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Background and Purpose: Two previous "Patterns Of Practice" surveys (POP I and POP II), including more than 4000 patients affected by prostate cancer treated with radical external beam radiotherapy (EBRT) between 1980 and 2003, established a "benchmark" Italian data source for prostate cancer radiotherapy. This report (POP III) updates the previous studies., Methods: Data on clinical management and outcome of 2525 prostate cancer patients treated by EBRT from 2004 to 2011 were collected and compared with POP II and, when feasible, also with POP I. This report provides data on clinical presentation, diagnostic workup, radiation therapy management, and toxicity as collected within the framework of POP III., Results: More than 50% of POP III patients were classified as low or intermediate risk using D'Amico risk categories as in POP II; 46% were classified as ISUP grade group 1. CT scan, bone scan, and endorectal ultrasound were less frequently prescribed. Dose-escalated radiotherapy (RT), intensity modulated radiotherapy (IMRT), image guided radiotherapy (IGRT), and hypofractionated RT were more frequently offered during the study period. Treatment was commonly well tolerated. Acute toxicity improved compared to the previous series; late toxicity was influenced by prescribed dose and treatment technique. Five-year overall survival, biochemical relapse free survival (BRFS), and disease specific survival were similar to those of the previous series (POP II). BRFS was better in intermediate- and high-risk patients treated with ≥ 76 Gy., Conclusions: This report highlights the improvements in radiotherapy planning and dose delivery among Italian Centers in the 2004-2011 period. Dose-escalated treatments resulted in better biochemical control with a reduction in acute toxicity and higher but acceptable late toxicity, as not yet comprehensively associated with IMRT/IGRT. CTV-PTV margins >8 mm were associated with increased toxicity, again suggesting that IGRT-allowing for tighter margins-would reduce toxicity for dose escalated RT. These conclusions confirm the data obtained from randomized controlled studies.

In this review we summarize the currently available evidence about the role of hybrid machines for MR-guided radiotherapy for prostate stereotactic body radiotherapy. Given the novelty of this technology, to date few data are accessible, but they all report very promising results in terms of tolerability and preliminary clinical outcomes. Most of the studies highlight the favorable impact of on-board magnetic resonance imaging as a means to improve target and organs at risk identification with a consequent advantage in terms of dosimetric results, which is expected to relate to a more favorable toxicity pattern. Still, the longer treatment time per session may potentially affect the patient's compliance to the treatment, although first quality of life assessment studies have reported substantial tolerability and no major impact on quality of life. Finally, in this review we hypothesize some future scenarios of further investigation, based on the possibility to explore the superior anatomy visualization and the role of daily adapted treatments provided by hybrid MR-Linacs.

Background: Coronavirus Disease 2019 (COVID-19) pandemic had an overwhelming impact on healthcare worldwide. Outstandingly, the aftermath on neoplastic patients is still largely unknown, and only isolated cases of COVID-19 during radiotherapy have been published. We will report the two-months experience of our Department, set in Lombardy "red-zone"., Methods: Data of 402 cancer patients undergoing active treatment from February 24 to April 24, 2020 were retrospectively reviewed; several indicators of the Department functioning were also analyzed., Results: Dedicated measures allowed an overall limited reduction of the workload. Decrease of radiotherapy treatment number reached 17%, while the number of administration of systemic treatment and follow up evaluations kept constant. Conversely, new treatment planning faced substantial decline. Considering the patients, infection rate was 3.23% (13/402) and mortality 1.24% (5/402). Median age of COVID-19 patients was 69.7 years, the large majority were male and smokers (84.6%); lung cancer was the most common tumor type (61.5%), 84.6% of subjects were stage III-IV and 92.3% had comorbidities. Remarkably, 92.3% of the cases were detected before March 24. Globally, only 2.5% of ongoing treatments were suspended due to suspect or confirmed COVID-19 and 46.2% of positive patients carried on radiotherapy without interruption. Considering only the last month, infection rate among patients undergoing treatment precipitated to 0.43% (1/232) and no new contagions were reported within our staff., Conclusions: Although mortality rate in COVID-19 cancer patients is elevated, our results support the feasibility and safety of continuing anticancer treatment during SARS-Cov-2 pandemic by endorsing consistent preventive measures.

Background: Radiotherapy is one of the standard treatments for cutaneous lymphoma and Total Skin Electrons Beam Irradiation (TSEBI) is generally used to treat diffuse cutaneous lymphoma and some cases of localized disease. Helical IMRT (HI) allows to treat complex target with optimal dose distribution and organ at risk sparing, so helical tomotherapy has been proposed as alternative technique to TSEBI but only one preliminary report has been published., Methods: Three patients treated (from May 2013 to December 2014) with Helical IMRT, with a total dose between 24 and 30 Gy, were retrospectively evaluated. Data about dosimetric features, response and acute toxicity were registered and analyzed. Planned target coverage was compared with daily in vivo measures and dose calculation based on volumetric images used for set up evaluation as well., Results: The patients had a mean measured surface fraction dose ranging from 1.54 Gy up to 2.0 Gy. A planned target dose ranging from 85 to 120% of prescription doses was obtained. All doses to Organs At Risk were within the required constraints. Particular attention was posed on "whole bone marrow" planned V 10Gy , V 12Gy and V 20Gy values, ranging respectively between 23 and 43%, 20.1 and 38% and 9.8 and 24%. A comparison with the theoretical homologous values obtained with TSEBI has shown much lower values with TSEBI. Even if treatment was given in sequence to the skin of the upper and lower hemi-body, all the patients had anaemia, requiring blood transfusions, leukopenia and thrombocytopenia., Conclusion: Based on our limited results TSEBI should still be considered the standard method to treat total skin because of its pattern of acute and late toxicities and the dose distribution. In this particular case the better target coverage obtained with HI can be paid in terms of worse toxicity. Helical IMRT can instead be considered optimal in treating large, convex, cutaneous areas where it is difficult to use multiple electrons fields in relation with the clinical results and the limited and reversible toxicities.

Background/aim: Androgen receptor plays a key role in prostate cancer development and is a causative agent of its radio-resistance. The present study investigated the potential radio-sensitizing effect of enzalutamide, a second-generation anti-androgen, in human prostate cancer cells., Materials and Methods: The radio-sensitizing effect of enzalutamide was assessed in the androgen-dependent LNCaP cells and the androgen-independent PC3 cells by clonogenic assay and γ-H2AX assay., Results: Enzalutamide-treated LNCaP cells showed a significant decrease of cell survival at all radiation doses tested. An increased number of γ-H2AX-positive nuclei was observed, suggesting a possible impairment of the DNA repair machinery. Conversely, enzalutamide did not exhibit a significant radio-sensitizing effect on PC3 cells., Conclusion: The combination of enzalutamide with ionizing radiation significantly improves radio-sensitivity of hormone-dependent LNCaP cells. Translated in the clinical practice, our results may help to find additional strategies to improve effectiveness of radiotherapy., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: To evaluate biochemical relapse-free survival (bRFS), overall survival (OS), late rectal and bladder toxicities in a retrospective single institution series, also applying an in-house software for biological dose calculation., Methods: 258 patients submitted to radiotherapy after prostatectomy were considered. Differences between groups were calculated using the log-rank test and the relevant clinical and therapeutic variables were considered for multivariate analysis. PRODVH is an in-house system able to calculate mean dose-volume histograms (DVHs) of a series of patients, to convert them in biologically effective DVHs (BEDVHs) and allowing to compare them with ANOVA and t Student test., Results: Adjuvant radiotherapy (ART) and salvage radiotherapy (SRT) were performed in 131 (50.8%) and 127 patients (49.2%). At multivariate analysis advanced T stage, androgen deprivation total (ADT) and SRT resulted as independent variables related to a worst bRFS (p = 0.019, 0.001 and 0.02), while GS > 7 and SRT affected negatively OS (p 0.047 and 0.039). High grade toxicity events occurred mainly in patients treated with 3-dimensional conformal radiotherapy (3DCRT) (proctitis p = 0.006; cystitis: p = 0.041). A significantly more favorable mean rectum BEDVH for patients with G0 or G1 rectal toxicity was shown (p < 0.001). Mean BEDVH for both bladder (p < 0.01) and rectum (p < 0.05) were also significantly better for volumetric modulated arc therapy-image guided radiotherapy (VMAT-IGRT) plans than for 3DCRT plans., Conclusion: ART is better than SRT in terms of bRFS and OS, particularly for more aggressive cases, advanced T stage and higher Gleason Score. Postoperative prostate cancer radiotherapy should be applied as soon as possible after surgery. The use of modern techniques such as VMAT-IGRT significantly reduces toxicity.

Background: Malignant meningiomas, rare tumors that account for approximately 1%-3% of all meningioma, have high recurrence, morbidity, and mortality rate and a particularly poor outcome. Surgical excision followed by adjuvant radiotherapy is the current approach for the treatment of these tumors., Methods: In the case reported, the disease, characterized by a high proliferative index (Ki67 60%-70%), was treated with endoscopic surgery limited to the extracranial portion; then the patient underwent radiotherapy, on the residual tumor volume, to a total dose of 66 Gy delivered in 33 fractions (2 Gy/fraction) by helical intensity-modulated radiation therapy with image-guided radiotherapy daily checks (tomotherapy)., Results: Two and a half years after the treatment, the patient is alive and a partial response is maintained. The patient is healthy overall with grade I fatigue and grade II hearing loss as late toxicity (Common Terminology Criteria for Adverse Events 4.1)., Conclusions: Within a multidisciplinary approach, new radiotherapy techniques confirm their effectiveness and reliability for the treatment of malignant meningioma.

To analyse the pattern of recurrence of patients treated with Stupp protocol in relation to technique, to compare in silico plans with reduced margin (1 cm) with the original ones and to analyse toxicity. 105 patients were treated: 85 had local recurrence and 68 of them were analysed. Recurrence was considered in field, marginal and distant if >80 %, 20-80 % or <20 % of the relapse volume was included in the 95 %-isodose. In silico plans were retrospectively recalculated using the same technique, fields angles and treatment planning system of the original ones. The pattern of recurrence was in field, marginal and distant in 88, 10 and 2 % respectively and was similar in in silico plans. The margin reduction appears to spare 100 cc of healthy brain by 57 Gy-volume (p = 0.02). The target coverage was worse in standard plans (pt student < 0.001), especially if the tumour was near to organs at risk (pχ2 < 0.001). PTV coverage was better with IMRT and helical-IMRT, than conformal-3D (pAnova test = 0.038). This difference was no more significant with in silico planning. A higher incidence of asthenia and leuko-encephalopathy was observed in patients with greater percentage of healthy brain included in 57 Gy-volume. No differences in the pattern of recurrence according to margins were found. The margin reduction determines sparing of healthy brain and could possibly reduce the incidence of late toxicity. Margin reduction could allow to use less sophisticated techniques, ensuring appropriate target coverage, and the choice of more costly techniques could be reserved to selected cases.

Background: To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients., Methods: Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively. For each patient, 4 "treatment plans" (VMAT SRS and SIB, helical IMRT SRS and SIB) were calculated and accepted if PTV boost was included in 95 % isodose and dose constraints of the main organs at risk were respected without major deviations. Homogeneity Index (HI), Conformal Index (CI) and Conformal Number (CN) were considered to compare the different plans. Moreover, time of treatment delivery was calculated and considered in the analysis., Results: Volume of brain metastasis ranged between 1.43 and 51.01 cc (mean 12.89 ± 6.37 ml) and 3 patients had double lesions. V95% resulted over 95 % in the average for each kind of technique, but the "target coverage" was inadequate for VMAT planning with two sites. The HI resulted close to the ideal value of zero in all cases; VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS showed mean CI of 2.15, 2.10, 2.44 and 1.66, respectively (optimal range: 1.5-2.0). Helical IMRT-SRS was related to the best and reliable finding of CN (0.66). The mean of treatment time was 210 s, 467 s, 440 s, 1598 s, respectively, for VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS., Conclusions: This dosimetric comparison show that helical IMRT obtain better target coverage and respect of CI and CN; VMAT could be acceptable in solitary metastasis. SIB modality can be considered as a good choice for clinical and logistic compliance; literature's preliminary data are confirming also a radiobiological benefit for SIB. Helical IMRT-SRS seems less effective for the long time of treatment compared to other techniques.

The extent of surgery predicts overall survival (OS) in patients treated for glioblastoma (GBM). The therapeutic approach after partial resection (PR) or biopsy alone (BA) is not clearly defined. This retrospective analysis was therefore planned to analyse clinical features, treatment and survival of patients undergoing PR or BA. We analysed the clinical/therapeutic features and the outcome of 232 patients submitted to BA/PR and treated with radiotherapy (RT) with/without chemotherapy. Two subgroups (pre- and post-Temozolomide-era) were identified. The BA/PR ratio did not change with the accrual periods. In the TMZ-era, 50 % of the patients had chemotherapy; "small" volume, hypo-fractionated and "low" dose RT (<54 Gy) were delivered to 93, 38 and 44 % of the patients; corresponding values for the previous period were 4, 28, 11 and 2 % (P < 0.001). Better two-year OS was evident in the TMZ-era (18 vs 7 %); PR and chemotherapy affected OS in patients treated with hypo-fractionated, low doses RT (P = 0.02, 0.04). Limited volume, more often MRI-based, and "short" RT treatments were given mostly to unfavourably selected patients, without compromising the results of the whole group. This strategy, combined with an increased use of chemotherapy, resulted in reduced treatment burden, in an improved 2-year OS rate and prospectively in better quality of life, even in this prognostically worse subset of glioma patients.

Aims and Background: We investigated efficacy, safety, and prognostic factors of reirradiation in patients with recurrent or second primary head and neck cancer., Methods: Records of 75 consecutive patients treated with reirradiation between August 2005 and December 2013 were reviewed., Results: Median overall survival (OS) and cancer-specific survival (CSS) were 29.5 and 33.6 months. Median local control (LC) and progression-free survival (PFS) were 21.7 and 16.2 months. Univariate analysis showed that patients younger than 70 years, with a Karnofsky Performance Status (KPS) &gt;90 or with 2 or less comorbidities at time of reirradiation, have a better OS; KPS &gt;90 and biological equivalent dose (BED) &gt;72 Gy positively influenced the PFS. At multivariate analysis, KPS at reirradiation was an independent predictive factor for OS, while BED was an independent predictive factor for CSS and OS. At univariate analysis, patients with planning target volume (PTV) &gt;221 mL had worse LC and PFS rates, with results confirmed at multivariate analysis. The rate of fatal treatment-related adverse events was 6.7% (3 carotid blowout, 1 soft tissue necrosis, and 1 thromboembolic event)., Conclusions: This study confirms the role and outcomes of reirradiation. A careful selection of patients could minimize acute and late side effects and influence survival: elderly patients, with significant medical comorbidities or poor KPS, are worse candidate for reirradiation. Total dose delivered with reirradiation and PTV appear to be other potential prognostic factors. Further studies of dose escalation are needed to establish the total dose that could achieve better LC rates with a safer toxicity profile.

Aim: We retrospectively analyzed our Institution experience with these patients. The endpoints of the analysis were overall survival (OS), disease-free survival (DFS), local control (LC), metastasis free survival (MFS); results were compared with the literature., Background: Medulloblastoma in adult patients is a very rare disease; the 5 and 10-year overall survival rates range between 33-78% and 27-56%, respectively. The collection of more clinical data is strongly needed., Materials and Methods: From September 1975 to October 2006, we treated 16 adult patients (9 males and 7 females) with a histological diagnosis of medulloblastoma. Acute and late toxicities were scored according to RTOG toxicity scale. Karnofski performance status (KPS) and neurological performance status (NPS) pre- and post-RT were reported. Median age was 27 years (range 18-53 years). All the patients received cranio-spinal irradiation, two patients were also given chemotherapy. Median follow-up period was 121.5 months., Results: In January 2014, 10/16 patients were alive without evidence of disease, 6/16 died with progressive disease (1 local and spinal, 3 spinal and 2 extraneural). Ten-year LC, OS, DFS, MFS were, respectively, 84%, 67%, 60% and 59%. Univariate analysis shows that gross total resection is associated with better survival. No acute or late G3-G4 toxicity was observed., Conclusions: This experience and the analysis of the literature confirm the efficacy of postoperative RT but also the need of large datasets to better define prognostic factors and the possible role of the association of chemotherapy.

Aims and Background: To present the Italian state-of-the-art contribution to radiobiology of external beam radiotherapy, brachytherapy, and radionuclide radiotherapy., Methods and Study Design: A survey of the literature was carried out, using PubMed, by some independent researchers of the Italian group of radiobiology. Each paper was reviewed by researchers of centers not comprising its authors. The survey was limited to papers in English published over the last 20 years, written by Italian investigators or in Italian institutions, excluding review articles., Results: A total of 135 papers have been published in journals with an impact factor, with an increase in the number of published papers over time, for external beam radiotherapy rather than radionuclide radiotherapy. The quantity and quality of the papers researched constitutes a proof of the enduring interest in clinical radiobiology among Italian investigators., Conclusions: The survey could be useful to individuate expert partners for an Italian network on clinical radiobiology, addressing future collaborative investigations.

One-hundred patients treated with curative radiotherapy (RT) ± chemotherapy (CT) for an anal canal carcinoma (T1-4N0-3M0) were retrospectively analyzed. Five- and 10-year local control (LC) rates were 73% and 67%, respectively. Acute and late G3-G4 toxicity rates were 32% and 12%, respectively. Two patients underwent a colostomy for a G4 anal toxicity. This study confirms the outcomes of RT ± CT in the treatment of anal canal cancer. Concomitant CT and LC statistically influenced Overall Survival and Colostomy-Free Survival. CT also statistically reduced the risk of nodal relapse. High rates of acute skin toxicity impose tailored volumes and techniques of irradiation.

Aims and Background: Radiotherapy is the standard treatment of glioblastoma. Three-dimensional conformal radiotherapy is the standard technique to treat glioblastoma. Intensity-modulated radiotherapy and helical intensity-modulated radiotherapy (tomotherapy) are becoming widely used. The present study compared three-dimensional conformal radiotherapy, intensity-modulated radiotherapy and tomotherapy in terms of target coverage and preservation of organs at risk., Methods: Ten patients treated with three-dimensional conformal radiotherapy, with a target volume close to or superimposed to the organs at risk, were retrospectively selected. The plans were re-planned with step-and-shoot 3/5 fields intensity-modulated radiotherapy and tomotherapy. Target coverage and sparing of organs at risk were statistically compared., Results: Mean planning target volume V95% improved with sophisticated techniques (87.2%, 93.2%, 97.6% with three-dimensional conformal radiotherapy, intensity-modulated radiotherapy and tomotherapy, respectively). The comparison of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy did not show significant differences, whereas differences were significant when three-dimensional conformal radiotherapy and tomotherapy as well as intensity-modulated radiotherapy and tomotherapy were compared. Mean planning target volume/clinical target volume D99-D98-D95 were not different between three-dimensional conformal radiotherapy and intensity-modulated radiotherapy, but they were different between tomotherapy and three-dimensional conformal radiotherapy and intensity-modulated radiotherapy, with better clinical target volume/and planning target volume coverage with the tomotherapy plans. Brain D33/66 were 31.1/11.8 Gy, 37.5/18.3 Gy and 28.5/14.7 Gy with three-dimensional conformal radiotherapy, intensity-modulated radiotherapy and tomotherapy, respectively. Mean brainstem, optic nerves and chiasma Dmax were always within the defined constraints. The homogeneity index improved with intensity-modulated radiotherapy/tomotherapy compared to three-dimensional conformal radiotherapy. Tomotherapy was better than intensity-modulated radiotherapy in all patients., Conclusions: In this selected group of patients, a significant dosimetric advantage was evident for tomotherapy compared with three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. Significant advantages were evident in terms of panning target volume coverage (V95), D99, D98 and D95. The clinical significance of the results should be defined.

Introduction: Medulloblastoma, the most frequent brain tumor in childhood, also occurs with a wide range of characteristics in adult patients. Late relapse is common in adult medulloblastoma, and the overall survival of relapsed patients usually ranges from 12 to 15 months. Treatment at recurrence is still debated and after reoperation includes stereotactic or normofractionated radiotherapy, and high-dose chemotherapy with autologous bone marrow transplantation., Case Presentation: We report on the case of a 31-year-old Caucasian woman who underwent re-irradiation for a recurrence of medulloblastoma at nine years after first irradiation (56Gy), focusing on the radiobiological background and a review of previous studies involving re-irradiation of recurrent medulloblastoma. After surgical excision of the relapsed tumor and medical multi-agent treatment, the site of recurrence was treated using three-dimensional conformal radiotherapy to a total dose of 52.8Gy (1.2Gy/fraction/twice daily). A total biological equivalent dose of 224.6Gy (α:β = 2 Gy) was delivered to the posterior fossa (first and second treatments). No radionecrosis or local recurrence was evident at 18 months after re-irradiation., Conclusion: Re-irradiation can be considered a possible and safe treatment in selected cases of recurrent medulloblastoma in adults. The reported radiobiological considerations could be useful in other cases involving re-irradiation of brain tumors.

Background and Purpose: To evaluate survival, locoregional control and toxicity in a series of 56 mesothelioma patients treated from May 2005 to May 2010 with post-operative radiotherapy after extrapleural pneumonectomy (EPP) in three Italian Institutions (Brescia, Florence, and Modena)., Material and Methods: Fifty-six patients treated with adjuvant radiotherapy (RT) after EPP were analyzed. Four patients were treated with 3DCRT, 50 with IMRT and two with helical tomotherapy. Forty-five to 50 Gy in 25 fractions were given to the affected hemithorax and to ipsilateral mediastinum, with a simultaneous integrated boost to the sites of microscopically involved margins up to 60 Gy in 20/56 cases., Results: Three year locoregional control (LRC), distant metastasis free (DMF), disease free (DF), disease specific (DSS) and overall survival (OS) rates are 90%, 66%, 57%, 62%, and 60%, respectively., Conclusion: Postoperative RT with modern techniques is an effective method to obtain excellent local control and cure rates in mesothelioma patients submitted to EPP., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Dentinal sensitivity (DS) occurs frequently in adult populations in western countries. The purpose of this work was to assess the effectiveness of a new intraoral fluoride releasing device (IFRD) in reducing the level of pain in patients with primary or postsurgical dentine sensitivity., Methods: A total of 49 individuals were selected for this study, 15 of whom had post-periodontal surgery dentine sensitivity and 34 with primary sensitivity. An IFRD was applied to 39, while 10 received a placebo device. All individuals in the control group suffered from primary sensitivity. The IFRD used in this study consists of sodium fluoride encased in an acrylic polymer which releases fluoride at a rate of approximately 0.04 mg/day. All patients were asked to rinse with cold water (10 degrees C) and to indicate the level of pain on a 0 to 10 visual analog scale, 0 equalling "no pain" and 10 "maximum bearable pain." All subjects were evaluated once a week during 4 months. Statistical analysis of dentine sensitivity was performed as a univariate study, in relation to the main factors: age, gender, and primary sensitivity or postsurgical etiology., Results: Symptoms decreased dramatically in all treated patients. The level of sensitivity did not change during the first week after IFRD application, but decreased significantly within the fourth week and remained absent through the duration of the treatment (P <0.01). Difference in sensitivity with respect to different etiology was significant only after 4 weeks (P= 0.01), while there was no statistical difference with respect to age or gender., Conclusions: This paper is an initial study to evaluate the effectiveness of the IFRD. The method is fast, painless, inexpensive, and it appears to be suitable as a routine treatment. The presented data support the conclusions at this stage and warrant more comprehensive evaluation.

In the first weeks of pregnancy there is a significant increase of vasodilatator prostaglandins in maternal blood. This increase could be in a cause-effect relation with the increase of progesterone, BHCG and HPRL typical of the first phase of pregnancy. Blood samples of 12 normotensive women reveal that there is not a correlation between placental hormons, HPRL and the increase of prostaglandins, but these hormones seem to offer an important control on other more complex biochemical mechanisms that cause the increase of vasodilator prostaglandins.

The role of prostaglandin (PG) system in preeclampsia (pre-E) was investigated. Urinary excretion of PGE2,6-keto PGF1 alpha,2,3 dinor 6-keto PGF1 alpha, TxB2 and 2,3-dinor-TxB2 and kallikrein were determined in 10 normotensive pregnant women and 14 with pre-E. 6-keto PGF1 alpha and 2,3-dinor 6-keto PGF1 alpha (the main renal and extrarenal metabolites of vasodilator PGI2) and PGE2 excretion was lower in pre-E. TxB2 metabolites in urine were similar in the two groups of women. Our data are consistent with the hypothesis of an imbalance between vasodilator and vasoconstrictor PGs in pre-E.