Secondary radiation measurements for particle therapy applications: charged particles produced by 4He and 12C ion beams in a PMMA target at large angle.

Proton and carbon ion beams are used in the clinical practice for external radiotherapy treatments achieving, for selected indications, promising and superior clinical results with respect to x-ray based radiotherapy. Other ions, like [Formula: see text] have recently been considered as projectiles in particle therapy centres and might represent a good compromise between the linear energy transfer and the radiobiological effectiveness of [Formula: see text] ion and proton beams, allowing improved tumour control probability and minimising normal tissue complication probability. All the currently used p, [Formula: see text] and [Formula: see text] ion beams allow achieving sharp dose gradients on the boundary of the target volume, however the accurate dose delivery is sensitive to the patient positioning and to anatomical variations with respect to photon therapy. This requires beam range and/or dose release measurement during patient irradiation and therefore the development of dedicated monitoring techniques. All the proposed methods make use of the secondary radiation created by the beam interaction with the patient and, in particular, in the case of [Formula: see text] ion beams are also able to exploit the significant charged radiation component. Measurements performed to characterise the charged secondary radiation created by [Formula: see text] and [Formula: see text] particle therapy beams are reported. Charged secondary yields, energy spectra and emission profiles produced in a poly-methyl methacrylate (PMMA) target by [Formula: see text] and [Formula: see text] beams of different therapeutic energies were measured at 60° and 90° with respect to the primary beam direction. The secondary yield of protons produced along the primary beam path in a PMMA target was obtained. The energy spectra of charged secondaries were obtained from time-of-flight information, whereas the emission profiles were reconstructed exploiting tracking detector information. The obtained measurements are in agreement with results reported in the literature and suggests the feasibility of range monitoring based on charged secondary particle detection: the implications for particle therapy monitoring applications are also discussed.

Secondary radiation measurements for particle therapy applications: prompt photons produced by 4He, 12C and 16O ion beams in a PMMA target.

Charged particle beams are used in particle therapy (PT) to treat oncological patients due to their selective dose deposition in tissues with respect to the photons and electrons used in conventional radiotherapy. Heavy (Z > 1) PT beams can additionally be exploited for their high biological effectiveness in killing cancer cells. Nowadays, protons and carbon ions are used in PT clinical routines. Recently, interest in the potential application of helium and oxygen beams has been growing. With respect to protons, such beams are characterized by their reduced multiple scattering inside the body, increased linear energy transfer, relative biological effectiveness and oxygen enhancement ratio. The precision of PT demands online dose monitoring techniques, crucial to improving the quality assurance of any treatment: possible patient mis-positioning and biological tissue changes with respect to the planning CT scan could negatively affect the outcome of the therapy. The beam range confined in the irradiated target can be monitored thanks to the neutral or charged secondary radiation emitted by the interactions of hadron beams with matter. Among these secondary products, prompt photons are produced by nuclear de-excitation processes, and at present, different dose monitoring and beam range verification techniques based on prompt-γ detection are being proposed. It is hence of importance to perform γ yield measurement in therapeutic-like conditions. In this paper we report on the yields of prompt photons produced by the interaction of helium, carbon and oxygen ion beams with a poly-methyl methacrylate (PMMA) beam stopping target. The measurements were performed at the Heidelberg Ion-Beam Therapy Center (HIT) with beams of different energies. An LYSO scintillator, placed at [Formula: see text] and [Formula: see text] with respect to the beam direction, was used as the photon detector. The obtained γ yields for the carbon ion beams are compared with results from the literature, while no other results from helium and oxygen beams have been published yet. A discussion on the expected resolution of a slit camera detector is presented, demonstrating the feasibility of a prompt-γ-based monitoring technique for PT treatments using helium, carbon and oxygen ion beams.

Secondary radiation measurements for particle therapy applications: nuclear fragmentation produced by 4He ion beams in a PMMA target.

Nowadays there is a growing interest in particle therapy treatments exploiting light ion beams against tumors due to their enhanced relative biological effectiveness and high space selectivity. In particular promising results are obtained by the use of 4He projectiles. Unlike the treatments performed using protons, the beam ions can undergo a fragmentation process when interacting with the atomic nuclei in the patient body. In this paper the results of measurements performed at the Heidelberg Ion-Beam Therapy center are reported. For the first time the absolute fluxes and the energy spectra of the fragments-protons, deuterons, and tritons-produced by 4He ion beams of 102, 125 and 145 MeV u-1 energies on a poly-methyl methacrylate target were evaluated at different angles. The obtained results are particularly relevant in view of the necessary optimization and review of the treatment planning software being developed for clinical use of 4He beams in clinical routine and the relative bench-marking of Monte Carlo algorithm predictions.

A novel radioguided surgery technique exploiting ß(-) decays.

The background induced by the high penetration power of the radiation is the main limiting factor of the current radio-guided surgery (RGS). To partially mitigate it, a RGS with ß(+)-emitting radio-tracers has been suggested in literature. Here we propose the use of ß(-)-emitting radio-tracers and ß(-) probes and discuss the advantage of this method with respect to the previously explored ones: the electron low penetration power allows for simple and versatile probes and could extend RGS to tumours for which background originating from nearby healthy tissue makes probes less effective. We developed a ß(-) probe prototype and studied its performances on phantoms. By means of a detailed simulation we have also extrapolated the results to estimate the performances in a realistic case of meningioma, pathology which is going to be our first in-vivo test case. A good sensitivity to residuals down to 0.1 ml can be reached within 1 s with an administered activity smaller than those for PET-scans thus making the radiation exposure to medical personnel negligible.

Measurement of charged particle yields from PMMA irradiated by a 220 MeV/u (12)C beam.

The radiation used in hadrontherapy treatments interacts with the patient body producing secondary particles, either neutral or charged, that can be used for dose and Bragg peak monitoring and to provide a fast feedback on the treatment plans. Recent results obtained from the authors on simplified setups (mono-energetic primary beams interacting with homogeneous tissue-like target) have already indicated the correlation that exists between the flux of these secondaries coming from the target (e.g. protons and photons) and the position of the primary beam Bragg peak. In this paper, the measurements of charged particle fluxes produced by the interaction of a 220 MeV/u carbon ion beam at GSI, Darmstadt, with a polymethyl methacrylate target are reported. The emission region of protons (p), deuterons (d) and tritons (t) has been characterized using a drift chamber while the particle time-of-flight, used to compute the kinetic energy spectra, was measured with a LYSO scintillator. The energy released in the LYSO crystal was used for particle identification purposes. The measurements were repeated with the setup at 60° and 90° with respect to the primary beam direction. The accuracy on the fragments emission profile reconstruction and its relationship with the Bragg peak position have been studied. Based on the acquired experimental evidence, a method to monitor the dose profile and the position of the Bragg peak inside the target is proposed.

Charged particle's flux measurement from PMMA irradiated by 80 MeV/u carbon ion beam.

Hadrontherapy is an emerging technique in cancer therapy that uses beams of charged particles. To meet the improved capability of hadrontherapy in matching the dose release with the cancer position, new dose-monitoring techniques need to be developed and introduced into clinical use. The measurement of the fluxes of the secondary particles produced by the hadron beam is of fundamental importance in the design of any dose-monitoring device and is eagerly needed to tune Monte Carlo simulations. We report the measurements carried out with charged secondary particles produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a poly-methyl methacrylate target. Charged secondary particles, produced at 90° with respect to the beam axis, have been tracked with a drift chamber, while their energy and time of flight have been measured by means of a LYSO scintillator. Secondary protons have been identified exploiting the energy and time-of-flight information, and their emission region has been reconstructed backtracking from the drift chamber to the target. Moreover, a position scan of the target indicates that the reconstructed emission region follows the movement of the expected Bragg peak position. Exploiting the reconstruction of the emission region, an accuracy on the Bragg peak determination in the submillimeter range has been obtained. The measured differential production rate for protons produced with E(Prod)(kin) > 83 MeV and emitted at 90° with respect to the beam line is dN(P)/(dN(C)dΩ) (E(Prod)(kin) > 83 MeV, θ = 90°) = (2.69 ± 0.08(stat) ± 0.12(sys)) × 10⁻4 sr⁻¹.

Therapeutic alternatives in Behçet's syndrome.

Behçet's Syndrome (BD) is a chronic, relapsing, recurrent systemic vasculitis with an unknown cause. The disease affects all organs of the body concurrently or consecutively. Its various clinical manifestations result from ubiquitous small-vessel vasculitis, which is the underlying pathology. An Italian study has reported an increased association of the extended haplotype B51-DR5-DQw3. Without a known etiology BD syndrome has no uniformly acceptable therapy. Our study addresses therapeutic alternatives for the treatment of BD, with the systemic use of interferon alpha-2a., which has antiviral. immunomodulatory, antiproliferative, and antitumoral properties. Ten patients diagnosed with BD were referred from September 2002 to September 2005 to the Department of Gynaecology, Obstetrics and Reproduction of the Second University of Naples. The International Study Group (ISG) Criteria for Behçet's Disease (27) was applied. Patients were treated with oral prednisone; sulfasalazine; clobetasol; and interferon alpha-2a. Every month all patients had a complete blood count, platelet count, and liver function test. Biopsies of genital ulcerations identified small vessel vasculitis with mononuclear cell and lynphocytic infiltrates. HLA-B27 and B5 were positive in three subjects. The pathergy test was positive in all patients. Today the therapy is still ongoing, and none of the patients in therapy with our protocol present clinical symptoms of BD or intolerance. Laboratory findings are in a normal range and none have had neurological failure. Our findings may be attributable to less severe disease in a patients, to our smaller number of patients, or to other unknown factors. Nonetheless, these findings remain to be confirmed in a larger number of patients.

Alcohol sclerotherapy: a new method for Bartholin gland cyst treatment.

AIM: Bartholin gland cysts are one of the most common gynecologic problems. Around 2% of women suffer from these pathologies. Bartholin gland cyst are generally asymptomatic, but sometimes extremely painful to restrict physical activity. The treatment choice is related to the patient's age, the size of the cyst or abscess and relapses, but different approaches are possible. The aim of this study is to investigate the efficicacy and safety of the alcohol sclerotherapy versus the only aspiration to cure symptomatic cysts or abscesses of the Bartholin's gland. METHODS: Between January 2002 and June 2004, 18 patients suffering from Bartholin symptomatic unilateral cysts or with abscess are selected. These patients have been divided into 2 groups and they have been treated with alcohol sclerotherapy or aspiration. The simple aspiration removes only the cyst fluid. The alcohol sclerotherapy allows to destroy the epithelial covering of the cyst by a coagulative necrosis and then a fibrosis which covers the cavity and prevents the reformation of liquid. RESULTS: Treatment has been satisfactory for all the patients, and treatment time has been shorter with alcohol sclerotherapy. None of the patients, in both groups, presented sexual dysfunctions or dyspareunia. CONCLUSIONS: Alcohol sclerotherapy might be an ideal and safe procedure in the treatment of the Bartholin's gland or abscesses with a low percentage of relapses.

Ovarian hyperstimulation syndrome: distinction between local and systemic disease.

The ovarian hyperstimulation syndrome (OHSS) is an iatrogenic, unpredictable and potentially life-threatening complication in patients submitted to pharmacological ovarian stimulation. Information on risk factors, etiopathogenetic mechanisms, prevention strategies and therapeutic management is continuously updated. The present study retrospectively analyzed 123 women affected by different grades of OHSS as a result of pharmacological ovulation induction. Hospital admission was suggested in 14 patients with severe OHSS, whereas patients with moderate or mild OHSS were followed in the out-patient section of our department. The results confirmed the efficacy of the therapeutic scheme adopted. The syndrome is localized to the ovaries at the time that the condition is triggered; when organs different from the ovaries become involved, OHSS assumes systemic aspects. The different clinical signs are the basis of a proposal of a local and systemic classification.

[Myomectomy during cesarean section and outside pregnancy. Different outcomes of scars]. / Miomectomia in corso di taglio cesareo e al di fuori della gravidanza. Differenti esiti della cicatriche.

BACKGROUND: The purpose of this study is the comparison between the scar of myomectomy performed during cesarean section and out of the pregnancy. METHODS: Eighteen pregnant patients were submitted to cesarean section between 37 and 39 weeks of gestation for previous myomectomy. The previous myomectomy has been performed in 8 patients during a cesarean section, in 10 patients out of pregnancy; in all patients only one subserous-intramural myoma of uterine fundus or body with a maximum diameter of 4-5 cm has been excised. RESULTS: In myomectomies performed during cesarean section the scar appeared more linear, with good well defined limits, less wide and with modest introflection in comparison to surrounding myometrium. The myometrial thickness did not present variations and was well contracted. CONCLUSIONS: Our results show substantial differences: in fact, according to personal opinion, the different evolution of the healing process is due to variations occurring in pregnancy and particularly for local immunology system which in pregnancy is hyperactive. The presence and increased synthesis of immunological substances support a better healing with an optimal functional recovery.

The use of armspan measurement to assess the nutritional status of adults in four Ethiopian ethnic groups.

OBJECTIVES: To investigate the use of armspan as a proxy for height in the assessment of nutritional status using body mass index (BMI) for four ethnic groups in Ethiopia. DESIGN: Cross-sectional study. SETTING: Four regions in Ethiopia, namely Oromia, Amhara, Tigre and Somali Region. SUBJECTS: A total of 1706 (884 males and 822 females) Ethiopians aged 18-50 y from four different ethnic groups. METHODS: Anthropometric measurements (weight, height and armspan) were obtained using standard techniques. BMI using height (BMI-ht) and using armspan (BMI-as) were calculated, t-tests were used to compare means, and linear regression to investigate the relationship between BMI-ht and BMI-as. RESULTS: Ethnic and sex differences in the relationship between height and armspan, and their derived variables (BMI-ht and BMI-as), were found. Armspan and height (r=0.83-0.9), and BMI-ht and BMI-as (r=0.89-0.97), were highly correlated in all ethnic groups. BMI-as cut-offs equivalent to the conventional BMI-ht classification of chronic energy deficiency were similar in the Oromo, Amhara and Tigre, but substantially higher in the Somalis. CONCLUSION: Armspan can be used as a proxy for height to estimate BMI, but the relationship between the two measures varies considerably with ethnicity and sex. Unless sex- and ethnicity-specific cut-offs are applied, the use of BMI-as using conventional cut-offs will overestimate the prevalence of underweight in these populations. SPONSORSHIP: HelpAge International.

Impact of folivory on photosynthesis is greater than the sum of its holes.

The effects of herbivores on plant production and fitness may not relate directly to the quantity of biomass removed because folivory may alter photosynthetic rates at a considerable distance from the damaged tissue [Welter, S. C. (1989) in Insect-Plant Interactions, ed. Bernays, E. A. (CRC, Boca Raton), pp. 135-151.]. An impediment to understanding the effects of leaf damage on photosynthesis has been an inability to map photosynthetic function within a single leaf. We developed an instrument for imaging chlorophyll fluorescence and used it to map the effects of caterpillar feeding on whole-leaf photosynthesis in wild parsnip. The adverse effects of caterpillar feeding on photosynthesis were found to extend well beyond the areas of the leaflet in which caterpillars removed tissue. These "indirectly" affected areas remained impaired for at least 3 days after the caterpillars were removed and were six times as large as the area directly damaged by the caterpillars. Although photosynthesis in indirectly affected areas was reduced and not eliminated, these areas accounted for three times as much of the overall reduction in photosynthesis as the area removed by the caterpillars. The size of the indirect effects was positively correlated with defense-related synthesis of furanocoumarins, suggesting that costs of chemical defense may be one factor that accounts for the indirect effects of herbivory on plants.

Regression of ovarian enlargement in pharmacological ovulation induction.

The aim of the present study was to determine a possible relationship between ovarian functionality and regression of ovarian enlargement according to the different categories and degree of severity of ovarian hyperstimulation syndrome (OHSS). Among a group of sterile woman (n = 111), two subgroups were studied: group A (n = 15), patients affected by severe syndrome; and group B (n = 96), patients with massive ovarian enlargement only. The protocol of ovarian stimulation was conducted in various in vitro fertilization (IVF) centers; ultrasonographic examination and hematological checks were carried out daily; patients with severe OHSS were hospitalized. In women of group A, severe symptoms disappeared in 7-11 days; in nine patients with regular cycles ovary size returned to normal in about 30-40 days, whereas in six subjects with anovulatory cycles, the resolution was recorded in about 50-60 days; serum estradiol returned to physiological levels within 20-30 days. Women of group B showed a spontaneous regression at different times: in 43 subjects that presented regular ovulatory cycles, the resolution was recorded in about 30-40 days, whereas in 36 women with anovulatory cycles before pharmacological induction, resolution occurred in 50-60 days, and in 17 cases with polycystic ovary syndrome before pharmacological ovulation, an incomplete resolution was obtained; serum estradiol levels returned to a physiological range within 20-30 days. Our results show that in patients with regular ovulatory cycles, resolution of symptoms is obtained in a shorter time than in patients with anovulatory cycles before pharmacological induction.

Internal jugular vein catheterization under echographic guidance.

Having examined the various disadvantages of the catheterization of the central veins performed using the Seldinger technique, we report our results of internal jugular vein catheterization under echographic guidance in 38 uremic patients. The echographic guidance technique allows an easier and safer utilization of the internal jugular vein as vascular access in emergency situations.