Postoperative radiotherapy of childhood medulloblastomas

The purpose of this work is to review the result of radiotherapy in the treatment of medulloblastoma in pediatric patients. Between 1986 and 1998, 66 children (45 boys and 21 girls) received postoperative irradiation in our institute. Their mean age was 8.29 years. Irradiation was performed by linear accelerator, 36 Gy were applied in the high risk group (partial tumor resection, tumor cell positivity in the liquor, metastases within the central nervous system) and 30 Gy in the low risk group (total tumor resection, negative liquor cytology, no metastases within the central nervous system) on the entire cerebrum and spinal cord. This was followed in both groups by the application of 20-20 Gy boost irradiation on the posterior scala. Studying the survival it has been found that the surgical radicality did not significantly influence the survival chances of patients, however, with the increase in the tumor size the survival chance significantly decreases (p = 0.03). When predicting life expectancy, however, the stage of tumor, the age of patients, the risk group and the M stage yielded essential information. At the age of 8 years and less, the rate of survivors is 67.6%, for those over 8 years is 75.9% (p = 0.21), however the younger age was not significant. The appearance of metastases considerably deteriorates the chances of survival (from 81.5% to 66.7%, p = 0.02). In the low risk group of patients the 5-year survival is 80%, while in the high risk group it is significantly lower, 67.4% (p = 0.04).

[Management of the axilla in breast cancer: evidences and unresolved issues]

In this study the evidences governing the management of the axilla were examined and on the base of these evidences, the optimal clinical practice was outlined. Computerized searches for publications, debating specific treatment of axilla, were done of MEDLINE data. Level of evidence was determined using standard criteria: 1. metaanalysis of randomized trials, 2. randomized trial, 3. prospective and retrospective studies, 4. reports and opinion of expert committees and working teams. The probability of lymph node involvement is related directly to the size of the primary tumour, and even with small tumour (up to 10 mm), the risk of nodal metastases is in the order of 10-20%. To date, the best strategy for determining complete lymph node status (qualitative and quantitative information) is through axillary dissection. For an accurate staging, at least ten nodes have to be obtained. Formal axillary sampling does not provide total quantitative data in patients with involved axilla. Sentinel node biopsy is a promising alternative to axillary dissection for staging but it is still under way. Axillary dissection should be omitted in patients with ductal carcinoma in situ since the probability of nodal involvement is less than 1%. In invasive breast cancer, the risk of axillary recurrence in the untreated axilla varies from about 10% to 40%. For women with stage I-II breast cancer at least level I and II axillary node dissection should be offered as the standard procedure to reduce the risk of regional recurrence. Women at high risk of axillary recurrence (> or = 4 involved nodes, < 6 nodes were obtained from a positive axilla) will require axillary irradiation after axillary dissection. However, there is a lack of higher level evidence to support the benefit of post-dissection axillary irradiation. Evidences suggest that axillary irradiation is as effective as axillary dissection in preventing regional recurrence. The following factors have to be considered for decisions regarding dissection or irradiation: patient wishes, general condition, age, the necessity of pathological nodal status for systemic therapy and the risk of post-treatment morbidity. At this time, there is no well defined subgroup of patients in whom axillary intervention can be safely omitted. In selected patients with clinically negative axilla, the decision to observe the axilla rather than use surgery or irradiation should be made jointly between the women and her specialists (surgeon, radiation and medical oncologist). The benefits of axillary treatment in prolonging survival are unclear. Studies have reported different effects on survival. Until evidences remain insufficient, the risk of axillary recurrence has to be minimized, and more and more patients have to be provide to get treatments in randomized clinical trials. Patient should be fully informed about the benefits and the potential side effects of treatments. A combination of radiotherapy and axillary dissection results an increased morbidity rate compared with either alone.

[Breast-conserving treatment for early invasive lobular breast cancer: 15 years results]

BACKGROUND

Infiltrating lobular cancer is biologically different from invasive ductal cancer and there is disagreement regarding appropriate local management of this disease.

PURPOSE

To examine treatment outcomes after breast-saving surgery for patients with invasive lobular breast cancer.

MATERIAL AND METHODS

Between 1983 and 1987, 77 women with early, stage I-II invasive lobular breast cancer were treated with complete gross excision of the tumour and axillary dissection. Fifty-eight of these patients were treated with 50 Gy ipsilateral breast irradiation, and 19 did not receive radiotherapy. During 176 month median follow-up local-regional recurrences, distant metastases, contralateral breast cancers, breast cancer deaths and deaths caused by other disease were scored. The probability of survival was estimated by Kaplan-Meier method. In uni- and multivariate analysis the Cox-model was used. Relative risk (RR) and associated confidence intervals (CI) were calculated from the regression coefficients. Statistical differences in proportions and means were assessed by log rank and Fisher exact-tests.

RESULTS

In the saved breast, the actual rate of local recurrence at 15 years was 13% for irradiated and 53% for non-irradiated patients (RR: 0.1; 95% CI: 0.03-0.31; p: < 0.0001). The incidence of total breast cancer relapses (local-regional recurrences and distant metastases) was also higher for non-irradiated than for irradiated patients (74% vs. 40%; p: 0.0168). In multivariate analysis irradiation (no vs. yes) showed a significant effect on local tumour control (RR: 0.08: 95% CI: 0.02-0.28; p: 0.0001), but menopausal (pre vs. post), T-(T1 vs. T2) and N-(N0 vs. N1) status did not. The breast cancer specific survival at 15 years was 74% without and 62% with local recurrence (RR: 1.45; 95% CI: 0.53-3.96; p: 0.4697). The majority of local recurrences (9 of 14) were curable by salvage surgery. For all patients the rate of contralateral breast cancer was 6.5%.

CONCLUSION

Results of long-term follow-up confirmed that breast-conserving surgery and radiotherapy is a reasonable treatment for patients with early invasive lobular breast cancer. The majority of local recurrences are curable by salvage surgery.

The importance of interstitial radiotherapy in the treatment of the base of tongue tumors: a retrospective analysis

The authors have reviewed their experience with interstitial brachytherapy for the base of tongue cancer with the purpose of introducing treatment strategy and technique and presenting results. Between January 1993 and May 1999 twenty-one patients with primary squamous cell cancer of the base of tongue (T1-4N0-2) were treated by interstitial radiotherapy (RT). Seventeen patients with advanced stage cancer received brachytherapy (BT) boost after 60-66 Gy teletherapy and 4 patients with early stage (T1-2N0) were managed by sole BT after tumor excision and elective neck node dissection in case of positive or very narrow (< 5 mm) margin. High-dose rate (HDR) after-loading unit (Ir-192 source) was used with rigid needles or flexible plastic tubes. The treatment plan was performed by PLATO 3D BT planning system. The mean dose of boost BT or sole BT was 20 Gy (12-24 Gy) and 27 Gy (24-30 Gy), respectively. All treatments were delivered on consecutive days with a twice daily fractionation schedule, except the rigid needle technique (n = 4), where the dose was 12 Gy with a single fraction. After definitive RT of advanced stage disease, the rate of complete or partial remission was 65% (11/17) and 35% (6/17), respectively. At a mean follow-up time of 32 months the local tumor control for the entire patient population was 62% (13/ 21). Five patients (24%) died of local and/or regional failure and sixteen patients (76%) are alive (6 with local and/or regional disease and 10 without evidence of disease). All of the four sole BT treated patients belong to the latter group. The incidence of grade 2 or grade 3 mucositis was 48% and 52%, respectively. To achieve good local control with adequate doses, avoiding surgical morbidity and associated functional loss and to minimize late radiation sequelae, the combination of percutan and interstitial RT seems to be very advantageous in the treatment of the advanced tumor of the base of tongue. For patients with early stage (T1-2N0) cancer, sole postoperative BT of the tumor bed - by positive or very narrow margins - seems to be a feasible option. However, more patients and longer follow-up is required to define the value of sole BT.

The application of image fusion in stereotactic brachytherapy of brain tumours

BACKGROUND

The visualization of any morphological volume (i.e. CT, MRI) together with an additional second morphological volume (i.e. CT, MRI) or functional data set, which may come from SPECT or PET, is a new method for treatment planning, verification and follow-up of interstitial irradiation.

METHOD

The authors present their experience on interstitial irradiation of brain tumours with stereotactically implanted I-125 seeds supported by image fusion. The image fusion was performed by the BrainLab-Target 1.13 software on Alfa 430 (Digital) workstation before, during, and after interstitial irradiation of brain tumours with Iodine125 seeds.

RESULTS AND INTERPRETATION

On the basis of 20 brachytherapeutic image fusion of stereotactic CT (slices with fiducials) with additional stereotactic CT, MRI, PET and SPECT images provides more accurate and precise target volume, more exact localization of catheters and isotope seeds (verification fusion), differentiation between the localization and amount of the necrotic and proliferating parts of the tumours and shows the volume changes in consequence of interstitial irradiation. The image fusion should help to improve the accuracy and minimize the perifocal morbidity of interstitial irradiation.

Postirradiation angiosarcoma of the chest wall and breast: issues of radiogenic origin, diagnosis and treatment in two cases

The authors report two cases of postradiation angiosarcoma (AS) among 5,100 breast cancer patients treated in the period 1980-1994 at the National Institute of Oncology, Budapest. Relevant data in the literature is also reviewed to analyze the questions of radiogenic origin, diagnosis and treatment. Secondary AS occurred in these cases in a previously irradiated field after a 6- and 8-year latency period, respectively. Detailed histopathological and immunohistochemical examinations from the biopsy specimens confirmed the diagnosis as AS. The first patient was treated successfully with radical surgery. The second patient, with unresectable AS, died of rapid local progression within 4 months. The incidence of chest wall and breast AS after radiotherapy was found to be 0.46 per 1,000 in our patient population, which means an estimated odds ratio of 2.9 for secondary AS. Patients treated with radiotherapy for primary breast cancer are at higher risk for developing secondary AS compared to the healthy population. An etiological relationship between radiotherapy and subsequent AS of the chest wall and breast is likely, but still controversial. Initial radical surgery is the only effective treatment for achieving long-term survival. These very rare cases deserve special attention due to the atypical clinical appearance, difficulties of differential diagnosis and poor prognosis.

The impact of radiotherapy on the incidence and time of occurrence of local recurrence in early-stage breast cancer after breast conserving therapy

There is still little information on the delay of local recurrence after conservatively treated and irradiation breast cancer. To evaluate the impact of radiation therapy (RT) on the incidence and on the time of occurrence of ipsilateral breast tumor recurrence (IBTR), we reviewed the treatment results in 415 women with UICC Stage I or II unilateral breast cancer. All underwent breast conserving surgery (BCS) and full axillary dissection between 1983 and 1987. Out of them 309 patients were irradiated and 106 were not. The median dose of RT was 50 Gy in five weeks to the whole breast. Systemic therapy, when it was given, consisted of 6-cycles of CMF for node positive premenopausal women and 20 mg tamoxifen for three years for postmenopausal women. The median follow up time was 120 months in survivors. The 10-year actuarial IBTR rate was 36.6% for the nonirradiated and 9.1% for the irradiated women (p = 0.0000); 48.6% for patients treated with CMF and 4.2% for those treated with CMF plus RT (p = 0.0051); 29.0% for patients treated with tamoxifen and 7.9% for those treated with tamoxifen plus RT (p = 0.0318). The patient's age and the presence of an extensive intraductal component (EIC) were both highly associated with the likelihood of tumor recurrence in the treated breast. Patients under 41 years of age had an actuarial 10-year IBTR rate of 75% without RT and 17. 1% with RT (p = 0.0006). Women with an EIC positive tumor had an IBTR rate of 88.9% when RT was not given and 27.2% when RT was given (p = 0.0003). In invasive lobular cancer, irradiated patients had a IBTR rate of 2.3%, compared to 53.2% for nonirradiated patients (p = 0.0008). RT resulted in a significant delay in the appearance of IBTR (p = 0.0250) and the median time was increased by 20.0 months. We conclude that RT has the property of not only preventing but also delaying IBTR. In invasive lobular tumors the risk of IBTR is very high when RT is omitted, but BCS plus radiation therapy is effective treatment. Patients wih EIC positive tumor are at high risk of IBTR even when a median dose of 50 Gy is given to the whole breast.

Assessment of functional knee bracing: an in vivo three-dimensional kinematic analysis of the anterior cruciate deficient knee

OBJECTIVE

To describe three-dimensional tibial and femoral movements in vivo and examine the effect of a brace on knee kinematics during moderate to intense activity.

DESIGN

Skeletal kinematics of anterior cruciate ligament deficient knees was measured with and without braces during moderate to intense activity.

BACKGROUND

Invasive markers implanted into the tibia and femur are the most accurate means to directly measure skeletal motion and may provide a more sensitive measure of the differences between brace conditions.

METHODS

Steinmann traction pins were implanted into the femur and tibia of four subjects having a partial or complete anterior cruciate ligament rupture. Non-braced and braced conditions were randomly assigned and subjects jumped for maximal horizontal distance to sufficiently stress the anterior cruciate ligament.

RESULTS

Intra-subject peak vertical force and posterior shear force were generally consistent between conditions. Intra-subject kinematics was repeatable but linear displacements between brace conditions were small. Differences in angular and linear skeletal motion were observed across subjects. Bracing the anterior cruciate ligament deficient knee resulted in only minor kinematic changes in tibiofemoral joint motion.

CONCLUSION

In this study, no consistent reductions in anterior tibial translations were observed as a function of the knee brace tested. Relevance. Investigations have reported that knee braces fail when high loads are encountered or when load is applied in an unpredictable manner. Questions remain regarding tibiofemoral joint motion, in particular linear displacements. The pin technique is a means for direct skeletal measurement and may provide a more sensitive measure of the differences between brace conditions.

Prediction of functional disability, recurrences, and chronicity after 1 year in 180 patients who required sick leave for acute low-back pain

The aim of the study was to identify factors that predict low-back pain outcome at 12 months and thus to identify patients at risk for poor long-term outcomes. One hundred-eighty patients, all disabled by acute low-back pain, were included. Outcome (dependent) variables were Oswestry disability score, recurrences during the study year, and chronicity defined as 90 or more days off work for low-back pain during the study year, or a disease-specific sick-leave rate (a variable created by the authors) of more than 25%. Stepwise logistic regression analysis was performed. Thirty-three percent of the patients had an Oswestry score greater than 25, indicating moderate disability at the 1-year follow-up evaluation. Pain on coughing at study entry predicted a high likelihood of disability at 1 year, with a threefold risk. Many work days missed as a result of low-back pain in the past 2 years and lack of stimulating work tasks predicted recurrences during the year. A high Oswestry score assessed at study entry was the only factor that predicted chronicity. The factors revealed in the current study should help the clinician to identify patients at risk. The authors propose that the revealed predictors should be investigated extensively at the patient's first visit for acute low-back pain.

Cations of cisternal cerebrospinal fluid in humans and the effect of different doses of nimodipine on CSF calcium after stroke

Cisternal samples of cerebrospinal fluid (CSF) were analyzed for protein, albumin, sodium (Na), potassium (K), and calcium (Ca) content in 21 control subjects and 64 patients who had experienced acute stroke. A second cisternal CSF sample was taken in 37 of the stroke patients after 2-3 weeks treatment with the calcium antagonist nimodipine. Increased permeability of the blood-brain barrier was reflected by the significantly higher CSF/serum ratio of albumin in stroke patients than in control subjects (0.0046 vs. 0.0028,p = 0.0012). Serum and CSF concentrations of Na, K, and Ca did not differ between control subjects and stroke patients. In control subjects and in stroke patients, concentration of calcium in cisternal CSF ([Ca]) was smaller than values reported by others in lumbar samples. In stroke patients, the pH of CSF was lower than that of simultaneously taken blood (7.38 vs. 7.44, p < 0.001). No differences between stroke patients and control subjects were found for the cisternal CSF/serum ratios of Na (1.0 and 0.99), K (0.61 and 0.63), and Ca (0.25 and 0.24). When patients and controls were pooled together, CSF total [Ca] correlated weakly with serum total [Ca] (Spearman r = 0.28, p = 0.014) and with serum ionized [Ca] (Spearman r = 0.27, p = 0.016). After 2-3 weeks of nimodipine treatment, CSF [Ca] was significantly lower in the subgroup treated with 60 mg nimodipine four times daily (240 mg/d) than with 30 mg four times daily. A nimodipine dosage of 30 mg four times daily (120 mg/d) did not affect CSF [Ca]. A 240 mg daily dosage, but not a 120 mg daily dosage, of nimodipine may affect the Ca transport system in humans at the choroid plexus.

Back muscle fatigue in healthy men and women studied by electromyography spectral parameters and subjective ratings

To obtain reference data for future studies of patients with low back pain, back muscle fatigue was studied by surface electromyography at L1 and L5 lumbar levels in 55 healthy subjects exerting 80% of maximal voluntary contraction of the back extensors in a sitting position. Reference data were the initial value and rate of decrease (slope) of the median frequency during the contraction. The aim was also to study the effects of contraction time, gender differences, electrode locations and correlations with torque, age and subjective ratings. Initial median frequency was 52 Hz +/- 7.5, with no difference between electrode locations; steeper slopes were found at L5 level (-0.44%/s +/- 0.25) than at L1 (-0.36%/s +/- 0.26). No right-left differences and no gender differences were found for these parameters. A correlation was observed between slope and initial median frequency, higher for men (r approximately -0.7) than for women (r approximately -0.5). Intersubject coefficient of variation for the slope was smallest for the longest (45 seconds) recording time (60-70%), but still much higher than for the initial median frequency (14%). The torque and the subjective ratings of fatigue showed no correlation with the electromyography variables. We conclude that the same reference values can be used for men and women. Owing to the large intersubject range of the slope, the clinical use of this variable may, however, be impeded.

[CT- and MRI-guided conformal interstitial and external beam radiotherapy of primary brain tumors: prospects in Hungary]

The technical improvements gained over the last decade in neuroradiology and radiotherapy have brought significant theoretical and experimental changes in the treatment of primary glial brain tumours. The follow-up of patients with CT, MRI and isotope diagnostic examinations proves that the relapses take place in the vicinity of the primary site in most cases. Consequently, the conventional large fields or whole brain irradiation techniques have been phased out and the conformal irradiation methods focused on the tumorous targets have gained ground. The exact neuroanatomic projection, the image based 3-dimensional treatment planning methods and the conformal irradiation techniques ensure that only the tumorous or the potentially infiltrated regions become irradiated with maximal protection of the normal brain tissues. The increased protection of the normal tissues makes a dose escalation possible, which may result in the augmentation of the therapeutic benefits. In Hungary both the interstitial and the external beam conformal radiotherapies of the CNS have become accessible in practice over the recent years. In possession of manifold treatment modalities (percutaneous fractionated conformal radiotherapy, stereotactic radiosurgery, high dose rate after-loading and low dose rate interstitial irradiation), it is found necessary to overview the indicative territories, advantages, limitations and possible complications of different interventions. The authors describe the possible routes of further improvements and ways of dose escalation. Nevertheless, it is emphasised that gliomas--with reduced radiosensitivity and high potential to infiltrate the adjacent brain tissues-represent the illness in the whole CNS. It implies that in the future it will probably be necessary to initiate systemic therapeutic modalities in the course of routine treatment strategies in addition to the focused and more effective radiotherapy regimens.

[Evidence-based radiotherapy in the treatment of operable breast cancer: results in the 1990-ies]

The aim of this study was to give information about the evidence based radiation oncology in the treatment of operable breast cancer for specialists involved in the national public health. It was performed a review of the English language clinical studies published in the nineties, in which specific radiotherapy questions of operable breast cancer were debated. Clinical studies were classified according to the level of obtained evidence: randomized study (level I.), cohort study (level II.), retrospective study (level III.) and meta-analysis (mathematical synthesis of results). 1. Findings of one large randomized study indicate that lumpectomy plus irradiation is more beneficial than lumpectomy alone for women with ductal carcinoma in situ. Findings are supported by retrospective studies. 2. There are four complete published randomized studies comparing the outcome of conservative surgery alone to that of conservative surgery plus radiation for patients with stage I-II. breast cancer. The local recurrence rate is unacceptably high when random patients are treated without radiotherapy. Meta-analysis of these studies conferred statistically significant survival advantages on women receiving irradiation. In one randomized clinical trial the delivery of a 10 Gy boost to the tumor bed after 50 Gy to the whole breast significantly reduces the risk of early local recurrence. Additional follow-up evaluation and more evidence will be required to define the indications for boost irradiation. In one randomized trial with unselected patients there was a significant superiority in local control for whole breast irradiation compared to partial breast irradiation, but interim results of prospective studies with carefully selected women appear promising. 3. Findings of three randomized controlled clinical trials indicate that postmastectomy radiotherapy reduces mortality from breast cancer by preventing locoregional recurrences in node positive patients. One study examined the effect of radiation on overall survival by meta-analysis of earlier published randomized studies and demonstrated the reduction of breast cancer deaths in irradiated patients. 4. The value of irradiation of parasternal lymph nodes is uncertain by retrospective studies and is currently being studied in a large European randomized trial. After an adequate axillary lymphadenectomy the incidence of axillary recurrence is low and there is no indication for irradiation. Results of two retrospective studies indicate that irradiation of supraclavicular lymph nodes is beneficial in patients with four or more positive axillary lymph nodes. In summary, thank to the intensive clinical research in radiotherapy, the irradiation of patients with operable breast cancer is based on level I. scientific evidences in the majority of the cases. Results of randomized controlled clinical trials and meta-analyses indicate that radiotherapy is more than locoregional control: breast cancer deaths are reduced among irradiated patients.

[Reexcision and perioperative brachytherapy in the treatment of local relapse after breast conservation: a possible alternative to mastectomy]

Breast conserving surgery and postoperative radiotherapy became widely accepted in the last two decades for the treatment of early invasive breast cancer. In spite of adequate surgery and radiotherapy, the rate of ipsilateral breast tumor recurrence is approximately 10%. In such cases salvage mastectomy is the standard treatment, however wide reexcision of the recurrent tumor is also a reasonable option for selected patients. The risk of second local relapse is higher following further breast conservation compared to mastectomy. The authors report the technique of tumor reexcision combined with intraoperative implantation and perioperative high dose rate (HDR) bracytherapy of the tumor bed for the salvage of recurrence in a previously irradiated breast. One can perform two operative interventions at the same time with this method. Irradiation can be started safely within 48 hours after surgery. A review of the literature is also performed by the authors to demonstrate the role and indication of perioperative brachytherapy in the treatment of breast tumor relapse and other cancer recurrences. Reexcision is a practicable alternative to mastectomy for solitary, parenchymal breast tumor relapse measured 2 cm or less in diameter. Perioperative brachytherapy may decrease the risk of second relapse without increasing radiation side effects. Further prospective study is required to define the value of the prescribed method in comparison with salvage mastectomy.

Between-days reliability of subjective and objective assessments of back extensor muscle fatigue in subjects without lower-back pain

BACKGROUND

It is important to evaluate the reliability of common used methods of examining muscle fatigue from the lower back since the methods are used in patient evaluation.

METHODS

To establish between-days reliability, ten subjects without lower-back pain performed a Sorensen test, a prone test for back extensor muscles against gravity, on three separate days. EMG was recorded from the L1 and L5 of the back extensor muscles. Fatigue was subjectively rated using a Borg CR-10 scale. Intraclass correlation coefficient, standard error of measurement and coefficient of variation were calculated from a one-way ANOVA. Percent agreement was also calculated.

RESULTS

The study revealed good reliability for the slope for the total time (ICC 0.65-0.90), the initial and end median frequency (ICC 0.75-0.89), median frequencies at Borg ratings of three (ICC 0.63-0.88), five (ICC 0.62-0.84) and seven (ICC 0.67-0. 87), endurance time (ICC 0.89). The Borg ratings of the first minute agreed better than those of the second and the third. The Borg ratings at the second and the third test agreed to 40-80%, indicating a need for a practice session.

CONCLUSION

The protocol used for assessing fatigue in the back extensor muscles proved to be reliable and is recommended for further use.

Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio

BACKGROUND AND PURPOSE

To investigate the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and to analyze which implant parameters have influence on the DNR.

MATERIALS AND METHODS

Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined.

RESULTS

Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR.

CONCLUSIONS

In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but also the high dose volume. The optimization on dose points and geometry provides the most uniform dose distribution. The dose non-uniformity ratio can be minimized by selecting the isodose line of the midpoints between the catheters in the whole volume for the dose prescription, but the dose coverage may not be adequate. For a clinically acceptable plan, a compromise should be made between dose non-uniformity and coverage.

CT-image-based conformal brachytherapy of breast cancer. The significance of semi-3-D and 3-D treatment planning

PURPOSE

To compare the conventional 2-D, the simulator-guided semi-3-D and the recently developed CT-guided 3-D brachytherapy treatment planning in the interstitial radiotherapy of breast cancer.

PATIENTS AND METHODS

In 103 patients with T1-2, N0-1 breast cancer the tumor bed was clipped during breast conserving surgery. Fifty-two of them received boost brachytherapy after 46 to 50 Gy teletherapy and 51 patients were treated with brachytherapy alone via flexible implant tubes. Single, double and triple plane implant was used in 6, 89 and 8 cases, respectively. The dose of boost brachytherapy and sole brachytherapy prescribed to dose reference points was 3 times 4.75 Gy and 7 times 5.2 Gy, respectively. The positions of dose reference points varied according to the level (2-D, semi-3-D and 3-D) of treatment planning performed. The treatment planning was based on the 3-D reconstruction of the surgical clips, implant tubes and skin points. In all cases the implantations were planned with a semi-3-D technique aided by simulator. In 10 cases a recently developed CT-guided 3-D planning system was used. The semi-3-D and 3-D treatment plans were compared to hypothetical 2-D plans using dose-volume histograms and dose non-uniformity ratios. The values of mean central dose, mean skin dose, minimal clip dose, proportion of underdosaged clips and mean target surface dose were evaluated. The accuracy of tumor bed localization and the conformity of planning target volume and treated volume were also analyzed in each technique.

RESULTS

With the help of conformal semi-3-D and 3-D brachytherapy planning we could define reference dose points, active source positions and dwell times individually. This technique decreased the mean skin dose with 22.2% and reduced the possibility of geographical miss. We could achieve the best conformity between the planning target volume and the treated volume with the CT-image based 3-D treatment planning, at the cost of worse dose homogeneity. The mean treated volume was reduced by 25.1% with semi-3-D planning, however, it was increased by 16.2% with 3-D planning, compared to the 2-D planning.

CONCLUSION

The application of clips into the tumor bed and the conformal (semi-3-D and 3-D) planning help to avoid geographical miss. CT is suitable for 3-D brachytherapy planning. Better local control with less side effects might be achieved with these new techniques. Conformal 3-D brachytherapy calls for new treatment planning concepts, taking the irregular 3-D shape of the target volume into account. The routine clinical application of image-based 3-D brachytherapy is a real aim in the very close future.

Cost-minimisation analysis of three conservative treatment programmes in 180 patients sick-listed for acute low-back pain

OBJECTIVE

To perform a cost-minimization analysis of three conservative treatment regimes for acute low-back pain (LBP).

DESIGN

A prospective randomized clinical trial. Patients were assigned at random to one of three treatment programmes: General Practitioner Programme (GPP-) controls, Manual Therapy Programme (MTP) or Intensive Training Programme (ITP).

SETTING

Primary care and physiotherapists in Stockholm, Sweden.

PATIENTS

180 patients sick-listed for acute LBP.

MAIN OUTCOME MEASURES

Direct, indirect and total costs for three treatment programmes.

RESULTS

The direct costs for treatment were lowest in the GPP group -- 2744 Swedish crowns (SEK) per patient. More patients in the MTP and ITP underwent operations for disk hernia and radiological investigations than in the GPP. Indirect costs, defined as sick-leave for LBP represent about 90% of the total cost.

CONCLUSIONS

With respect to total costs, the findings were similar between the three treatment programmes. The GPP had the lowest direct costs. It is not possible to conclude which treatment programme is to be recommended as a least cost alternative. The strong effect of indirect costs on the total cost stresses that further studies should focus on methods of shortening sick-leave.

[Current diagnostic method, prognosis estimation and therapy of papillary thyroid cancer: recommendations of the medical universities and the National Oncologic Institute of Budapest]

Physical examination, cervical ultrasonography (US) and aspiration cytology are the mainstays of the preoperative diagnostics of papillary thyroid carcinoma. For the staging of suspected malignant cases, cervical and mediastinal CT (MRI for inconclusive results) is indicated before any surgery. The end-result of primary treatment is assessed by total-body iodine scintigraphy and the serum human thyroglobulin (hTG) level. For long-term follow-up, physical examination and the serum hTG level are the most reliable tools (6-monthly), supplemented by cervical US and chest X-ray (yearly), and total-body iodine scintigraphy (2-yearly). If these furnish positive results, further examinations may be indicated. In suspected relapses of hTG non-producing and iodine non-accumulating papillary carcinomas, 201thallium chloride or 99mTc-sesta-MIBI (methoxy-isobutyl-isonitrile) scintigraphy, and positron emission tomography with 18fluoro-deoxyglucose or 11C-methionine may be of help. For estimation of the prognosis (cause-specific survival) of the patients, the MACIS score system of the Mayo Clinic is widely accepted, the patients being divided into low-risk and intermediate/high-risk categories. The recommended standard surgical intervention is near-total thyroidectomy (2-4 g residual glandular tissue left at the upper pole of the less-involved lobe), with a central cervical lymph node dissection for diagnostic purposes. In cases of lymph node dissemination, dissection (radical, modified radical, selective or microdissection) of any of the involved compartments (central, right or left cervical, or upper mediastinal) is indicated for therapeutic reasons, the method of which is depending on the extent of the metastatic involvement. Following adequate surgical intervention, no adjuvant radioiodine therapy is indicated for low-risk cases with a tumour of less than 1 cm diameter. For other low-risk or intermediate/high-risk patients, radioiodine ablation (R0N0M0) or a therapeutic radioiodine dosage (R2N1M1) is indicated. In cases at high-risk of local/regional relapse and in radioiodine non-accumulating tumorous cases, external radiotherapy may be applied. Thyroid hormone medication in a TSH suppressive dose is indicated during the first 5 postsurgical years: the goal is to achieve a TSH level below 0.1 (determined by a 3rd generation assay). If no relapse occurs or the case is a low-risk one, following the 5 years, it is enough to maintain the TSH level in a subnormal range (0.1-0.3).

Possibilities of preventing osteoradionecrosis during complex therapy of tumors of the oral cavity

In recent years, there has been a dramatic increase in the number of tumors of the head and neck. Their successful treatment is one of the greatest challenges for physicians dealing with oncotherapy. An organic part of the complex therapy is preoperative or postoperative irradiation. Application of this is accompanied by a lower risk of recurrences, and by a higher proportion of cured patients. Unfortunately, irradiation also has a disadvantage: the development of osteoradionecrosis, a special form of osteomyelitis, in some patients (mainly in those cases where irradiation occurs after bone resection or after partial removal of the periosteum). Once the clinical picture of this irradiation complication has developed, its treatment is very difficult. A significant result or complete freedom from complaints can be attained only rarely. Attention must therefore be focussed primarily on prevention, and the oral surgeon, the oncoradiologist and the patient too can all do much to help prevent the occurrence of osteoradionecrosis. Through coupling of an up-to-date, functional surgical attitude with knowledge relating to modern radiology and radiation physics, the way may be opened to forestall this complication that is so difficult to cure.

Polymorphous low-grade adenocarcinoma of the nasopharynx. Case report and review of the literature

BACKGROUND

The polymorphous low-grade adenocarcinoma of the nasopharynx is a rare disease. Polymorphous low-grade adenocarcinoma is a minor salivary gland neoplasm which occurs frequently in the mucosa of the soft and hard palates, in the buccal mucosa and in the upper lip. To date this entity has been identified within the oral cavity and only one case within the nasopharynx and some cases in the parotid gland. It has a slow infiltrating growing pattern with frequent perineural invasion and low metastatic potential.

CASE REPORT

We report on a patient with non-papillary polymorphous low-grade adenocarcinoma in the nasopharynx which extended intracranially. The patient underwent primary radiotherapy. The CT showed partial response to radiotherapy and the patient is alive 51 months after the diagnosis his state being unchanged.

CONCLUSION

The treatment for minor salivary gland tumor is primarily surgical. It is reported that the polymorphous low-grade adenocarcinoma has been known to have poor response to radiotherapy. However, we believe that in addition to its favorable biological behavior, the radiotherapy in this localization may result in longer survival.

Sole brachytherapy of the tumor bed after breast conserving surgery: a new radiotherapeutic strategy for patients at low risk of local relapse

The aim of the study was to test the hypothesis, if there were subgroups of early breast cancer patients in which sole brachytherapy (BT) of the tumor bed was a feasible and safe treatment option after breast conserving surgery (BCS). Forty four prospectively selected patients with Stage I-II breast cancer were entered into a protocol of postoperative tumor bed irradiation using interstitial high dose rate (HDR) implants. The HDR fractionation schedules were calculated according to the linear quadratic model. In 8 patients 7 x 4.33 Gy, in the other 36 patients 7 x 5.2 Gy were delivered to the tumor bed with 2 cm margin. The treatment planning was based on the 3 dimensional (3D) reconstruction of the clipped excision cavity, catheters and skin points. A conformal semi-3D dose planning was used. The side effects were assessed by mammograms, MRI- and clinical examinations. At a median follow up of 20 (7-36) months 1 (2.3%) local and 1 (2.3%) regional failure was observed. Distant metastasis did not occur. The cosmetic results were judged to be excellent in each case. G2 radiation side effects were observed in 2 (4.5%) cases. Postoperative sole BT of the tumor bed with careful patient selection and adequate quality assurance seems to be a feasible alternative to whole breast radiotherapy after BCS. Sole BT shortens the time of radiotherapy from 5-6 weeks to 5 days, and reduces the costs of treatment. The skin and volume sparing effect of interstitial irradiation may decrease the side effects of radiotherapy. A randomized study is in progress to define which subgroups of patients should be candidates for BT alone after BCS.