induced changes in the breast several years later. Thirty-nine cases with marked normal tissue changes were matched on several variables with 65 controls with no changes attributable to radiotherapy. Dermal fibroblast strains were established from duplicate skin biopsies, and clonogenic cell survival assays performed in triplicate after both high ( approximately 1.6 Gy/min) and low ( approximately 1 cGy/min) dose-rate irradiation. Laboratory studies were blind to patient identity, treatment outcome and radiotherapy schedule.

RESULTS

Analysis of 1128 clonogenic survival curves confirmed significant inter-patient variation in fibroblast radiosensitivity as measured by clonogenic survival. However, no association between fibroblast radiosensitivity and the development of late radiotherapy normal tissue effects was detected.

CONCLUSIONS

Inter-individual variation in cellular radiosensitivity may not be the main determinant of complication risk in patients undergoing radiotherapy for breast cancer. Other biological and technical factors may be more important in explaining the marked inter-patient differences in normal tissue damage evident several years after curative radiotherapy.

Comparison of DNA repair protein expression and activities between human fibroblast cell lines with different radiosensitivities

In order to investigate the molecular basis of variation in response to ionising radiation (IR) in radiotherapy patients, we have studied the expression of several genes involved in DNA double-strand break repair pathways in fibroblast cell lines. Ten lines were established from skin biopsies of cancer patients with different normal-tissue reactions to IR, and 3 from a control individual. For all 10 test cell lines, the cellular radiosensitivity was also known. Using Western blots we measured, in non-irradiated cells, the basal expression levels of ATM, Rad1 and Hus1, involved in the control of cellular DNA damage checkpoints, together with DNA-PKcs, Ku70, Ku80; XRCC4, ligaseIV and Rad51, involved in radiation- induced DSB repair. We also analysed the in vitro enzymatic activities, under non-irradiated conditions, of the DNA-PK and XRCC4/ligaseIV complexes. The levels of expression of the different proteins were similar in all the cell lines, but the activities of the DNA-PK and XRCC4/ligaseIV complexes showed some differences. These differences did not correlate with either the normal tissue response of the patient in vivo or with cellular radiation sensitivity in vitro. The activity differences of these enzyme complexes, therefore, do not account for the variation of responses seen between patients.

Clinical impact of dosimetry quality assurance programmes assessed by radiobiological modelling of data from the thermoluminescent dosimetry study of the European Organization for Research and Treatment of Cancer

The European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group initiated its mailed thermoluminescence dosimetry (TLD) programme in 1986. The aim of the present study was to evaluate the clinical relevance of variations in beam output detected in the period 1993 to 1996. A total of 140 beam outputs were checked (26 for cobalt-60 units and 114 for linear accelerators) in 35 centres. Clinical dose-response data for tumour control and normal tissue morbidity were used to assess the variation in clinical outcome resulting from variability in beam output. For 75 checked beams with nominal accelerating potentials (n. a.p.) of 6 MV or less the mean ratio, +/- standard deviation (S.D.) of measured to stated output was 1.004+/-0.020. For 65 beams with n. a.p. of 8 MV or more, the ratio was 1.009+/-0.021. Even with this relatively high level of precision, broad distributions of estimated tumour control or normal tissue morbidity were found. In the 10% of the beams with the most pronounced underdosage, the loss in tumour control probability was estimated at 7-8 percentage points. Likewise, in the 10% of the beams with the most pronounced overdosage, the increase in mild/moderate morbidity was 19-22 percentage points. For severe morbidity the same beams raised the estimated incidence of severe complications from 5% to 9-10%. An estimation of the loss of uncomplicated cure probability was about 1% for both high and low energy beams. Sequential mailings considerably improved the uniformity of clinical outcome. We conclude that small deviations in beam output may lead to clinically important variations in outcome. Substantial reductions in the variation between measured and stated output can be achieved by sequential mailings. Mailed TLD checks should be an integral part of a continuously ongoing quality assurance activity in radiotherapy.

Radiation therapy of the older patient

Radiotherapy has a major role in the multidisciplinary approach to cancer therapy. It is widely used for curative and palliative treatment of cancer involving various sites. Radiotherapy is of particular benefit to older and frail cancer patients as an alternative to surgery and to systemic therapy. The available data on the sensitivity of normal tissues to radiotherapy in elderly patients strongly suggest that older patients with good functional status tolerate radiotherapy as well as younger patients and have comparable tumor response and survival rates. Aggressive radiotherapy should not be withheld from older patients because of chronological age alone.

Immediate toxicity during fractionated total body irradiation as conditioning for bone marrow transplantation

BACKGROUND

Total body irradiation followed by bone marrow transplantation is well established as a part of the conditioning regimen in high dose therapy. The immediate tolerance of fractionated total body irradiation (FTBI) was investigated prospectively.

METHODS

From January 1995 to December 1998 162 patients received a FTBI, 6x2 Gy on 3 consecutive days, lung dose 10 Gy, for allogeneic (n=112) or autologous (n=50) bone marrow transplantation. High dose chemotherapy (mostly Cyclophosphamide) was administered after the FTBI. A standardized supportive therapy was administered. The immediate toxicity of FTBI was evaluated prospectively prior to each radiation fraction using a defined questionnaire.

RESULTS

Main symptoms distressing the patient during irradiation period were gastrointestinal symptoms like nausea and emesis. The prevalence of nausea per fraction increased to 26.1% after the 4th fraction, with a significant higher prevalence in children younger than 10 years at 1st and 2nd fractions. 42.6 and 22. 8%, respectively, of all patients complained of nausea and episodes of emesis, during FTBI. Mild xerostomia and parotiditis were observed in 29.9 and 7.1% of all patients. Further gastrointestinal side effects during FTBI were loss of appetite in 16.0%, indisposition in 25.3%, mild oesophagitis in 3.7% and diarrhoea in 3. 7% of the patients. During FTBI 41.4% of the patients developed a temporary skin irritation (mild erythema). Pruritus was registered in 3.7% of the patients. Headache was observed in 14.8% and Fatigue syndrome in 49.2% of women and 28.3% of men (P<0.005).

CONCLUSION

FTBI is a well tolerated therapeutic regimen in high dose therapy. The 162 patients investigated revealed no severe immediate side effects.

Correlation between normal tissue complications and in vitro radiosensitivity of skin fibroblasts derived from radiotherapy patients treated for variety of tumors

PURPOSE

To assess the relationship between fibroblast intrinsic radiosensitivity in vitro and late reactions of normal tissues in patients treated by definitive radiotherapy for variety of tumors.

PATIENTS AND METHODS

Ten patients were selected for this study. They were treated by radical radiotherapy for variety of tumors, including non-Hodgkin's lymphoma, prostate, glottic larynx, anal canal, cervix, bladder, thyroid gland, and tonsil pillar. Five patients did not develop any significant late reactions (normally sensitive group, NS). The other five developed late complications in different normal tissues and organs that proved to be fatal in one patient (clinically hyper-sensitive group, HS). Fibroblast cultures were established from punch skin biopsy and radiosensitivity in vitro was measured. The survival fraction at 2 Gy (SF2) was calculated and compared between the two groups.

RESULTS

SF2 ranged between 0.10 and 0.38 with a mean of 0.24. The mean SF2 for each of the NS and the HS groups were 0.31 and 0.17, respectively. The non-parametric rank test of Mann-Whitney shows that the difference between the two groups is statistically significant (p = 0.01).

CONCLUSION

This study indicates that the in vitro radiosensitivity of skin fibroblasts is correlated with late complications in different organs and normal tissues following radiotherapy for variety of tumors. It also lends support to the existence of a common genetic component determining the radiosensitivity of cells targeted by the late effects of ionizing radiation.

Analysis by alkaline comet assay of cancer patients with severe reactions to radiotherapy: defective rejoining of radioinduced DNA strand breaks in lymphocytes of breast cancer patients

Therapeutic exposure to ionising radiation reveals inter-individual variations in normal tissue responses. To examine whether a defect in DNA repair capacity might be involved in such hypersensitive phenotypes, we analysed, using the alkaline comet assay, the response as a function of time to in vitro irradiation at 5 Gy of lymphocytes from 17 breast cancer and 9 Hodgkin's disease patients who developed severe reactions to radiotherapy in comparison with 22 patients with "average" reactions and 24 healthy donors. A difference between breast cancer over-reactors and both patients with normal reactions and healthy donors was observed 30 and 60 min after exposure. A subgroup of breast cancer over-reactors (7/17) reproducibly demonstrated increased levels of residual damage. When the kinetic analyses were prolonged to 120 min, results were in favour of delayed kinetics of rejoining in these patients. Among Hodgkin's disease over-reactors, only one patient showed defective repair. Interestingly, all patients with the most severe complications (grade 4 RTOG/EORTC), i.e., 5 breast cancer and 1 Hodgkin's disease, showed impaired rejoining. Our results suggest that impairment in DNA strand break processing may be associated, in specific subgroups of breast cancer patients, with an individual risk of major toxicity of radiation therapy. Thus, the alkaline comet assay appears to be useful for documenting the DNA repair phenotype in cancer patients.

Subcutaneous calcification as a late effect of orthovoltage chest wall irradiation

Adjuvant radiotherapy to the breast or chest wall is given to some patients with breast cancer, to reduce the risk of local recurrence. It is known to be associated with various late sequelae, including subcutaneous fibrosis, telangiectasia and pulmonary fibrosis. Delivering radiotherapy to the chest wall and nodal drainage areas presents the technical problem of matching the glancing and anterior supraclavicular fields. Overlap between these fields will result in underlying tissues receiving a larger dose than intended; similarly, a gap results in an inadequate dose. We present the case history of a patient with subcutaneous calcification occurring as a late sequela of radiotherapy to the chest wall and anterior supraclavicular field. This has not been previously reported and is thought to have arisen from a high dose region in an area of overlap between fields.

[In vitro radiosensitivity of skin fibroblasts can identify a group of patients with complications in various health tissues after radiotherapy]

PURPOSE

A retrospective study of the in vitro radiosensitivity of skin fibroblasts derived from two groups of patients treated by definitive radiotherapy for a variety of tumors who either displayed or did not display severe complications.

PATIENTS AND METHODS

Seven radiotherapy patients were selected: three were treated for head and neck, prostate and non-Hodgkin lymphoma tumors, and did not develop any significant complications (control group); four patients were treated for bladder, thyroid, head and neck and anal canal tumors and developed serious acute and especially late reactions (hypersensitive group). Primary cell cultures of skin fibroblasts were established and their radiosensitivity studied by the clonogenic assay after exposing to single radiation doses ranging between 1 and 8 Gy.

RESULTS

The survival fraction at 2 Gy (SF2) ranged from 0.27 to 0.38, with a mean of 0.33 for the control group, and from 0.10 to 0.20 with a mean of 0.17 for the hypersensitive group. The Mann-Whitney non-parametric test showed that the difference between the two means was statistically significant (p = 0.03).

CONCLUSION

The data are in favor of a correlation between the radiosensitivity of patients' fibroblasts and the reactions of different normal tissues to radiotherapy. This association supports the use of the clonogenic survival, or a surrogate test, as a predictive assay. The multiplicity of normal tissues and organs implicated in this association suggests the existence of genetic factors that determine, at least in part, the radiosensitivity of target cells involved in the expression of normal tissues complications following radiotherapy.

TGF-beta1 levels in pre-treatment plasma identify breast cancer patients at risk of developing post-radiotherapy fibrosis

A serious complication of radiotherapy in the treatment of cancer patients is the late onset of fibrosis in normal tissues. Transforming growth factor beta (TGF-beta) is emerging as a key mediator of the fibrotic process through its effects on stimulation of fibroblast proliferation, migration and extracellular matrix (ECM) synthesis. The fact that radiation-induced vascular injury tends to precede the development of fibrosis has led to the suggestion that vascular damage is crucial in its pathogenesis. CD105, the specific type III vascular receptor for TGF-beta1 and -beta3, modulates cell proliferation and ECM production in response to TGF-beta in vitro. In this study, we have quantified the levels of TGF-beta1 and soluble CD105-TGF-beta1 complex in 91 pre-radiotherapy plasma samples from early-stage (T1 or T2) breast cancer patients utilising an enhanced chemiluminescence ELISA system. During the follow-up period, 24 patients had developed moderate and one severe fibrosis of the breast. The mean TGF-beta1 level in these 25 patients was 203.2 +/- 37.3 pg/ml, which was significantly elevated above the level for those with no fibrosis. Furthermore, a significantly lower CD105-TGF-beta1 complex level was observed in the former compared to the latter. Spearman's correlation analysis showed that TGF-beta1 was positively correlated and the CD1O5-TGF-beta1 complex inversely correlated with the occurrence of breast fibrosis. Using a cut-off value of 96 pg/ml, the sensitivity and specificity of TGF-beta1 levels in predicting breast fibrosis were 76% and 74%, respectively. Our results indicate that TGF-beta1 and the receptor-ligand complex appear to be of clinical value in identifying patients at risk of developing post-radiotherapy fibrosis.

A correlation between residual radiation-induced DNA double-strand breaks in cultured fibroblasts and late radiotherapy reactions in breast cancer patients

BACKGROUND AND PURPOSE

Prediction of late normal tissue reactions to radiotherapy would permit tailoring of dosage to each patient. Measurement of residual DNA double strand breaks using pulsed field gel electrophoresis (PFGE) shows promise in this field. The aim of this study was to test the predictive potential of PFGE in a group of retrospectively studied breast cancer patients.

MATERIALS AND METHODS

Thirty nine patients, treated uniformly for breast cancer 9-15 years previously, with excision of the tumour and radiotherapy to the breast and drainage areas, were assessed clinically using the LENT SOMA scale, and a 5-mm punch biopsy taken from the buttock. Fibroblast cell strains were established and used to study residual DNA double strand breaks, using PFGE.

RESULTS

There were significant correlations between the DNA assay results and the fibrosis score (r(s) = 0.46; P = 0.003), the combined fibrosis and retraction score (r(s) = 0.45, P = 0.004) and the overall LENT score (r(s) = 0.43; P = 0.006). Using polychotomous logistic regression, the fibroblast DNA assay result was an independent prognostic factor for fibrosis severity.

CONCLUSIONS

There is a relationship between residual radiation-induced DNA damage in fibroblasts and the severity of the late normal tissue damage seen in the patients from whom the cells were cultured.

Ku70/80 gene expression and DNA-dependent protein kinase (DNA-PK) activity do not correlate with double-strand break (dsb) repair capacity and cellular radiosensitivity in normal human fibroblasts

The expression of the Ku70 and Ku80 genes as well as the activity of the DNA-dependent protein kinase (DNA-PK) were studied in 11 normal human fibroblast lines. The proteins studied are known to be part of a double-strand break (dsb) repair complex involved in non-homologous recombination, as was demonstrated for the radiosensitive rodent mutant cell lines of the complementation groups 5-7. The 11 fibroblast lines used in this study represent a typical spectrum of normal human radiosensitivity with the surviving fraction measured for a dose of 3.5 Gy, SF3.5 GY, ranging from 0.03 to 0.28. These differences in cell survival were previously shown to correlate with the number of non-repaired dsbs. We found that the mRNA signal intensities of both Ku70 and Ku80 genes were fairly similar for the 11 cell lines investigated. In addition, the DNA-PK activity determined by the pulldown assay was fairly constant in these fibroblast lines. Despite the correlation between cell survival and dsb repair capacity, there was no correlation between dsb repair capacity and DNA-PK activity in the tested normal human fibroblast lines. Obviously, in this respect, other proteins/pathways appear to be more relevant.

[Radiotherapy of the elderly patient. Radiotherapy tolerance and results in older patients]

BACKGROUND

Despite a growing number of elderly patients receiving radiation therapy little is known about side effects and outcome of irradiation in this section of the population.

METHODS

In a review article epidemiologic data, aspects of radiation-biology as well as side effects and outcome of radiation therapy of elderly patients are discussed.

RESULTS

Cancer incidence rises with age (Figure 1) and is exceeding 3.5% for males older than 85 years. With a life expectancy of more than 4 years, curative therapy is indicated even at this age. Furthermore several retrospective studies indicate that local control and disease-Specific survival after radiation therapy of elderly patients is comparable with that of younger persons (Tables 3 and 4). The exception contains elderly patients with Grade-III to IV gliomas or with rectal carcinoma who show a reduced survival which is perhaps caused by less aggressive combined treatment (tumor resection). Although some biological and molecular data indicate a rise in radiation sensitivity with growing age like the reduction of the capacity of some DNA-repair enzymes, there is no convincing evidence in animal studies or in retrospective clinical studies that radiation therapy is generally less well tolerated by older individuals (Tables 1 and 2). Some age-depending differences in organ toxicities are described in 3 large studies, which evaluate the data of patients who were enrolled in different EORTC-trials: Older patients suffer more of functional mucositis in case of radiation therapy to the head and neck, they have an increased weight loss and a higher frequency of late esophageal damage when irradiated in the thorax, and they show a higher prevalence of sexual dysfunction when treated with radiation therapy to the pelvis. On the other hand younger patients suffer more from acute toxicity like skin damage, nausea, and deterioration of the performance status during pelvic radiotherapy. When discussing the dose intensity of radiation therapy concomitant disease which leads to extensive atherosclerotic vessel damage should be kept in mind. Old patients should be monitored closely during therapy, since the loss of electrolytes or fluid is often not very well tolerated.

CONCLUSION

The indication to radiation therapy of elderly cancer patients should take into account their performance status as well as the extent and the severity of comorbidity. Age per se is seldom a contraindication for radiation therapy. Regarding the available data in literature there is no indication for a dose reduction in radiation therapy only because of age, especially in the curative setting.

Lack of correlation between residual radiation-induced DNA damage, in keratinocytes assayed directly from skin, and late radiotherapy reactions in breast cancer patients

PURPOSE

To study the relationship between the severity of late reactions to radiotherapy in breast cancer patients, and the extent of residual radiation-induced DNA damage, using a rapid assay of keratinocytes obtained directly from skin biopsies.

METHODS AND MATERIALS

A review was made of 32 patients with breast cancer, treated uniformly by radiotherapy between 1983 and 1988, following breast-conserving surgery. Their late radiotherapy reactions were scored (9-14 years post-radiotherapy) using a modified LENT SOMA scale, and a 5-mm buttock skin punch biopsy was obtained. Intact skin was irradiated at room temperature, and after allowing 24 h for repair, the tissue was disaggregated and the cells processed for pulsed field gel electrophoresis (PFGE). Residual DNA damage was expressed as the fraction of DNA released (FDR) following 150 Gy.

RESULTS

Studies using flow cytometry on disaggregated breast skin showed that over 90% of the cells were keratinocytes. The PFGE assay was robust with low background FDRs in unirradiated skin samples (mean 3.2%) and a wide range of FDRs following irradiation from 11.5% to 26.6%. No correlation was found between the FDR at 150 Gy (FDR 150) and any of the late reaction scores or retrospective acute reaction scores. There was, however, a borderline significant correlation for family history and FDR 150 (p = 0.059).

CONCLUSION

Rapid measurement of residual DNA damage in irradiated differentiated keratinocytes, the predominant cell population in skin biopsies, showed no correlation with the severity of symptomatic early or documented late reactions in a retrospectively studied group of 32 breast cancer patients.

Describing patients' normal tissue reactions: concerning the possibility of individualising radiotherapy dose prescriptions based on potential predictive assays of normal tissue radiosensitivity. Steering Committee of the BioMed2 European Union Concerted Action Programme on the Development of Predictive Tests of Normal Tissue Response to Radiation Therapy

Clinical radiotherapeutic doses are limited by the tolerance of normal tissues. Patients given a standard treatment exhibit a range of normal tissue reactions, and a better understanding of this individual variation might allow for individualisation of radiotherapeutic prescriptions, with consequent improvement in the therapeutic ratio. At present, there is no simple way to describe normal tissue reactions, which hampers communication between clinic and laboratory and between groups from different centres. There is also no method for comparing the severity of reactions in different normal tissues. This arises largely because there is no definition of a "normal" reaction, an "extreme" reaction or the particular term "over-reactor" (OR). This report proposes definitions for these terms, as well as a simple terminology for describing normal tissue reactions in patients having radiotherapy. The "normal" range represents the individual variation in normal tissue reactions amongst large numbers of patients treated in the same way which is within clinically acceptable limits. The term "OR" is applied to an individual whose reaction is more severe than the normal range but also implies that this forced a major change in the radiotherapeutic prescription or that the reactions were very severe or fatal. A "severe OR" would develop serious problems with a typical radical dose, while an "extreme OR" would have such difficulties at a much lower dose. To describe the normal range, a numerical scale is suggested, from 1 to 5, resistant to sensitive. The term "highly radiosensitive" (HR) is suggested for category 5. An "informal" relative scale, as suggested here, is quick and simple. It should allow comparison between different hospitals, compensate for differences in radiotherapeutic dose and technique and allow comparison of reactions between different anatomical sites. It should be adequate for discriminating patients at the extremes of the normal range from those at the centre. It is hoped that the definitions and terminology proposed here will aid communication in the field of predictive testing of normal tissue radiosensitivity.

[Late effects of mammary radiotherapy on skin and subcutaneous tissues]

Late damages to the skin and subcutaneous tissues are almost inescapable because of the high skin doses required in the irradiation of breast tumours. While the clinical and histological descriptions date back to the first decades of the therapeutic use of ionising radiation, the recent advances in cellular and molecular biology have significantly contributed to the increased understanding of late skin injury mechanisms. In particular, sub-cutaneous fibrosis appears to be the partly reversible results of a continuous and self-maintained local process, possibly sensitive to therapeutic intervention. A second very active research avenue is the development of biologic assays potentially able to predict the probability of increased normal tissue injury after irradiation in individual patients. Such a test would allow the adaptation of the treatment modalities to the radiobiological behaviour of normal tissues. To date, these expectations have not been met. The quality of the irradiation and its modalities (total dose, fractionation, inter fraction interval) remain the main ways to achieve an optimal functional and cosmetic outcome.

Demonstration of increased collagen synthesis in irradiated human skin in vivo

Fibrosis is a common side-effect of radiation therapy. As a complex network of cytokines and other mediators plays a central role in the process leading to fibrosis, we used an in vivo method to measure skin collagen synthesis, taking into account the physiological conditions. We determined suction blister (i.e. interstitial) fluid concentrations of types I and III procollagen propeptides, reflecting types I and III collagen synthesis, in irradiated and unirradiated skin of breast cancer patients 1-5 years after surgery and radiation therapy, hence using the patients as their own controls. The mean concentrations of the measured collagen markers were approximately two times higher in the irradiated skin than in the unirradiated contralateral breast skin. The difference slowly diminishes with time. These results indicate that abundant collagen synthesis in the irradiated skin continues several years after discontinuation of the radiation therapy, leading to fibrosis. The method outlined here offers a new in vivo perspective to study events leading to radiation fibrosis.

20 MHz ultrasonic imaging for quantitative assessment and documentation of early and late postradiation skin reactions in breast cancer patients

BACKGROUND AND PURPOSE

In dermatology high resolution ultrasonic systems proved to be valuable in following up genuine and experimental inflammatory dermatoses. The opportunities of 20 MHz ultrasonic imaging for quantitative assessment of early and late postradiation skin reactions are investigated.

MATERIAL AND METHODS

Between April and November 1996, 96 high resolution ultrasound examinations of the skin in 29 patients treated for breast cancer at the University of Ulm were analyzed. Total doses between 46 and 60 Gy were applied. The time interval between the completion of radiotherapy and ultrasonic examination was < or =3 months in 18 patients and 6-135 months in 11 patients. For examinations we used a digital high resolution ultrasonic system with a ceramic 20 MHz transducer. Irradiated and non-irradiated skin were compared.

RESULTS

A change of thickness and texture of the dermis depending on the time interval between the completion of radiotherapy and ultrasonic examination and on the administered radiation dose was found. There were significant differences between irradiated and non-irradiated skin regarding the dermal thickness in early (P < 0.001) as well as in late (P = 0.0018) reactions. Echogenicity of the upper and lower corium of irradiated skin decreased in early and late reaction. In upper corium the greatest reduction of signal intensity occurred in early reactions (P = 0.0001). Early reactions of the lower corium differed significantly from late changes (P = 0.001). Discrepancies between visible skin reactions described by examining physicians and ultrasonically proven changes were obvious mainly in late reactions.

CONCLUSIONS

There are specific textures of early and late postradiation skin reactions in comparison to non-irradiated skin. High resolution digital 20 MHz ultrasound is non-invasive and quantitative, and in contrast to physical examination, an easy reproducible method for assessing and documenting early and late skin reaction during and after radiation therapy treatment.

[Predictive tests of response to radiotherapy. Assessment and perspectives in 1997]

The potential tailoring of radiotherapy modalities to the biological characteristics of individual tumours and normal tissues appears to be an exciting way to improve the therapeutic, ratio in radiation therapy patients. Numerous assays have been proposed to provide the clinician with the biological information necessary to predict the outcome after irradiation and to guide the treatment prescription, but none of them has made its way to daily practice. Major difficulties are due to the technical burden of the procedures, the poor characterization of the assayed cells, and, moreover, the high complexity of tumour and normal tissues biology. The present paper reviews the present status of the assessment of tumour cells radiosensitivity, proliferation and oxygenation. Research remains extremely active in the field of biological predictors of response to irradiation. Future steps forwards are expected from progress in the available technologies, (re-)discovery of apoptosis and investigation of normal tissue tolerance.

Hyperthermia may decrease the development of telangiectasia after radiotherapy

CASE REPORT

A patient with recurrent breast cancer was reirradiated twice on adjacent fields with a time interval of 9 months. The first time she was treated with reirradiation alone, the second time with reirradiation plus hyperthermia. The reirradiation schedule for both fields was 8 x 4 Gy in 4 weeks. Both fields overlapped partly with the field of postoperative radiotherapy, which was applied 57 and 66 months earlier to a total dose of 40.5 Gy.

RESULTS

During the 52 to 61 months follow-up, a remarkable difference in telangiectasia development, between the parts of the reirradiation fields overlapping with the primary radiotherapy field, became apparent. Telangiectasia was observed 9 months after treatment with reirradiation alone and progressed to confluent in 47 months after treatment. In the reirradiation plus hyperthermia area, the maximum observed telangiectasia was slight until 52 months after treatment.

DISCUSSION

The difference in the development of telangiectasia between these fields cannot be explained by differences in any of the known radiation treatment related prognostic factors. A protective effect by hyperthermia has been suggested by Haveman and coworkers, who have shown experimentally that heat treatment leads to enhanced proliferation of endothelial cells, thereby inducing a fast repopulation and replacement of X-ray damaged cells.

CONCLUSION

This difference in telangiectasia formation is an interesting observation. Whether such a protective effect of hyperthermia is of general relevance has to become clear from more extensive clinical studies.

Intrinsic radiosensitivity of healthy donors and cancer patients as determined by the lymphocyte micronucleus assay

The purpose of the study was to evaluate the usefulness of the cytokinesis-block micronucleus (MN) assay in assessment of radiosensitivity of lymphocytes in cancer patients. Lymphocytes from 15 cervical cancer patients, 21 head and neck cancer patients, seven lung cancer patients and 19 healthy donors were analysed using MN assay. The proportion of binucleate cells (BC) in cancer patients ranged from 22 to 56% and was significantly lower than in the control group (38-68%). MN frequency assessed five times over 6 months in four healthy donors showed that the interindividual variation was significantly higher than intraindividual. Before (0 Gy) and after irradiation (2 and 4 Gy) no statistical differences in the mean number of MN/BC were observed between healthy donors and cancer patient groups. Nevertheless, statistical cluster analysis allowed each group of donors to be divided into radioresistant and radiosensitive subgroups of patients. They showed significantly different dose response. Separate comparison of the mean MN frequency within all examined radioresistant and radiosensitive subgroups, showed statistically significant differences only after a dose of 4 Gy. At this dose, the lung cancer patients and cervical cancer patients from radiosensitive subgroups presented significantly higher radiosensitivity than the healthy donors. However, healthy donors from radioresistant subgroup did not differ significantly from cancer patients. This work has shown a high variation in interindividual radiosensitivity of donors and suggests the possibility of identifying radiosensitive patients on the basis of MN assay performed on lymphocytes.