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1.

Aim

To identify factors influencing toxicity in patients affected by localized prostate cancer treated with conformal image-guided radiotherapy.

Background

Image guidance in combination with conformal techniques is the standard of care in localized prostate cancer, but factors affecting toxicity are still under investigation.

Materials and methods

294 patients were analyzed. Median age at diagnosis was 71?year. 76?Gy (38?×?2?Gy) were delivered to the target volume. We used the χ2 test to analyse associations between toxicity and dosimetric and clinical parameters. Multivariate analysis was performed using binary logistic regression. Kaplan–Meier method was used for survival analysis.

Results

Median follow-up was 62.9 months. Acute grade ≥2 gastro-intestinal toxicity (GI) was 12.1%. Acute genito-urinary (GU) toxicity of grade ≥2 was 33.9%. Actuarial 4 and 5 years late grade ≥2 GI was 3% and 4%, respectively. Four and 5-year late grade ≥2 GU toxicity was 6% and 10%. At multivariate analysis for acute toxicity rectal V70 was correlated with GI toxicity (p?=?0.01, HR 2.73 CI 1.19–6.26), and smoking habit with GU toxicity (p?<?0.01, HR 2.50 CI 1.51–4.14). For late toxicity, rectal V70 was correlated with gastro-intestinal toxicity (p?=?0.04, HR 4.76 CI 1.07–21.13), and pre-radiotherapy urinary symptoms with genito-urinary toxicity (p?=?0.01, HR 2.84 CI 1.29–6.22).

Discussion

Conformal image-guided radiotherapy shows low rates of toxicity. Smoking should be avoided during radiotherapy. Besides the evaluation of high doses received by the organs at risk, individual factors, such as co-morbidities and lifestyle choices, have an impact on normal-tissue complication risk.  相似文献   

2.

Aim

To evaluate whether hypofractionation with integrated boost to the tumour bed using intensity-modulated radiation therapy is an acceptable option and to determine whether this treatment compromises local control, toxicity and cosmesis.

Background

Retrospective studies have demonstrated that patients who are treated with HF and integrated boost experience adequate local control, a dosimetric benefit, decreased toxicity and acceptable cosmesis compared with conventional fractionation.

Materials and methods

A retrospective, observational and longitudinal study was conducted from January 2008 to June 2015 and included 34 patients with breast cancer (stage 0–II) who were undergoing conservative surgery.The prescribed doses were 45?Gy in 20 fractions (2.25?Gy/fraction) to the breast and 56?Gy in 20 fractions (2.8?Gy/fraction) to the tumour bed.

Results

Thirty-four patients were included. The mean follow-up was 49.29 months, and the mean age was 52 years. The mean percentage of PTV from the mammary region that received 100% of the prescribed dose was 97.89% (range 95–100), and the mean PTV percentage of the tumour bed that received 100% of the dose was 98% (95–100).The local control and the overall survival were 100%, and the cosmesis was good in 82% of the patients. Grade 1 acute toxicity was present in 16 patients (47%), and grade 1 chronic toxicity occurred in 6 cases (18%).

Conclusion

The results of the present study demonstrate that hypofractionation with integrated boost using intensity-modulated radiation therapy is an acceptable option that provides excellent local control and low toxicity.  相似文献   

3.

Aim

The present retrospective study was to compare toxicity and survival outcomes in a group of low-risk PCa patients treated with either the preoperative planning technique (145?Gy) or the real-time IoP technique (160?Gy).

Background

The two most common permanent seed implantation techniques are preoperative planning (PP) with 145?Gy and real-time intraoperative planning (IoP) with 160?Gy. Although IoP has largely replaced PP at many centres in recent years, few studies have directly compared these two techniques.

Materials and methods

Retrospective study of 408 patients with low-risk PCa treated with permanent seed implant brachytherapy at our institution between October 2003 and December 2014. Of these, 187 patients were treated with PP at a dose of 145?Gy while 221 received real-time IoP with 160?Gy.

Results

At a median follow up of 90 months, 5- and 8-year rates of biochemical relapse-free survival (BRFS) were 94.8% and 86% with the IoP technique versus 90.8% and 83.9%, respectively, with PP. The maximum dose to the urethra was <217?Gy with both techniques. Despite the higher dose, IoP did not cause any significant increase in toxicity (p?=?0.11).

Conclusions

The present study shows that real-time intraoperative brachytherapy at a dose of 160?Gy yield better biochemical control than preoperative planning at 145?Gy. In addition, urinary toxicity did not increase, despite the dose escalation, probably because the dose constraints to the urethra were met despite the increased dose escalation. These findings support the use of real-time IoP.  相似文献   

4.

Aim

This study evaluated the frequency and long-term dynamics of early and late post irradiation damage after proton–photon or photon therapy for locally advanced prostate cancer.

Background

The results of a randomized study of proton–photon or photon therapy using several fractionation regimes were analyzed in 272 patients with high and intermediate risk of progression.

Materials and methods

Three variants of proton boost fractionation were studied sequentially: 3.0 (8 daily fractions), 4.0 (5 fractions, 3 or 5 fractions/week), and 5.5 (3 fractions, 3 fractions/week) Gy(RBE).

Results

A significant decrease in the severity of both acute and late gastrointestinal injuries is achievable with a proton beam. The dynamics of late gastrointestinal and genitourinary toxicity over a 10-year period were generally characterized by a decrease in severity of morbidity by 30% and 15%, respectively.

Conclusions

Local irradiation with a fractional dose of 3.0–5.5 Gy(RBE) and a cumulative dose of 28.0–28.8 Gy(RBE) for protons significantly reduces the early and late rectitis severity, but does not reduce the risk of lower urinary tract injuries. Fractionation regimens do not significantly differ in toxicity levels.  相似文献   

5.

Aim

To develop a tool in order to guide pre-irradiation dental care (PIDC) for patients with oropharyngeal cancers.

Background

Osteoradionecrosis of the jaws is a potential complication of radiotherapy (RT) for head and neck cancers. To prevent this complication, PIDC can involve multiple dental extractions as a preventative measure to avoid post-RT complications. However, there is no standardized tool to guide PIDC.

Materials and methods

From January 2005 to October 2015, 120 head and neck cancer patients were prospectively included in a study investigating dysgeusia after RT. From this cohort, patients were enrolled according to the following inclusion criteria: histopathological confirmation of oropharyngeal squamous cell carcinoma; stage T1-4 N1-3 M0; ≤10 missing teeth. Individual teeth were retrospectively delineated on planning computed tomography and doses to dentition were assessed to generate templates.

Results

Thirty-three patients were included. Molars received highest doses with a mean dose of 50?Gy (range; 19–75?Gy). Ipsi-lateral and contralateral wisdom teeth received RT dose superior to 50?Gy in 92% and 56% of cases, respectively. Patients with advanced disease (T4 or N2c-3) received higher mean doses on inferior and ipsi-lateral dental arches compared to other patients (T1-3 N0-2b): 42?Gy vs. 39?Gy and 44?Gy vs. 39?Gy (p?<?0.05), respectively.

Conclusion

Pre-RT dose distribution templates are an objective way to prepare PIDC. Further studies with a larger cohort are needed to validate these templates.  相似文献   

6.

Aim

To identify clinical and dosimetric factors associated with the development of hematologic toxicity (HT) for cervical cancer (CC) treated with chemotherapy and 3D conformal radiotherapy.

Background

Chemoradiotherapy is the standard of care management for CC patients with IB2-IVA clinical stages (CS). This treatment carries toxicities, standing out the one that occurs at the hematologic level.

Subjects and methods

CC patients with IB2-IVA CS treated with chemotherapy and 3D conformal radiotherapy (50?Gy) plus Brachyterapy (7?Gy x3 or 9?Gy x2) at our institution between March 2016 and March 2017. Clinical and dosimetric factors were studied as was their probable association with the development of HT.

Results

59 patients were analyzed. 89.8% of the subjects developed some grade of HT and 50.2% developed ≥grade 2 toxicity. No statistical relationship was found for the dosimetric factors: V10?>?90% (p?=?0.47) and V20?>?80% (p?=?0.17). Regarding clinical factors: neither age >50 years (p?=?0.88) nor diabetes mellitus (DM) showed statistical relationship with development of ≥grade 2 HT (p?=?0.88 and p?=?0.61, respectively). On the contrary, obesity showed a significant association (p?=?0.02). For other factors analyzed, we found statistical correlation for epidermoid histology and ≥III A CS (p?=?0.01 and p?=?0.02, respectively).

Conclusions

We did not find statistical relationship between HT and the clinical factors of age >50 years and DM. Statistical relationship for the dosimetric factors V10?>?90% and V20?>?80% was not found as well. On the contrary, obesity, epidermoid histology and ≥IIIA CS, showed statistical significance for development of HT ≥grade 2.  相似文献   

7.

Objectives

Radiotherapy in patients with sinonasal mucosal melanoma (SNMM) was given as alternative treatment to surgery in cases with advanced, inoperable tumors or those not eligible for surgery. We presented the outcomes for patients with SNMM treated with radiotherapy alone.

Material and methods

The retrospective review of 6 consecutive SNMM (nasal cavity – 4 pts. and paranasal sinus – 2 pts.) patients (3 males and 3 females at mean age 64 years) treated between 2008 and 2016 was presented. The stage of disease was: T3 (1 pt.), T4a (3 pts.), T4b (2 pts.); with N0 and M0 in all patients. All patients underwent definitive primary photon radiotherapy (IMRT) alone; dose 66–72?Gy was delivered in 22–24 fractions given in 5 fractions (3?Gy) a week.

Results

The complete remission was observed in all our patients but only one patient survived 5 years without disease. Five patients died due to multiple distant metastases; two of those patients developed associated local recurrence 7–8 months after radiotherapy.

Conclusion

SNMM has a poor prognosis due to its high metastatic potential. Based on our numerically small report and data from literature we concluded that primary radiotherapy alone assured complete remission and even 5-year disease-free survival in only a few individual patients.  相似文献   

8.

Aim

To evaluate the association between dose–volume histogram (DVH) values in organs at risk (OAR) and patient-reported HRQoL outcomes.

Background

Data on the association between DVHs and health-related quality of life (HRQoL) in prostate cancer (PCa) patients are limited.

Materials and methods

Five-year follow-up study of 154 patients with organ-confined (stage T1/T2) PCa treated with EBRT between January 2003 and November 2005. HRQoL was evaluated with the Expanded Prostate Cancer Index (EPIC). DVH for OARs (penile bulb, rectum and bladder) were created for all patients for whom data were available (119/154; 77%). The functional data analysis (FDA) statistical method was used. HRQoL data was collected prospectively and data analysis was performed retrospectively.

Results

Worsening of urinary incontinence and obstructive symptoms correlated with higher DVH dose distributions at 24 months. Increased rectal bleeding at months 24 and 60 correlated with higher DVH dose distributions in the 40–70?Gy range. Patients with deterioration in rectal incontinence presented a higher DVH distribution range than patients without rectal incontinence. Penile bulb DVH values and erectile dysfunction were not significantly associated.

Conclusions

DVH parameters and post-radiotherapy HRQoL appear to be closely correlated, underscoring the importance of assessing DVH values prior to initiating EBRT to determine the risk of developing HRQoL related adverse effects. Advanced treatment modalities may be appropriate in high risk cases to minimize treatment-related toxicity and to improve treatment outcomes and HRQoL. Future studies are needed to better elucidate the association between pre-treatment DVH parameters in organs at risk and subsequent HRQoL.  相似文献   

9.

Background

Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) represents a revolution in the identification of microorganisms of clinical interest. Many studies have confirmed the accuracy and fastness of this tool with routine strains.

Aims

To identify clinical isolates of Candida from patients diagnosed with candidemia.

Methods

Vitek-MS? system was used with a collection of 298 blood isolates of the genus Candida represented by 9 different species. Sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA cluster was used as the reference method.

Results

The results of Vitek-MS? were concordant with those obtained with the reference method for 279 (93.62%) isolates (Kappa coefficient (κ) = 0.91). Vitek-MS? misidentified 10 (3.36%) isolates and did not identify 9 (3.02%) isolates.

Conclusions

This study determines the potential of Vitek-MS? in yeast identification, being a reliable and fast alternative in the clinical laboratory, with an acceptable sensitivity of 82% (IC 95%: 70–90.6%), in comparison with a 100% (IC 95%: 92.9–100%) sensitivity of the conventional methods.  相似文献   

10.

Aim

The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6?MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16?MeV applied in the left breast, considering the adoption of a combined photon (16?Gy) and electron (30?Gy) protocols.

Materials and methods

The modified ICRP-reference female model of 60?kg, 163?cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered.

Results

CR associated with the 6?MV, 4?MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16?MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3–5.0?Gy.

Conclusions

To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16?Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8?MeV portal while 12–16?MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8–12?MeV may bring benefits, reducing CR. The lowest risk was found to 46?Gy electron portals exclusively.  相似文献   

11.

Aim

To evaluate the dose distribution to the left anterior descending (LAD) coronary artery in patients treated with postoperative three-dimensional conformal radiotherapy (3DCRT).

Background

Postoperative radiotherapy may increase the risk of heart disease, particularly in patients with left-sided breast cancer. Clinical data on doses to the LAD are limited.

Materials and methods

Retrospective study of 14 patients who underwent postoperative 3DCRT for left breast cancer in 2014. All data were retrieved from medical records. Means, medians, ranges, and percentages were calculated.

Results

The mean dose to the LAD in patients with V25 < 1% was 0.12 cGy. Dmean, Dmax and V25 to the heart were, respectively, 3.7 Gy (range, 0.9–4.18), 40.3 Gy (9.28–62.9), and 1.59 cGy. The mean Dmean and Dmax values in the sample were 9.71 Gy and 33.2 Gy, respectively. The maximum dose to the LAD (D2%) ranged from 3.66 to 53.01 Gy. Due to the spacing of the CT slices (5 mm), it was not possible to completely contour the entire artery. The mean dose to the heart (3.3 Gy) was considered acceptable.

Conclusions

The maximum dose to the LAD was as high as 53 Gy, suggesting an increased risk of cardiac morbidity. This study underscores the value of contouring the LAD and the value of the breath hold technique to reduce maximum cardiac doses. Smaller CT cuts (2.5 mm) can improve contouring. Larger studies with long-term follow up are needed to determine the radiation tolerance dose for the LAD.  相似文献   

12.

Aim

In this study, we intend to compare two different setup procedures for female breast cancer patients.

Background

Imaging in radiotherapy provides a precise localization of the tumour, increasing the accuracy of the treatment delivery in breast cancer.

Materials and methods

Twenty breast cancer patients who underwent whole breast radiotherapy (WBRT) were selected for this study. Patients were divided into two groups of ten. Group one (G1) was positioned by tattoos and then the patient positioning was adjusted with the aid of AlignRT (Vision RT, London, UK). In group two (G2), patients were positioned only by tattoos. For both groups, the first 15 fractions were analyzed, a daily kilovoltage (kV) cone beam computed tomography (CBCT) image was made and then the rotational and translational displacements and, posteriorly, the systematic (Σ) and random (σ) errors were analyzed.

Results

The comparison of CBCT displacements for the two groups showed a statistically significant difference in the translational left–right (LR) direction (ρ = 0.03), considering that the procedure with AlignRT system has smaller lateral displacements. The results of systematic (Σ) and random (σ) errors showed that for translational displacements the group positioned only by tattoos (G2) demonstrated higher values of errors when compared with the group positioned with the aid of AlignRT (G1).

Conclusions

AlignRT could help the positioning of breast cancer patients; however, it should be used with another imaging method.  相似文献   

13.

Background

Posaconazole is used for the prophylaxis of invasive fungal disease (IFD). Previous studies have shown it to be cost-effective compared to fluconazole/itraconazole. However, posaconazole has never been economically evaluated in developing countries.

Aims

The aim of the present study was to perform a cost-effectiveness analysis of posaconazole compared to fluconazole in public (SUS) and private hospitals (PHS) in Brazil.

Methods

A cost-effectiveness simulation was conducted on the basis of a pivotal study on the use of posaconazole in acute myeloid leukemia (AML) patients, adjusting the costs to Brazilian data.

Results

A pharmacoeconomic analysis was performed on a hypothetical sample of 100 patients in each drug group. The total cost of posaconazole use alone was USD$ 220,656.31, whereas that for fluconazole was USD$ 83,875.00. Our results showed that patients with IFD remain hospitalized for an additional 12 days, at an average cost of USD$ 850.85 per patient per day. The total money spent by PHS for 100 patients for 100 days was USD$ 342,318.00 for the posaconazole group and USD$ 302,039.00 for the fluconazole group. An analysis of sensitivity (10%) revealed no intergroup difference.

Conclusions

In Brazil posaconazole is cost-effective, and should be considered for the prophylaxis of patients with AMD/myelodysplasia (AML/MDS) undergoing chemotherapy.  相似文献   

14.

Aim

The aim of the study was to analyze the long-term stability of electron beams generated by the Novac11? IORT accelerator.

Background

Novac11? (NRT®) is a mobile electron accelerator designed to irradiate small areas of tissue, up to 10?cm in diameter, with electron beams during surgical procedures. It is characterized by a great mobility guaranteed by a number of degrees of freedom enabling irradiation in the conditions of an operating theatre.

Materials and methods

Over the period of January 2013 and September 2016, the measurement sessions of the output of clinically used beam qualities (6, 8 and 10?MeV) were carried out 41 times. Because of the unsatisfactory long-term stability, an extra procedure of tuning of the magnetron, suggested by the manufacturer, was introduced in October 2015, 15 measurements were performed since then. The output of the Novac11? accelerator was measured in the reference conditions recommended by the IAEA Report 398, the measurements of the charge in the ionization chamber at the reference depth were carried out with a Dose1? electrometer and a plane-parallel chamber PPC05? from IBA®.

Results

The introduction of the tuning of the magnetron procedure resulted in satisfactory long-term stability of the measured outputs below 2%.

Conclusions

After the introduction of the STV parameter tuning procedure, the long-term stability of the Novac11? output increased considerably and is within the values declared by the manufacturer.  相似文献   

15.

Aim

To evaluate the influence of the beam shape created by X-rays with “flat beams” and without “flattening-filter-free [FFF] beams” a flattening filter, and the isocenter locations for FFF beams on the treatment of a large irradiated volume for tumours.

Background

The increase of dose rate and the decrease of out-of-field dose can be expected for FFF beams and lead to effective and safety radiotherapy. On the other hand, the bell-shaped dose profile is thought to be a factor of negating these advantages.

Materials and methods

Treatment plans for 15 patients with head and neck cancer were created using XiO (Elekta, Stockholm AB, Sweden) in fixed-gantry step-and-shoot delivery under the same dose constraints. Seven fields of FFF beams with 7?MV and flat beams with 6?MV were used with the technique of intensity-modulated radiation therapy (IMRT). We compared the dose homogeneity and conformity of targets and dose constraints for organs as the plan quality and evaluated physical parameters: monitor unit (MU) values, number of segments and their locations from the isocenter in beam's-eye-view.

Results

No significant differences were found in the plan quality. The isocenter locations do not affect the physical parameters for FFF beams. It has been confirmed that the number of segments and MU values were 40% higher with FFF beams than with flat beams (p?<?0.05).

Conclusion

This study demonstrates flat dose distribution is more suitable for IMRT with large and complex targets.  相似文献   

16.

Background

Candiduria is a common infection among hospitalised patients. Although the clinical relevance of yeasts in urine is not clearly defined, fungal urinary tract infections have increased significantly in the last decades, becoming a growing public health problem. Candida albicans is the most commonly reported species in urinary infections, although other species of the genus are becoming particularly important, because some of them are linked with resistance to antifungal drugs.

Aims

This study aimed to evaluate the frequency of Candida species causing candiduria in a hospital in Honduras.

Methods

A simple and cost-effective PCR-RFLP approach was used, by amplifying a partial sequence of the ribosomal ITS1-ITS2 region and a subsequent digestion with the enzyme MspI.

Results

During 2016, an analysis was performed on 73 urine samples from patients of different ages. Seven species were found. Candida albicans/dubliniensis was the most frequent species (30%); Candida glabrata (28.8%) was the most isolated among the rest of the species. Candida kefyr was the least frequent species found (2.5%).

Conclusions

This study shows, for the first time in Honduras, the frequency of the Candida species isolated from urine using PCR-RFLP for their identification. This approach could be applied in future epidemiological studies at local and national level.  相似文献   

17.

Aim

The aim of this research is to establish if variation exists in the dose delivered for head and neck (HN) localisation computed tomography (CT) imaging in radiation therapy (RT); to propose a national diagnostic reference levels (DRLs) for this procedure and to make a comparison between the national DRL and a DRL of a European sample.

Background

CT has become an indispensable tool in radiotherapy (RT) treatment planning. It is a requirement of legislation in many countries that doses of ionising radiation for medical exposures be kept ‘As Low As Reasonably Achievable’. There are currently no dose guidelines for RT localisation CT of the HN.

Materials and methods

All RT departments in Ireland and a sample of European departments were surveyed. Dose data on CT dose length product (DLP); dose index volume (CTDIvol); current time product; tube voltage and scan length was acquired for ten average-sized HN patients from each department. DRLs were proposed for DLP and CTDIvol using the rounded 75th percentile of the distribution of the means.

Results

42% of Irish departments and one European department completed the survey. Significant variation was found in the mean DLP, CTDIvol and scan lengths across the Irish departments. The proposed Irish DRL is 882?mGy?cm and 21?mGy and the European department DRL is 816?mGy?cm and 21?mGy, for DLP and CTDIvol, respectively.

Conclusions

Variation exists in doses used for HN RT localisation CT. DRLs have been proposed for comparison purposes with the aim of dose optimisation.  相似文献   

18.

Objective

Parotid gland incidentalomas are unexpected hypermetabolic foci in the parotid region that can be found when scanning the whole-body by PET/CT. The role of SUVmax is controversial to differentiate benign or malignant tumours in this indication. The aim of this study was to determine PET/CT features of malignant parotid incidentaloma, in order to improve medical care.

Methods

We retrospectively reviewed 10,756 PET/CT scans performed during 3?years at our center in search of parotid gland incidentalomas. Twenty-eight patients were included. For each lesion, we have collected the results of parotid MRI, histology and/or subsequent imaging. Logistic regression was used to compare SUVmax, SUVmean, MTV and TLG, and ROC curves were used to assess threshold values.

Results

Prevalence of parotid gland incidentalomas was 1.29% (n?=?139). Thirty-seven were included, among them, 46% were malignant. SUVmax, MTV and TLG were significantly higher for malignant tumours (P?≤?0.001). MTV?>?4?mL and TLG?>?7.5?mL were strongly associated with a malignant lesion (MTV and TLG: P?<?0.001; SUVmax: P?=?0.005; SUVmean: P?=?0.07). According to ROC curves, MTV thresholded at 4 had an AUC of 0.92 (Se 75%, Sp 100%) to differentiate benign and malignant lesions.

Conclusions

MTV and TLG were predictive factors of malignancy, stronger than SUVmax. However, given the high proportion of malignant lesions and the suboptimal sensitivity of the MTV further exploration must be requested for any parotid gland incidentaloma.  相似文献   

19.

Aim

The aim of the study is to evaluate the differences in dosimetry between tandem-ovoid and tandem-ring gynaecologic brachytherapy applicators in image based brachytherapy.

Background

Traditionally, tandem ovoid applicators were used to deliver dose to tumor in intracavitary brachytherapy. Tandem-ring, tandem-cylinder and hybrid intracavitary, interstitial applicators are also used nowadays in cervical cancer brachytherapy.

Methods and materials

100 CT datasets of cervical cancer patients (stage IB2 – IIIB) receiving HDR application (50 tandem-ovoid and 50 tandem-ring) were studied. Brachytherapy was delivered using a CT-MRI compatible tandem-ovoid (50 patients) and a tandem-ring applicator (50 patients). DVHs were calculated and D2cc was recorded for the bladder and rectum and compared with the corresponding ICRU point doses. The point B dose, the treated volume, high dose volume and the treatment time were recorded and compared for the two applicators.

Results

The mean D2cc of the bladder with TR applicator was 6.746 Gy. TO applicator delivered a mean D2cc of 7.160 Gy to the bladder. The mean ICRU bladder points were 5.60 and 5.63 Gy for TR and TO applicator, respectively. The mean D2cc of the rectum was 4.04 Gy and 4.79 Gy for TR and TO applicators, respectively. The corresponding ICRU point doses were 5.10 Gy and 5.66 Gy, respectively.

Conclusions

The results indicate that the OAR doses assessed by DVH criteria were higher than ICRU point doses for the bladder with both tandem-ovoid and tandem-ring applicators whereas DVH based dose was lower than ICRU dose for the rectum. The point B dose, the treated volume and high dose volume was found to be slightly higher with the tandem-ovoid applicator. The mean D2cc dose for the bladder and rectum was lower with tandem-ring applicators. The clinical implication of the above dosimetric differences needs to be evaluated further.  相似文献   

20.

Introduction

The incidence of breast carcinoma (BC) has increased in the last years. Between 2 and 12% of patients diagnosed with BC will develop bilateral breast carcinoma (BBC). The treatment of these carcinomas is more aggressive than unilateral BC.

Purpose

To perform a retrospective qualitative analysis of BBC patients whose treatment has included brachytherapy (BT) and to present a revised literature on this issue.

Material and methods

The cases of BBC whose treatment included brachytherapy were revised. The literature on this issue was refreshed.

Results

Five women, aged between 54 and 78 at the time of the diagnosis, submitted to conservative surgery followed by external radiotherapy (RT) with boost of BT or exclusive BT (APBI), in the IPO-P BT Service between 2003 and 2016.

Discussion

The patients with BBC have slightly higher rates of local recurrences, mostly in the tumor bed, where there is a higher risk of local recurrence. Patients treated with BT had lower rates of recurrences than those treated with photons and electrons.

Conclusions

BBC represents a complex challenge for doctors, because in some cases there is a tendency to use more aggressive treatments and, at the same time, it is not easy to achieve the timing for the correct treatment.  相似文献   

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