Mitochondria in Multiple Sclerosis: Molecular Mechanisms of Pathogenesis.

Mitochondria, the organelles that function as the powerhouse of the cell, have been increasingly linked to the pathogenesis of many neurological disorders, including multiple sclerosis (MS). MS is a chronic inflammatory demyelinating disease of the central nervous system (CNS) and a leading cause of neurological disability in young adults in the western world. Its etiology remains unknown, and while the inflammatory component of MS has been heavily investigated and targeted for therapeutic intervention, the failure of remyelination and the process of axonal degeneration are still poorly understood. Recent studies suggest a role of mitochondrial dysfunction in the neurodegenerative aspects of MS. This review is focused on mitochondrial functions under physiological conditions and the consequences of mitochondrial alterations in various CNS disorders. Moreover, we summarize recent findings linking mitochondrial dysfunction to MS and discuss novel therapeutic strategies targeting mitochondria-related pathways as well as emerging experimental approaches for modeling mitochondrial disease.

Constitutive and stimulated production of VEGF by human megakaryoblastic cell lines: effect on proliferation and signaling pathway.

Release of vascular endothelial growth factor (VEGF) and other candidate angiogenic factors such as basic fibroblast growth factor and transforming growth factor beta, may play a role in sustaining neoplastic cell proliferation and tumor growth. We evaluated VEGF expression and synthesis in the two erythromegakaryocytic cell lines B1647, HEL and one megakaryocytic cell line MO7 expressing erythroid markers. In this study RT-PCR was performed to evaluate VEGF expression and that of its receptor KDR; VEGF production was assayed by Elisa test and western blot analysis; sensitivity to VEGF was tested by thymidine incorporation. VEGF and its receptor KDR were expressed in B1647 and HEL, both as mRNAs and as proteins, while only KDR transcript was found in MO7 cells. Only B1647 and HEL cells showed a strong spontaneous proliferating activity. In fact, measurable amounts of VEGF were present in the unstimulated cell medium, thus suggesting an autocrine production of VEGF by B1647 and HEL cells, but not by MO7, which was inhibited in mRNA-silencing conditions. This production could not be further boosted by other growth factors, whereas it was inhibited by TGF-beta1. Finally, analysis of Shc signal transduction proteins following stimulation with VEGF indicated that only p46 was tyrosine phosphorylated. These data indicate that leukemic cells may be capable of autocrine production of VEGF which, in turn, maintains cell proliferation, possibly mediated by Shc p46 phosphorylation.

Treatment and prognosis in a series of primary extranodal lymphomas of the ocular adnexa.

BACKGROUND: The aim of this study was to assess clinicopathological characteristics and outcome in a series of primary ocular adnexal lymphomas (POALs). PATIENTS AND METHODS: Nineteen patients with localised (stage IE) POAL were followed for a median of 96 months (24-156). The diagnosis was based on surgical biopsies followed by immunohistochemistry in 16 cases or fine-needle aspiration followed by immunocytophenotypic analysis in three cases. Twelve patients were treated with local radiotherapy (RT), five with chemotherapy (CT), and two refused further therapy after apparently radical tumour removal achieved by the diagnostic excisional biopsy. RESULTS: The histological and immunological pattern was consistent with a diagnosis of MALT-type lymphoma (11 cases), follicular center non-Hodgkin's lymphoma (three cases). a large-cell variant of Burkitt's lymphoma (one case), and large-cell transformed MALT lymphoma (one case). Low-grade lymphoma was diagnosed in the three cases which underwent fine-needle aspiration biopsy. All of the patients achieved and maintained complete remission except for those treated with surgical excision alone (two MALT conjunctival lymphoma cases): one of these relapsed locally, the other experienced the systemic spread of a transformed diffuse large-cell lymphoma and died 72 months after diagnosis. The side effects consisted of two cases of RT-related cataract after 52 and 72 months. CONCLUSIONS: Regardless of histology, prognosis was excellent when surgery plus RT was adopted, and CT seems to be a valid alternative to RT. Surgery alone may be sub-optimal.

Cis/carboplatin + vinorelbine +/- radiotherapy in stage III and IV non small cell lung carcinoma.

The aim of this study was the retrospective evaluation of the effectiveness of cis/carboplatin + vinorelbine +/- radiotherapy in 118 patients with advanced non small cell lung carcinoma (NSCLC). To evaluate the response, pts were divided into three groups: a) Stage III pts. who received both chemotherapy and radiotherapy treatment (RC + RP = 43.75%, median survival 16.25 months); b) Stage III pts. who underwent only CT because RT was contraindicated (RC + RP = 21.95%, median survival 12.7 months); c) Stage II pts treated with CT alone (RC + RP = 20%, median survival = 12.1 months). Toxicity was mild. The results of the present study, both in terms of response rate and survival, confirm the effectiveness of the combination cis/carboplatin + vinorelbine +/- radiotherapy as palliative treatment of advanced NSCLC.

Increased survival time in brain glioblastomas by a radioneuroendocrine strategy with radiotherapy plus melatonin compared to radiotherapy alone.

The prognosis of brain glioblastoma is still very poor and the median survival time is generally less than 6 months. At present, no chemotherapy has appeared to influence its prognosis. On the other hand, recent advances in brain tumor biology have suggested that brain tumor growth is at least in part under a neuroendocrine control, mainly realized by opioid peptides and pineal substances. On this basis, we evaluated the influence of a concomitant administration of the pineal hormone melatonin (MLT) in patients with glioblastoma treated with radical or adjuvant radiotherapy (RT). The study included 30 patients with glioblastoma, who were randomized to receive RT alone (60 Gy) or RT plus MLT (20 mg/daily orally) until disease progression. Both the survival curve and the percent of survival at 1 year were significantly higher in patients treated with RT plus MLT than in those receiving RT alone (6/14 vs. 1/16). Moreover, RT or steroid therapy-related toxicities were lower in patients concomitantly treated with MLT. This preliminary study suggests that a radioneuroendocrine approach with RT plus the pineal hormone MLT may prolong the survival time and improve the quality of life of patients affected by glioblastoma.

A randomized study of low-dose subcutaneous interleukin-2 plus melatonin versus supportive care alone in metastatic colorectal cancer patients progressing under 5-fluorouracil and folates.

Chemotherapy with 5-fluorouracil (5-FU) and folates represents the first-line standard therapy for metastatic colorectal cancer, whereas at present there is no conventional second-time treatment. Because of its importance in generating an effective anticancer immune response, interleukin-2 (IL-2) could constitute a new promising therapy of advanced colon cancer. Generally, IL-2 may determine tumor regressions in colon cancer only when it is given at high toxic doses. Our preliminary studies have shown that the pineal hormone melatonin may amplify IL-2 activity, which becomes active also at low doses in several tumor histotypes. On the basis, we have performed a clinical trial to evaluate the impact of low-dose IL-2 plus melatonin on the survival time in metastatic colon cancer, which progressed in response to 5-FU plus folates. The study included 50 metastatic colorectal cancer patients, who did not respond or progressed after initial response to first-line chemotherapy with 5-FU and folates. Patients were randomized to receive supportive care alone or low-dose subcutaneous IL-2 (3 million IU/day for 6 days/week for 4 weeks) plus melatonin (40 mg/day orally). No spontaneous tumor regression occurred in patients receiving supportive care alone. A partial response was achieved in 3/25 patients treated with immunotherapy. Percent survival at 1 year was significantly higher in patients treated with immunotherapy than in those treated with supportive care alone (9/25 vs. 3/25, p < 0.05). This study suggests that low-dose subcutaneous IL-2 plus melatonin may be effective as a second-line therapy to induce tumor regression and to prolong percent survival at 1 year in metastatic colorectal cancer patients progressing under 5-FU and folates.

A randomized study of neuroimmunotherapy with low-dose subcutaneous interleukin-2 plus melatonin compared to supportive care alone in patients with untreatable metastatic solid tumour.

Recent advances in our knowledge of psychoneuroimmune interactions involved in the control of tumour growth have shown the possibility of manipulating host anticancer defenses through a neuroimmunotherapeutic strategy. In particular, our previous studies have demonstrated that the concomitant administration of the pineal neurohormone melatonin may amplify the antitumour efficacy of interleukin-2 (IL-2) in humans. On this basis, a study was planned to investigate the influence of neuroimmunotherapy with low-dose IL-2 plus melatonin on survival time and on performance status in untreatable metastatic cancer patients. The study included 100 patients with metastatic solid tumours, for whom no standard therapy was available. They were randomized to receive IL-2 (3 x 10(6) IU/day subcutaneously for 4 weeks) plus melatonin (40 mg/day orally) or supportive care alone. Partial tumour regressions were seen in 9/52 (17%) patients treated with the immunotherapy, and in none of the patients treated with supportive care alone. The percentage of survival at 1 year was significantly higher in patients treated with IL-2 and melatonin than in those receiving the supportive care alone (21/52 versus 5/48, P < 0.005). Moreover, the performance status improved in 22/52 patients of the immunotherapy group and in only 8/48 patients treated with supportive care (P < 0.01). This study shows that cancer neuroimmunotherapy with low-dose IL-2 and the pineal hormone melatonin may prolong survival time and improve the quality of life of patients with metastatic solid tumours who do not respond to conventional therapies.

Modulation of cancer endocrine therapy by melatonin: a phase II study of tamoxifen plus melatonin in metastatic breast cancer patients progressing under tamoxifen alone.

Recent observations have shown that the pineal hormone melatonin (MLT) may modulate oestrogen receptor (ER) expression and inhibit breast cancer cell growth. On this basis, we have evaluated the biological and clinical effects of a concomitant MLT therapy in women with metastatic breast cancer who had progressed in response to tamoxifen (TMX) alone. The study included 14 patients with metastasis who did not respond (n = 3) to therapy with TMX alone or progressed after initial stable disease (SD) (n = 11). MLT was given orally at 20 mg day-1 in the evening, every day starting 7 days before TMX, which was given orally at 20 mg day-1 at noon. A partial response was achieved in 4/14 (28.5%) patients (median duration 8 months). The treatment was well tolerated in all cases, and no MLT-induced enhancement of TMX toxicity was seen; on the contrary, most patients experienced a relief of anxiety. Mean serum levels of insulin-like growth factor 1 (IGF-1), which is a growth factor for breast cancer, significantly decreased on therapy, and this decline was significantly higher in responders than in patients with SD or progression. This pilot phase II study would suggest that the concomitant administration of the pineal hormone MLT may induce objective tumour regressions in metastatic breast cancer patients refractory to TMX alone.

The role of intraoperative therapy by electron beam and combination of adjuvant chemotherapy and external radiotherapy in carcinoma of the pancreas.

AIMS AND BACKGROUND: In the treatment of pancreatic carcinomas, one modality is intraoperative radiotherapy (IORT). A study was carried out to assess the feasibility of IORT alone or in a multimodality approach with postoperative adjuvant chemotherapy and external radiotherapy and to compare local control and survival of patients. Another objective of this retrospective study was to verify prognostic factors in resected patients treated with IORT. METHODS: From January 1985 through September 1992, 54 adenocarcinomas of the pancreas (unresectable and resected patients) were treated with IORT by electron beam at the San Raffaele Hospital and then analyzed. Comparison was also carried out between IORT-treated resected patients and a non-randomized control group of resected patients treated without IORT in the same period. RESULTS: In unresectable patients treated by laparotomy bypass and IORT, overall median survival was 6 months and 8 months in non-metastatic patients. Relief of severe pain present in 14 patients was observed in 85% within 12 days of IORT. As regards resected patients, the most important finding was that significantly better local control resulted from IORT. In fact, overall, local relapses were 25% in the IORT group and 55.8% in the non-IORT group (control group); instead, survival of the IORT group was not significantly longer than that of the control group. From a statistical analysis of resected patients treated with IORT and performed on prognostic factors on the basis of available data, survival was significantly influenced by tumor pathologic grading and diameter; postoperative adjuvant therapy was not a significant prognosis factor. CONCLUSIONS: IORT has a role in local control of unresectable pancreatic carcinomas and in control of resultant severe pain. In resected patients, IORT is effective in decreasing local recurrences but has little impact on survival. To obtain more satisfactory results, new and more effective adjuvant therapies and better abdominal prophylaxis should be tested.

A randomized study of immunotherapy with low-dose subcutaneous interleukin-2 plus melatonin vs chemotherapy with cisplatin and etoposide as first-line therapy for advanced non-small cell lung cancer.

AIMS AND BACKGROUND: The therapeutic role of chemotherapy in advanced non-small cell lung cancer (NSCLC) is controversial because of its potentially detrimental action on host anticancer defenses. On the contrary, IL-2 would seem to prolong survival time by improving the immune status, even though it is generally less effective in determining tumor regression in NSCLC. Our previous studies have suggested the possibility of increasing tumor sensitivity to IL-2 by concomitant administration of immunomodulating neurohormones, such as the pineal hormone melatonin (MLT). On this basis, a study was carried out to evaluate the efficacy of immunotherapy with low-dose IL-2 plus MLT versus chemotherapy in advanced NSCLC. METHODS: The study included 60 patients with locally advanced or metastatic NSCLC, who were randomized to receive immunotherapy or chemotherapy. The immunotherapy consisted of IL-2 (3 million IU/day subcutaneously for 6 days/week for 4 weeks) and MLT (40 mg/day orally every day, starting 7 days before IL-2); in nonprogressing patients, a second cycle was repeated after a 21-day rest period, then they underwent a maintenance period consisting of one week of therapy every month until progression. Chemotherapy consisted of cisplatin (20 mg/m2) and etoposide (100 mg/m2)/day intravenously for 3 days; cycles of chemotherapy were repeated every 21 days until progression. RESULTS: No complete response was obtained. A partial response was achieved in 7/29 patients treated with chemotherapy and in 6/31 patients receiving chemotherapy. The difference was not significant. In contrast, the mean progression-free period and the percentage survival at 1 year was significantly higher in patients treated with immunotherapy than in those treated with chemotherapy. Toxicity was substantially lower in patients receiving immunotherapy than in those given chemotherapy. CONCLUSIONS: This randomized study showed that immunotherapy with low-dose IL-2 plus MLT is a better tolerated and more effective therapy in terms of survival time than chemotherapy containing cisplatin in patients affected by advanced NSCLC.

Pineal-opioid system interactions in the control of immunoinflammatory responses.

Several studies have demonstrated involvement of the pineal gland in the regulation of neuropeptide secretion and activity. In particular, the existence of links between the pineal gland and the brain opioid system has been documented. Both opioid peptides and melatonin (MLT), the most investigated pineal hormone, play an important role in neuromodulation of the immunity. Moreover, the immune effects of MLT are mediated by endogenous opioid peptides, which may be produced by both the endocrine system and the immune cells. In addition, the immune dysfunctions that characterize some human diseases, such as cancer, depend not only on the immune system per se, but also at least in part, on altered secretion of immunomodulating neurohormones, including MLT and opioid peptides. Therefore, the exogenous administration of neurohormones could potentially improve the immune status in humans. The present study evaluates the effects of MLT on changes in the number of T lymphocytes, natural killer cells, and eosinophils induced by exogenous administration of interleukin-2 (IL-2). Macrophage activity was also evaluated by determining serum levels of its specific marker, neopterin. The study was performed in 90 patients with advanced solid neoplasms, who received IL-2 at a dose of 3 million IU/day subcutaneously for 6 days a week for 4 weeks plus MLT at a daily dose of 40 mg. Both drugs were given in the evening. The results were compared to those in 40 cancer patients treated with IL-2 alone. The mean increase in T lymphocytes, natural killer cells, and eosinophils was significantly higher in patients treated with IL-2 plus MLT than in those who received IL-2 alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative radiation therapy adjuvant to resection in the treatment of pancreatic cancer.

BACKGROUND: Local recurrence is the most frequent site of failure after resection for pancreatic cancer. Tolerance, local control, and survival obtained by the association of resection and intraoperative radiation therapy (IORT) were reported. METHODS: Between June 1985 and March 1993, 90 resections for pancreatic cancer were performed at the authors' institution. For 43 patients, IORT was added to resection (Group 1), whereas the other 47 patients underwent resection alone (Group 2), because of either the unavailability of linear accelerator or the patient's refusal. In Group 1, radiation doses from 12.5 to 20 Gy, with electron beam energies between 6 and 12 MeV, were delivered. Extension of the disease was similar in the two groups of patients: mean diameter of the tumor was 3.2 cm in Group 1 and 3.4 cm in Group 2; percentage of third degree stage disease (International Union Against Cancer classification) was 65.1% in Group 1 and 57.4% in Group 2; and tumor clearance was incomplete in 39.5% of patients in Group 1 and in 34.0% in Group 2. RESULTS: Operative mortality and overall early post-operative complications were respectively 2.3% and 23.2% in Group 1 and 2.1% and 23.4% in Group 2. One-year, 2-year, and 3-year survival rates were respectively 71%, 24%, and 7% in Group 1 and 49%, 16%, and 10% in Group 2 (P was not significant). Median disease free survival was 13 months in Group 1 and 8 months in Group 2 (P was not significant). A local recurrence was detected in 27.0% of patients in Group 1 and in 56.4% of patients in Group 2 (P < 0.01). CONCLUSIONS: The results suggest a better local control in patients with pancreatic cancer undergoing adjuvant IORT.

Weekly epirubicin plus low-dose interleukin-2 subcutaneous therapy in breast cancer: preliminary immunobiological results.

Experimental studies have shown that IL-2 may antagonize chemotherapy-induced lymphocytopenia. On this basis, we have evaluated the influence of low-dose IL-2 on lymphocyte and NK cell numbers in cancer patients treated with the anthracycline drug, epirubicin. The study included 7 metastatic breast cancer women treated with epirubicin at a dose of 25 mg/m2 i.v. weekly. IL-2 was given subcutaneously at 3 million IU/day for 6 days/week. Venous blood samples were drawn at weekly intervals, and the results were compared to those seen in 14 patients treated with epirubicin alone. Lymphocyte mean number observed on treatment was higher in patients concomitantly treated with IL-2 than in those receiving epirubicin alone, without, however, significant differences. In addition, NK cell mean number was significantly higher in patients receiving IL-2 than in those treated with epirubicin alone. These preliminary results would suggest that IL-2 may antagonize lymphocyte and NK cell declines during cancer chemotherapy with anthacyclines. Further studies will be required to confirm these results and to establish their possible influence on chemotherapy-induced tumor regressions.

A clinical-study of immunotherapy versus endocrine therapy versus chemotherapy in the treatment of advanced pancreatic adenocarcinoma.

The advanced carcinoma of pancreas still remains an untreatable disease. Both chemotherapy and hormono-therapy seem not to prolong the survival time. Also immunotherapy with IL-2 has been shown to have no efficacy. Our experimental studies suggested the possibility of enhancing the antitumor activity of IL-2 by the administration of immunomodulating neurohormones, such as melatonin (MLT). This study was carried out to evaluate the efficacy of IL-2 plus MLT in advanced cancer of the pancreas. Fifty patients, with advanced adenocarcinoma of the pancreas, were randomized to receive chemotherapy consisting of 5-FU plus folates, endocrine therapy with LHRH and somatostatin analogues, supportive care alone or immunotherapy with subcutaneous low-dose IL-2 plus MLT. A partial response was obtained in 1/13 patients treated with chemotherapy and in 2/12 patients receiving immunotherapy; no tumor regression was seen in the other groups. The percent of survival at 1 year achieved in patients treated with immunotherapy was significantly higher than in the other groups tested (3/12 vs 1/38; p<0.02). This preliminary study would suggest that the immunotherapy with IL-2 plus MLT may represent a new promising treatment of advanced pancreatic adenocarcinoma.

Immunoendocrine therapy with interleukin-2 (IL-2) and medroxyprogesterone acetate (MPA): a randomized study with or without MPA in metastatic renal cancer patients during IL-2 maintenance treatment after response or stable disease to IL-2 subcutaneous therapy.

AIMS AND BACKGROUND: It is known that interleukin-2 (IL-2) activated cytotoxic lymphocytes require a cell-cell contact to exert their anticancer action. Therefore, the pronounced fibrosis that generally characterizes the neoplastic mass could counteract the action of cytotoxic lymphocytes. Some preliminary studies have shown that progesterone and its analogs may inhibit fibroblast proliferation. On the basis of such evidence, we have designed a clinical study with or without the progestational agent medroxyprogesterone acetate (MPA) in metastatic renal cancer patients in maintenance therapy with IL-2 following response or stable disease (SD) after two cycles of IL-2 subcutaneous immunotherapy, in an attempt to evaluate the influence of MPA on free-from progression (FPP) period. METHODS: The study included 30 consecutive patients who were randomized to receive IL-2 alone (3 million IU twice/day for 5 days/month subcutaneously) or IL-2 plus low-dose MPA (500 mg orally one day/week) without interruption until disease progression. RESULTS: A FPP period longer than 1 year was obtained in 8/14 patients treated with IL-2 plus MPA and in only 3/16 patients treated with IL-2 alone. The difference was statistically significant. On the contrary, no significant difference was seen in the mean number of lymphocytes and eosinophils, which was evaluated monthly. Finally, no hyperglycemic or thromboembolic complications occurred in patients concomitantly treated with MPA. CONCLUSIONS: This preliminary study would suggest that the concomitant administration of low-dose MPA may prolong the FFP period in metastatic renal cancer patients under maintenance therapy with IL-2. A longer follow-up will be required to evaluate the influence of MPA on overall survival.

Radioendocrine therapy of brain tumors with the long acting opioid antagonist naltrexone in association with radiotherapy.

AIMS AND BACKGROUND: Malignant gliomas remain untreatable as the different therapeutic combinations are generally only palliative. Recent experimental evidence suggests that endogenous opioid peptides are involved in brain tumor growth. The aim of the present study was to evaluate the effect on survival of concomitant administration of the long-acting opioid antagonist naltrexone (NTX) in patients with malignant astrocytomas treated with radiotherapy (RT). METHODS: 21 patients with high grade malignant gliomas were randomized to receive RT alone or RT plus NTX. The dose of RT was 60 Gy. NTX was given orally at a dose of 100 mg every other day without interruption until disease progression. RESULTS: The objective tumor regression rate in patients treated with RT plus NTX was higher than that of those treated with RT alone but not significantly so. On the contrary, the percentage of survivals at 1 year was significantly higher in patients treated with RT plus NTX than in those treated with RT alone (5/10 vs 1/11, P < 0.05). NTX therapy was substantially well tolerated in most patients. CONCLUSIONS: The finding of longer survival in brain tumor patients treated with RT plus NTX than in those who received RT alone suggests in vivo involvement of endogenous opioid peptides in regulating the growth of malignant astrocytomas.

Development of a computer-controlled moving bar (CCMB) conformal technique for neck irradiation.

The development of an original conformal technique for neck cancer is in progress in our Institute. This technique uses a computer-controlled moving bar (CCMB): a portion of a blocking bar rotates during the rotation of the gantry in a 2 pi arc field in order to shield the spinal cord over the whole irradiated volume. This technique should solve in a relatively simple way some problems for different clinical situations when cervical node irradiation is required together with the primary tumor. The technique has been tested in an acrylic cylindrical phantom and in the humanoid RANDO phantom for two different irradiation conditions (neck completely bent and partially aligned).

Concurrent carboplatin (CBDCA), vindesine (VDS) and radiotherapy in stage III non small cell lung cancer (NSCLC).

AIMS: Aim of the study was to test, in a cooperative and prospective trial, the effectiveness and feasibility of a chemoradio-therapy program in stage III non small cell lung cancer (NSCLC). METHODS: The schedule consisted in carboplatin (CBDCA) 150 mg/m2/iv on days 1, 3, 5 and vindesine VDS 2.5 mg/m2/iv on days 1, 8, 15, 22 every 4 weeks for 2 cycles followed by radiotherapy 60 Gy with CBDCA 50 mg/m2 weekly as radioenhancer. The same schedule was proposed as neoadjuvant treatment in 10/47 patients (stage III A) and as exclusive treatment in 37/47 (stage III B) admitted patients. RESULTS: In the neoadjuvant subgroup partial remission was obtained in 5/10 patients, and 3 of them underwent surgery with consequent CR. In the stage III B subgroup, 2 complete remissions were obtained (survival 14 and 9+ months). Toxicity was mild. CONCLUSIONS: Our results confirm the feasibility of the schedule in stage III NSCLC.

[Dosimetric problems and their solution in the preparation of a 6-dual-field total-skin technique]. / Alcuni problemi dosimetrici e loro soluzione nella preparazione di una tecnica di total skin a sei campi duali.

The six-field total skin electron irradiation (TSEI) technique needs an accurate preliminary dosimetric study. The American Association Physics in Medicine (AAPM) defined a dosimetric protocol that recommends the careful dosimetry of the horizontal, the dual and the six-dual fields by using both a cubic and a cylindrical phantoms. In our Institute, in a TSEI development program, we carried out the preliminary dosimetry according to AAPM criteria. We also investigated some dosimetric problems--e.g., the so-called "cable effect", which takes place when the detector cable in a TSEI field is not well shielded, polarity effects and photon contamination. As to the "cable effect", it is especially marked with the Markus NE2534 chamber; moreover, this effect, if not considered, can lead to overestimation of X-rays contamination.