Biomedical subjects

V Vavassori

Publications and source records attributed to V Vavassori.

10 recordsLinked to original sources

PubMed2004

Fitting late rectal bleeding data using different NTCP models: results from an Italian multi-centric study (AIROPROS0101).

BACKGROUND AND PURPOSE: Recent investigations demonstrated a significant correlation between rectal dose-volume patterns and late rectal toxicity. The reduction of the DVH to a value expressing the probability of complication would be suitable. To fit different normal tissue complication probability (NTCP) models to clinical outcome on late rectal bleeding after external beam radiotherapy (RT) for prostate cancer. PATIENTS AND METHODS: Rectal dose-volume histograms of the rectum (DVH) and clinical records of 547 prostate cancer patients (pts) pooled from five institutions previously collected and analyzed were considered. All patients were treated in supine position with 3 or 4-field techniques: 123 patients received an ICRU dose between 64 and 70 Gy, 255 patients between 70 and 74 Gy and 169 patients between 74 and 79.2 Gy; 457/547 patients were treated with conformal RT and 203/547 underwent radical prostatectomy before RT. Minimum follow-up was 18 months. Patients were considered as bleeders if showing grade 2/3 late bleeding (slightly modified RTOG/EORTC scoring system) within 18 months after the end of RT. Four NTCP models were considered: (a) the Lyman model with DVH reduced to the equivalent uniform dose (LEUD, coincident with the classical Lyman-Kutcher-Burman, LKB, model), (b) logistic with DVH reduced to EUD (LOGEUD), (c) Poisson coupled to EUD reduction scheme and (d) relative seriality (RS). The parameters for the different models were fit to the patient data using a maximum likelihood analysis. The 68% confidence intervals (CI) of each parameter were also derived. RESULTS: Forty six out of five hundred and forty seven patients experienced grade 2/3 late bleeding: 38/46 developed rectal bleeding within 18 months and were then considered as bleeders The risk of rectal bleeding can be well calculated with a 'smooth' function of EUD (with a seriality parameter n equal to 0.23 (CI 0.05), best fit result). Using LEUD the relationship between EUD and NTCP can be described with a TD50 of 81.9 Gy (CI 1.8 Gy) and a steepness parameter m of 0.19 (CI 0.01); when using LOGEUD, TD50 is 82.2 Gy and k is 7.85. Best fit parameters for RS are s=0.49, gamma=1.69, TD50=83.1 Gy. Qualitative as well as quantitative comparisons (chi-squared statistics, P=0.005) show that the models fit the observed complication rates very well. The results found in the overall population were substantially confirmed in the subgroup of radically treated patients (LEUD: n=0.24 m=0.14 TD50=75.8 Gy). If considering just the grade 3 bleeders (n=9) the best fit is found in correspondence of a n-value around 0.06, suggesting that for severe bleeding the rectum is more serial. CONCLUSIONS: Different NTCP models fit quite accurately the considered clinical data. The results are consistent with a rectum 'less serial' than previously reported investigations when considering grade 2 bleeding while a more serial behaviour was found for severe bleeding. EUD may be considered as a robust and simple parameter correlated with the risk of late rectal bleeding.

Combined Modality Therapy↗

PubMed1994

Role of postoperative radiation therapy in the management of early stage primary gastric non-Hodgkin's lymphomas: a retrospective analysis.

BACKGROUND: Clinical approaches to early primary gastric non-Hodgkin's lymphomas have not yet been clearly defined, and the role of postoperative radiotherapy remains a matter of discussion. METHODS: Twenty-seven patients with early primary gastric non-Hodgkin's lymphoma were observed from December 1978 to December 1990 at our Institution. They were staged according to Musshoff and Schmidt-Volmer (19) as I E (n = 16), II E 1 (n = 7) and II E 2 (n = 4). All of them underwent local combined treatment, consisting of surgery and postoperative radiotherapy; chemotherapy was also administered to 10 patients, mainly with the CHOP regimen, for 4-6 cycles before radiotherapy. Irradiation was delivered using 10 MV photons from a linear accelerator. Large abdominal fields were employed in 21 cases with daily fractions of 1.5-2 Gy up to a median total dose of 30 Gy (range: 27-36 Gy). Six patients were irradiated only on the surgical bed up to 40.5 Gy (range: 39-40.5 Gy). RESULTS: The 5-year overall and disease-free survivals were respectively 92.4% and 89.8%. The main known prognostic indicators, stage of disease, type of surgery as well as age and sex, were not found to be statistically significant in our series. No clear difference emerged between patients sequentially treated with the combination surgery-chemotherapy-radiotherapy and those who did not receive adjuvant chemotherapy. Two patients recurred at distant sites, but no local failure was seen during the follow-up. CONCLUSIONS: Although no firm conclusion can be drawn, our experience, in agreement with recent published reports, points out that the use of postoperative radiotherapy is associated not only to favorable results in terms of local control and survival, but also, and moreover, to a negligible incidence of side effects and sequelae. However, in the absence of multi-institutional prospective randomized studies, whose activation is nowadays strongly warranted, the exact role of adjuvant therapies remains a matter of discussion, and the optimal treatment of early primary gastric non-Hodgkin's lymphoma still depends on individual experience and the physician's philosophy.

Adult↗

PubMed1994

The role of radiotherapy in the treatment of stage III non-small cell lung cancer: a survey of clinical practices in Lombardy, Italy, by the Airo*-Lombardia Cooperative Group.

AIMS AND BACKGROUND: The role of radiotherapy in the treatment of stage III non-small cell lung cancer is controversial. The aim of this survey was to investigate the use of this modality in current clinical practice in Lombardy, a highly industrialized region of northern Italy. METHODS: A questionnaire was sent to all 13 radiotherapy centers in Lombardy, covering statistical, clinical, technical and strategical aspects, and the responses were analyzed. RESULTS: A wide range of attitudes was observed among participating radiation oncologists; the percentage of cases treated with curative intent varied largely between centers (4-100%), as did the proportion of patients given to radiation only rather than combined modality treatment (5-100% vs 0-90%). CONCLUSIONS: An urgent need exists for better cooperation between all clinicians involved in lung cancer treatment, pursuing the goals of a more uniform clinical practice and a more aggressive clinical research attitude.

Carcinoma, Non-Small-Cell Lung↗

PubMed1992

Postoperative radiation therapy for adult soft tissue sarcomas: a retrospective study.

From 1977 to 1988, 81 adult patients with localized soft tissue sarcomas at different sites received postoperative external beam radiotherapy (55 Gy median dose) following primary conservative surgery. Sixty were new referrals after primary surgery and 21 were irradiated after excision of recurrent disease. With a median follow-up of 4 years (range: 2-13) the 5-year overall survival (Kaplan-Meier) and local control were 55.5% and 56% respectively, while 5-year disease-free survival is 49%. There were 26 (32%) local relapses and 22 (27%) distant failures. Local recurrence was the sole pattern of failure in 16 patients (20%). Functional and cosmetic results were good to excellent in most cases. In our series local control is the main prognostic variable influencing survival (P less than 0.0001), and its probability seems to show a link with the type of surgical procedure, with a trend (P less than 0.13) in favor of wide total excision. Postoperative radiation therapy represents an acceptable treatment strategy for ASTS, but further improvements are expected from future controlled clinical trials, aiming at the achievement of the definitive cure of these tumors.

Adult↗

PubMed1991

[Radiotherapy in the combined therapy of limited stage pulmonary microcytoma. The experience of the Department of Oncologic Therapy at the Multiregional Hospital of Varese (1980-1989)].

From January 1980 to December 1989, 86 patients with limited small cell lung carcinoma (SCLC) were treated in our Institution. Sixty-eight of them were males, 18 females; mean age was 58 years (range: 40-74); Karnofsky index was 80 or higher. All patients received induction multiagent chemotherapy (CAV or CAVE), usually fractionated into 3/4 cycles. Radiotherapy was administered by means of a 10 MV Linear Accelerator, 2-3 Gy/day, 5 days/week. Radiation dose was 60 Gy for 39 patients, 50 Gy for 25 patients, and 30 Gy for 22 patients. Parallel opposed fields (AP and PA) were used for administering the 30-Gy dose, while higher doses were delivered by multiportal arrangement (3/4 fields). Overall survival (corrected Kaplan-Meier) was 21.3% and 13.4% at 2 and 3 years, respectively; 2 years' survival according to dose was 24.5% for 60 Gy, 19.9% and 11% for 50 and 30 Gy, respectively. Mean survival time (MST) was 14 months for 60 Gy, 13 months and 10 months, respectively, for 50 and 30 Gy. Survival and disease-free survival rates were similar in patients who received 50 and 60 Gy. No major complications related to irradiation were observed, not even in the group receiving the highest dose. Our data are similar to those reported in the literature.

Brain Neoplasms↗

PubMed1991

[Exclusive radiotherapy of carcinoma of the hypopharynx. Retrospective study of a series of 100 patients].

From January 1980 to December 1987, 100 patients with carcinoma of the hypopharynx, staged according to TNM (UICC-1978) criteria, received exclusive radiation therapy at the Radiotherapy Department of the General Hospital of Varese. The median follow-up is 9 months (range: 1-97). Irradiation was delivered with 60Co or with 10 MV photons and tissue-equivalent bolus. Two opposed parallel lateral fields or rotational technique were used, with progressive shrinking of treated volume in order to spare the spinal cord after 45 Gy. Direct fields of electron beams (6-15 MeV) were employed as boosts on the residual nodes. Median total doses: 64.5 Gy to T and N1-3, 45 Gy to N0. A conventional fractionation (2 Gy once a day, 5 times a week) was used in 37 outpatients, while an accelerated hyperfractionated regimen (1.5 Gy twice a day, 5 times a week, with a six hours' interval between each fraction) was employed in 63 inpatients, in order to shorten hospitalization. The five-year overall survival (Kaplan-Meier) of the 100 treated patients is 10%, while the five-year disease-free survival of the 40 patients in complete clinical remission at the end of radiation therapy is 19.8%. The five-year loco-regional control rate after exclusive radiotherapy is 19.1%. Complete remission at the end of treatment seems to represent the only significant prognostic variable affecting survival: five-year overall survival is 32% for the 40 patients achieving complete remission and only 4.4% for the others (p less than 0.05). On the contrary, tumor extension (T class) seems to affect only the two-year local control rate: 35.2% and 10.9% for T1 + T2 and T3 + T4 respectively (p less than 0.1). The main cause of failure after radiation therapy is represented by the lack of control at the primary site (T) alone or associated with regional adenopathies (N). The analysis of isoeffect parameters, according to CRE model, has not shown any evident dose-response relationship for local control. Late effects were observed in 7% of the patients and were similar to those reported in the literature. The occurrence of both distant metastases, 3% in our experience, and secondary tumors (9%) is lower than those previously reported. The present retrospective study strongly reconfirms the inadequacy of exclusive radiation therapy as the sole treatment modality for carcinoma of the hypopharynx and suggests the need of combination therapy (surgery and radiation) as primary treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1988

[Definitive radical radiotherapy in tumors of the prostate. Analysis of statistics].

The records were analyzed of 50 patients treated by definitive external beam irradiation for carcinoma of the prostate in the Oncologic Radiotherapy Department of the "Ospedali Riuniti" of Bergamo, Italy, from January 1981 to December 1985. Our series of patients included 22 cases of stage B and 28 cases of stage C tumors. The actuarial 5-year survival rates, according to the Kaplan-Meier method, were for the whole group 69.9%; 79.5% and 54.9% for stage B and stage C tumors respectively. Relationships were also analyzed of tumor control and survival to stage, grading, and total dose of radiations. The recent increasing interest is explained in the use of radiation therapy in the treatment of this kind of patients. A special emphasis is put on the role of CT in determining both field size and dose distribution, and on the use of high-voltage energy in order to make treatment more technically reliable and reduce its morbidity.

Actuarial Analysis↗

PubMedDate not supplied

Combined modality treatment for esophageal cancer.

This paper describes the mechanisms of action of ionizing radiations combined with antineoplastic drugs. Some relevant drugs for the combined modality treatments of locally advanced lung cancer are reported. The meta-analyses including randomized trials comparing single agent (radiotherapy or chemotherapy) versus combined chemotherapy and radiotherapy in patients with unresectable non small cell lung cancer and limited small cell lung cancer are then reviewed. The clinical outcome in relation to different schedules of chemoradiotherapy (sequential, alternating and concurrent) is also focussed.

Chemotherapy, Adjuvant↗

PubMedDate not supplied

The role of radiotherapy in the treatment of carcinoma of the prostate: a survey of clinical practices in Lombardy, Italy, by the AIRO-Lombardia Cooperative Group. Italian Association for Radiation Oncology.

AIMS AND BACKGROUND: We report the results of a survey performed in 1994 by the AIRO-Lombardia Cooperative Group, on the clinical patterns of radiation treatment for prostatic carcinoma in Lombardy, Italy, involving all radiotherapy centers serving an overall local population of about 8,800,000 people. METHODS: A questionnaire was sent to all 13 radiotherapy centers throughout Lombardy, asking for demographic and treatment details concerning the local population of patients with a localized (T1-4, N0-1, M0) carcinoma of the prostate treated with radiotherapy; 12 centers responded, making the basis for the present report. RESULTS: Analysis of collected data showed that in Lombardy: a) approximately 400 patients per year are irradiated for a localized carcinoma of the prostate, accounting for less than 30% of the total expected number of patients with this disease presentation; b) a complete staging (with PSA, transrectal ultrasonography, abdomino-pelvic CT or MRI scan and total-body bone scan) is performed in over 95% of patients before initiating radiotherapy; c) significant differences exist between radiotherapy centers as regards treatment planning and delivery. CONCLUSIONS: An urgent need exists for implementing procedures aimed at standardizing radiotherapy procedures within Lombardy.

Carcinoma↗

PubMedDate not supplied

Minimal requirements in prostate cancer irradiation: a consensus document by the AIRO Lombardia Cooperative Group.

PURPOSE: With the aim of establishing clinical and technical criteria to homogenize radiotherapy practice, a working group of AIRO-Lombardia (Associazione Italiana di Radioterapia Oncologica--Gruppo regionale della Lombardia) has tried to define minimal requirements for radical and postoperative irradiation in prostate cancer. The document has been structured in such a way as to be also of interest to the urological and medical oncology communities. METHODS: The working group, composed of representatives of most of the regional radiotherapy departments in the Lombardy region, had monthly meetings during 1996 and 1997. The document on minimal requirements has been derived from the participants' combined experience and knowledge, from review of the literature, and from a 1995 regional survey on current practice of prostate irradiation. RESULTS: Minimal requirements for radical and postoperative irradiation of prostate cancer have been defined with respect to treatment strategies, pre-treatment diagnostic evaluation and staging, treatment prescription, preparation and execution, and quality assurance procedures. CONCLUSION: Standards of reference for minimal requirements in prostate cancer irradiation adapted to the regional structures and resources have been defined.

Humans↗