MR-Guided HDR Brachytherapy Boost in Localized Prostate Cancer - Results of a Phase II Trial

PURPOSE/OBJECTIVE(S)

Dose escalation in localized prostate cancer using brachytherapy combined with external beam radiation (EBRT) has demonstrated improved biochemical control compared to EBRT alone. However, ultrasound guided LDR brachytherapy might be associated with increased GU toxicity. We report the results of a prospective study of MR-guided HDR brachytherapy (MRgHDR) in combination with EBRT for localized prostate cancer.

MATERIALS/METHODS

Intermediate- (IR) and high-risk (HR) prostate cancer patients were eligible. Patients received either 15Gy single fraction or 10Gy x 2 fractions using MRgHDR technique, followed by EBRT (37.5 Gy, [prostate only] -IR or 45-46 Gy - [prostate + pelvic nodes] -HR). Toxicity (CTCAE v4) and HRQoL (EPIC) were recorded at 1, 3 and 6 months, then at 1, 2, 3, and 5 years. Androgen deprivation therapy (ADT) was used according to the appropriate disease risk category. Biochemical failure was defined according to Phoenix definition (nadir+2).

RESULTS

From 2010-2018, 120 patients were enrolled, 53 (44%) had IR and 67 (56%) had HR disease. Median age was 69 years (range, 46-78), median PSA was 12.1 ng/ml (3.2-148). ADT was used in 84 (70%) of patients, of whom 51 (60%) patients received <1 year and 33 (40%) received >1 year of ADT. A single fraction of 15Gy was given to 94 patients (78%) and the remaining 26 patients (22%) received 10Gy x 2 fractions. EBRT dose was 37.5Gy in 52 (43%) patients while 67 (56%) received 45-46Gy. One patient received only the first fraction of 10Gy, declined the second fraction and subsequently received 60Gy EBRT to the prostate. The median follow up was 58 months (11-134). Overall, 5-year biochemical control was 90% while it was 95% and 86% for IR and HR, respectively. At 5 years 7% patient had nodal or distant relapse or both. While the 5-yr distant control rates were 95% and 91% in the IR, HR, respectively. Acute grade ≥2 GU and GI toxicity was 6.7% and 5% respectively. Acute toxicity trended back to baseline by 6 months in all patients except one. Late grade ≥ 2 GU and GI worst toxicity was seen in 10% and 4.2%, respectively. As with acute toxicity, late toxicity tended to improve over time. Only one patient experienced severe toxicity (Grade 3 GU - frequency) at 6 months but subsequently this resolved. HRQol will be reported separately.

CONCLUSION

MRgHDR brachytherapy boost in conjunction with EBRT provides comparable biochemical outcomes compared to the literature. Severe toxicity rates were minimal. Further follow-up will determine if these outcomes are sustained.

Enhancement of alcohol-induced hypoglycaemia by H2-receptor antagonists

The oral ethanol loading test (0.5 g/kg body mass) was carried out in 3 groups with 10 healthy male volunteers each before and after 7 days of administration of either cimetidine (CAS 51481-61-9), ranitidine (CAS 66357-59-3), or famotidine (CAS 76824-35-6). The parameters determined during 6 h comprised the blood levels of ethanol, acetaldehyde, glucose, lactate, pyruvate and bicarbonates, as well as blood pH, PCO2 and PO2. Only ranitidine significantly increased the mean blood ethanol concentration and none of the drugs modified the blood acetaldehyde concentration. Hypoglycaemia following alcohol ingestion was significantly enhanced by all H2-receptor antagonists, but was most pronounced after famotidine. The alcohol-induced rise in blood pyruvate and lactate rather had a tendency to decrease during the second test. The presented results suggest that the evident enhancement of alcohol-induced hypoglycaemia by H2-receptor antagonists is not dependent on the increase of ethanol absorption from the gastrointestinal tract, but represents rather a specific effect of these drugs on glucose metabolism.

[Lactate metabolism in acute myocardial infarction]

In 18 patients with acute myocardial infarction admitted to the Cardiological Care Department within 6 hours after the onset of chest pain, before administration of drugs and then in the 2nd, 3rd, 5th and 7th day, the levels of glucose, pyruvate, lactate in venous blood, the lactate/pyruvate ratio (L/P) and pH, actual hydrocarbons, PCO2 and PO2 in capillary arterialized were determined. Depending on the clinical status at admission the patients were classified into 2 groups: I--without complications (I class according to Killip-Kimbal; n = 10), and II--with complications (II-IV class of cardiac failure according to Killip-Kimbal and/or complex ventricular arrhythmias e.i. III-V class according to Lown and heart block of Mobitz--type II and III degree; n = 8). None of the patients had diabetes, chronic respiratory tract diseases, renal failure and liver cirrhosis. The control group consisted of 11 healthy persons. On the first day of myocardial infarction, the significant increase of blood glucose, lactate, pyruvate, as well as significant decrease of blood pH, HCO3- and PO2, and non significant increase of L/P ratio were observed in both groups as compared to the control group. Also there were non significant difference of the glucose, lactate, pyruvate L/P ratio and pH, PCO2 and HCO3- values between the I and II group on the first day of the acute myocardial infarction, with exception of the PO2, which was significantly lower in the group II. In the following days an increase of PO2 was observed. Since this effect coincided with a decrease of lactate concentration (significant only in the group II) it could be concluded, that the observed decrease of the lactate concentration resulted from the higher supply of oxygen. The obtained results have shown, that increase of glycaemia values and decrease of PO2 values may be considered as biochemical markers for hemodynamic complications of acute myocardial infarction.

Alcohol tolerance in patients with non-insulin-dependent (type 2) diabetes treated with sulphonylurea derivatives

The oral ethanol loading test (0.5 g/kg body mass given as 40% solution) was carried out in 5 groups, each of 10 out-patients with non-insulin-dependent (type 2) diabetes before and after 10 days of treatment with one of the following sulphonylurea derivatives: tolbutamide (CAS 64-77-7) 0.5 t.i.d., chlorpropamide (CAS 94-20-2) 0.5 once daily morning, glibornuride (CAS 26944-48-9) 0.025 t.i.d., glibenclamide (CAS 10238-21-8) 0.005 t.i.d. and glipizide (CAS 29094-61-9) 0.005 t.i.d. The response to alcohol (facial flush, heart rate, blood pressure) were compared, and blood concentrations of ethanol, acetaldehyde, pyruvate, lactate, hydrocarbonates as well as blood pH, pO2 and pCO2 were determined in fasting state and during 6 hours after alcohol ingestion. In all patients the family history of diabetes and the presence and degree of vascular complications were registered. Evident flushing phenomenon was observed in 6 patients treated with chlorpropamide, in 3 treated with tolbutamide, in 2 treated with glibenclamide, in one receiving glibornuride and in none treated with glipizide. All drugs caused a greater rise of blood ethanol and acetaldehyde levels in relation to the control tests, but the difference reached statistical significance only in the group receiving chlorpropamide. Moreover, patients (pooled) with positive thermographic response had also significantly higher blood levels of ethanol and acetaldehyde during the second test. The ratio of acetaldehyde to ethanol concentration in blood (mumol:mmol) was not significantly changed in any group indicating parallel impairment of both steps of ethanol metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

[Alcohol tolerance in patients with non-insulin-dependent diabetes (type 2) treated orally with drugs--derivatives of sulphonylurea]

The oral ethanol loading test (0.5 g per kg b.m. given as 40% solution) was carried out in 5 groups, each of 10 patients with non-insulin-dependent (type 2) diabetes before and after 10 days of treatment with one of the following sulphonylurea derivatives: tolbutamide 0.5 t.i.d., chlorpropamide 0.5 once daily morning, glibornuride 0.025 t.i.d, glibenclamide 0.005 t.i.d. and glipizide 0.005 t.i.d. The response to alcohol (facial flush, heart rate, blood pressure) were compared, and blood concentration of ethanol, acetaldehyde, pyruvate, lactate, carbonates as well as blood pH, pO2 and pCO2 were determined in fasting state and during 6 hours after alcohol ingestion. In all patients the family history of diabetes and the presence and degree of vascular complications were registered. Evident flushing phenomenon was observed in 6 patients treated with chlorpropamide, in 3 treated with tolbutamide, in 2 treated with glibenclamide, in one receiving glibornuride and in none treated with glipizide. All drugs caused a greater rise of blood ethanol and acetaldehyde levels in relation to the control tests, but the difference reached statistical significance only in the group receiving chlorpropamide. Moreover, patients (pooled) with positive thermographic response had also significantly higher blood levels of ethanol and acetaldehyde during the second test. The ratio of acetaldehyde to ethanol concentration in blood (mumol:mmol) was not significantly changed in any group indicating parallel impairment of both steps of ethanol metabolism. All studied drugs intensified to a similar degree the alcohol-induced hypoglycaemia, but had no significant effect on the decrease of blood pyruvate level neither on the increase of blood lactate level. They didn't change the post-alcohol decrease of blood bicarbonate and pH, and didn't modify the behaviour of partial gas pressure. There was also no difference between pooled groups of patients with positive and negative thermographic reaction with respect to family history of diabetes and frequency and intensity of vascular complications. It is concluded that in patients with non-insulin-dependent (type 2) diabetes the second generation sulphonylurea derivatives are associated with lower risk of alcohol intolerance in case of its incidental ingestion in small amounts. The hypothesis of association of positive thermographic reaction to alcohol during treatment with sulphonylurea derivatives with more frequent occurrence of diabetes in family members and lower tendency to vascular complications was not confirmed.