[Integration of computerized tomography imaging with single photon emission in a commercial system for developing radiotherapy fields: application to conformational irradiation for lung carcinoma].

Purpose: Single photon emission computed tomography (SPECT) of lung perfusion permits to map functioning lung parenchyma with higher sensitivity than CT. Delivering higher radiation doses is used to increase local control in lung carcinoma; this strategy is based on radiobiological and clinical studies. Lung parenchyma is a dose-limiting tissue in patients irradiated for lung cancer.

Use of dose-volume histograms and biophysical models to compare 2D and 3D irradiation techniques for non-small cell lung cancer.

For non-small cell lung cancer (NSCLC), unsatisfactory local control (LC) still remains an important cause of failure. It has been suggested that improved LC can be achieved with both higher radiation dosage and adequate target coverage. Modern three-dimensional treatment planning systems (3D-TPSs) offer many tools for planning optimization.

Dosimetry of Gamma Knife and linac-based radiosurgery using radiochromic and diode detectors.

In stereotactic radiosurgery the choice of appropriate detectors, whether for absolute or relative dosimetry, is very important due to the steep dose gradient and the incomplete lateral electronic equilibrium. For both linac-based and Leksell Gamma Knife radiosurgery units, we tested the use of calibrated radiochromic film to measure absolute doses and relative dose distributions. In addition a small diode was used to estimate the relative output factors.

Quality control by portal film analysis in radiotherapy for prostate cancer: a comparison between two different institutions and treatment techniques.

Aims And Background: Accuracy and reproducibility of patient setup during radiotherapy for prostate cancer were investigated in two different Institutions (A and B), within their Quality Assurance programs. The purpose of the study was to evaluate and compare setup accuracy and reproducibility in Institutions A and B, which adopt different patient positioning and treatment techniques for prostate irradiation.

Materials And Methods: A retrospective analysis of portal localization films taken during the treatment course was performed: 30 and 21 patients in Institutes A and B, respectively, entered the study.

Set-up error in supine-positioned patients immobilized with two different modalities during conformal radiotherapy of prostate cancer.

Background: Conformal radiotherapy requires reduced margins around the clinical target volume (CTV) with respect to traditional radiotherapy techniques. Therefore, high set-up accuracy and reproducibility are mandatory.

Purpose: To investigate the effectiveness of two different immobilization techniques during conformal radiotherapy of prostate cancer with small fields.

Intra- and inter-observer variability in contouring prostate and seminal vesicles: implications for conformal treatment planning.

Background And Purpose: Accurate contouring of the clinical target volume (CTV) is a fundamental prerequisite for successful conformal radiotherapy of prostate cancer. The purpose of this study was to investigate intra- and inter-observer variability in contouring prostate (P) and seminal vesicles (SV) and its impact on conformal treatment planning in our working conditions.

Materials And Methods: Inter-observer variability was investigated by asking five well-trained radiotherapists of contouring on CT images the P and the SV of six supine-positioned patients previously treated with conformal techniques.

Dose calculation and dosimetry tests for clinical implementation of 1D tissue-deficit compensation by a single dynamic absorber.

Background And Purpose: In this study the possibilities for implementing 1D tissue-deficit compensation techniques by a dynamic single absorber were investigated. This research firstly involved a preliminary examination on the accuracy of a pencil beam-based algorithm, implemented for irregularly shaped photon beams in our 3D treatment planning system (TPS) (Cadplan 2.7, Varian-Dosetek Oy), in calculating dose distributions delivered in ID non-uniform fields.

Laparoscopic hernia repair: a prospective comparison of TAPP and IPOM techniques.

The aim of the study was to evaluate the safety and efficacy of two techniques of laparoscopic hernia repair: the transabdominal preperitoneal technique (TAPP) and the intraperitoneal onlay mesh technique (IPOM). In May 1992 a prospective randomized trial was initiated to compare TAPP and IPOM. Until October 1994, 115 patients with 148 hernias took part in the trial (59 TAPP and 56 IPOM).

Detection of systematic errors in external radiotherapy before treatment delivery.

The execution of an independent control of monitor units (MU) and dose distribution calculation, together with a check of the data reported in the treatment chart is an effective tool in strongly reducing the occurrence of systematic errors before treatment delivery. In this paper we report the results of the analysis of 6272 controls (about 5000 patients) registered over more than 5 years; 70 serious errors (producing a deviation larger than 5% from the prescribed daily dose) and 147 minor errors were detected and corrected before the start of the treatment. The error rate was found to be strongly operator-dependent (serious error rate ranging from 0.

Reduced postoperative morbidity after elective laparoscopic cholecystectomy: stratified matched case-control study.

To answer the question whether laparoscopic cholecystectomy (LC) or open cholecystectomy (OC) is safer in terms of complications and to what extent the "learning curve" influences the frequency of complications after LC, we conducted a matched case-control study. First, 200 patients undergoing LC (LC group A), and two groups of 200 patients undergoing LC at two different periods of the learning curve (LC groups B and C) were matched, taking into account sex, age, anesthesiologic risk, and surgical difficulties. We evaluated the frequency and grade of postoperative complications of these patients and of the last 200 patients undergoing OC before the introduction of LC, retrospectively matched with the LC groups.

Variations of tumor control and rectum complication probabilities due to random set-up errors during conformal radiation therapy of prostate cancer.

Background And Purpose: The effect of random set-up errors on tumor control probability (TCP) and rectum complication probability (NTCP) on 3D conformal treatment planning of prostate cancer has been investigated by applying the convolution method originally proposed by Leong (Leong, J. Implementation of random positioning error in computerized radiation treatment planning systems as a result of fractionation. Phys.

Comparing 3-, 4- and 6-fields techniques for conformal irradiation of prostate and seminal vesicles using dose-volume histograms.

Background And Purpose: Comparing some isocentric coplanar techniques for conformal irradiation of prostate and seminal vesicles.

Materials And Methods: Five conformal techniques have been considered: (A) a 3-fields technique with an antero-posterior (AP) field and two lateral (LAT-LAT) 30 degrees wedged fields; (B) a 3-fields technique with an AP field and two oblique posterior (OBL) 15 degrees wedged fields with relative weights of 0.8, 1 and 1, respectively; (C) a 4-fields technique (AP-PA and LAT-LAT); (D) a 6-fields technique (LAT-LAT and four OBL at gantry angles 45 degrees, 135 degrees, 235 degrees and 315 degrees) with all the fields having the same weight; (E) the same 6-fields technique with lateral fields double-weighted with respect to the oblique fields.

Monitor unit calculation in 6 MV irregularly shaped beams--accuracy in clinical practice.

The results of an investigation of the accuracy of monitor unit (MU) calculation in clinical shaped beams are presented. Measured doses at the reference depth on the beam central axis (isocentre) or on a beam axis representative of the irradiated area (when the isocentre lies under a block or near the edges of the block's shadow) were compared with the expected doses when calculating MUs, by applying different methods normally used in clinical practice. Empirical (areas weighted, Wrede) and scatter summation (Clarkson) methods as well as a pencil-beam based algorithm were applied.

[The quality of life of the geriatric patient after a surgical intervention. VI. Interventions on the biliary tract].

After reviewing the literature on this subject, the authors examine the quality of life of geriatric patients after biliary tract surgery secondary to biliary tract carcinoma or non-neoplastic pathologies. From an analysis of the results the authors conclude that surgery is useful not only in non-neoplastic forms, but also in the event of carcinoma given that it is possible to improve the quality of life of these patients.

Optimizing the movement of a single absorber for 1D non-uniform dose delivery by (fast) simulated annealing.

A new simplified technique for 1D non-uniform dose delivery using a single dynamic absorber, driven by a computer system, has been recently proposed together with a simple analytic algorithm. This technique uses an optimized 'stepped' absorber's speed profile and the generated fluence profile is an approximation of the desired radiation beam. In the case of non-uniform beam profiles with multiple maxima/minima, the original proposed 'stepping algorithm' has some limitations and produces a too rough approximation of the desired profiles.

[Quality of life in geriatric patients after surgery. Note V. Pancreatic surgery].

After a brief review of the literature on this topic, the authors examine the Quality of Life in patients undergoing surgery for neoplasia of the pancreas. They found that radical pancreatic surgery for cancer in elderly patients produced better results than hepatic surgery, even if the death rate was again very high (45.95%).

On-line exit dose profile measurements by a diode linear array.

The possibility of using a commercial diode linear array (BMS Schuster Inc.) in on-line portal dosimetry has been investigated. The system is composed of 88 equispaced diodes (distance between diodes, 0.

Efficacy and safety of the standardised Ginseng extract G115 for potentiating vaccination against the influenza syndrome and protection against the common cold [corrected].

The aim of the study was to determine the properties of a standardized extract of ginseng root in inducing a higher immune response in vaccination against influenza. Attention was also paid to the common cold in this multicentre, two-arm, randomized, placebo-controlled, double-blind investigation. A total of 227 volunteers who visited 3 private practices in Milan received daily oral capsule doses of either placebo (113) or 100 mg of standardized ginseng extract Ginsana G 115 (114) for a period of 12 weeks within which they received an anti-influenza polyvalent vaccination at week 4.

Dynamic beam modulation by using a single computer-controlled absorber.

The authors have developed an apparatus able to generate ID intensity-modulated beams, using only one moving absorber within the irradiation field. A procedure for deriving optimized absorber-speed profiles in order to produce the desired fluence/dose profiles has been suggested. Experimental tests show that the system should be sufficiently reliable in reproducing modulated beam profiles of different shape: expected relative doses against measured relative doses have been found to be in agreement in a number of situations within 3% using a nonfocused device.

The role of intraoperative therapy by electron beam and combination of adjuvant chemotherapy and external radiotherapy in carcinoma of the pancreas.

Aims And Background: In the treatment of pancreatic carcinomas, one modality is intraoperative radiotherapy (IORT). A study was carried out to assess the feasibility of IORT alone or in a multimodality approach with postoperative adjuvant chemotherapy and external radiotherapy and to compare local control and survival of patients. Another objective of this retrospective study was to verify prognostic factors in resected patients treated with IORT.

[Extended resection in colorectal cancer. Personal experience].

At the moment of surgical intervention, colorectal cancer involves adjacent tissues or organs in a percentage of cases ranging between 5% and 12%. "En bloc" resection of these tumors, when not associated with distant metastasis, allows survival at 5 years in from 32% to 79% of cases. The authors discuss their personal experience on the subject of extended resection for carcinoma of the large intestine, in order to evaluate not only the possible anatomico-clinical peculiarities but also both short and long term results.

[Quality of life of the aged after surgery. 3. Hepatic carcinoma].

Following a review of the literature on this topic, the authors examine the quality of life in elderly patients who have undergone hepatic resection due to carcinoma in the past 5 years. An analysis of the results obtained showed that there was 20% wellbeing in right hepatectomized patients, only 14.29% in left hepatectomized and bisegmentectomized patients, and 11.