Does intensity-modulated radiation therapy (IMRT) alter prostate size? Magnetic resonance imaging evaluation of patients undergoing IMRT alone

AimTo assess the changes in prostate size in patients with prostate cancer undergoing intensity-modulated radiation therapy (IMRT).BackgroundThe effect of size change produced by IMRT is not well known.Materials and methodsWe enrolled 72 patients who received IMRT alone without androgen-deprivation therapy and underwent magnetic resonance imaging (MRI) examination before and after IMRT. The diameter of the entire prostate in the anterior–posterior (P-AP) and left–right (P-LR) directions was measured. The transitional zone diameter in the anterior–posterior (T-AP) and left–right (T-LR) directions was also measured.ResultsThe average relative P-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.94, 0.90, 0.89, 0.89, and 0.90, respectively; the average relative P-LR values were 0.93, 0.92, 0.91, 0.91, and 0.90, respectively. The average P-AP and P-LR decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. The average relative T-AP values at 3, 6, 12, 24, and 36 months after IMRT compared to the pre-IMRT value were 0.93, 0.88, 0.91, 0.87, and 0.89, respectively; the average relative T-LR values were 0.96, 0.90, 0.91, 0.87, and 0.88, respectively. The average T-AP and T-LR also decreased by approximately 10% during the 12 months post-IMRT, and remained unchanged thereafter. At 12 months after IMRT, the average relative T-AP was significantly lower in patients with recurrence than in those without recurrence.ConclusionsThe average prostate diameter decreased by approximately 10% during the 12 months after IMRT; thereafter remained unchanged

Solitary mediastinal lymph node metastasis of hepatocellular carcinoma: MR imaging findings.

A 65-year-old man with multiple hepatocellular carcinomas in the liver with type C viral hepatitis had a solitary mediastinal lymph node metastasis in the right paratracheal to tracheobronchial region. Surgical resection for the mediastinal metastasis was undertaken based on magnetic resonance (MR) imaging findings, suggesting its radicality. We assess the MR imaging findings and presumable pathways of lymphatic metastasis from the liver to mediastinal lymph nodes in this report.A 65-year-old man with multiple hepatocellular carcinomas in the liver with type C viral hepatitis had a solitary mediastinal lymph node metastasis in the right paratracheal to tracheobronchial region. Surgical resection for the mediastinal metastasis was undertaken based on magnetic resonance (MR) imaging findings, suggesting its radicality. We assess the MR imaging findings and presumable pathways of lymphatic metastasis from the liver to mediastinal lymph nodes in this report

11C-methionine positron emission tomography for target delineation o frecurrent glioblastoma in re-irradiation planning

AimTo define the optimal margin on MRI scans in the re-radiation planning of recurrent glioblastoma using methionine positron emission tomography (MET-PET).BackgroundIt would be very useful if the optimal margin on MRI to cover the uptake area on MET-PET is known.Materials and MethodsCT, MRI, and MET-PET were performed separately over the course of 2 weeks. Among the MRI scans, we used the contrast-enhanced T1-weighted images (Gd-MRI) and T2-weighted images (T2-MRI). The Gd-MRI-based clinical target volume (CTV) (CTV-Gd) and the T2-MRI-based CTV (CTV-T2) were defined as the contrast-enhanced area on Gd-MRI and the high intensity area on T2-MRI, respectively. We defined CTV x mm (x[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]5, 10, 15, 20) as x mm outside the CTV. MET-PET-based CTV (CTV-MPET) was defined as the area of accumulation of MET-PET. We calculated the sensitivity and specificity of CTV-Gd and CTV-T2 following comparison with CTV-MPET, which served as the gold standard in this study.ResultsThe sensitivity of CTV-T2 5[[ce:hsp sp="0.25"/]]mm (98%) was significantly higher than CTV-T2 (87%), and there was no significant difference in the sensitivity between CTV-T2 5[[ce:hsp sp="0.25"/]]mm and CTV T2 10, 15, or 20[[ce:hsp sp="0.25"/]]mm. The sensitivity of CTV-Gd 20[[ce:hsp sp="0.25"/]]mm (97%) was lower than that of CTV-T2 5[[ce:hsp sp="0.25"/]]mm (98%).ConclusionsA margin of at least 5[[ce:hsp sp="0.25"/]]mm around the high intensity area on T2-MRI is necessary in the target volume delineation of recurrent glioblastoma for the coverage of MET-PET findings in re-radiation therapy planning

Treatment outcomes and late toxicities of intensity-modulated radiation therapy for 1091 Japanese patients with localized prostate cancer

AimThis study aimed to evaluate the treatment result of intensity-modulated radiation therapy (IMRT) in a large number of Japanese patients with prostate cancer.BackgroundA total of 1091 patients with localized prostate cancer were recruited between March 2006 and July 2014. The patients were stratified into low- (n[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]205 [18.8%]), intermediate- (n[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]450 [41.2%]), high- (n[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]345 [31.6%]), and very high-risk (n[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]91 [8.3%]) groups according to the National Comprehensive Cancer Network classification. All patients were irradiated via IMRT at a dose of 74–78[[ce:hsp sp="0.25"/]]Gy with or without androgen-deprivation therapy. The mean follow-up period was 50 months (range, 2–120 months).ResultsThe biochemical failure-free rate (BFFR), the clinical failure-free rate, and the overall survival rate at the 5-year follow-up for all patients was 91.3%, 96.2%, and 99.1%, respectively. In univariate analysis, the prostate-specific antigen (PSA) levels (≤20 vs. >20[[ce:hsp sp="0.25"/]]ng/ml) were significantly correlated with BFFR. A trend toward higher BFFR was noted in patients with a Gleason score (GS) of ≤7 than in patients with GS ≥8. In multivariate analysis, only PSA (≤20 vs. >20[[ce:hsp sp="0.25"/]]ng/ml) was significantly correlated with BFFR. The cumulative incidence rate of gastrointestinal and genitourinary toxicity (≥grade 2) at the 5-year follow-up was 11.4% and 4.3%, respectively.ConclusionsThe findings of this study indicate that IMRT is well tolerated and is associated with both good long-term tumor control and excellent outcomes in patients with localized prostate cancer