[The effect of preoperative chemo-radiotherapy in the treatment of locally advanced squamous cell carcinoma in the upper- and middle-thirds of the esophagus]

AIM

The aim of this study was to compare the efficiency of the preoperative combined chemo-radiotherapy in the treatment of locally advanced squamous cell carcinoma in different locations of the oesophagus.

METHODS

Between 1997 and 2005, 102 patients with locally advanced (T3-4) squamous cell oesophageal cancer received preoperative chemo-radiotherapy. In 40 cases, the tumour was localised in the upper-third (Group I), while in 62 cases, in the middle-third of the oesophagus (Group II). Survival rates of patients receiving neoadjuvant therapy were compared with a historical control group. In addition, Group I and Group II were compared to each other, as well.

RESULTS

survival rate was significantly better after neoadjuvant therapy (p:0.0042) Resection was performed in 70% of the patients from Group I, and in 50% of those complete pathological remission (pCR) was observed. The perioperative morbidity and mortality rates were 43% and 14%, respectively. As far as Group II, 69% of the patients underwent oesophageal resection, with a perioperative mortality of 18% and morbidity rate of 62%. pCR was observed only in 7% of the cases. The median survivals (21 and 22 months) and the R0 resection rates (82 and 84%) were similar in the two groups. The pCR subgroup showed a significantly better survival rate.

CONCLUSION

In this study, we demonstrated that preoperative chemo-radiotherapy increases survival in locally advanced oesophageal cancer. A significantly higher rate of complete response was observed in patients with upper-third oesophageal cancer. It seems that this group has superior sensitivity to multimodal treatment; therefore, our results support a new prognostic factor in oesophageal cancer treatment.

[The results of ovarian cancer therapy in the Hungarian Centers in 2002-2003]

Authors presented data of treatment results and course of disease in 487 ovarian cancer patients treated by primary surgery and paclitaxel-carboplatin combination chemotherapy between July 1, 2002 and December 31, 2003.

PATIENTS

Most of our patients (87.8%) belonged to the age-group between 40-70 years. Distribution of their histological diagnosis was as 69.6% serous, 10.7% mucinous, 5.1% endometrial and 4.7% undifferentiated carcinoma. The grade distribution was found as 8.4% grade 1, 40.9% grade 2 and 35.9% grade 3.

RESULTS

The primary surgery was evaluated as optimal in 41.7%, suboptimal in 37.3% and exploration was performed in 21.1%. Most patients started chemotherapy 20 days after surgery and 74.2% of them got six courses. During the evaluation period 61 intervallum laparotomies were performed, and resulted on 55.7% optimal debulking. Complete remission was found in 58.9%, and partial remission in 14.7% of patients. This treatment resulted on a complete remission in 40.9% at the follow-up of 12 months.

[Complete regression after neoadjuvant chemotherapy in locally advanced gastric cancer causing peritonitis carcinomatosa--a case report]

Gastric cancer is one of the most frequent cause of mortality, survival data are insufficient. Several chemotherapeutic combinations were applied successfully in advanced gastric cancer, following total tumor regression and radical resection, but there are very few cases with total regression after a disease forming carcinosis and causing ascites. In our report, a middle age patient suffering from locally advanced gastric cancer with peritonitis carcinomatosa and ascites was treated with neoadjuvant chemotherapy (DCF: docetaxel, cisplatin, fluorouracil protocol) successfully, as at the restaging examination total tumor regression was found. Ascites and carcinosis disappeared, so we performed radical distal surgical resection. The histological preparation resulted in 100% tumor regression of the specimen. Postoperatively the patient was given adjuvant DCF chemotherapy. The therapeutic modality of cases with advanced gastric cancer, especially with carcinosis must be reassessed, because according to our and some international reports, these patients are also candidates for effective neoadjuvant therapy and curative resection. In our own and in the experience of some others the combinations with taxanes and its derivatives are one of the most effective.

Microarray analysis of radiation response genes in primary human fibroblasts

PURPOSE

To identify radiation-induced early transcriptional responses in primary human fibroblasts and understand cellular pathways leading to damage correction.

METHODS AND MATERIALS

Primary human fibroblast cell lines were irradiated with 2 Gy gamma-radiation and RNA isolated 2 h later. Radiation-induced transcriptional alterations were investigated with microarrays covering the entire human genome. Time- and dose dependent radiation responses were studied by quantitative real-time polymerase chain reaction (RT-PCR).

RESULTS

About 200 genes responded to ionizing radiation on the transcriptional level in primary human fibroblasts. The expression profile depended on individual genetic backgrounds. Thirty genes (28 up- and 2 down-regulated) responded to radiation in identical manner in all investigated cells. Twenty of these consensus radiation response genes were functionally categorized: most of them belong to the DNA damage response (GADD45A, BTG2, PCNA, IER5), regulation of cell cycle and cell proliferation (CDKN1A, PPM1D, SERTAD1, PLK2, PLK3, CYR61), programmed cell death (BBC3, TP53INP1) and signaling (SH2D2A, SLIC1, GDF15, THSD1) pathways. Four genes (SEL10, FDXR, CYP26B1, OR11A1) were annotated to other functional groups. Many of the consensus radiation response genes are regulated by, or regulate p53. Time- and dose-dependent expression profiles of selected consensus genes (CDKN1A, GADD45A, IER5, PLK3, CYR61) were investigated by quantitative RT-PCR. Transcriptional alterations depended on the applied dose, and on the time after irradiation.

CONCLUSIONS

The data presented here could help in the better understanding of early radiation responses and the development of biomarkers to identify radiation susceptible individuals.

Genotype-phenotype correlations in Hungarian patients with hereditary medullary thyroid cancer

The genotype and phenotype characteristics of Hungarian patients with RET proto-oncogene mutations operated on for hereditary medullary thyroid cancer (MTC) were studied. The genetic screening was performed in two centers and 40 patients with hereditary MTC or C-cell hyperplasia (CCH) from 18 unrelated families were analyzed. One patient having a mutation in exon 16 (Met918Thr) presented with the MEN2B phenotype, six patients from two families had hereditary MTC without pheochromocytoma (pheo) and primary hyperparathyroidism (PHPT), whereas 33 patients from 15 families showed the MEN2A phenotype. Two different mutations were identified in exon 10 (Cys609Tyr and Cys609Ser), five different mutations were present in exon 11 (Cys634Phe, Cys634Arg, Cys634Tyr, Cys634Trp and Cys634Ser), and two different mutations were localized in exon 14 (Val804Met and Val804Leu). Mutations in exon 10 were associated with hereditary MTC (Cys609Tyr) or with MEN2A syndrome (Cys609Ser). Mutations in exon 11 were always associated with the MEN2A phenotype. PHPT was present in one patient with mutation in exon 14 (Val804Met), whereas all other patients affected with mutations in exon 14 had hereditary MTC without PHPT and/or pheos.

[Progress in the treatment of gastrointestinal cancers due to introduction of neoadjuvant concept]

Formerly the treatment of gastrointestinal cancers was exclusively surgical. Though the results were improved by increased radicality, the real progress was achieved by the introduction of multimodal therapy, particularly by the neoadjuvant concept. The basic prerequisite for neoadjuvant treatment is precise staging and risk assessment. According to staging patients can be divided into three categories: (1) Early cancers, confined to the mucosal and submucosal layers, are approached with primary surgery. (2) Systemically metastasized tumors receive merely palliative treatment. (3) Locally advanced cancers are treated by neoadjuvant therapy. Due to neoadjuvant treatment the tumor can be downsized (or downstaged) in some patients. These are the responders benefiting from the therapy, because of the increased RO-resection rate, decreased recurrence rate and improved survival. The non-responders, by contrast have poor prognosis. Neoadjuvant treatment considerably improved the chance for cure for patients with gastrointestinal cancers, thus this method became an evidence based treatment for locally advanced gastrointestinal cancers.

Pattern of increased cerebral FDG uptake in Down syndrome patients

Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome patients. Standardized uptake values were determined on a pixel-by-pixel basis from the measured tissue-activity data. The results revealed a mean overall 18[F]-fluorodeoxyglucose uptake in the Down syndrome patients close to that observed in the control group, consisting of children and young adults. However, the standard deviation of the standardized uptake values was much higher in the Down syndrome group in almost all voxels relating to the gray matter. The statistical parametric mapping method was applied to compare the cerebral 18[F]-fluorodeoxyglucose accumulation patterns of the Down syndrome and control groups. Six regions (clusters) were found for which the glucose uptake was higher in the Down syndrome patients than in the control group. The anatomic localization of these clusters was based on magnetic resonance investigations and a brain-atlas technique. The localization of the identified clusters with an increased glucose metabolism in the Down syndrome patients suggests that these subjects have an enhanced resting neuronal activity in cortical areas involved in reasoning, cognition, and speech as compared with normal subjects.

Familial clustering of nasopharyngeal carcinoma in a non-endemic geographical region. Report of two Hungarian cases and a review of the literature

The aim of this study was to investigate the familial clustering of nasopharyngeal carcinoma (NPC) in a non-endemic geographical region on the basis of two case reports and a review of the literature. Following an upper respiratory infection, NPC (WHO type III) was detected in a 57-year-old female (Case 1) who presented with nasal symptoms and a year later in her 36-year-old son (Case 2) who presented with enlarged lymph nodes. After a full diagnostic work-up, cT2a cN0 cM0 (stage IIA; Case 1) and cT2a cN2 cM0 (stage III; Case 2) disease were identified, and telecobalt irradiation was administered to both patients. The mother achieved complete remission and has been disease-free during a 14-year follow-up period. After initial complete remission, the son experienced regional (cervical) and base of the skull relapses within 2 years, which were treated unsuccessfully by means of radical neck dissection, a second course of radiotherapy and chemotherapy. Epstein-Barr virus (EBV) was detected in pathology sections from both patients. The authors review 20 additional well-documented cases of familial clustering of NPC in non-endemic geographical regions from the English language literature. This clinical entity typically has WHO type III histology; it may occur following an upper respiratory tract infection, and EBV-related serological titers were elevated in all 20 investigated cases. No consequent promoting factors were identified. The present two cases and the review of the literature strongly suggest that familial clustering of NPC in non-endemic geographical areas may be related to EBV infections. The difference in outcome of our two cases may be explained by the fact that the disease in Case 2 was diagnosed 1 year later than that in Case 1 and hence at a more advanced stage.

Biphasic accumulation kinetics of [99mTc]-hexakis-2-methoxyisobutyl isonitrile in tumour cells and its modulation by lipophilic P-glycoprotein ligands

AIM

To study the accumulation and washout kinetics of [99mTc]-hexakis-2-methoxyisobutyl isonitrile (99mTc-MIBI) in MDR positive and MDR negative tumour cells and how this is modified by lipophilic P-glycoprotein ligands.

METHODS

The tumour cells were incubated in the presence and absence of the ligands and the uptakes of 99mTc-MIBI, rhodamine 123 and 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) were measured.

RESULTS

The accumulation of 99mTc-MIBI in the tumour cells followed biphasic kinetics. Verapamil and cyclosporin A increased the membrane fluidity and significantly enhanced the 99mTc-MIBI uptake of the MDR negative cells, while the rhodamine 123 uptake was not affected. Verapamil significantly increased the uptake of rhodamine 123 and 18FDG but did not modify that of 99mTc-MIBI in the MDR positive cells. Cyclosporin A significantly increased the 18FDG uptake of the MDR positive and negative tumour cells; these effects were ouabain-sensitive. Depolarization of the cytoplasmic membrane, acidification of the extracellular medium and the administration of CCCP decreased the accumulation of 99mTc-MIBI and rhodamine 123 uptake in the tumour cells.

CONCLUSIONS

Lipophilic P-glycoprotein ligands modified the biphasic accumulation kinetics of the 99mTc-MIBI uptakes of MDR negative and positive tumour cells in different and complex ways and could therefore mask the P-glycoprotein pump-dependent changes in tracer accumulation.

Angiography-proven liver metastases explain low efficacy of lymph node dissections in medullary thyroid cancer patients

AIM

To report the role of liver angiography in the staging of medullary thyroid cancer (MTC) patients.

MATERIAL AND METHODS

Sixty MTC patients with persistent or recurrent hypercalcitonemia (n=49), a characteristic general symptom (diarrhea, n=4) or a normal basal calcitonin level without general symptoms (n=7) were investigated by dynamic liver CT, MRI and angiography between 06/1998 and 06/2002.

RESULTS

Dual-phase CT and MRI investigations identified hepatic metastases with relatively low frequency (8/58 on MRI, and 7/60 on CT). Angiography indicated liver involvement in 54/60 cases. The hepatic metastases were typically multiple, hypervascular, small foci (only 13 foci measured >/=10 mm). With one exception significant disease progression was not observed over 5 years of follow-up.

CONCLUSIONS

Liver angiography is a powerful tool to reveal hepatic metastases in MTC patients. Frequent, inoperable liver metastases in hypercalcitoninemic MTC patients demonstrate that secondary lymph node dissection is an inefficient technique for restoration of a normal calcitonin level.

[Status report on the chemotherapy of ovarian cancer at special cancer centers in Hungary (2002-2003)]

Data on the first-line treatment of ovarian cancer in special centers of Hungary 2002 and 2003 are presented, involving 283 and 416 patients, respectively. Patients' age, clinical stage and histological type of the tumor were highly similar to literature data, while grades were different. Surgical effectiveness in case of IIIc staged tumors with >1 cm residual mass was 37%. The ratio of interval laparotomy was about 15%. Overall response rates of the first-line treatment of ovarian cancer was 82%, while the rate of complete remissions was 60%. The authors provide detailed analysis of factors that can improve the chemotherapy of ovarian cancer in Hungary.

[Primary treatment of early stage Hodgkin's disease]

Until the beginning of the 1990s, early stage Hodgkin's disease had been treated by (involved field) radiotherapy in most cases. Since the mid-1990s, by revealing a range of prognostic factors and late complications of radiotherapy, the treatment protocol has been modified. The use of combined modality therapy (programmed combined use of chemo- and radiotherapy) has gained ground. At present, in early stage Hodgkin's disease, 2-6 cycles ABVD followed by decreased dose involved field irradiation is considered to be the standard treatment. The number of chemotherapy cycles depends on the prognostic factors and reaction time. In cases of early stage nodular lymphocyte predominance with good prognosis, only involved field irradiation therapy is used.

[Treatment of primary mediastinal large B-cell lymphomas]

INTRODUCTION

Primary mediastinal large B-cell non-Hodgkin's lymphoma is a relatively rare disease with specific clinical symptoms. This tumour originates from a subset of B-cells of the thymus and at the time of the diagnosis the disease is predominantly localised in the mediastinum. The tumor grows rapidly and frequently involves other thoracic structures. The majority of the patients are young females. There are no histologic features that reliably distinguish these tumors from other diffuse large B-cell lymphomas. This is the only lymphoma subtype which can only be defined by the combination of clinical and pathologic features. Analysis with DNA microarrays verified that primary mediastinal and diffuse large B-cell lymphomas are different diseases.

AIMS

Comparing the effectiveness of two types of anthracycline-based standard chemotherapy regimens and the evaluation of the prognostic markers which are applied in large B-cell lymphomas.

METHODS

27 patients with primary mediastinal lymphoma were treated by the authors with anthracycline-based polychemotherapy with complementary radiotherapy from January 1995 to December 2002.

RESULTS

Complete remission was obtained in 15 patients (56%) and no relapse was observed in this group. 9 additional patients (33%) achieved partial remission, while in 3 cases (11%) the treatment was ineffective. The patients who failed to achieve complete remission were subsequently treated with more intensive chemotherapy. Afterwards, those patients who were chemosensitive, underwent high-dose chemotherapy with autologous peripheral blood stem-cell transplantation. The chemoresistant patients received palliative chemotherapy. The 5-year overall survival rate of the 27 patients was 62.11%.

CONCLUSION

The authors found that the procarbazine, prednisolone, adriamycin, cyclophosphamide, etoposide, cytosine-arabinoside, bleomycin, vincristine, methotrexate treatment was more effective than the cyclophosphamide, adriamycin, vincristine, prednisolone combination. The expected 5-year overall survival rates were 83.57% vs. 33.33%, respectively. This difference was significant (p = 0.017). No prognostic value of age adjusted international prognostic index, LDH- and b2-microglobulin levels were found. The results with the new standard of combined immuno-chemotherapy (rituximab--cyclophosphamide, adriamycin, vincristine, prednisolone) seem to be hopeful and more effective than earlier treatments.

Myasthenia in a patient with sarcoidosis and schizophrenia

A 44-year-old male patient was hospitalised with paranoid schizophrenia in 1985. Depot neuroleptic treatment was started which successfully prevented further psychotic relapses for the next ten years. His myasthenia gravis started with bulbar signs in 1997 and the symptoms soon became generalized. The diagnosis of myasthenia gravis was confirmed by electromyography, by positive anticholinesterase test and by the detection of anti-acetylcholine receptor antibodies in the serum. Mediastinal CT examination showed enlarged hilar lymph nodes on the left but no thymic pathology was observed. Mediastinoscopy was performed and biopsies were obtained from the affected nodes. Histology revealed sarcoidosis. The patient suffered respiratory crisis following the thoracic intervention (in September 1998). Combined oral corticosteroid (64 mg methylprednisolone/e.o.d.) and azathioprine (150 mg/day) treatment regimen was initiated and complete remission took place in both the myasthenic symptoms and the sarcoidosis. The follow-up CT scans showed no mediastinal pathology (January 2000). During steroid treatment a transient psychotic relapse occurred which was successfully managed by supplemental haloperidol medication added to his regular depot neuroleptics. The patient currently takes 150 mg/day azathioprine and receives 40 mg/month flupentixol depot i.m. His physical and mental status are stable and he has been completely symptom free in the last 24 months. The association of myasthenia gravis and sarcoidosis is very rare. To our best knowledge no case has been reported of a patient suffering from myasthenia gravis, sarcoidosis, and schizophrenia at the same time.

Partial breast irradiation with interstitial 60CO brachytherapy results in frequent grade 3 or 4 toxicity. evidence based on a 12-year follow-up of 70 patients

PURPOSE

To investigate the radiation-induced toxicity and cosmesis of brachytherapy (BT) alone in early stage breast cancer.

METHODS AND MATERIALS

A total of 70 women diagnosed with Stage I or II breast carcinoma participated in a BT study at the Municipal Oncoradiological Center, Uzsoki Hospital, Budapest, Hungary, between November 1987 and June 1992. They had undergone breast-conserving surgery with an unknown surgical margin. The postoperative tumor bed irradiation was performed with interstitial (60)Co sources with an active length of 4 cm, with 10-mm center-to-center spacing arranged in a single plane. The median number of inserted sources was 5 (range, 2-8), with a linear activity of 133-137 MBq/cm at the beginning of the study. The 50 Gy delivered dose at 5 mm from the surface of the (60)Co sources was administered during 10-22 h to the virtual postoperative lumpectomy cavity (i.e., plane). For radiobiologic considerations, the clinical target volume (CTV) was calculated retrospectively with a 10-mm safety margin, resulting in a 72-cm(3) median CTV (range, 36-108 cm(3)) irradiated with a reference dose of 28 Gy. In the assessment of the skin and subcutaneous toxicity, the RTOG late radiation morbidity scoring system was applied. The radiosensitivity of the cultured fibroblasts was determined by clonogenic assay to check whether individual radiosensitivity played a role in the development and course of radiation-induced side-effects.

RESULTS

The median follow-up was 12 years (range, 10-15 years). The population of the final study (34 cases) comprised all survivors with tumor-free breasts (27 cases) and patients with breasts erroneously ablated/excised for misinterpreted radiation-induced sequelae (7 patients). A total of 97% of the cohort (33/34) had grade > or =2, and 59% (20/34) had grade > or =3 radiation-induced toxicity. By the end of the follow-up, 85% of the patients experienced Grade > or =2 telangiectasis and 41% had Grade 3 telangiectasis. Eighty-eight percent had fibrosis of some form, and 35% had grade > or =3 fibrosis. Forty-one percent of the cohort displayed fat necrosis, which was always accompanied by Grade > or =3 fibrosis or telangiectasis. The cosmetic results were poor in 50% (17/34) of the patients. The radiosensitivity of the fibroblasts was increased in only 2/24 patients (8% of the investigated cases, in agreement with data published for the general population). Comparisons of our fibrosis prevalence data with those of others allowed an estimate of 0.47 h(-1) for the rate of recovery of DNA damage in the fibroblasts.

CONCLUSIONS

Interstitial (60)Co BT of the breast tumor bed alone with a limited CTV (median, 72 cm(3)) and a total dose of 28 Gy is associated with a high rate (59%) of grade > or =3 radiation-induced toxicity and a high rate (50%) of poor cosmetic outcome at the end of a median follow-up of 12 years. A relatively high BT dose rate (1.3-2.8 Gy/h) applied during a short overall treatment time (10-22 h) and a possible geographic miss (close to skin implantation) might have contributed to the development of these sequelae.

Characteristics of radiogenic lower motor neurone disease, a possible link with a preceding viral infection

OBJECTIVE

To investigate the pathogenesis of the rare radiogenic lower motor neurone disease (LMND) on the basis of a meta-analysis of the published case histories.

MATERIALS AND METHODS

The authors reviewed 47 well-documented radiogenic LMND cases from the English literature.

RESULTS

The disease typically occurs following the irradiation of radiosensitive cancers situated near the spinal cord. It arises predominantly (46 cases) in the lower extremities; only one case involved the upper extremities. There is a male predominance (male:female ratio 7.8:1), and the patients are characteristically young (13-40 years, with four exceptions). An overdose does not seem to be a particular risk factor for the development of the disease, as total dose, fraction size and biologically effective dose are typically below 50 Gy, 2 Gy and 128 Gy2, respectively, which are regarded as safe doses. Other risk factors (chemotherapy, operations, etc) have been identified only rarely. Radiogenic LMND is manifested in an apparently random manner, 4-312 (mean 48.7) months after the completion of radiotherapy.

DISCUSSION

The complete lack of a dose-effect relationship argues strongly against a pure radiogenic nature of the pathological process. The latency period is typically several years and it varies extremely, which excludes a direct and complete causal relationship between radiotherapy and LMND. As the interaction of ionizing radiation with living tissues is highly unspecific, thus a selective motor injury due to irradiation alone, without comparable effects on the sensory and vegetative fibers, seems improbable.

CONCLUSIONS

On analogy with the viral motor neurone diseases, we suppose that radiogenic LMND may be preceded by viral (enterovirus/poliovirus) infection. Based on the meta-analysis, it is suggested that irradiation may be only a single component of the set of factors jointly resulting in the clinical state regarded as radiogenic LMND.

FDG PET imaging in hereditary thyroid cancer

AIM

To report the role of different imaging methods in staging individuals with multiple endocrine neoplasia 2A (MEN2A) or familial medullary thyroid carcinoma (FMTC).

MATERIAL AND METHODS

Fourteen newly diagnosed gene carriers underwent cervical ultrasound scanning (US), cervical and mediastinal CT, MRI and whole-body meta-[131I]iodobenzylguanidine (MIBG) scintigraphy and [18F]fluorodeoxyglucose (FDG) PET scanning.

RESULTS

US identified seven true primary cancer. CT and MRI located only tumors > or =5 mm in diameter. MIBG scintigraphy and FDG PET could not identify MTC foci within the thyroid. Whole-body FDG PET identified two true-positive and one false-positive lymph node metastases. MIBG scintigraphy did not identify lymph node metastases. Total thyroidectomy was performed in 12 cases, and subtotal thyroidectomy in two subjects.

CONCLUSIONS

Whole-body FDG PET and cervical US help stage individuals carrying mutant genes verifying MEN2A or FMTC.

[Different histological findings in two specimens from pulmonary metastasectomy in the same patient]

INTRODUCTION

Out of the 3310 thoracic surgical procedures performed between 1980 and 2000 at the Department of Surgery of the National Institute of Oncology in Budapest, 258 were pulmonary metastasectomies involving 236 patients. Primary tumors were the following in order of decreasing frequency: testicular cancer, colorectal cancer, renal cancer, soft tissue tumor, breast cancer and others.

METHODS

In the present study the authors report two patients with multiple pulmonary metastases. The primary tumor was non-seminoma testicular cancer in case one and endometrial cancer in case two (previously treated for thyroid cancer). Histological examination of resected specimens revealed unsuspected focal inactive tuberculosis in the first case and medullary thyroid cancer in the second.

CONCLUSIONS

In the reported two cases the following conditions of metastasectomy were given: 1. satisfactory cardiopulmonary status, 2. possibility of surgical radicality, 3. locoregional disease control, 4. prior chemotherapy in chemosensitive tumor (case one). The generally accepted condition of metastasectomy-lack of clinically manifest disease in other distant organs--was not fulfilled in case two (suspected liver metastases).

A novel technique with a flexible applicator for MRI-based brachytherapy of cervical cancer

PURPOSE

To introduce a novel technique for magnetic resonance (MR)-based 3-dimensional planned high-dose rate intracervical brachytherapy (BT).

MATERIALS AND METHODS

During 2002, 16 patients received external beam radiotherapy and BT as part of radiochemotherapy for cervical cancer. A special adjustable applicator device was designed and used for BT. The isodose distribution was calculated from MR images with the applicator in place.

RESULTS

The planning target volume coverage was adequate and the radiation burden on the organs at risk was within acceptable limits. Complete regression was achieved in two patients (12.5%), and partial regression in ten (62.5%) patients. The overall response rate for the complex treatment was 93.75%. In three cases the disease was considered to be stable.

CONCLUSION

The MR-compatible, flexible applicator allows safe and reproducible cervical radiotherapy with no added discomfort or hazard for the patient.

PET identifies transitional metabolic change in the spinal cord following a subthreshold dose of irradiation

Positron emission tomographic (PET) investigations were performed to obtain in vivo information on symptomless radiation-induced pathological changes in the human spinal cord. PET investigations were carried out prior to radiotherapy and during the regular follow-up in an early hypopharyngeal cancer patient (the spinal cord was irradiated with a biologically effective dose of 80 Gy2), with [18F]fluorodeoxyglucose (FDG), [11C]methionine and [15O]butanol as tracers; radiosensitivity and electroneuronographic (ENG) studies were also performed. A very low background FDG accumulation (mean standardized uptake values, i.e. SUV: 0.84) was observed in the spinal cord before the initiation of radiotherapy. An increased FDG uptake was measured 2 months after the completion of radiotherapy (mean SUV: 1.69), followed by a fall-off, as measured 7 months later (mean SUV: 1.21). By 44 months after completion of irradiation, the FDG accumulation in the irradiated segments of the spinal cord had decreased to a level very close to the initial value (mean SUV: 1.11). The simultaneous [15O]butanol uptake results demonstrated a set of perfusion changes similar to those observed in connection with the FDG accumulation. The patient exhibited an extremely low [11C]methionine uptake within the irradiated and the nonirradiated spinal cord during the clinical course. She has not had any neurological symptoms, and the results of central ENG measurements before radiotherapy and 2 months following its completion proved normal. Radiobiological investigations did not reveal unequivocal signs of an increased radiosensitivity. A transitory increased spinal cord FDG uptake following radiotherapy may be related to the posttherapeutic mild inflammatory and regenerative processes. The normal [11C]methionine accumulation observed is strong evidence against intensive cell proliferation. The high degree of normalization of the temporarily increased FDG uptake of the irradiated spinal cord segments by 44 months is in good agreement with the results of monkey studies, which demonstrated a nearly complete recovery from radiation-induced spinal cord injury.

[Effect of imatinib treatment of gastrointestinal stromal tumors]

INTRODUCTION

Advanced malignant gastrointestinal stromal tumours are practically resistant to further radio- or chemotherapy. These tumours are characterized by the presence of C-KIT (a transmembrane tyrosin kinase) mutation which can be specified by CD117 expression. Imatinib (2-fenilaminopirimidine) is a selective inhibitor of the mutated C-KIT.

AIM

The purpose of our study was to determine the potential antitumour effect of imatinib in patients with gastrointestinal stroma tumour patients.

MATERIALS AND METHODS

An open, non-randomized trial was performed involving 38 patients each of which had received/metastatic disease associated with CD117 positivity. Consecutively daily doses of 400-600 mg imatinib was administered orally to the patients. The evaluation was carried out on 37 patients in a form of an interim analysis.

RESULTS

After a 3-18 months observation period 1 complete, 19 partial remissions and 10 static diseases could be registered (78%), in association of only grade 1-2 toxicity.

CONCLUSIONS

The imatinib treatment improved the quality of life of the patients with gastrointestinal stroma tumour and their life expectancy became considerably prolonged. Further follow-up of the patients as well as design of a prospective, randomized trial on a larger patient material is urgently needed.

Increased Metabolic Activity in the Spinal Cord of Patients with Long-Standing Lhermitte’s Sign

PURPOSE

To investigate the pathophysiology of the radiation-induced, chronic Lhermitte's sign (LS) on the basis of long-standing case histories with partial functional recovery.

PATIENTS AND METHODS

As radiotherapy in two nasopharyngeal cancer patients, a biologically effective dose (BED) of 103.8 Gy(2) (case 1) and 94.8 Gy(2) (case 2) was delivered to the cervical spinal cord. Neurologic signs relating to the irradiated spinal cord segments developed after 2 months (case 1) and 5 years (case 2), with radiation-induced damage equivalent to grade 3 (case 1) and grade 2 (case 2) toxicity (Common Toxicity Criteria, Version 2.0). The clinical status improved to grade 2 (case 1) and grade 1 (case 2). Positron emission tomography (PET) and fibroblast clonogen assay were applied 25 and 7 years postirradiation, respectively, to characterize this rare clinical picture.

RESULTS

PET demonstrated increased [(18)F]fluorodeoxyglucose (FDG) accumulation and [(15)O]butanol perfusion, but negligible [(11)C]methionine uptake in the irradiated spinal cord segments in both patients. In clonogenic assays, fibroblasts from case 1 displayed much higher radiation sensitivity than in healthy controls, while in case 2 the fibroblasts sensitivity was normal.

CONCLUSIONS

These data suggests a close direct relationship between regional perfusion and metabolism of the spinal cord, similarly as in the brain. The postirradiation recovery may be related to energy-demanding conduction, explaining the increased metabolism and perfusion. The increased radiosensitivity and higher spinal cord BED may have contributed to the more severe sequelae in case 1.

Autopsy verifies demyelination and lack of vascular damage in partially reversible radiation myelopathy

STUDY DESIGN

Case report of recovering radiation myelopathy.

OBJECTIVE

To present autopsy and functional imaging findings on a unique case of slowly recovering radiation myelopathy with the aim of the clarification of the underlying mechanism.

PATIENT

The cervical spinal cord and the distal part of the medulla oblongata of a 36-year-old thyroid cancer patient had been incorrectly irradiated with a total dose of 61 Gy and a fraction size of 3.4 Gy (J Neurol Sci 1999; 163:39-43), resulting in incomplete cervical transection with a 5-month latency period following the termination of radiotherapy. This was followed by a 9.5-year spontaneous improvement until her demise, during which the check-ups were supplemented by positron emission tomography (PET) investigations; these indicated increased [18F]deoxyglucose and [15O]butanol uptakes, but a diminished [11C]methionine accumulation by the irradiated spinal cord segment.

RESULTS

Autopsy revealed demyelination (with axonal loss) and neuronal damage in the cervical spinal cord and the distal part of the medulla oblongata. In the same region, only minimal vascular injury (thickening of some of the capillary walls) was detected, but not cell proliferation or chronic inflammation. Bilateral, secondary pyramidal tract degeneration caudal to the irradiated segment was observed. The PET and autopsy findings, although separated by 2 years, are consistent.

CONCLUSIONS

The pathological state of the spinal cord revealed by the autopsy is concordant with the incomplete cervical transection, implying that the functional recovery is supported by a process that probably differs from the restoration of the mechanism destroyed by the radiotherapy. For the restoration of the function, we suggest an altered conduction mechanism of the action potential, involving an increased number of sodium channels along the demyelinated segments of the injured axons, which is fully congruent with the PET findings.

Concurrent paclitaxel-cisplatin and twice-a-day irradiation in stage IIIA and IIIB NSCLC shows improvement in local control and survival with acceptable hematologic toxicity

Non-small-cell lung cancer (NSCLC) has one of the highest death rates among the various forms of cancer. In attempts to improve on this unsatisfactory outcome, different radiation schedules and chemo-therapy agents have been examined in phase II or III studies. These have led to modest improvements in local control and survival, but combined therapies are associated with substantial hematologic toxicity. In this phase II study, 80 consecutive stage IIIA or IIIB NSCLC patients were treated with concomitant chemotherapy and twice-a-day irradiation in a total dose of 60 Gy in 1.5 Gy fractions. Patients scheduled for surgery received 45 Gy only. Paclitaxel (30 mg/m 2 ) on days 1-4 and cisplatin (100 mg/m 2 ) on day 5 were administered in the first and fourth weeks of treatment. Granulocyte colony stimulating factor (30 ng/m 2 ) was given on days 10-15. The local control, the 1- and 2-year survival rates and the occurrence of acute hematologic toxicity in the non-surgically treated patients were examined. Fifty-two patients were treated without and 28 with surgery. Among the non-surgically treated cases, 43 were evaluable for response and 47 for acute toxicity during a median follow-up of 22 months. The rate of local control was 65% (28/43), and the 1- and 2-year survival rates proved to be 68% and 48%, respectively, with a median survival of 28 months. Severe acute grade 3-4 toxicities included grade 4 leukopenia in 6 cases (13%), grade 3 leukopenia in 4 cases (9%), grade 3 esophagitis in 3 cases (6%) and grade 3 anemia in 3 cases (6%). Our results and the relevant data from the literature support the application of twice-a-day irradiation with concomitant chemotherapy in stage IIIA and IIIB NSCLC. Local control and survival were improved relative to once-a-day irradiation with sequential or concomitant chemotherapy.

Local tumour irradiation enhances the anti-tumour effect of a double-suicide gene therapy system in a murine glioma model

BACKGROUND

Gliomas are invasive malignant tumours with poor prognosis. Combination of gene directed enzyme pro-drug therapy with existing treatment modalities might open new therapeutic potentials.

METHODS

Murine glioma 261 (Gl261) cells were transduced with an adenoviral vector (Adex-CAUPTK) encoding both uracil phosphoribosyltransferase and thymidine kinase genes which sensitise cells to 5-fluorouracil (5-FU) and ganciclovir (GC), respectively. Subcutaneous or intracranial tumours were established in C57Bl mice by transplanting drug-sensitising gene containing Gl261 cells. In vitro growing cells or established tumours were treated with 5-FU, GC and ionising radiation either alone or in combinations. Finally, subcutaneous tumours were established with non-transduced cells, directly injected with Adex-CAUPTK, and mice were treated with combinations of 5-FU, GC and tumour irradiation.

RESULTS

In vitro treatment of transduced Gl261 cells with both 5-FU and GC showed enhanced cytotoxic effect compared with single agents. Combination of drug treatments with irradiation greatly increased cytotoxicity. In subcutaneous and intracranial tumours double-agent treatment was more effective than a single drug. Combination with local irradiation highly improved the anti-tumour effect (90-100% survival) even when only part of the tumour cells carried drug-sensitising genes (40-50% survival at 10% rate). Treatment of established tumours with direct intra-tumour Adex-CAUPTK inoculations and intraperitoneal 5-FU, GC injections slowed down tumour progression that was further enhanced by local irradiation.

CONCLUSION

The combination of double-suicide gene therapy with local irradiation is a promising tool to eradicate small, residual tumours.

Reirradiation of locally recurrent nasopharyngeal carcinoma

PURPOSE

To study the efficacy of reirradiation as salvage treatment in patients with locally recurrent nasopharyngeal carcinoma.

PATIENTS AND METHODS

Between 1993 and 2000, 20 consecutive patients (twelve males and eight females) with nasopharyngeal cancer, previously irradiated in different Hungarian institutions, were reirradiated for biopsy-proven locally recurrent tumor. Histologically, 85% of the patients had WHO type III, 5% type II, and 10% type I disease. Stages I-IV (AJCC 1997 staging system) were assigned to five (25%), seven (35%), five (25%), and three (15%) patients, respectively; none of them had distant metastases, and only eight (40%) displayed regional dissemination. The median time period between termination of primary treatment and local recurrence was 30 (range, 10-204) months. Brachytherapy was the method most frequently used: in ten cases alone (especially for rT1 tumors), and in eight cases in combination with external beam therapy. Two patients with locally advanced disease underwent external beam therapy only. The median dose in the event of brachytherapy alone was 20 Gy (4 x 5 Gy or 5 x 4 Gy, range, 16-36 Gy), and the dose range for exclusive external irradiation was 30-40 Gy. In cases of combined irradiation, a median 20-Gy brachytherapy (range, 16-40 Gy) was associated with 30-40 Gy of external irradiation. Radiotherapy was supplemented by neck dissection (six patients), nasopharyngectomy (one patient), or chemotherapy (eleven patients).

RESULTS

16 patients were reirradiated once, three twice, and one patient three times, with a median equivalent dose for tumor effect of 36 Gy (mean, 44 Gy; range, 19-117 Gy; the estimated alpha/beta-ratio was 10 Gy). The median equivalent dose of reirradiation for late effect on normal tissue (with an estimated 70% delivery of the tumor dose) amounted to 30 Gy (mean, 37 Gy; range, 13-101 Gy, estimated alpha/beta-ratio 3 Gy). After a median follow-up of 37 (range, 12-72) months, the overall survival was 60% (12/20). Seven of the twelve surviving patients are currently tumor-free. After primary irradiation, xerostomy occurred in all patients as an unavoidable side effect of treatment. Following reirradiation, a severe (grade 3 or higher) late toxicity (CTC criteria, version 2) has been observed in two tumor-free patients (10%) so far (necrosis of soft palate and paresis of glossopharyngeal nerve).

CONCLUSION

Retreatment of nasopharyngeal carcinoma with radiotherapy (preferably a combined modality), can result in longterm local control and survival in a substantial proportion of patients, at the price of an acceptable morbidity.

[Principles of radiotherapy of non-small cell lung cancer]

The long-term survival probability for Hungarian lung cancer patients is 10% worse than the best results published in the most highly developed countries (the mean 5-year survival probability in Hungary is 5%, in contrast with the 15% survival probability in the USA). On the basis of the international recommendations and personal experience, an attempt was made to formulate the guidelines for radiotherapy as one of the fundamental non-small cell lung cancer (NSCLC) treatment modalities for national use. An expert panel was set up comprising physicians from 6 radiotherapeutic centers (the National Institute of Oncology / Semmelweis University, Budapest; the Beth Israel Medical Center, New York; the University of Kaposvár; the University of Essen; the University of Debrecen; and the County Hospital of Gyula). Experts in two important medical fields closely related to radiotherapy (surgery and diagnostic imaging) were also engaged in the elaboration of the manuscript. Discussion of the most important principles of the radiotherapy and an overview of the prognostic factors was followed by a critical analysis of the protocols applied in the radiotherapy of Hungarian NSCLC patients during recent decades. The new guidelines suggested for the radiotherapy of NSCLC are presented separately for the postoperative period, marginally resectable tumors, and the aggressive or non-aggressive radiotherapy of inoperable tumors. Detailed accounts are given of the techniques of external irradiation and brachytherapy, and of the acute and late radiation-induced damage of normal tissues. The authors believe that this document may be instrumental in improving the survival index of Hungarian NSCLC patients in the near future.

A review on radiogenic Lhermitte's sign

Radiation myelopathy is a rare, but extremely serious side-effect of radiotherapy. Recovery from radiation-induced motor sequelae is rare, whereas, the regeneration of sensory losses is relatively frequent. Among the sensory radiogenic injuries of the spinal cord, Lhermitte's sign (LS) is most frequent. This review describes the clinical picture and diagnostic imaging signs of radiogenic LS. There have been only a few studies on large patient groups with radiogenic LS, demonstrating a rate of occurrence of 3.6-13%, relating mainly to mantle irradiation or the radiotherapy of head and neck tumors. These cases typically manifest themselves 3 months following radiotherapy and gradually disappear within 6 months. Only 3 LS cases have been described in the English literature with extraordinarily severe symptoms lasting for more than 1 year. MRI, a sensitive tool in the detection of demyelination, failed to reveal any pathological sign accompanying radiogenic LS. However, positron emission tomography demonstrated increased [18F]fluorodeoxyglucose accumulation and [15O]butanol perfusion, but a negligible [11C]methionine uptake in the irradiated spinal cord segments in patients with long-standing LS. These imaging data are suggestive of a close direct relationship between the regional perfusion and metabolism of the spinal cord, very much like the situation in the brain. We postulate that an altered, energy-demanding conduction along the demyelinated axons of patients with chronic radiogenic LS may explain the increased metabolism and perfusion.

Malignant mucosal melanoma of the head and neck

Mucosal melanomas comprise about 1% of all malignant melanomas and exhibit far more aggressive behaviour than that of skin melanomas: they are more inclined to metastatize into regional and distant sites or recur locally, regionally or in distant locations, resulting in a high rate of cause-specific death. Mucosal melanomas in the head and neck region account for half of all mucosal melanomas, occurring mainly in the upper respiratory tract, oral cavity and pharynx. They appear with equal gender distribution and with a peak incidence in the age range 60-80 years. In consequence of their hidden location, they are usually diagnosed in a locoregionally advanced clinical stage, with a rate of 5-48% of regional and 4-14% of distant dissemination. The typical therapeutic approach is surgery, postoperative irradiation and systemic therapy. Local control with either surgery or radiotherapy is frequently (60- 70%) achieved, but the rates of local, regional and distant recurrences are high (50-90%, 20-60% and 30-70%, respectively). The reported 5-year actual survival rates are poor (17-48%), which is attributed mainly to a haematogenous dissemination. These characteristics demonstrate that identification of the precursor lesions and more effective local and systemic approaches are needed to improve the therapeutic results.

[Repeated radiotherapy in locally recurrent nasopharyngeal cancer]

PATIENTS AND METHODS

In the period between 1993 and 2000, 20 patients with nasopharyngael cancer were re-irradiated for locally recurrent carcinomas. The median duration between primary treatment and recurrence was 30 months. Brachytherapy was the method most frequently used in 10 cases alone, and in 8 cases in combination with external beam therapy. 2 patients underwent only external beam therapy. The external irradiation was performed with CT/MRI-based treatment planning. Brachytherapy involved a high dose rate afterloading method. The cumulative dose of re-irradiation was 20-60 Gy.

RESULTS

After a median follow-up of 37 months the overall survival and the local control were 60% (12/20) and 58% (7/12), respectively. 7 of the 12 surviving patients are currently tumour-free. After primary irradiation xerostomy occurred in all patients as an unavoidable side-effect of the treatment. A severe (grade 3 or higher according to the Common Toxicity Criteria version 2.0) late-side effect has so far been observed in 2 cases (10%). Authors' results lie in the medial range of the data in the international literature, though the rate of radiogen side-effects in the patient group is low. Both results are assumed to be a consequence of the re-irradiation dose being lower than the value considered optimum in the recent literature.

CONCLUSIONS

Re-irradiation of locally recurrent nasopharyngeal cancers is an efficient treatment modality, which should be used as a combination of external beam therapy and brachytherapy. The optimum cumulative dose is about 50-60 Gy. This dose results in a 5 years survival rate of about 40% with an acceptable (30%) risk. The results of re-irradiation may be improved, if PET is used to determine the extent of the surviving tumour tissue. This can help in the choice of the proper treatment modality.

[Cost-effective PET investigations in oncology]

The authors have reviewed the financial considerations of oncological FDG PET examinations by the guidelines of the Health Care Financing Administration (USA). By critical assessment of large number of clinical investigations,the cost-effectiveness of FDG PET scans has been confirmed in the following cases: differential diagnosis of solitary pulmonary nodule, diagnosis,staging and restaging of non-small cell lung cancer, colorectal cancer, malignant lymphomas, melanoma malignum, esophageal neoplasms and cancers of the head and neck. The role of this method in breast cancer is currently under intensive investigation. Due to the correct staging, PET examinations in these indications enable the clinicians to choose the optimal treatment ensuring the maximum probability of recovery and being cost-effective as unnecessary medical interventions become avoidable.

A PET study on the characterization of partially reversible radiogenic lower motor neurone disease

OBJECTIVE

To investigate the pathomechanism of the rare radiogenic lower motor neurone disease (LMND) on the basis of a case history involving a partial functional recovery.

PATIENT

A 31-year-old seminoma patient received postoperative para-aortic and para-iliac telecobalt irradiation with a biologically effective dose of 88 Gy(2) (44 Gy in 2 Gy fractions/day, with an estimated alpha/beta of 2 Gy) delivered to the spinal cord following a single cycle of chemotherapy. LMND developed 4 months after the completion of radiotherapy. The patient exhibited flaccid paraparesis of the lower extremities (without sensory or vegetative signs), followed by a worsening after further chemotherapy, due to pulmonary metastatization. A gradual spontaneous functional improvement commenced and led several years later to a stabilized state involving moderately severe symptoms.

METHODS

In the 15th year of the clinical course, magnetic resonance imaging (MRI) and positron emission tomography (PET) with [(18)F]fluorodeoxyglucose (FDG) and [(11)C] methionine were conducted. Four lines of experiments (clonogenic assay using fibroblasts isolated from a skin biopsy sample of the patient, comet assay, micronucleus assay, and the testing of chromosome aberrations after in vitro irradiation of peripheral blood samples) were performed in a search for an increased individual radiosensitivity.

RESULTS

MRI investigations failed to reveal any pathological change. PET demonstrated an increased FDG accumulation, but a negligible [(11)C] methionine uptake in the irradiated spinal cord segments. The radiobiological investigations did not indicate any sign of an increased individual radiosensitivity.

CONCLUSIONS

We suggest that the observed partial functional recovery and stabilization of the symptoms of radiogenic LMND may be explained by the higher than normal density of sodium channels expressed along the demyelinated axons of the restored conduction. The increased energy demands of this type of conduction are proved by a higher metabolic rate (increased FDG uptake) of the irradiated spinal cord segments without a substantial regenerative process (lack of detectable protein synthesis).

[Radiotherapy of MALT-lymphoma of the stomach]

INTRODUCTION

The stomach is the most common extranodal site of the low-grade MALT lymphoma. This lymphoma usually appears in elderly patients, with typically indolent signs. At the time of the diagnosis, the lymphoma is usually localized in the stomach and/or the adjacent lymph nodes. The choice in these cases is local treatment, which in the past involved only a surgical approach (total/partial gastrectomy), whereas more recently radiotherapy is preferred.

PURPOSE

The radiation fields cover the whole stomach and the paragastric lymph nodes. The radiation doses range from 30 to 40 Gy, given in 1.5 Gy fractions 5 days a week. An adequate dose distribution to the target volume can be achieved by 3D treatment planning and conformal irradiation.

METHODS

At our institute, 5 patients were treated with this method, the intention was curative in 3 cases, and palliative in 2 cases. The median dose in the 4 cases completed as initially planned was 33.6 Gy, delivered at 1.5 Gy per fraction. The adjacent critical organs do not exceed the tolerance doses by this method.

RESULTS

In these 4 cases, complete regression was achieved, as determined by endoscopy and biopsy. In the fifth, locally advanced case, irradiation had to be terminated because of gastric bleeding. During irradiation, no other severe acute side-effects were detected.

CONCLUSION

The literature and our preliminary results confirm that radiation therapy for early, localized MALT lymphoma of the stomach, or in disseminated cases, can be not only effective and safe, but offers the significant advantages of low treatment-related morbidity and preservation of the gastric function.

Ovarian steroid cell tumor and a contralateral ovarian thecoma in a postmenopausal woman with severe hyperandrogenism

A 49-year-old woman presented with rapidly progressing hirsutism, receding hairline, male-pattern baldness and deepening of voice, which had developed over the past 2 years. Hormonal evaluation showed a markedly elevated serum testosterone level (418 ng/dl) and no evidence of increased production of cortisol, dehydroepiandrosterone, dehydroepiadrosterone-sulfate, androstenedione, or 17-hydroxyprogesterone. Transvaginal ultrasound examination suggested the presence of a small mass within the left ovary, but all other radiological studies, including adrenal and ovarian computed tomography, magnetic resonance imaging, radio-labelled cholesterol scintigraphy and positron emission tomography, were negative. Subsequently, bilateral selective venous sampling showed a marked testosterone gradient in the right ovarian vein. Bilateral salpingo-oophorectomy was performed (the patient had had a previous vaginal hysterectomy), and histopathological examination revealed a 10-mm steroid cell tumor within the right ovary and a 15-mm thecal cell tumor within the left ovary. The postoperative serum testosterone level returned to normal and the patient showed a slow regression of clinical symptoms. The simultaneous occurrence of a virilizing ovarian steroid cell tumor and an apparently non-functioning thecoma within the contralateral ovary emphasizes the potential pitfalls that may exist in the preoperative evaluation of patients with markedly increased testosterone production.

[Positron emission tomography in the investigation of malignant testicular tumors]

Thirty-three [18F]-FDG and ten [11C]-methionine (altogether 43) PET studies were performed in 37 (24 non-seminoma and 13 seminoma) patients. All results were assessed on the basis of histology (or cytology) or clinical follow-up. PET scan identified metastatic disease in 13 cases while 30 investigations resulted in a negative medical report. There were 3 false-positive cases and no false-negative results were obtained. The false-positive results were likely to occur due to FDG accumulation in benign lesions. There were no false-positive findings with the use of [11C]-methionine. Sensitivity, specificity and accuracy were 100%, 91% and 93%, respectively, using both tracers.

[The PET scan in neuro-oncology--indications, differential diagnosis and clinical application]

Results of 157 PET (positron emission tomography) studies in 102 patients with known or presumed intracranial (ic.) tumors are reviewed. In 106 studies [18F]-2-fluoro-2-deoxy-D-glucose (FDG) and in 51 cases [11C]-methionine (MET) was used as the PET tracer. CT and MRI imaging accompanied the PET studies in each case. Results of pre- and/or postoperative studies are compared. PET was concluded to have a fundamental role in the precise differential diagnosis in case of ic. space-occupying pathologies since it is capable of providing information that is not obtainable or may be equivocal based solely on CT and/or MRI investigations. However, it is also mandatory to be aware of the limits of PET.

[Cerebral glucose metabolism in Down syndrome using positron emission tomography]

Resting cerebral glucose metabolism was assessed by PET using FDG in eleven Down syndrome (DS) patients. Standardized uptake values (SUV) were determined on a pixel by pixel basis from the measured tissue FDG-activity data. The results showed that the mean value of the global FDG-uptake in the DS patients was not significantly different from the one obtained in the control group consisting of children and young adults. The standard deviation of SUV, however, was much higher in the DS group in almost all regions. The statistical parametric mapping (SPM) method was applied to compare the relative cerebral FDG accumulation pattern of the populations. Six regions (clusters) were found in which the glucose-uptake was higher in the DS patients than in the control group. The anatomical localization of these clusters was based on MRI investigations and brain-atlas technique.

[The role of PET scan in the investigation of the lymphatic spreading of Hodgkin's disease]

The authors investigated the role of PET, as a non-invasive diagnostic method, in the analysis of lymphatic spreading of Hodgkin's disease (HD). Whole-body FDG scans were carried out in 71 patients along with [11C]-methionine examinations, if necessitated by inconclusive FDG results. Based on these findings involvement-frequencies were calculated for each lymphatic region. The three most frequently involved lymphatic regions were the mediastinum (83.1%), the left cervical and left supraclavicular regions (78.9%) and the right cervical and right supraclavicular regions (76.1%). These data support the hypothesis that HD originates from the cervical or supraclavicular regions and reaches the distant sites by basically retrograde spreading in a non-random manner. The appropriate values of site involvement-rate were compared with those obtained by other authors based on pathologic staging and a good correlation was found. The high level of correspondence between these involvement-frequencies supported the general validity (i.e. valid for both treated and untreated cases) of the principles governing lymphatic spreading of HD.

[Detection of recurrent head and neck cancer with positron emission tomography]

Differentiation between recurrence and post-therapeutic lesions in patients with previously treated head and neck cancer can be a real diagnostic problem. The authors discuss the role of positron emission tomography in restaging of this disease by a retrospective analysis based on 20 scans of 17 patients. PET findings were correct in identifying tumors in 85% of patients (11/13) in the group of positive PET results. All negative PET findings (4/4) were also correct during the follow-up. PET results were validated in 88% (15/17) of the patients. In one case silent distant metastases were also detected. PET is a reliable method in restaging previously treated head and neck cancer patients as it can differentiate post-therapeutic changes from tumor relapse.

[PET scan and double-independent pathologic investigations effectively support the detection of occult primary tumors]

Following the failure of conventional diagnostic procedures, whole-body FDG-PET investigations were carried out in 42 metastatic cancer patients to localize occult primary carcinomas. During the clinical follow-up, the presence of malignant tumor was ruled out in 3 cases, and 2 patients originally believed to have carcinoma were confirmed to be suffering from a malignant hematological disease. These false diagnoses were associated with the use of imaging methods only (2 cases) or cytology only (1 case), lack of double, independent pathological investigations (2 cases) or immunophenotyping (2 cases) and the occurrence of an unrecognized rare tumor in a hospital with a small patient turnover (1 case). The discovered 11 occult primaries (4 lung, 3 breast, 2 hypopharynx and 1 base of the tongue carcinomas and 1 non-Hodgkin lymphoma) led to a 28% diagnostic efficacy of PET (11/39 malignant pathological reports). This efficacy is doubled (60%) if PET reveals < or = 5 malignant lesions and the locations of the pathological foci are tumor-specific. We suggest PET investigations in the search for occult primaries following a controlled pathological diagnosis and the failure of conventional diagnostic procedures.

[The role of PET scan in the diagnosis of malignant melanoma]

Comprehensive, accurate staging has a critical role in planning rational treatment strategies for patients with malignant melanoma (MM). In the present study the authors investigate the value of FDG PET in staging and restaging based on the investigation of 37 high-risk MM patients and compare the results with the one obtained by conventional imaging techniques (X-ray, US, CT, MR and bone scan). Thirty-nine whole body PET scans were carried out. The authors concluded that FDG PET had the highest sensitivity among the imaging methods in detecting distant metastases of MM.

[Cost-effective PET scans in oncology]

The authors have reviewed the financial considerations of oncological FDG PET examinations by the guidelines of the Health Care Financing Administration (USA). By critical assessment of large number of clinical investigations, the cost-effectiveness of FDG PET scans has been confirmed in the following cases: differential diagnosis of solitary pulmonary nodule, diagnosis, staging and restaging of non-small cell lung cancer, colorectal cancer, malignant lymphomas, melanoma malignum, esophageal neoplasms and cancers of the head and neck. The role of this method in breast cancer is currently under intensive investigation. Due to the correct staging, PET examinations in these indications enable the clinicians to choose the optimal treatment ensuring the maximum probability of recovery and being cost-effective as unnecessary medical interventions become avoidable.

[Diagnostic possibilities of positron emission tomography in oncologic pulmonology]

The authors present the possibilities of applying positron emission tomography (PET) in oncopulmonology. In addition to reviewing the literature, they share their own experience obtained during the diagnostic work-up and follow-up of twenty-three patients. The basic indications and the relevant properties of the most frequently used radiopharmaceuticals are discussed. Finally, the authors raise the question of cost-effectiveness of PET-investigations vs. conventional techniques, and suggest possible algorithms to include this non-invasive imaging method in the diagnostic work-up of patients with malignant or benign pulmonary diseases.

[FDG PET scan of metastases in recurrent medullary carcinoma of the thyroid gland]

Searching for metastases of medullary thyroid cancer (MTC), FDG PET was applied. PET results were compared with those of conventional diagnostic imaging procedures. After primary treatment, 52 MTC patients with elevated serum tumor marker levels and/or general symptoms (diarrhoea/flush) underwent radiological (CT/MRI), 131-iodine labeled metaiodo-benzylguanidine (MIBG) whole-body scintigraphy and FDG PET investigations. At least one pathological lesion was detected in 49 patients by PET, 35 by CT, 32 by MRI and 3 by MIBG. FDG PET was far superior to the other methods in identifying metastases in the supradiaphragmatic lymphatic regions. In the follow-up of MTC patients, FDG PET was more sensitive in localizing tumorous LN involvement, especially in the cervical, supraclavicular and mediastinal lymphatic regions, compared to other imaging modalities.

[PET scan in patients with epipharyngeal tumors]

Whole-body FDG PET examinations in 10 cases of epipharyngeal tumour (8 males, 2 females, mean age: 48 years) have been performed since January 1999. The PET examinations were aimed at the accurate staging, follow-up of the patients after the treatment, identification of recurrencies and localization of the unknown primary tumor. Functional imaging resulted in "upstaging" in 3 patients as compared to staging by the conventional diagnostic tools. Four additional patients with hyperplastic epipharyngeal tissue were investigated for occult primary cancer after negative results of multiple excisions, resulting in one case of primary epipharyngeal cancer. Correct staging, early detection of recurrencies, localization of occult primary tumor and the better post-therapeutic assessment of epipharyngeal masses all facilitate a more reasonable therapeutic approach, which may improve survival results.