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Biomedical subjects

N Cellini

Publications and source records attributed to N Cellini.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Radiotherapy in rectal cancer: stage of the disease and therapeutic approach.

Rectal cancer requires treatments tailored according to the stage of the disease at diagnosis. In stage I lesions exclusive surgery is the elective treatment. Radiotherapy is used in those cases where the site of the lesion would sacrifice sphincter function. When the features of neoplasm are favourable (size < 5 cm, grading 1-2, histological type adenocarcinoma) local excision and postoperative radiotherapy enable to achieve results comparable to those of radical surgery. In operable lesions (T3-T4 (vagina) N0-2, M0) at high risk for local recurrence, high dose preoperative radiotherapy in some randomized studies has shown a significant improvement in local control and survival with a low toxicity, especially in patients undergoing radical surgery. Concomitant chemotherapy in postoperative radiotherapy has significantly improved local control and survival as compared to radiotherapy alone. Continuous infusion appears to reduce the toxicity, which is otherwise high. Randomized studies of preoperative radiochemotherapy vs radiation alone or vs postoperative radiochemotherapy are in progress in various Centers. Intensification with radiotherapy alone (IORT, fractionation) is also under study. In lesions unresectable for cure (T4, N0-3, M0) radiotherapy alone or combined with surgery did not show significant results. Intensification with concomitant chemotherapy and/or with IORT has enabled over 70% local control and 50% 5-year survival.

Adenocarcinoma↗
PubMedDate not supplied

Intraoperative radiation therapy (IORT) in rectal cancer: methodology and indications.

In intraoperative radiation therapy (IORT) a high dose of radiation is delivered to the tumor or to the tumor bed, thus favouring local control with no significant increase in toxicity. At present it is used to deliver a boost dose of radiation for rectal cancer in protocols which include preoperative external beam radiation therapy (ERT). From various experiences carried out in a number of centers, the technical and methodological features of this procedure have been defined also relatively to cost-effectiveness in terms of a longer surgical treatment, involved specialized staff and resources. At the 5th IORT International Congress held in Lyon in September, 1994, of over 70 clinical studies reported, 15 were on rectal cancer with about 700 patients undergoing IORT. The growing interest in the use of this procedure in rectal cancer is explained by the natural history of the disease, burdened with a high rate of local recurrence, and by the possibility of preventing it with high doses of radiation. In primary tumors unresectable for cure and in local recurrence it is evidenced that ERT+surgery+IORT enable an improvement in local control and survival as compared to ERT alone. Results are better when surgery is radical. Several studies deal with the role of preoperative combined concomitant radiochemotherapy which can favour a radical surgery. A sizeable percentage of these patients will present with metastasis, thus adjuvant chemotherapy seems suitable. A role of IORT is envisaged also for resectable high risk tumors, however results should be confirmed by larger clinical series.

Combined Modality Therapy↗
PubMedDate not supplied

Concomitant radiochemotherapy in rectal cancer: methodology and indications.

Concomitant radiochemotherapy (CRC) is based on the administration of chemotherapeutic agents concurrently with radiation therapy. It is aimed at the spatial cooperation of radiotherapy (ERT) and chemotherapy and the enhancement of the local action of radiotherapy. In this study the role of ERT enhancement in the treatment of rectal cancer, is analyzed. 5FU is the commonly used drug. Clinical and experimental evidence indicates radiotherapy to be enhanced when the drug is administered in continuous infusion after radiation and for a suitable dose of 5FU. In these conditions, toxicity is usually mild. In contrast, when the drug is administered as bolus, the experimental evidence seems to indicate only additivity. However the clinical experience has shown an improvement in local control and survival at the expense of a higher toxicity. In patients with resectable lesions at high risk for local recurrence, randomized CRC studies have shown a high rate of local control between 85% and 90%, a 5-year survival between 55% and 60%, significantly better as compared to control arms: exclusive surgery (GITSG7 175), exclusive ERT (NCCTG), bolus CRC (Intergroup). Acute toxicity is mostly hematological and gastrointestinal. In patients with lesions unresectable for cure, CRC allows high surgical radicality (85-90%). Complete pathologic response is 4 to 20%. Local control is high (80-90%) and 3-year survival is 70 to 90%. Grade 3-4 acute gastrointestinal toxicity was shown to be higher in combinations with bolus 5FU. In recurrence CRC has been used for palliation. Control of pain to the pelvis was similar to that achieved with radiotherapy alone. In a single experience was CRC used preoperatively and results seem encouraging.

Combined Modality Therapy↗
PubMedDate not supplied

Carcinoma of the pancreatic head area. Therapy: intraoperative radiotherapy.

Pancreatic tumors represent a major field of application of intraoperative radiotherapy (IORT) with electron beams. First clinical studies were carried out principally on unresectable tumors and control of pain was observed in most of them. However, as for prognosis, IORT alone has yielded disappointing results. The use of IORT to boost external beam radiotherapy (ERT) frequently applied in recent trials, has improved local control but not survival rate because of the high incidence of abdominal metastasis. To-date, results of IORT used as an adjuvant to radical surgery have been controversial. As in unresectable tumors, studies have been focused on the combination IORT+ERT, however the intensification of the dose delivered to the tumor bed and the consequent better local control has not resulted in a better prognosis. A more significant contribution of IORT to the treatment of pancreatic tumors may come in the future from the combination of IORT with more effective methods in the control of the abdominal disease ("prophylactic" ERT to the liver or upper abdomen, intra-arterial or intraperitoneal chemotherapy) or from variously timed combinations with ERT (neoadjuvant ERT+IORT).

Combined Modality Therapy↗
PubMedDate not supplied

Carcinoma of the pancreatic head area. Therapy: intraluminal brachytherapy.

Intraluminal brachytherapy (Il-BRT) consists in the treatment of neoplasms by the positioning of radioactive sources in the lumen of cavitary organs such as the esophagus, the trachea, the bronchi and bile ducts. This procedure has been used to deliver relatively high doses of irradiation to bile duct and periampullary carcinomas while sparing the adjacent organs. Results of a number of reports appeared in the last fifteen years document the feasibility and tolerance of the procedure. Moreover these data seem to suggest that Il-BRT is able to prolong the survival of patients undergoing biliary drainage and that its use as boost dose in external beam radiotherapy (ERT) enhances the results of the latter. Combined ERT+Il-BRT is associated to an incidence of gastrointestinal ulcerations related to the total dose delivered. Better patient selection and standardization of reference dose represent prerequisites for testing this procedure in prospective randomized trials.

Brachytherapy↗
PubMedDate not supplied

Carcinoma of the pancreatic head area. Therapy: concomitant radiochemotherapy.

A series of studies carried out by the Gastrointestinal Tumor Study Group have shown the efficacy of the combination of external beam radiotherapy (ERT) and 5-fluorouracil (5-FU) chemotherapy (CHEM) in unresectable and resectable tumors of the exocrine pancreas. In the former in particular, this method was shown to be superior to ERT alone as well as to polychemotherapy alone. In these studies 5-FU was administered during (concomitant chemotherapy: C-CHEM) or after ERT (adjuvant chemotherapy: A-CHEM). This led several authors to consider this combined treatment as reference standard for pancreatic carcinoma. Its prognosis is still definitely poor because of the difficult local eradication as well as because of the frequent early distant spread, especially at the abdominal level (hepatic and peritoneal). An improvement of present results may stem from the combination of ERT+C-CHEM +/- A-CHEM with methods of dose intensification at the local level (e.g. IORT) concurrently with the use of treatments aiming at a better control of the abdominal spread (e.g. ERT+C-CHEM for prophylaxis of the liver or upper abdomen).

Antimetabolites, Antineoplastic↗
PubMedDate not supplied

Radiation therapy information systems (RTISs): state of the art and new perspectives.

Information technology in radiotherapy finds three separate fields of application: direct computerization is essentially aimed at the conformation of target volume. It is present in devices used for treatment planning and execution. Indirect computerization is essentially aimed at the acquisition of patient's data relevant to the routine and clinical management and at the ready access to the acquired information. Communication networks are intended to facilitate the definition of the patient's integrated reporting, to optimize available resources and multicentric research. Present information technology in radiotherapy is based on the need for a radiation therapy information system (RTIS). It should be designed as a transverse access between the various subsystems, unified in planning, even if implemented at different times and with different technologies, ready to work on a geographic scale, now feasible with the international communication networks.

Computer Communication Networks↗
PubMedDate not supplied

Quality assurance in radiotherapy of neoplasms of the upper abdomen.

Neoplasms of the upper abdomen involve complex problems for radiotherapy. In fact, the anatomical structures are close to each other, lymphatic vessels are numerous and complex, there are organs of low radiation tolerance whose reciprocal position is of difficult assessment and finally there is high visceral mobility due to the diaphragmatic movements. Moreover most organs cannot be identified with the simulator and bone references are of little use. Therefore, treatment of these sites requires the routine application of quality assurance programs, checks of treatment reproducibility, in particular: In a number of clinical settings, CT study of the region (in treatment position) must be included in treatment planning and set-up with simulator and fluoroscopy. Before, during, and after radiotherapy, clinical exams and laboratory tests should be performed to assess the integrity of critical organs.

Abdominal Neoplasms↗
PubMedDate not supplied

Quality assurance in radiotherapy of prostatic cancer.

External beam radiotherapy is a widely experimented treatment modality in prostatic cancer. Recently published studies have documented a close dependence of clinical results, in terms of local control and toxicity in particular, on radiation therapy quality. Efforts to improve results of conventional radiotherapy were directed towards the identification of new therapeutic modalities (conformal therapy, fast neutron radiotherapy, neoadjuvant hormonotherapy) as well as towards the optimization of treatment accuracy. In this respect, the following procedures have been particularly effective: 1. the systematic use of CT and retrograde urethrography in PTV definition; 2. immobilization systems which allow a significant reduction in positioning errors; 3. checks before and during treatment by "portal imaging" which allow the identification and correction of a relevant percentage of inaccuracies. The general evolution in treatment planning occurred in recent years has introduced into prostatic cancer radiotherapy new methods and calculation algorithms. While at present the use of new and at the same time complex techniques makes the need for quality assurance of radiation treatments increasingly critical, it is in any case a daily requirement even in most conventional routine treatments.

Humans↗