Cardiac dose reduction with deep inspiration breath hold for left-sided breast cancer radiotherapy patients with and without regional nodal irradiation

Background

Deep inspiration breath hold (DIBH) reduces heart and left anterior descending artery (LAD) dose during left-sided breast radiation therapy (RT); however there is limited information about which patients derive the most benefit from DIBH. The primary objective of this study was to determine which patients benefit the most from DIBH by comparing percent reduction in mean cardiac dose conferred by DIBH for patients treated with whole breast RT ± boost (WBRT) versus those receiving breast/chest wall plus regional nodal irradiation, including internal mammary chain (IMC) nodes (B/CWRT + RNI) using a modified wide tangent technique. A secondary objective was to determine if DIBH was required to meet a proposed heart dose constraint of D_mean < 4 Gy in these two cohorts.

Methods

Twenty consecutive patients underwent CT simulation both free breathing (FB) and DIBH. Patients were grouped into two cohorts: WBRT (n = 11) and B/CWRT + RNI (n = 9). 3D-conformal plans were developed and FB was compared to DIBH for each cohort using Wilcoxon signed-rank tests for continuous variables and McNemar’s test for discrete variables. The percent relative reduction conferred by DIBH in mean heart and LAD dose, as well as lung V₂₀ were compared between the two cohorts using Wilcox rank-sum testing. The significance level was set at 0.05 with Bonferroni correction for multiple testing.

Results

All patients had comparable target coverage on DIBH and FB. DIBH statistically significantly reduced mean heart and LAD dose for both cohorts. Percent reduction in mean heart and LAD dose with DIBH was significantly larger in the B/CWRT + RNI cohort compared to WBRT group (relative reduction in mean heart and LAD dose: 55.9 % and 72.1 % versus 29.2 % and 43.5 %, p < 0.02). All patients in the WBRT group and five patients (56 %) in the B/CWBRT + RNI group met heart D_mean <4 Gy with FB. All patients met this constraint with DIBH.

Conclusions

All patients receiving WBRT met D_mean Heart < 4 Gy on FB, while only slightly over half of patients receiving B/CWRT + RNI were able to meet this constraint in FB. DIBH allowed a greater reduction in mean heart and LAD dose in patients receiving B/CWRT + RNI, including IMC nodes than patients receiving WBRT. These findings suggest greatest benefit from DIBH treatment for patients receiving regional nodal irradiation.

Intensity-Modulated Radiotherapy (IMRT) vs Helical Tomotherapy (HT) in Concurrent Chemoradiotherapy (CRT) for Patients with Anal Canal Carcinoma (ACC): an analysis of dose distribution and toxicities

Purpose

Intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) have been adopted for radiotherapy treatment of anal canal carcinoma (ACC) due to better conformality, dose homogeneity and normal-tissue sparing compared to 3D-CRT. To date, only one published study compares dosimetric parameters of IMRT vs HT in ACC, but there are no published data comparing toxicities. Our objectives were to compare dosimetry and toxicities between these modalities.

Methods and materials

This is a retrospective study of 35 ACC patients treated with radical chemoradiotherapy at two tertiary cancer institutions from 2008–2010. The use of IMRT vs HT was primarily based on center availability. The majority of patients received fluorouracil (5-FU) and 1–2 cycles of mitomycin C (MMC); 2 received 5-FU and cisplatin. Primary tumor and elective nodes were prescribed to ≥54Gy and ≥45Gy, respectively. Patients were grouped into two cohorts: IMRT vs HT. The primary endpoint was a dosimetric comparison between the cohorts; the secondary endpoint was comparison of toxicities.

Results

18 patients were treated with IMRT and 17 with HT. Most IMRT patients received 5-FU and 1 MMC cycle, while most HT patients received 2 MMC cycles (p < 0.01), based on center policy. HT achieved more homogenous coverage of the primary tumor (HT homogeneity and uniformity index 0.14 and 1.02 vs 0.29 and 1.06 for IMRT, p = 0.01 and p < 0.01). Elective nodal coverage did not differ. IMRT achieved better bladder, femoral head and peritoneal space sparing (V30 and V40, p ≤ 0.01), and lower mean skin dose (p < 0.01). HT delivered lower bone marrow (V10, p < 0.01) and external genitalia dose (V20 and V30, p < 0.01). Grade 2+ hematological and non-hematological toxicities were similar. Febrile neutropenia and unscheduled treatment breaks did not differ (both p = 0.13), nor did 3-year overall and disease-free survival (p = 0.13, p = 0.68).

Conclusions

Chemoradiotherapy treatment of ACC using IMRT vs HT results in differences in dose homogenity and normal-tissue sparing, but no significant differences in toxicities.

One compared with two cycles of mitomycin C in chemoradiotherapy for anal cancer: analysis of outcomes and toxicity

BACKGROUND

Concurrent chemoradiation with fluorouracil (5fu) and mitomycin C (mmc) is standard treatment for anal canal carcinoma (acc). The current protocol in Alberta is administration of 5fu and mmc during weeks 1 and 5 of radiation. However, administration of the second bolus of mmc has been based largely on centre preference. Given limited published data on outcomes with different mmc regimens, our objective was to compare the efficacy and toxicity of 1 compared with 2 cycles of mmc in acc treatment.

METHODS

Our retrospective study evaluated 169 acc patients treated with radical chemoradiotherapy between 2000 and 2010 at two tertiary cancer centres. All patients were treated with 2 cycles of 5fu and with 1 cycle (mmc1) or 2 cycles (mmc2) of mmc. Acute toxicities, disease-free (dfs) and overall survival (os) were analyzed.

RESULTS

Baseline demographics, performance status, and stage were similar in the groups of patients who received mmc1 (52%) and mmc2 (48%). Before treatment, median hematologic parameters were comparable, except for white blood cell count, which was higher in the mmc2 group, but within normal range. The 5-year os and dfs were similar (75.1% and 54.2% for mmc1 vs. 70.7% and 44.2% for mmc2, p = 0.98 and p = 0.63 respectively). On multivariate analysis, mmc2 was the factor most strongly associated with specific acute toxicities: grade 3+ leukopenia (hazard ratio: 4.82; p < 0.01), grade 3+ skin toxicity (hazard ratio: 4.76; p < 0.001), and hospitalizations secondary to febrile neutropenia (hazard ratio: 9.91; p = 0.001).

CONCLUSIONS

In definitive chemoradiotherapy for acc, 1 cycle of mmc appears to offer outcomes similar to those achieved with 2 cycles, with significantly less acute toxicity.

Does higher gadolinium concentration play a role in the morphologic assessment of brain tumors? Results of a multicenter intraindividual crossover comparison of gadobutrol versus gadobenate dimeglumine (the MERIT Study)

BACKGROUND AND PURPOSE

Gadobenate dimeglumine has proved advantageous compared with other gadolinium-based contrast agents for contrast-enhanced brain MR imaging. Gadobutrol is a more highly concentrated agent (1.0 mol/L). This study intraindividually compared 0.1-mmol/kg doses of these agents for qualitative and quantitative evaluation of brain tumors.

MATERIALS AND METHODS

Adult patients with suspected or known brain tumors underwent 2 identical MR imaging examinations at 1.5T, 1 with gadobenate dimeglumine and the other with gadobutrol, both at a dose of 0.1-mmol/kg body weight. The agents were injected in randomized order separated by 3-14 days. Imaging sequences and acquisition timing were identical for the 2 examinations. Three blinded readers evaluated images qualitatively for diagnostic information (lesion extent, delineation, morphology, enhancement, global preference) and quantitatively for CNR and LBR.

RESULTS

One hundred fourteen of 123 enrolled patients successfully underwent both examinations. Final diagnoses were intra-axial tumors, metastases, extra-axial tumors, "other" tumors, and "nontumor" (49, 46, 8, 7, and 4 subjects, respectively). Readers 1, 2, and 3 demonstrated preference for gadobenate dimeglumine in 46 (40.7%), 54 (47.4%), and 49 (43.0%) patients, respectively, compared with 6, 7, and 7 patients for gadobutrol (P < .0001, all readers). Highly significant (P < .0001, all readers) preference for gadobenate dimeglumine was demonstrated for all other qualitative end points. Inter-reader agreement was good for all evaluations (κ = 0.414-0.629). Significantly superior CNR and LBR were determined for gadobenate dimeglumine (P < .019, all readers).

CONCLUSIONS

Significantly greater morphologic information and lesion enhancement are achieved on brain MR imaging with 0.1-mmol/kg gadobenate dimeglumine compared with gadobutrol at an equivalent dose.

Validation of the 2005 St. Gallen risk categories for operated breast cancers using a database from a regional cancer center in Hong Kong

11019

Background: Breast cancer risk categories were revised by the St Gallen international expert consensus meeting in 2005. This study was to validate their application in Hong Kong. Methods: The clinical outcomes of female breast cancer patients presented from 1994 to 2002 were retrospectively analyzed. Patients with non-invasive cancers, unknown HER-2 status, unclear primary (T) or nodal (N) stage, distant metastases at presentation, induction chemotherapy or no definitive surgery were excluded. Results: 902 breast cancers were eligible for further analysis. Adjuvant radiotherapy, hormonal therapy and chemotherapy were given in 74%, 68% and 56% of patients respectively. The median follow-up was 5.4 years (range 0.3- 12.5 years). The risk categories were highly predictive of all survival outcome parameters (p<0.00005; Table). In the intermediate risk category, node-negative patients with endocrine responsive/ responsiveness uncertain tumors had better 5-year distant failure-free survival (DFFS) than the rest with either 1–3 positive nodes or endocrine non-responsive tumors (95% vs 89%, p=0.005). Patients with 1–3 positive nodes and HER-2 overexpressed tumors were classified as high risk but their 5-year DFFS was similar to that in the worse subgroup of intermediate risk and significantly better than those with ≥4 positive nodes (89% vs 65%, p=0.0001). Further analysis showed that HER-2 overexpression had adverse impact on DFFS of patients with ≥4 positive nodes (hazard ratios (HR) 1.78; 95% CI, 1.12 - 2.84; p=0.015) but not on those with ≤ 3 positive nodes (HR 1.15; 95% CI, 0.67 - 1.97; p= 0.61). Conclusions: The 2005 St Gallen risk category is a useful clinical tool but we cannot confirm the adverse impact of HER-2 overexpression in our patients with ≤ 3 positive nodes.

[Table: see text]

No significant financial relationships to disclose.

Long circulating lipid nanocapsules for drug detoxification

Uncoated and poly(ethylene glycol) (PEG)-decorated lipid nanocapsules (NC) prepared from medium chain triglycerides were investigated both in vitro and in vivo as parenteral detoxifying colloids for their ability to sequester haloperidol, docetaxel and paclitaxel. In vitro studies showed that the uptake depended on the nature of the drug and the composition of NC core and shell. In the case of haloperidol, maximal affinity was achieved upon incorporation of a complexing fatty acid. In plasma lipoprotein distribution studies, the association of both haloperidol and docetaxel into triglyceride-rich lipoprotein fraction was significantly increased in the presence of NC. The ability of the NC to lower the free drug concentrations in incubation medium was confirmed by cytotoxicity studies, where the antiproliferative activity of docetaxel was significantly decreased in the presence of NC. Using docetaxel as drug model, the NC were finally evaluated for their uptake potential in mice by one of the following administration sequences between the drug solution (Taxotere, DTX) and NC: NC-DTX, PEG(NC)-DTX and DTX-PEG(NC). Irrespective of the administration sequence, the NC increased the blood levels of docetaxel due to the in situ sequestration of drug by the circulating carrier. These findings suggest that lipid NC could be used as a non-specific mode to deal with the sequestration of molecules with high affinity for oils.

Sources of variation in multi-centre brain MTR histogram studies: body-coil transmission eliminates inter-centre differences

OBJECT

1. Identify sources of variation affecting Magnetisation Transfer Ratio (MTR) histogram reproducibility between-centres. 2. Demonstrate complete elimination of inter-centre difference.

MATERIALS AND METHODS

Six principle sources of variation were summarised and analysed. These are: the imager coil used for radiofrequency (RF) transmission, imager stability, the shape and other parameters describing the Magnetisation Transfer (MT) pulse, the MT sequence used (including its parameters), the image segmentation methodology, and the histogram generation technique. Transmit field nonuniformity and B1 errors are often the largest factors. PLUMB (Peak Location Uniformity in MTR histograms of the Brain) plots are a convenient way of visualising differences. Five multi-centres studies were undertaken to investigate and minimise differences.

RESULTS

Transmission using a body coil, with a close-fitting array of surface coils for reception, gave the best uniformity. Differences between two centres, having MR imagers from different manufacturers, were completely eliminated by using body coil excitation, making a small adjustment to the MT pulse flip angle, and carrying out segmentation at a single centre. Histograms and their peak location and height values were indistinguishable.

CONCLUSIONS

Body coil excitation is preferred for multi-centre studies. Analysis (segmentation and histogram generation) should ideally be carried out at a single site.

Ameloblastoma in the Hong Kong Chinese. Part 2: systematic review and radiological presentation

OBJECTIVES

The aim of this part of the study was to determine the radiological presentation on conventional radiographs of central ameloblastomas in the Hong Kong Chinese and compare them with other reported series by a systematic review (SR).

METHODS

The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit and a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and handsearching of key journals. The principal selection criterion was that the study should represent a complete collection of cases.

RESULTS

Only 13 reports gave any radiological details. The present study of the Hong Kong Chinese contained 61 cases. With the exception of radiodensity and shape of radiolucency, the majority of the 13 other reports did not record the other radiological features that could be important in the diagnosis. The present study agreed with the synthesis of the 13 reports with regards to complete radiolucency and cortication of ameloblastomas, but disagreed with regards to other important features. The present study had a significantly higher proportion of unilocular lesions, better marginal definition, and more frequent perforation of the cortex and buccolingual expansion. Nine of the ten maxillary lesions straddled both anterior and posterior sextants with four crossing the midline, whereas only 13 of the 51 mandibular cases affected both sextants, of which eight crossed the midline. The unicystic form, which was most prevalent, appeared significantly more frequently as unilocular radiolucencies in comparison with the non-unicystic forms. The frequencies of unicystic forms and unilocular presentations were significantly greater in the young. The lesions in the young were significantly sited solely in the posterior sextant. The lower border of the mandible was reached and affected by ameloblastoma in 36 cases in the present report. It was displaced and thinned in 15 cases whereas in just five it was at least partially undisplaced with the lesion expanding down past it either buccally or lingually to it. The unicystic form was significantly more associated with root resorption, tooth displacement and crowns of unerupted teeth.

CONCLUSIONS

Radiologically, ameloblastomas in the Hong Kong Chinese differ significantly with regards to many features. This can be in part explained by the higher proportion of the unicystic form.

Ameloblastoma in the Hong Kong Chinese. Part 1: systematic review and clinical presentation

OBJECTIVES

The aim of Part 1 of this study was to determine the clinical presentation of central ameloblastomas in the Hong Kong Chinese and to compare them with other reported series by a systematic review (SR).

METHODS

The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit as well as a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and hand searching of key journals. The principal selection criterion was that the study should represent a complete collection of cases.

RESULTS

Fifty-three published series of cases were included in the SR. They generally reported little more than sex, mean age and range, and affected jaw. Only 16 studies considered recurrence. Sixty-one cases of ameloblastoma were identified in the present study. There were 30 males and 31 females, contrary to the predilection for males in other reports. Eighty-four percent of cases were found in the mandible, agreeing with the SR. The mean age at first presentation was 30.5 years, lower than that of the SR; only a Korean report and a small Bangladeshi report showed younger presentation. The present report had the shortest period between first becoming aware of the lesion and seeking treatment; this period was significantly shorter for younger patients. Although the present study was in agreement with the SR with regard to swelling, this study reported a significantly higher proportion of patients presenting with pain.

CONCLUSION

Although the presentation of ameloblastoma within this Chinese community was broadly similar to that observed in other populations, it differed in a number of important respects. It had a younger age at first presentation than many other communities, including other Orientals; it was associated with a shorter period between first becoming aware of the lesion and seeking treatment, particularly in the young; and it was more frequently associated with pain than in the SR.

Computed tomography of fibrous dysplasia

OBJECTIVE

Fibrous dysplasia (FD) is an uncommon, but important lesion affecting the jaws. The aim of this study was to reveal its presentation on computed tomography (CT) in a consecutive series of cases.

METHODS

The files of the Department of Oral and Maxillofacial Surgery of Hong Kong University between 1989 and 2000 were reviewed for cases of FD.

RESULTS

Of the ten cases investigated by CT, two were rejected because of extensive biopsy or surgery before the CT investigation. Seven of the remaining eight cases were Chinese and one was Indian. The mandible and maxilla were equally affected. The cortex was generally intact, except when adjacent to the teeth in the maxilla. The margins were generally poorly-defined, but well-defined on at least some sections of each maxillary case. Five cases were extensive, affecting or nearly affecting the whole hemi-mandible or hemi-maxilla to the midline. All cases displayed expansion, which was fusiform in the mandible and an enlargement of the normal contour in the maxilla. The maxillary antrum was completely obturated in three maxillary cases; one displayed a rounded dome-shaped lesion more suggestive of a benign neoplasm. The orbital floor was displaced in three cases; one of those cases presented with proptosis. All maxillary cases extended back to the pterygoid process, but did not displace it. The "bone windows" of eight cases generally displayed a "ground-glass" pattern; one also displayed cyst-like radiolucencies. The soft tissue window, which depicts mineralized tissue as "white", showed that five cases were completely mineralized.

CONCLUSION

CT can be used to determine the extent, specific dimensions and radiodensity of FD.

Odontogenic myxomas in the Hong Kong Chinese: clinico-radiological presentation and systematic review

AIM

The aim of this study was to determine the clinical and radiological presentation on plain films of central odontogenic myxomas (OM) in the Hong Kong Chinese and compare them to other reported series by a systematic review (SR).

METHODS

The study had two elements, that of a complete series of all OMs presenting at a major Chinese maxillofacial surgical unit and a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for OM cases. The relevant literature was identified by electronic databases, review of citation lists and handsearching of key journals. The principal selection criterion was that the study should represent a complete collection of cases.

RESULTS

The SR revealed that only a quarter of the reports provided any quantitative radiological details. Just under half of the included reports provided the relative period prevalence of OMs compared to other odontogenic tumours, but these reports almost completely excluded consideration not only of the radiology but also specific clinical details. Furthermore, they did not report of recurrence data, an important feature of the OM. Most of the most recent reports were concerned with relative period prevalence. The relative period prevalence and 'number of OMs per hospital per year' of studies separated by two or more decades in Hong Kong and Nigeria indicate an increase in the number of lesions diagnosed as OMs. The 10 Hong Kong cases were broadly consistent with the predilections for females and the mandible of other reports. The mean age at first presentation in the present report is 36.9, older than the other reports. Most lesions are large, affecting both posterior and anterior quadrants. They appear to be larger than those in many other reports. Two of the OMs are accompanied by histories of recent rapid growth. Tooth displacement and root resorption are more frequently observed in OMs in the present study. Although all OMs in the present study are still being followed up after surgery, none have recurred.

CONCLUSION

Although the presentation of larger lesions in the older Chinese could in part be explained by attitudes rooted in traditional medicine in spite of the widespread availability of modern medical care in Hong Kong, there is a history of recent rapid growth in at least two cases. An emphasis by recent reports on the OMs' relative period prevalence of concurrent odontogenic lesions, has omitted recording the radiology and the specific clinical details usually required for diagnosis.,

The generation and characterization of a cell line derived from a sporadic renal angiomyolipoma: use of telomerase to obtain stable populations of cells from benign neoplasms

Angiomyolipomas are benign tumors of the kidney derived from putative perivascular epithelioid cells, that may undergo differentiation into cells with features of melanocytes, smooth muscle, and fat. To gain further insight into angiomyolipomas, we have generated the first human angiomyolipoma cell line by sequential introduction of SV40 large T antigen and human telomerase into human angiomyolipoma cells. These cells show phenotypic characteristics of angiomyolipomas, namely differentiation markers of smooth muscle (smooth muscle actin), adipose tissue (peroxisome proliferator-activator receptor gamma, PPARgamma), and melanocytes (microophthalmia, MITF), thus demonstrating that a single cell type can exhibit all of these phenotypes. These cells should serve as a valuable tool to elucidate signal transduction pathways underlying renal angiomyolipomas.

Outcome measure for paediatric rehabilitation: use of the Functional Independence Measure for children (WeeFIM). A pilot study in Chinese children with neurodevelopmental disabilities

PURPOSE

To study the use of Functional Independence Measure for children (WeeFIM) in monitoring neurorehabilitation programmes for children with neurodevelopmental disabilities.

METHODS

The neurorehabilitation team of the Children's Habilitation Institute of the Duchess of Kent Children's Hospital were trained to administer the WeeFIM. The WeeFIM was administered to children with various neuro-developmental impairment groups undergoing neurorehabilitation programmes in the hospital inpatient and also outpatient setting. The WeeFIM was scored on hospital admission and prior to discharge for those admitted for the rehabilitation programme. The WeeFIM profile was then monitored half yearly. The pilot study used WeeFIM in assessing 104 children with different medical disease categories. The disease or impairment categories included very low birth weight babies (n = 44), cerebral palsy (n = 19), Down's syndrome (n = 9), pervasive developmental disorder (n = 11), Duchenne Muscular Dystrophy (n = 18), and others (n = 3).

RESULTS

WeeFim could be used to measure disability, monitor progress, enhance communication, measure the effectiveness of treatment, and document the benefits of rehabilitation intervention. It also served as a networking of neurorehabilitation programmes for different impairment categories in a continuum of settings: hospital, community, school and at home. WeeFIM was found to be a quick and reliable functional assessment instrument in this rehabilitation facility.

CONCLUSIONS

WeeFIM could be used to assist neurorehabilitation clinicians in the selection of short term realistic goals and long term rehabilitation strategies for children with various neurodevelopmental disabilities, and the subsequent progress of the children could be monitored objectively.