Biomedical subjects

Vincenzo Valentini

Publications and source records attributed to Vincenzo Valentini.

45 records · Page 3Linked to original sources

PubMedDate not supplied

Underlying anatomy for CTV contouring and lymphatic drainage in rectal cancer radiation therapy.

Despite the low local recurrence rate that can be achieved by adequate surgery (total mesorectal excision--TME), radiation therapy was shown to play a significant role in reducing this risk. The widespread use of TME in many European Centers has introduced a new terminology and the need to identify the area at major risk for local failure using this surgical procedure. In the surgical series where extended extra-mesorectal surgery was performed, the role of lymphatic spread was evidenced, especially for low rectal cancer, through the pelvic parietal fascia and lateral pelvic spaces. The aim of this study was to better define some anatomic concepts and the main risk factors which impact on CTV contouring and field conformation in rectal cancer treatment. This information helps formulating guidelines for CTV contouring in daily radiotherapy practice, in order to define the best therapy, according to the tumor stage and location.

Combined Modality Therapy↗

PubMedDate not supplied

Lymphatic drainage and CTV in carcinoma of the prostate.

The prostate lymphatics drain into the periprostatic subcapsular network, from which 3 groups of ducts originate: the ascending ducts from the cranial prostate draining into the external iliac lymph nodes, the lateral ducts running to the hypogastric lymph nodes and the posterior ducts draining from the caudal prostate to the subaortic sacral lymph nodes of the promontory. Internal, external iliac and obturator lymph nodes are the most frequently involved by prostate carcinoma. Metastases to presacral and common iliac lymph nodes are rare. For the limited staging accuracy, present indications for seminal vesicle irradiation and pelvic node prohylactic irradiation are essentially based on risk categories and estimation algorithms; the latter while are widely used in international studies are not free of limitations as stressed since they were introduced. A method to deliver high doses to the tumor while limiting the irradiation of critical organs might be the delivery of a boost to the tumor only. This approach could become increasingly feasible with the diffusion of imaging procedures able to better define tumor extension.

Humans↗

PubMedDate not supplied

Radiation therapy of breast cancer. Reasoned approach to a clinical case.

The case of a patient undergoing quadrantectomy of lower quandrants of the right breast and ipsilateral axillary lymph node dissection for breast cancer followed by adjuvant radiotherapy is discussed. The stage of the disease and prognostic factors are analyzed for prognosis. Comorbidities ruled out chemotherapy. Radiation therapy was planned followed by clinicoinstrumental controls. After the second control ipsilateral costal bone metastases were observed; radiation therapy for palliation was prescribed.

Bone Neoplasms↗

PubMedDate not supplied

Compensation for gaps in radiotherapy: suggested teaching approach to its calculation.

Unplanned gaps in radiotherapy can impact on its clinical effect, especially in tumors with accelerated repopulation. In the literature, several technical solutions have been proposed. According to the situation, compensation for the effect on the tumor to the detriment of normal tissue tolerance can be achieved. An approach, modulated according to the gap duration and timing is proposed aimed at constant tumor control with no significant increased risk of side-effects. The decisional algorithm and calculation formulae are used in our center in teaching addressed to residents to make them familiar with the possible clinical applications of radiobiological knowledge.

Algorithms↗

PubMedDate not supplied

Biological optimization of the dose in rectal carcinoma.

Surgery remains the main procedure for rectal cancer therapy. However, in the past decades various radiation therapy modalities were used to improve outcomes. The optimization of the clinical results of radiotherapy alone with concomitant boost or hyperfractionated, accelerated radiotherapy or chemoradiation requires a better understanding of biological evidences on RT effect, considering the possible presentation of this tumor: "visible" unresectable, "visible" resectable and subclinical disease. Furthermore, parameters as tumor volume, hypoxic fraction, intrinsic radiosensitivity, doubling time and clonogen proliferation are factors shown to have an impact on tumor control probability.

Dose Fractionation, Radiation↗

PubMedDate not supplied

Electron beam dosimetry of Total Skin Electron Therapy (TSET).

Total Skin Electron Therapy (TSET) was carried out using an electron beam with a nominal energy of 6 MeV. The beam was adequately filtered and angled in order to create dual fields. The uniformity of the dose distribution to the patient was 10%. The relative dosimetry of the dual beam was performed using a silicon diode and an ionization chamber in a standard water phantom. X-Omat V films were irradiated in a cylindrical PMMA phantom in order to obtain the dose distribution for the six TSET dual fields used in the treatment. Absolute dosimetry was carried out with a calibrated ionization chamber placed in a cylindrical water phantom. The dose contribution per monitor unit of the single dual beams was determined with this method.

Dose Fractionation, Radiation↗

PubMedDate not supplied

Persisting perianal ulcer after radiotherapy for anal cancer: recurrence of disease or late radiation-related complication?

We report the case of a 47-year-old HIV-negative male affected by a perianal ulcer which occurred after chemoradiation delivered for anal cancer. In spite of a negative biopsy the lesion was highly suspected to be a disease recurrence. Uncontrollable pain and anal stenosis were also present; abdominoperineal resection with a large excision of perianal tissues and reconstruction with bilateral musculocutaneous gracilis flaps was therefore performed. Histology did not confirm tumor recurrence. Thirteen months after surgery, the patient is still alive and free of disease. The introduction of radiotherapy and concomitant chemotherapy has revolutionized the treatment of anal cancer, avoiding demolitive surgery in a large subset of patients. Radionecrosis is an uncommon but potentially devastating event occurring in up to 10% of patients undergoing radiotherapy for anal cancer. It causes clinical (pain, anal stenosis, mucositis and diarrhea) and diagnostic problems (recurrence vs. benign post-attinic lesion). In the present article we review this uncommon complication, discuss the technical surgical aspects associated with a very large perianal tissue removal, and data of the most recent literature in this field.

Anal Canal↗

PubMedDate not supplied

Concurrent 5-fluorouracil, mitomycin C and radiation, with or without brachytherapy, in recurrent endometrial cancer: a scoring system to predict clinical response and outcome.

AIMS AND BACKGROUND: This prospective, phase II study aimed to test the efficacy of concurrent 5-fluorouracil, mitomycin C and radiation, with or without brachytherapy, on the clinical outcome of a series of recurrent endometrial cancer patients and to determine the prognostic impact of a subset of factors. METHODS: Thirty patients with locally recurrent, nonmetastatic endometrial cancer received external beam radiation (4-week split course: 23.4 + 23.4 Gy) plus two courses of concomitant chemotherapy (5-fluorouracil, 96-h continous infusion, days 1-4; 1 g/m2/day; mitomycin C, 10 mg/m2, bolus iv, day 1). Nineteen patients (63.3%) underwent endocavitary, low-dose brachytherapy boost (20-25 Gy); eight patients (26.7%) received external beam radiation boost (14-20 Gy). RESULTS: Eleven complete responses (36.7%), 11 partial responses (36.7%), 6 disease stabilizations (20.0%) and 2 progressions (6.6%) were observed. After a median follow-up of 27 months (range, 1-108), overall actuarial 3-year survival, progression-free survival and local progression-free survival were 46.8%, 35.2% and 41.2%, respectively. Two patients (6.7%) experienced hematological grade 3 toxicity. Two patients (6.7%) had grade 3 intestinal toxicity. Severe late toxicity was infrequent, only 3 patients showing severe vaginal stenosis (10.0%). A clinical score of 0 to 1 was assigned to each patient on the basis of the absence (score = 0) or presence (score = 1) of any of the following prognostic factors: time between surgery and recurrence shorter than 12 months, pelvic wall site of recurrence, positive lymph nodes, hemoglobin < 11 g/dL. With this device, it was clear that patients with a low score had a significantly better outcome (clinical remission: 77.2% of patients with a score < 2 vs 25.0% of patients with a score > or = 2, P = 0.009), better local control of the disease (50.2% vs. 0 at 3 years, P = 0.014,) and better overall survival (65.8% vs 0 at 3 years, P = 0.003). CONCLUSIONS: Our data suggest that this combined modality therapy was relatively well tolerated and resulted in reasonable local control and survival. The scoring system proved to be helpful in identifying patients with the best chance of benefiting from the treatment.

Adult↗

PubMedDate not supplied

Impact of dose and volume on rectal tolerance.

Based on the successful results achieved in survival and local control with radiotherapy of prostate cancer recent studies tried to establish some models to reliably predict late rectal toxicity. In fact, the rectum, due to its location, represents an organ at risk of acute and late toxicity with the onset of acute or chronic radiation proctitis. The concept of late consequential effect has gained ground. It implies that the late damage might be a direct consequence of the acute damage. Dose-escalation studies, conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) led to the identification of parameters, based on dose-volume histograms (DVH), able to separate patients at low and high risk of toxicity. Precise predictive dosimetric factors play a major role in the definition of the onset of toxicity. The monitoring system of late toxicity used by the authors is presented.

Dose Fractionation, Radiation↗