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. In Institute A, patients were treated in a prone position, utilizing an individualized immobilization cast (either an alpha cradle or a heat and vacuum-formed cellulose acetate cast) with an open table top and individual abdominal wall compressor to minimize small bowel irradiation; a 5-field conformal technique was used. In Institute B, patients were treated in a supine position without any immobilization device; a 6-field BEV-based technique (conformal only for patients treated with a radical aim) was adopted. A total of 598 portal films (420 from Institute A and 178 from Institute B) were analyzed. The mean number of films per patient was 12 (range, 4-29). Systematic and random setup errors were estimated utilizing the statistical method suggested by Bijhold et al. (1992).

RESULTS

When patients with a mean (systematic) error larger than 5, 8 and 10 mm in craniocaudal, lateral and posterior-anterior directions, respectively, were compared, no statistically significant difference between the two groups was observed. Similarly, when comparing portal films, a significant difference (P <0.01) appeared only in the craniocaudal direction (errors > 5 mm: Institute A = 24%; Institute B = 11%). In both Institutes, the SD of random and systematic error distribution ranged from 1.8 to 4.2 mm, with a small prevalence of systematic errors. Only for craniocaudal shifts in Institute A was the random error larger than the systematic error, and it was significantly worse than in Institute B (1 SD, 4.2 mm in Institute A vs 1.8 mm in Institute B).

CONCLUSIONS

Setup errors observed in Institutes A and B were similar and in accord with data reported in the literature. In Institute B, satisfactory geometrical treatment quality was achieved without patient immobilization. In Institute A, the goal of minimizing small bowel irradiation and prostate motion through the aforementioned technique, which makes patient position less comfortable, did not seem to considerably increase daily setup uncertainty.

Burkholderia puraquae sp. nov., a novel species of the Burkholderia cepacia complex isolated from hospital settings and agricultural soils

Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). These opportunistic pathogens are also widely distributed in natural and man-made environments. After a 12-year epidemiological surveillance involving Bcc bacteria from respiratory secretions of Argentinean patients with CF and from hospital settings, we found six isolates of the Bcc with a concatenated species-specific allele sequence that differed by more than 3 % from those of the Bcc with validly published names. According to the multilocus sequence analysis (MLSA), these isolates clustered with the agricultural soil strain, Burkholderia sp. PBP 78, which was already deposited in the PubMLST database. The isolates were examined using a polyphasic approach, which included 16S rRNA, recA, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), DNA base composition, average nucleotide identities (ANIs), fatty acid profiles, and biochemical characterizations. The results of the present study demonstrate that the seven isolates represent a single novel species within the Bcc, for which the name Burkholderia puraquae sp. nov. is proposed. Burkholderia puraquae sp. nov. CAMPA 1040^T (=LMG 29660^T=DSM 103137^T) was designated the type strain of the novel species, which can be differentiated from other species of the Bcc mainly from recA gene sequence analysis, MLSA, ANIb, MALDI-TOF MS analysis, and some biochemical tests, including the ability to grow at 42 °C, aesculin hydrolysis, and lysine decarboxylase and β-galactosidase activities.

[Cystic Fibrosis Cloud database: An information system for storage and management of clinical and microbiological data of cystic fibrosis patients]

The epidemiological and clinical management of cystic fibrosis (CF) patients suffering from acute pulmonary exacerbations or chronic lung infections demands continuous updating of medical and microbiological processes associated with the constant evolution of pathogens during host colonization. In order to monitor the dynamics of these processes, it is essential to have expert systems capable of storing and subsequently extracting the information generated from different studies of the patients and microorganisms isolated from them. In this work we have designed and developed an on-line database based on an information system that allows to store, manage and visualize data from clinical studies and microbiological analysis of bacteria obtained from the respiratory tract of patients suffering from cystic fibrosis. The information system, named Cystic Fibrosis Cloud database is available on the http://servoy.infocomsa.com/cfc_database site and is composed of a main database and a web-based interface, which uses Servoy's product architecture based on Java technology. Although the CFC database system can be implemented as a local program for private use in CF centers, it can also be used, updated and shared by different users who can access the stored information in a systematic, practical and safe manner. The implementation of the CFC database could have a significant impact on the monitoring of respiratory infections, the prevention of exacerbations, the detection of emerging organisms, and the adequacy of control strategies for lung infections in CF patients.

[Pertussis predictors in hospitalized infants with acute lower respiratory tract infection]

BACKGROUND

Pertussis, or whooping cough, caused by Bordetella pertussis (BP) is a re-emerging problem in our environment. Although generally considered that the disease is relatively easy to identify infections respiratory syncytial virus (RSV) can present with similar symptoms in infants remains difficult discrimination.

OBJECTIVE

Compare clinical symptoms at admission and complementary studies in infants hospitalized with acute respiratory infection (ARI) and RSV by BP to establish markers that enable their early clinical prediction.

MATERIALS AND METHODS

Observational, analytical, case-crossover cross comparing younger than 6 months hospitalized with suspected IRA and pertussis (2007-2012) in which BP identified (PCR and culture) and / or VRS (immunofluorescence in nasal secretions). Coinfections were excluded. Bivariate analysis was performed by calculating OR with 95% CI. Were considered significant at p <0.05. The variables studied were age, sex, hits cough, cyanosis, vomiting, apnea, wheezing and CBC with differential

RESULTS

We included 174 infants, 72 (41%) BP and 102 (59%) VRS. Age 2 ± 1 months (range :1-6). In both groups was documented cough and wheeze (OR: 1.2 (0.9 to 1.5) p: 0.1 and OR = 0.9 (0.8 to 1.06) p: 0.2, respectively ). Cyanosis (87% vs. 6%, OR: 14.8 p <0.01), apnea (38% vs. 3%, OR: 13.4 p <0.01) and vomiting (26% vs. 5% , OR: 3.4 p <0.01) were more frequent in infants with BP. The absolute lymphocyte count was significantly higher in children with BP (9387 ± 6317 vs. 5127 ± 2766, p <0.01). By ROC curve was identified at 9000 cells / ml as the best point to differentiate VSR BP (AUC = 0.73, 95% CI :0,64-0, 81).

CONCLUSIONS

In infants under 6 months with IRA income presence of apnea, cyanosis and lymphocytosis allowing predict significantly differentiate between pertussis those with RSV infections.

Clinical target volume localization using conventional methods (anatomy and palpation) and ultrasonography in early breast cancer post-operative external irradiation

PURPOSE

To evaluate the accuracy of three methods, anatomy (A), palpation (P) and ultrasounds (US) in localizing the clinical target volume (CTV) in patients (pts) with early breast cancer (EBC) undergoing breast external irradiation as part of conservation therapy.

MATERIAL AND METHODS

One hundred consecutive pts with EBC (T(is) 1%, T1 78%, T2 21%, N- 68%, N+ 32%), treated with conservation surgery and breast irradiation with opposed tangential portals, were prospectively analyzed. Anatomically, palpatory or ultrasound defined field borders for CTV localizations were determined in the same position thanks to the utilization of a vacuum-formed cellulose acetate immobilization cast, removed during CTV definitions.

RESULTS

P and US CTV localizations have been found to coincide on the four margins (superior, inferior, medial, lateral) in only 1/100 pts, while no pt showed identical A and US CTV localizations. Only 31/397 (8%) field measurements with A, and 98/395 (25%) with P corresponded to US border definition. If mean and median values of each field border were considered, the CTV was generally overestimated with P appearing more accurate than A in a gross definition of the target (P < 0.01). However, a geographical miss of at least one field border of CTV occurred in 55% of pts with A and in 36% of pts with P. The most critical margin to be defined with conventional methods was the superior one: an underestimation of the cranial border of CTV with A was observed in 51% and with P in 22% of pts (22% and 8%, respectively, when an underestimation by more than 1.5 cm was considered). When pre-menopausal and peri/post-menopausal groups of pts were separately analyzed, conventional methods were highly inaccurate to define the superior border in younger pts, in which a geographical miss was noted with A in 62% and with P in 35% of cases (P < 0.05). When an underestimation of more than 1.5 cm was evaluated, these values were reduced to 33% and 12%, respectively (P = 0.02). Also, in the subgroup of pre-menopausal patients the CTV defined by palpatory reference lines appeared to be more accurate than A-method (P < 0.01).

CONCLUSIONS

Conventional methods frequently appear inadequate to localize residual mammary gland in EBC post-operative external irradiation. This analysis evidentiates the inaccuracy of empirical CTV definition, and suggests that palpation or anatomical reference borders should be critically used and that state of art imaging methods should be included in treatment planning, particularly in pre-menopausal pts. If economical or individual variables have to be taken into account, palpation might be considered in post-menopausal women.

[Clinical and methodological aspects of quality assurance in external radiotherapy: optimization of radiotherapy in early cancer of the breast]

Since 1988, a specific physical and clinical quality assurance program for external whole breast irradiation has been activated in our department. Three areas of clinical investigation and related audit loops are analyzed to show our policy to improve the quality of patient care. Quality control procedures deal with (a) the evaluation of the adequacy of conventional methods of clinical target volume (CTV) localization, (b) the evaluation of the adequacy of the conventional method of determining the planning target volume (PTV) and (c) the systematic and objective assessment of acute and late side-effects. Corrective actions to maintain or meet the standards are also reported. The localization of residual mammary gland using conventional methods (anatomy and/or palpation) was compared in 100 patients with US localization: conventional methods were often inadequate and thus the use of US in PTV determination is necessary. Portal film analysis helped reduce ideal margins from 20 mm to 11 mm. The amount of irradiated ispilateral lung, retrospectively calculated in 88 consecutive patients, appeared adequate to the chosen reference standard. The systematic study of late skin reactions had shown in some patients telangectasia regions outside the boost area: since 1991, a corrective action, decreasing the thickness of the customized immobilization cast inside the treatment area, from 2 mm to 0.2 mm, has been adopted. These examples show that the routine application of quality assurance procedures can help optimize radiation treatment.

Hyperfractionated radiotherapy and concomitant cisplatin in stage III non-small cell lung cancer: a phase II study by the AIRO-Lombardia Cooperative Group

A multicenter Phase II study was performed by the AIRO-Lombardia Cooperative Group on 36 patients with Stage III non-small cell lung cancer. The treatment schedule included hyperfractionated radiotherapy, 1.2 Gy twice daily (5 days/week) up to a total dose of 69.6 Gy, and concomitant cisplatin by continuous infusion using a portable pump, 16 mg/m2/week for 6 weeks. Overall, adequate treatment (defined as a total dose > 66 Gy in < 46 days and 6 weeks of infusional cisplatin) was received by 56% of accrued patients. Response was complete in 6% and partial in 56% of patients; median survival was 8 months and 1-year survival rate was 37%. Site of first failure was local in 43%, distant in 43%, local and distant in 10% and unknown in 3% of failing patients. Grade 3 esophagitis was recorded in 14% of patients and a fatal case of late pulmonary toxicity was reported. On the basis of feasibility, toxicity and survival results, the planned extension to Phase III was abandoned by the Group.

Introducing the Sick of Smoking Program to South Australian GPs. The results of peer-led small group educational sessions

In South Australia 288 general practitioners were trained in the use of a minimal intervention stop smoking program. Follow up 8 months later indicated widespread incorporation into practice. It was estimated that use of the program resulted in a cost of less than $24 for each smoker who ceased.

Quality control in the conservative treatment of breast cancer: patient dosimetry using silicon detectors

Twenty patients with early breast cancer were treated with external irradiation, delivered with two tangential beams (6 MV X-rays) using a half-beam block (HBB) and 3-D compensating filters. All patients were immobilized with individualized cellulose acetate casts. Patient dosimetry was performed using p-type silicon detectors. Midline doses were calculated by combined entrance and exit dose measurements. The mean ratio of the measured and the prescribed doses was 96.6 +/- 3.8% at the reference point, 96.8 +/- 4.3% at off-axis points on the central plane and 96.8 +/- 7.6% at off-plane points.

[Postoperative radiotherapy in the treatment of adenocarcinoma of the endometrium in pathological stage I]

We report on 49 patients with pathologic stage I endometrial adenocarcinoma who underwent postoperative whole-pelvis irradiation (RT) (45-50 Gy in 5-6 weeks) from November 1981 to December 1988. RT was performed when one or more of the following unfavorable prognostic factors were discovered: myometrial infiltration greater than 1/3 (42 cases, or 85.7%), poorly-differentiated tumor (10, or 20.4%), tubaric angles involvement (4; or 8.2%), pelvic nodal metastases (1, or 2.0%). Five-year actuarial disease-free survival was 91.4%. After an average follow-up of 58 months, we observed recurrent disease in 4 patients (8.2%) (3 cases with distant metastases, 6.1%; 1 case with vaginal relapse, 2.0%). All recurrences were observed within 18 months from treatment and occurred only in patients with both myometrial infiltration greater than 1/3 and poorly or moderately differentiated tumor. The patient with vaginal relapse had a complete response after endocavitary curietherapy, but died later on from lung metastases. None of the treated patients experienced severe complications related to the treatment. Our results are comparable with those of the most recent literature, and confirm the good tolerance and efficacy of postoperative RT to prevent loco-regional relapses in early stage endometrial cancer with unfavorable prognostic factors.