Dosimetric predictors of acute bone marrow toxicity in carcinoma cervix — experience from a tertiary cancer centre in India

BackgroundThe objective of this study was To determine the dose volume parameters predicting acute haematological toxicity in carcinoma cervix patients undergoing concurrent chemoradiotherapy.Materials and methodsAll patients that presented to the hospital between Jan 2019 and Dec 2019 were prospectively analyzed. Patients diagnosed to have Carcinoma Cervix and planned for concurrent chemoradiation by volumetric modulated arc therapy (VMAT) were included for analysis. Patients were assessed at baseline and every week during treatment for acute haematological toxicities. Dose volume parameters from treatment plans were correlated with RTOG grade of haematological toxicities.ResultsA total of 34 patients diagnosed to have squamous cell carcinoma of cervix were treated by radical radiotherapy by VMAT technique and concurrent chemotherapy. The most common stage of presentation was stage IIB (61.7%). 29 patients (85.2%) completed five cycles of weekly cisplatin. Statistical analysis for sensitivity and specificity of dosimetric parameters was performed using receiver operating characteristic (ROC) curve. The probability of developing bone marrow toxicity was analyzed using T test. Mean dose to bone marrow exceeding 28.5 Gy was significantly associated with bone marrow toxicity (sensitivity — 82.4%, specificity — 70.6%). On analyzing dose volume parameters, volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy (V20, V30 and V40) more than 71.75%, and 49.75% and 22.85%, respectively, was significantly associated with bone marrow toxicity.ConclusionsOur study concludes that mean dose to bone marrow exceeding 28.5 Gy has high sensitivity and specificity for predicting bone marrow toxicity in patients receiving IMRT. Volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy significantly correlated with acute haematological toxicity.     

Comparison of dosimetric variation between prostate IMRT and VMAT due to patient's weight loss: Patient and phantom study

Aim

This study compared the dosimetric impact between prostate IMRT and VMAT due to patient''s weight loss.

Background

Dosimetric variation due to change of patient''s body contour is difficult to predict in prostate IMRT and VMAT, since a large number of small and irregular segmental fields is used in the delivery.

Materials and methods

Five patients with prostate volumes ranging from 32.0 to 86.5 cm³ and a heterogeneous pelvis phantom were used for prostate IMRT and VMAT plans using the same set of dose–volume constraints. Doses in IMRT and VMAT plans were recalculated with the patient''s and phantom''s body contour reduced by 0.5–2 cm to mimic size reduction. Dose coverage/criteria of the PTV and CTV and critical organs (rectum, bladder and femoral heads) were compared between IMRT and VMAT.

Results

In IMRT plans, increases of the D99% for the PTV and CTV were equal to 4.0 ± 0.1% per cm of reduced depth, which were higher than those in VMAT plans (2.7 ± 0.24% per cm). Moreover, increases of the D30% of the rectum and bladder per reduced depth in IMRT plans (4.0 ± 0.2% per cm and 3.5 ± 0.5% per cm) were higher than those of VMAT (2.2 ± 0.2% per cm and 2.0 ± 0.6% per cm). This was also true for the increase of the D5% for the right femoral head in a patient or phantom with size reduction due to weight loss.

Conclusions

VMAT would be preferred to IMRT in prostate radiotherapy, when a patient has potential to suffer from weight loss during the treatment.     

Dosimetric impact of Acuros XB on cervix radiotherapy using RapidArc technique: a dosimetric study

BackgroundAcuros XB (AXB) may predict better rectal toxicities and treatment outcomes in cervix carcinoma. The aim of the study was to quantify the potential impact of AXB computations on the cervix radiotherapy using the RapidArc (RA ) technique as compared to anisotropic analytical algorithm (AA) computations.Materials and methodsA cohort of 30 patients previously cared for cervix carcinoma (stages II–IIIB) was selected for the present analysis. The RA plans were computed using AA and AXB dose computation engines under identical beam setup and MLC pattern.ResultsThere was no significant (p > 0.05) difference in D_95% and D_98% to the planning target volume (PTV); moreover, a significant (p < 0.05) rise was noticed for mean dose to the PTV (0.26%), D_50% (0.26%), D_2% (0.80%) and V_110% (44.24%) for AXB computation as compared to AA computations. Further, AXB estimated a significantly (p < 0.05) lower value for maximum and minimum dose to the PTV. Additionally, there was a significant (p < 0.05) reduction observed in mean dose to organs at risk (OARs) for AXB computation as compared to AA, though the reduction in mean dose was non-significant (p > 0.05) for the rectum. The maximum difference observed was 4.78% for the rectum V_50Gy, 1.72%, 1.15% in mean dose and 2.22%, 1.48% in D_2% of the left femur and right femur, respectively, between AA and AXB dose estimations.ConclusionFor similar target coverage, there were significant differences observed between the AAA and AXB computations. AA underestimates the V_50Gy of the rectum and overestimates the mean dose and D_2% for femoral heads as compared to AXB. Therefore, the use of AXB in the case of cervix carcinoma may predict better rectal toxicities and treatment outcomes in cervix carcinoma using the RA technique.     

Relations between doses cumulated in bone marrow and dose delivery techniques during radiation therapy of cervical and endometrial cancer

PurposeTo compare normal tissue complication probability (NTCP) and average doses in the bone marrow (BM), obtained for five different radiotherapy delivery and planning strategies of cervical and endometrial cancer.Material/methods50 patients were taken to analysis. For each case, 3 different dose delivery techniques were used: 4-field, X15MV, 3DCRT; 7-field, X6MV, IMRT; and 2-arc, X6MV, VMAT. Two optimization scenarios were used for the IMRT and VMAT plans generation: with (+) and without (−) the inclusion of the BM as an optimized structure. Average doses and dose-volume histogram parameters for the PTV, BM, bladder, rectum, bowels and femoral heads were compared. In addition, the BM doses were analyzed with respect to the PTV and/or volume of the BM, and NTCP for the BM were computed.ResultsThe dose in PTV for evaluated plans was similar. The worst doses in organs at risk were obtained for 3DCRT. Using the BM during the optimization of IMRT and VMAT reduces an average dose in BM without increasing the doses in the bladder, rectum and bowels. Differences between doses in BM for IMRT(+) and VMAT(+) plans were similar while NTCP was lower for VMAT(+). A correlation between average dose in BM and the volume ratio of BM and PTV was found for each technique.ConclusionUsing the BM during the optimization of the IMRT and VMAT plans effectively reduces the dose in BM without increasing the dose in the bladder, rectum and bowels. The VMAT(+) plans were characterized by the lowest NTCP.     

Dexamethasone stimulates osteogenic differentiation in vertebral and femoral bone marrow cell cultures: Comparison of IGF-I gene expression

Osteoblast-like cell cultures have been established from the marrow of adult rat vertebrae. We have simultaneously examined the response to dexamethasone (dex) treatment in cultures of young adult female vertebral and femoral marrow cells. Alkaline phosphatase (AP) activity was analyzed as well as the expression of mRNAs for osteocalcin (OC) and insulin-like growth factor I (IGF-I). The vertebral and femoral marrow cells were maintained for 7 days in primary culture with or without 10⁻⁸ M dex and then 6 days in secondary culture without dex or with 10⁻⁸ M or 10⁻⁷ M dex. All cells were examined on day 6 of secondary culture. Vertebral and femoral cultures each expressed the highest AP enzyme levels when grown with dex in primary culture (10⁻⁸ M) and secondary culture (10⁻⁷ M). Under all experimental conditions, vertebral cultures had lower AP enzyme activity than femoral cultures. When dex was omitted from secondary culture, OC gene expression was not detected in either vertebral or femoral passaged cells even if dex was present in primary culture. For dex conditions where OC was expressed, vertebral cultures had higher OC mRNA steady-state levels than femoral cultures. IGF-I gene expression was detected by Northern analysis in both vertebral and femoral secondary cultures. However, vertebral marrow cultures had much higher IGF-I mRNA levels compared to femoral cultures whether or not dex was present in primary culture. These findings demonstrate that dex supports the differentiation of both vertebral and femoral adult marrow osteogenic cells into osteoblasts. Our results support the hypothesis that osteoblastic marrow cultures differ depending upon which location in the skeleton they are from and that there are skeletal site–dependent differences in the insulin-like growth factor system components. J. Cell. Biochem. 71:382–391, 1998. © 1998 Wiley-Liss, Inc.     

Comparison of gingiva‐derived and bone marrow mesenchymal stem cells for osteogenesis

Presently, bone marrow is considered as a prime source of mesenchymal stem cells; however, there are some drawbacks and limitations. Compared with other mesenchymal stem cell (MSC) sources, gingiva‐derived mesenchymal stem cells (GMSCs) are abundant and easy to obtain through minimally invasive cell isolation techniques. In this study, MSCs derived from gingiva and bone marrow were isolated and cultured from mice. GMSCs were characterized by osteogenic, adipogenic and chondrogenic differentiation, and flow cytometry. Compared with bone marrow MSCs (BMSCs), the proliferation capacity was judged by CCK‐8 proliferation assay. Osteogenic differentiation was assessed by ALP staining, ALP assay and Alizarin red staining. RT‐qPCR was performed for ALP, OCN, OSX and Runx2. The results indicated that GMSCs showed higher proliferative capacity than BMSCs. GMSCs turned more positive for ALP and formed a more number of mineralized nodules than BMSCs after osteogenic induction. RT‐qPCR revealed that the expression of ALP, OCN, OSX and Runx2 was significantly increased in the GMSCs compared with that in BMSCs. Moreover, it was found that the number of CD90‐positive cells in GMSCs elevated more than that of BMSCs during osteogenic induction. Taking these results together, it was indicated that GMSCs might be a promising source in the future bone tissue engineering.     

Retracted: Icariin attenuates methotrexate chemotherapy-induced bone marrow microvascular damage and bone loss in rats

Methotrexate (MTX), a widely used antimetabolite in paediatric cancer to treatment, has been widely reported to cause bone loss and bone marrow (BM) microvascular (particularly sinusoids) damage. Investigations must now investigate how MTX-induced bone loss and microvasculature damage can be attenuated/prevented. In the present study, we examined the potency of icariin, an herbal flavonoid, in reducing bone loss and the dilation/damage of BM sinusoids in rats caused by MTX treatment. Groups of young rats were treated with five daily MTX injections (0.75 mg/kg) with and without icariin oral supplementation until Day 9 after the first MTX injection. Histological analyses showed a significant reduction in the bone volume/tissue volume (BV/TV) fraction (%) and trabecular number in the metaphysis trabecular bone of MTX-treated rats, but no significant changes in trabecular thickness and trabecular spacing. However, the BV/TV (%) and trabecular number were found to be significantly higher in MTX + icariin-treated rats than those of MTX alone-treated rats. Gene expression analyses showed that icariin treatment maintained expression of osteogenesis-related genes but suppressed the induction of adipogenesis-related genes in bones of MTX-treated rats. In addition, icariin treatment attenuated MTX-induced dilation of BM sinusoids and upregulated expression of endothelial cell marker CD31 in the metaphysis bone of icariin + MTX-treated rats. Furthermore, in vitro studies suggest that icariin treatment can potentially enhance the survival of cultured rat sinusoidal endothelial cells against cytotoxic effect of MTX and promote their migration and tube formation abilities, which is associated with enhanced production of nitric oxide.     

RANKL from bone marrow adipose lineage cells promotes osteoclast formation and bone loss

Receptor activator of NF‐κB ligand (RANKL) is essential for osteoclast formation and bone remodeling. Nevertheless, the cellular source of RANKL for osteoclastogenesis has not been fully uncovered. Different from peripheral adipose tissue, bone marrow (BM) adipose lineage cells originate from bone marrow mesenchymal stromal cells (BMSCs). Here, we demonstrate that adiponectin promoter‐driven Cre expression (Adipoq^Cre ) can target bone marrow adipose lineage cells. We cross the Adipoq^Cre mice with rankl^fl/fl mice to conditionally delete RANKL from BM adipose lineage cells. Conditional deletion of RANKL increases cancellous bone mass of long bones in mice by reducing the formation of trabecular osteoclasts and inhibiting bone resorption but does not affect cortical bone thickness or resorption of calcified cartilage. Adipoq^Cre; rankl^fl/fl mice exhibit resistance to estrogen deficiency and rosiglitazone (ROS)‐induced trabecular bone loss but show bone loss induced by unloading. BM adipose lineage cells therefore represent an essential source of RANKL for the formation of trabecula osteoclasts and resorption of cancellous bone during remodeling under physiological and pathological conditions. Targeting bone marrow adiposity is a promising way of preventing pathological bone loss.     

孕期应激对子代大鼠骨髓淋巴干细胞发育的影响

孕期应激对子代产生的影响是多方面的,这种影响是复杂的。研究表明,出生前的应激经历可导致出生后子代长期的免疫功能改变。这些改变追其根源与骨髓淋巴干细胞的改变有关。本文综述了大鼠孕期经历应激的子代骨髓淋巴干细胞所受的影响及免疫系统的相关改变,并根据现有的研究提出假说,为进一步研究孕期应激导致子代免疫系统改变的机理研究提供新的思路。     

Association of a synthetic bone graft and bone marrow cells as a composite biomaterial

Porous calcium phosphates have osteoconductive properties. The aim of this study was to obtain synthetic calcium phosphate bone graft substitute. X-ray diffraction was employed to investigate the formation of the beta-tricalcium phosphate (β-TCP) phase. We evaluated the effects of bone marrow on the osteoconductivity and mechanical properties of synthetic bone graft (SG). SG cylinders loaded with bone marrow (SGBM) and SG alone were implanted into rabbits femoral condyle bone defects. Histological examinations revealed the resorption of the SG, trabecular bone with osteoblasts and osteoid substance around the implants, and colonization inside the porous β-TCP by newly formed bone. Histomorphometry conducted after three months revealed the osteoid surface to be higher in SGBM than SG (p < 0.05). The compressive strengths of SG and SGBM were significantly higher than the anatomic control at all time periods. The elastic modulus of SBG and SGBM became weaker after implantation. The present results indicate that gB-TCP is a good matrix for bone marrow, which contributes osteoinductive properties in an orthotopic. The composite biomaterial may be useful in reconstructive bone surgery.     

Interaction between two group IV metals-lead and zirconium-in bone marrow cells ofMus musculus in vivo

The interaction between two group IV metals, the highly toxic lead and the relatively inactive and low toxic zirconium, was studied in the bone marrow chromosomes ofMus musculus in vivo. Low and high doses of zirconium oxychloride were fed orally to the experimental mice (i) 2 h before, (ii) 2 h after or (iii) together with different doses of lead nitrate. Protection against lead-induced clastogenicity was observed only when the lower dose of zirconium was administered prior to lead. All other combinations gave an additive or synergistic effect as was seen by significant increases in the frequencies of chromosomal aberrations.     

P62 deficiency shifts mesenchymal/stromal stem cell commitment toward adipogenesis and disrupts bone marrow homeostasis in aged mice

With advancing age have been observed bone and bone marrow phenotypic alterations due to the impaired bone tissue homeostatic features, involving bone remodeling, and bone marrow niche ontogeny. The complex “inflamm-aging” pathological scenario that culminates with osteopenia and mesenchymal/stromal and hematopoietic stem cell commitment breakdown, is controlled by cellular and molecular intramural components comprising adapter proteins such as the sequestosome 1 (p62/SQSTM1). p62, a “multiway function” protein, has been reported as an effective anti-inflammatory, bone-building factor. In this view, we considered for the first time the involvement of p62 in aging bone and bone marrow of 1 year and 2 years p62^−/− mice. Interestingly, p62 deficiency provoked accelerated osteopenia and impaired niche operational activities within the bone marrow. The above findings unearthed the importance of p62 in mesenchymal stem cell maintenance/differentiation schedule in old animals and provide, at least in part, a mechanistic scenario of p62 action.     

孕期应激对子代大鼠骨髓淋巴干细胞发育的影响

孕期应激对子代产生的影响是多方面的,这种影响是复杂的。研究表明,出生前的应激经历可导致出生后子代长期的免疫功能改变。这些改变追其根源与骨髓淋巴干细胞的改变有关。本文综述了大鼠孕期经历应激的子代骨髓淋巴干细胞所受的影响及免疫系统的相关改变,并根据现有的研究提出假说,为进一步研究孕期应激导致子代免疫系统改变的机理研究提供新的思路。     

Adenovirus-mediated BMP2 expression in human bone marrow stromal cells

Recombinant adenoviral vectors have been shown to be potential new tools for a variety of musculoskeletal defects. Much emphasis in the field of orthopedic research has been placed on developing systems for the production of bone. This study aims to determine the necessary conditions for sustained production of high levels of active bone morphogenetic protein 2 (BMP2) using a recombinant adenovirus type 5 (Ad5BMP2) capable of eliciting BMP2 synthesis upon infection and to evaluate the consequences for osteoprogenitor cells. The results indicate that high levels (144 ng/ml) of BMP2 can be produced in non-osteoprogenitor cells (A549 cell line) by this method and the resultant protein appears to be three times more biologically active than the recombinant protein. Surprisingly, similar levels of BMP2 expression could not be achieved after transduction with Ad5BMP2 of either human bone marrow stromal cells or the mouse bone marrow stromal cell line W20-17. However, human bone marrow stromal cells cultured with 1 microM dexamethasone for four days, or further stimulated to become osteoblast-like cells with 50 microg/ml ascorbic acid, produced high levels of BMP2 upon Ad5BMP2 infection as compared to the undifferentiated cells. The increased production of BMP2 in adenovirus transduced cells following exposure to 1 microM dexamethasone was reduced if the cells were not given 50 microg/ml ascorbic acid. When bone marrow stromal cells were allowed to become confluent in culture prior to differentiation, BMP2 production in response to Ad5BMP2 infection was lost entirely. Furthermore, the increase in BMP2 synthesis seen during differentiation was greatly decreased when Ad5BMP2 was administered prior to dexamethasone treatment. In short, the efficiency of adenovirus mediated expression of BMP2 in bone marrow stromal cells appears to be dependent on the differentiation state of these cells.     

Modulation of one of three murine bone marrow stromal cell lines to adipose cells by serum and insulin

Adipose cells have been recognized as an integral component of the bone marrow hematopoietic microenvironment in vivo and as an essential cell type required for in vitro maintenance of stem cells. Four stromal cell lines obtained from the adherent cell population of murine bone marrow cultures have been enriched and purified by multiple trypsinizations. We noted that these cell lines exhibited an accumulation of vacuoles of lipid, the extent of which varied be-tween cell lines in response to a change from medium containing 10% fetal calf serum to medium containing 20% horse serum. The lipid was lost when the cell lines were transferred back into the medium supplemented with fetal calf serum. In light of the reported lipogenic and antilipolytic effects of insulin on fibroblasts and adipocytes, we investigated the ability of insulin to induce adipocyte transformation of these bone marrow stromal cell populations. Three cell lines were exposed to bovine insulin at concentrations ranging from 10^?9 to 10^?6 M. All three cell lines responded to the insulin by accumulating lipid, but the extent of accumulation and the insulin concentration at which maximum lipid content was attained were population specific. One cell line (MC₁) responded fully at physiological levels of insulin (10^?9 M), whereas the other two showed lipid accumulation only at pharmacological concentrations. The initial growth of MC₁ was inhibited in the presence of 10^?9 M insulin which is compatible with the observed differentiation to adipocytes. The growth of MC₃ was unaltered in the presence of physiological concentrations of insulin, whereas that of MC₄ was accelerated. Grafts of organ cultures of the cell lines under the kidney capsule of syngeneic mice developed specific characteristics rep-resentative of the different cell lines. In particular, the majority of the grafts of MC₁ consisted primarily of fat cells which were not observed in the grafts of MC₃ and MC₄. These data strongly suggest that these cell lines comprise cells with different potentialities and that the MC₁ line represents a preadipocyte stromal cell of bone marrow.     

Differentiation of embryonic stem cells in adult bone marrow

Embryonic stem cells (ESCs) are a potential source of generating transplantable hematopoietic stem and progenitor cells, which in turn can serve as "seed" cells for hematopoietic regeneration. In this study, we aimed to gauge the ability of mouse ESCs directly differentiating into hematopoietic cells in adult bone marrow (BM). To this end, we first derived a new mouse ESC line that constitutively expressed the green fluorescent protein (GFP) and then injected the ESCs into syngeneic BM via intra-tibia. The progeny of the transplanted ESCs were then analyzed at different time points after transplantation. Notably, however, most injected ESCs differentiated into non-hematopoietic cells in the BM whereas only a minority of the cells acquired hematopoietic cell surface markers. This study provides a strategy for evaluating the differentiation potential of ESCs in the BM micro-environment, thereby having important implications for the physiological maintenance and potential therapeutic applications of ESCs.     

The frequency of bone marrow cells that bind erythropoietin

The frequencies of rat and mouse bone marrow cells capable of binding erythropoietin were studied by both direct fluorescence and indirect immunofluorescence. We found that between 1-2% of the cells bound erythropoietin, that the binding was specific, and that the number of cells that bound erythropoietin was, in part, a function of the erythropoietic state of the donor animal. A statistical method for evaluating the data obtained is included.