Effects of single dose irradiation on pancreatic beta-cell function

Radioprotective effects of α2-adrenergic receptor agonist dexmedetomidine on X-ray irradiation-induced pancreatic islet cell damage

Comprehensive epidemiological analyses conducted in the last 30 years have revealed a link between radiation and DM. We aimed to determine the effects of dexmedetomidine pretreatment on radiation-induced pancreatic islet cell damage. Twenty-four rats were divided into three groups: group 1 (control group), group 2 (only X-ray irradiation group), and group 3 (X-ray irradiation + dexmedetomidine). We observed necrotic cells with vacuoles accompanying loss of cytoplasm in the islets of Langerhans, extensive edematous areas, and vascular congestions in group 2. In group 3, we observed a decrease in necrotic cells in the islets of Langerhans, and edematous areas and vascular congestion was also reduced. We determined a decrease in β-cells, α-cells, and D-cells in the islets of Langerhans in group 2 compared to the control group. In group 3, β-cells, α-cells, and D-cells were elevated compared to group 2. Ionizing radiation may induce DM. Dexmedetomidine appears to exert a radioprotective effect.

Volumetric decrease of pancreas after abdominal irradiation, it is time to consider pancreas as an organ at risk for radiotherapy planning

Background

Volumetric shrinkage of normal tissues such as salivary glands, kidneys, hippocampus are observed after radiotherapy. We aimed to assess the alterations in pancreatic volume of patients who received abdominal radiotherapy and define pancreas as an organ at risk for radiation treatment planning.

Material-methods

Forty-nine patients operated for gastric adenocarcinoma who received adjuvant abdominal radiotherapy were in the study group, 27 patients with early stage disease who did not need adjuvant treatment after surgery comprised the control group. An experienced radiologist contoured the pancreas of all the patients from computed tomographies imported to the planning system obtained either for radiation planning purpose or for follow-up after surgery. The same procedure was repeated one year later for both groups. Measured volume of the pancreas was expressed in cm³.

Results

Mean pancreatic volumes were similar in both groups at the onset of the study, 51,34 ± 20,33 cm³, and 50,12 ± 23,75 cm³ in the irradiated and the control groups respectively (p = 0,63). One year later, mean pancreatic volumes were significantly decreased in each group; 22,48 ± 10,53 cm³, 44,18 ± 23,08 cm³ respectively, p < 0,001. However, the decrease in pancreatic volume was significantly more pronounced in the irradiated group in comparison to the control group, p < 0,001.

Conclusion

Volumetric decrease in normal tissues after radiotherapy is responsible for loss of organ function and radiation related late side effects. Although pancreas is a radiation sensitive organ losing its volume and function after radiation exposure, it is not yet considered as an organ at risk for radiation treatment planning. Pancreas should be contoured as an organ at risk, dose-volume histogram for the organ should be created, and safe organ doses should be determined. This is the first study declaring pancreas as an organ at risk for radiation toxicity and the necessity of defining dose constraints for the organ.

Pancreatic radiation effect in apoptosis-related rectal radiation toxicity

Pancreatic radiation effect (PRE) can be a component of gastrointestinal tract (GIT) radiotoxicity. This inter-organ correlation between the GIT and the pancreas was assessed through a rat model. Separate local irradiation to the abdomen and the pelvis was applied concurrently for 8-week-old male Sprague Dawley rats. Abdominal irradiation was categorized into pancreatic shield (PS) and non-pancreatic shield (NPS) irradiation. After 5 Gy and 15 Gy irradiation, the rectal mucosa was analyzed at the first week (early phase, Ep) and the 14th week (late phase, Lp). A slow gain in body weight was observed initially, particularly in the NPS group receiving a 15 Gy dose (P < 0.001). The large number of apoptotic bodies after 15 Gy at Ep decreased at Lp. At Ep for the 5-Gy group, the NPS group revealed more fibrotic change than the PS group (P = 0.002). Cleaved caspase-3 (CCP3) expression was greater at Lp, and the Ep-Lp increase was prominent in the NPS-15-Gy group (P = 0.010). At Lp, for 15 Gy irradiation, CCP3 was expressed more in the NPS group than in the PS group (P = 0.032). Despite no direct toxicity difference between the PS and NPS groups, small changes in parameters such as fibrosis or CCP3 expression suggest that pancreatic shielding does have an effect on the radiation response in the rectal mucosa, which suggests a need for a multi-organ effect-based approach in GIT radiotoxicity assessment.

Radiation-induced injury of the exocrine pancreas after chemoradiotherapy for gastric cancer

BACKGROUND AND PURPOSE

The pancreas is located almost entirely within the treatment area for radiotherapy of gastric cancer. The aim of this study was to analyze radiation-induced injury of the exocrine pancreas.

MATERIAL AND METHODS

The study included 127 gastric cancer patients, who underwent preoperative or postoperative chemoradiotherapy. A total dose of 45 Gy was given in 25 fractions. Concurrent chemotherapy was 5-fluorouracil-based. Lipase and α-amylase were assayed before, during and after treatment.

RESULTS

Lipase and α-amylase deficiencies were found in 48.2% and 19.7% of patients, respectively. In the univariant analysis, age and pretreatment α-amylase and lipase activities influenced on risk of injury of the exocrine pancreas (p<0.05). Younger patients (<65 years) had a lower risk of hypoamylasemia than older patients. The probability of insufficiency was lower than 0.2 for patients with pretreatment α-amylase and lipase activities above 50 U/L and 55 U/L, respectively. The multivariate analyses of the time to hypolipasemia showed that only pretreatment lipase activity was significant.

CONCLUSIONS

Gastric cancer patients have an increased risk of exocrine pancreatic insufficiency after chemoradiotherapy. Thus, the pancreas should be regarded as an OAR. Measuring lipase activity should be the standard for assessing radiation-induced pancreatic injury.

Screening and management of adverse endocrine outcomes in adult survivors of childhood and adolescent cancer

5 year survival for childhood and adolescent cancer in developed countries is now in excess of 80% and the number of survivors of cancer continues to increase worldwide. After completion of therapy, many of these survivors will face a lifelong risk of endocrine late effects. We summarise the available evidence related to the prevalence and risk factors for endocrine late effects among adult survivors of childhood and adolescent cancer. Present screening, surveillance, and treatment recommendations differ by country and region, so we also highlight the continued effort to harmonise the international guidelines for this population.

Reduced beta-cell reserve and pancreatic volume in survivors of childhood acute lymphoblastic leukaemia treated with bone marrow transplantation and total body irradiation

BACKGROUND

Impaired glucose tolerance (IGT) and diabetes mellitus (DM) occur more frequently after bone marrow transplantation and total body irradiation (BMT/TBI), but the mechanism is unclear. This study investigates insulin sensitivity, β-cell reserve and pancreatic volume in adult survivors of childhood acute lymphoblastic leukaemia (ALL).

METHOD

Survivors (aged 16-26 years) of ALL treated with BMT/TBI (10-14·4 Gy) Group 1 (n = 20, 10 m) were compared with a chemotherapy-only Group 2 (n = 28, 11 m). Participants underwent assessments of insulin sensitivity by whole body composite-insulin-sensitivity-index (ISIcomp ) from oral glucose tolerance tests (OGTTs); first (AIRarg , AIRg , AUCin10 ) and second (AUC in second phase ) phase insulin responses from arginine-intravenous glucose tolerance tests; and pancreatic volume by abdominal magnetic resonance imaging (MRI). Data were analysed by odds ratio, Chi-square or Fisher's exact tests, Student's t-tests, analysis of covariance (ancova) and Pearson's or partial correlations (5% significance).

RESULTS

Abnormal OGTTs were documented in Group 1 (DM = 2, IGT = 7). Insulin secretion adjusted for insulin sensitivity was lower in Group 1 than Group 2 as a whole [LogAIRarg (P = 0·008), logAIRg (P = 0·013) and logAUCin10 (P = 0·014)] and after exclusion of those with abnormal glucose tolerance [logAIRarg (P = 0·011), logAIRg (P = 0·007) and logAUCin10 (P = 0·006)]. Group 1 had lower pancreatic volume than Group 2 [52·0 (14·2) vs 72·8 (23·5), P = 0·001] cm(3) , and results were consistent after adjustment for size by body surface area (P = 0·019). Pancreatic volume correlated with logAIRarg adjusted log ISIcomp (partial correlation = 0·34, P = 0·025).

CONCLUSIONS

Adult survivors of childhood BMT/TBI for ALL demonstrated reduced β-cell reserve and smaller pancreatic volume, both likely additional aetiological factors, with reduced insulin sensitivity, in their increased risk of diabetes.

Postoperative chemoradiotherapy following pancreaticoduodenectomy. Impact of dose-volumetric parameters on the development of diabetes mellitus

PURPOSE

The purpose of this research was to analyze the relationship between dose-volumetric parameters and the development of diabetes mellitus (DM) in patients treated with chemoradiotherapy (CRT) following curative resection for upper gastrointestinal (GI) cancers.

PATIENTS AND METHODS

Medical records of patients who underwent postoperative CRT following curative resection, either pancreaticoduodenectomy (PD) or pylorus preserving pancreaticoduodenectomy (PPPD) for upper GI cancers including pancreas, biliary, ampullary, and duodenal cancers, between January 2006 and December 2008 were retrospectively reviewed. A total of 42 patients who were regularly followed for at least 2 years were included for analysis. Dose-volumetric parameters such as remnant pancreatic volume, mean dose, maximum dose (Dmax), and percentage of volume receiving specific dose or more were obtained from pre- and postoperative CT scan images and treatment plan.

RESULTS

Dmax and V50 (percentage of volume receiving at least 50 Gy) were statistically significant factors for the development of DM (p = 0.013, p = 0.031, respectively). The sensitivity and specificity of Dmax was 0.875 and 0.559, with cut-off value of 51.1 Gy, respectively. V50 had sensitivity of 0.875 and specificity of 0.618 for cut-off value of 16 %. No patient-related factor other than pretreatment cerebrovascular events was associated with the development of DM. On multivariate analysis, V50 was the only factor with statistical significance (p = 0.028), whereas Dmax showed borderline significance (p = 0.079).

CONCLUSION

V50 was the only independent factor associated with the development of diabetes and may function as guideline to predict the development of DM in patients receiving CRT following curative resection.

Burden of morbidity in 10+ year survivors of hematopoietic cell transplantation: report from the bone marrow transplantation survivor study

Long-term morbidity after hematopoietic cell transplantation (HCT) is unknown. The risk of physical and psychological health in 324 patients who had survived 10 or more years after HCT and a sibling comparison group (n = 309) was evaluated. Using the Common Terminology Criteria for Adverse Events, the 15-year cumulative incidence of severe/life-threatening/fatal conditions was 41% (95% confidence interval, 34% to 48%). HCT survivors were 5.7 times as likely to develop a severe/life-threatening condition (P < .001) and 2.7 times as likely to report somatic distress (P < .001) compared with siblings. Compared with allogeneic HCT recipients with no chronic graft-versus-host disease (GVHD), those with active chronic GVHD were at a 1.8-fold higher risk of severe/life-threatening health conditions (P = .006) and a 4.5-fold higher risk of somatic distress (P = .04); allogeneic HCT recipients with resolved chronic GVHD were not at increased risk of morbidity compared with those with no chronic GVHD. Only 27% of the HCT survivors returned to the transplantation center for their cancer-related care. The burden of long-term physical and emotional morbidity borne by survivors remains substantial, even beyond 10 years after HCT; however, specialized health care is underused. Patients, families, and healthcare providers need to be made aware of the high burden, so they can plan for post-HCT care, even many years after HCT.

Risk of endocrine pancreatic insufficiency in patients receiving adjuvant chemoradiation for resected gastric cancer

BACKGROUND

Adjuvant radiotherapy combined with 5-fluorouracil based chemotherapy has become the new standard after curative resection in high risk gastric cancer. Beside many complications due to surgery, the addition of chemotherapy and radiotherapy as adjuvant treatment may lead to both acute and late toxicities. Pancreatic tissue irradiation during this adjuvant treatment because of incidental and unavoidable inclusion of the organ within the radiation field may affect exocrine and endocrine functions of the organ.

MATERIALS AND METHODS

Fifty-three patients with gastric adenocarcinoma were evaluated for adjuvant chemoradiotherapy after surgery. While 37 out of 53 patients were treated postoperatively due to either serosal or adjacent organ or lymph node involvement, 16 patients without these risk factors were followed up regularly without any additional treatment and they served as the control group. Fasting blood glucose (FBG), hemoglobin A1c (HBA1c), insulin and C-peptide levels were measured in the control and study groups after the surgery and 6 months and 1 year later.

RESULTS

At the baseline there was no difference in FBG, HbA1c, C-peptide and insulin levels between the control and the study groups. At the end of the study there was a statistically significant decline in insulin and C-peptide levels in the study group, (7.5 ± 6.0 vs 4.5 ± 4.4 IU/L, p: 0.002 and 2.3 ± 0.9 vs 1.56 ± 0.9 ng/ml, p: 0.001) respectively.

CONCLUSIONS

Adjuvant radiotherapy in gastric cancer leads to a decrease in beta cell function and insulin secretion capacity of the pancreas with possible diabetes risk. Radiation-induced pancreatic injury and late effects of radiation on normal pancreatic tissue are unknown, but pancreas is more sensitive to radiation than known. This organ should be studied extensively in order to determine the tolerance doses and it should be contoured during abdominal radiotherapy planning as an organ at risk.

Diabetes mellitus in long-term survivors of childhood cancer. Increased risk associated with radiation therapy: a report for the childhood cancer survivor study

BACKGROUND

Childhood cancer survivors are at increased risk of morbidity and mortality. To further characterize this risk, this study aimed to compare the prevalence of diabetes mellitus (DM) in childhood cancer survivors and their siblings.

METHODS

Participants included 8599 survivors in the Childhood Cancer Survivor Study (CCSS), a retrospectively ascertained North American cohort of long-term survivors who were diagnosed between 1970 and 1986 as well as 2936 randomly selected siblings of the survivors. The main outcome was self-reported DM.

RESULTS

The mean ages of the survivors and the siblings were 31.5 years (age range, 17.0-54.1 years) and 33.4 years (age range, 9.6-58.4 years), respectively. Diabetes mellitus was reported in 2.5% of the survivors and 1.7% of the siblings. After adjustment for body mass index, age, sex, race/ethnicity, household income, and insurance, the survivors were 1.8 times more likely than the siblings to report DM (95% confidence interval [CI], 1.3-2.5; P < .001), with survivors who received total body irradiation (odds ratio [OR], 12.6; 95% CI, 6.2-25.3; P < .001), abdominal irradiation (OR, 3.4; 95% CI, 2.3-5.0; P < .001), and cranial irradiation (OR, 1.6; 95% CI 1.0-2.3; P = .03) at increased risk. In adjusted models, an increased risk of DM was associated with total body irradiation (OR, 7.2; 95% CI, 3.4-15.0; P < .001), abdominal irradiation (OR, 2.7; 95% CI, 1.9-3.8; P < .001), use of alkylating agents (OR, 1.7; 95% CI, 1.2-2.3; P < .01), and younger age at diagnosis (0-4 years; OR, 2.4; 95% CI, 1.3-4.6; P < .01).

CONCLUSION

Childhood cancer survivors treated with total body or abdominal irradiation have an increased risk of diabetes that appears unrelated to body mass index or physical inactivity.

Accelerated radiochemotherapy in pancreatic cancer is not necessarily related to a pathologic pancreatic function decline in the early period

PURPOSE

To evaluate the functional effects of ionizing radiation in patients with unresectable pancreatic cancer in the early period after accelerated radiochemotherapy (ART).

METHODS AND MATERIALS

To analyze the exocrine component, the amino acid consumption test and fecal elastase 1 were performed in 13 patients immediately before and 4-8 weeks after ART. Pancreatic duct morphology was evaluated before therapy. Weight loss and clinical steatorrhea were recorded. Endocrine parameters were examined according to standardized criteria.

RESULTS

The relative change of the amino acid consumption test results and the median elastase concentration was 41.2% and 56.4%, respectively. Five patients still had normal test results after ART and 5 patients developed pathologic values. The median relative weight loss of the total body weight was 7.7% +/- 4.5%. No steatorrhea occurred. Of the 5 patients with normal values, 3 had a mean organ dose of <40 Gy. Of the 5 patients with pathologic values, 4 had a mean organ dose of >41 Gy. The endocrine function measurements remained unchanged.

CONCLUSION

Although a nominal reduction of exocrine function parameters occurred in most patients, ART was not necessarily related to a pathologic level in the early period. Diabetes was not established. The functional impairment that was existent in the patient population presumably contributed to the weight loss. Pancreatic enzyme preparations may also play a role in maintaining an anabolic state during and after radiochemotherapy.