Strontium-89 (Sr-89) is a pure emitter with maximum beta energy of 1.46 MeV, average beta energy of 0.58 MeV, and a physical half-life of 50.5 days. It is rapidly taken up by bone and preferentially retained at the sites of osseous metastases. Its biological half-life is >50 days at the metastatic sites, but about 14 days only in the normal bone. The dose of its absorption in the tumor-bearing bone ranges from 21 +/- 4 to 231 +/- 56 cGy/MBq, 2-25 times higher than in the normal bone. Strontium-89 therapy is an effective palliative treatment of bone metastases from prostate cancer, with analgesic effectiveness in 80%.
Bone Neoplasms ; radiotherapy ; secondary ; Humans ; Male ; Neoplasm Metastasis ; Prostatic Neoplasms ; pathology ; radiotherapy ; Strontium Radioisotopes ; therapeutic use

BACKGROUNDImage-guided radiation therapy (IGRT) is the preferred method for curative treatment of localized prostate cancer, which could improve disease outcome and reduce normal tissue toxicity reaction. IGRT using cone-beam computed tomography (CBCT) in combination with volumetric-modulated arc therapy (VMAT) potentially allows smaller treatment margins and dose escalation to the prostate. The aim of this study was to compare the difference of dosimetric diffusion in conventional IGRT using 7-field, step-and-shoot intensity-modulated radiation therapy (IMRT) and hypofractionated IGRT using VMAT for patients with localized prostate cancer.

METHODSWe studied 24 patients who received 78 Gy in 39 daily fractions or 70 Gy in 28 daily fractions to their prostate with/without the seminal vesicles using IMRT (n = 12) or VMAT (n = 12) for prostate cancer between November 2013 and October 2015. Image guidance was performed using kilovoltage CBCT scans equipped on the linear accelerator. Offline planning was performed using the daily treatment images registered with simulation computed tomography (CT) images. A total of 212 IMRT plans in conventional cohort and 292 VMAT plans in hypofractionated cohort were enrolled in the study. Dose distributions were recalculated on CBCT images registered with the planning CT scanner.

RESULTSCompared with 7-field, step-and-shoot IMRT, VMAT plans resulted in improved planning target volume (PTV) D95% (7663.17 ± 69.57 cGy vs. 7789.17 ± 131.76 cGy, P < 0.001). VMAT reduced the rectal D25 (P < 0.001), D35 (P < 0.001), and D50 (P < 0.001), bladder V50 (P < 0.001), D25 (P = 0.002), D35 (P = 0.028), and D50 (P = 0.029). However, VMAT did not statistically significantly reduce the rectal V50, compared with 7-field, step-and-shoot IMRT (25.02 ± 5.54% vs. 27.43 ± 8.79%, P = 0.087).

CONCLUSIONSTo deliver the hypofractionated radiotherapy in prostate cancer, VMAT significantly increased PTV D95% dose and decreased the dose of radiation delivered to adjacent normal tissues comparing to 7-field, step-and-shoot IMRT. Daily online image-guidance and better management of bladder and rectum could make a more precise treatment delivery.

Aged ; Aged, 80 and over ; Humans ; Male ; Prostate ; pathology ; radiation effects ; Prostatic Neoplasms ; pathology ; radiotherapy ; Radiotherapy Dosage ; Radiotherapy, Image-Guided ; methods ; Radiotherapy, Intensity-Modulated ; methods ; Retrospective Studies

Over 80% of the patients with prostate cancer (PCa) develop bone metastasis, which seriously affects the patients' quality of life and remains a major cause of morbidity. Radium-223 (Ra-223), a newly approved agent targeting bone metastasis of PCa, can improve the quality of life and prolong the overall survival of the PCa patients with bone metastasis. This article presents an overview of the clinical trials recently published on the management of bone metastasis of PCa with Ra-223.
Bone Neoplasms ; radiotherapy ; secondary ; Clinical Trials as Topic ; Humans ; Male ; Prostatic Neoplasms ; pathology ; Quality of Life ; Radioisotopes ; Radium ; therapeutic use

OBJECTIVETo evaluate the efficacy of strontium-89 (89Sr) in the treatment of painful bone metastases of prostate cancer.

METHODSA total of 116 patients with painful bone metastases of prostate cancer received bilateral orchiectomy and incretion, followed by intravenous injection of 89Sr at the dose of 1.48-2.22 MBq (40-60 microCi)/kg. The clinical effects were evaluated by follow-up analysis.

RESULTSAfter the 89Sr treatment, appetite and sleep were evidently improved in 33.6% and 56.0% of the patients respectively, the applied dose of anodyne reduced in 61.2%, pain alleviated in 83.6%, with an absolute palliation rate of 24.1%. Pain relief started at 3-21 (10.2 +/- 6.5) days and lasted 3-12 (5.3 +/- 2.2) months. Flare ache occurred in 31.9% of the patients. Compared with pre-treatment, the mean score on Karnofsky's performance status (KPS) was 20.0% higher, and the WBC count decreased to 3.0-3.9 x 10(6)/L in 18.1% of the patients. Whole body bone scintigraphy of 53 followed-up patients showed that 39 (73.6%) of them exhibited an obvious decrease in the number of metastases, 10 (18.9% remained in a stabilized state and only 4 (7.5% deteriorated.

CONCLUSION89Sr, capable of inhibiting bone metastasis, palliating pain and improving the quality of life with few adverse effects, can be used as a desirable therapeutic for painful bone metastases of prostate cancer.

Aged ; Aged, 80 and over ; Bone Neoplasms ; radiotherapy ; secondary ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Pain, Intractable ; radiotherapy ; Prostatic Neoplasms ; pathology ; Strontium Radioisotopes ; therapeutic use ; Treatment Outcome

Bone metastases are a major problem in the clinical management of patients with prostate cancer. Despite the use of analgesic for the relief of such pain, the outcomes are not often satisfactory. Strontium-89 (89Sr) is a pure beta-emitting radioisotope to be avidly concentrated in the areas of high osteoblastic activity. The aim of this study was to evaluate the efficacy of 89Sr in the therapy for bone metastases of prostate carcinoma. 116 patients received intravenous injection of 89Sr at the dose of 3mCi (111MBq). All patients underwent physical examination and Karnofsky's Performance Score (KPS) evaluation before and after administration; the analgesic effects were evaluated by scores of pain. The complete response (CR) was defined as scores of pain > 75%; no response (NR) was defined as scores of pain < 25% the remaining was partial response (PR). The changes of bone metastases were screened by CT, MRI and 99mTc-MDP bone scintigraphy according to the standards of WHO. After the treatment with 89Sr, the total response rate was 80.2%. In the 116 cases, 21 cases (18.1%) displayed complete response and 72 cases (62.1%) displayed partial response, but 23 cases (19.2%) showed no response. The mean score on Karnfsky's performance status (KPS) was 20.0% higher. About 1/3 cases exhibited an obvious decrease in the number of metastases, and some foci disappeared. Thirteen cases (12%) showed a greater decrease in prostate-specific antigen (PSA) value. 89Sr chloride is an effective and safe therapy of the bone metastases from prostate cancer.
Adult ; Aged ; Aged, 80 and over ; Bone Neoplasms ; radiotherapy ; secondary ; Humans ; Male ; Middle Aged ; Prostatic Neoplasms ; pathology ; radiotherapy ; Strontium Radioisotopes ; therapeutic use

PURPOSE: The validity of tomotherapy-based simultaneous integrated boost (TOMOSIB) was assessed in terms of acute intestinal/urinary toxicity by comparing with 3-dimensional conformal radiotherapy (3DCRT) in cases of whole-pelvis radiation therapy (WPRT) for prostate cancer. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent curative WPRT were retrospectively reviewed. Twenty six (68.4%) received 3DCRT and the others (31.6%) were treated with TOMOSIB. A local boost to the prostate circumferential area was added to WPRT sequentially for 3DCRT and concomitantly for TOMOSIB. The total median prostate or prostatic bed dose was 64.8 Gy including median 45.0 Gy of WPRT. Acute toxicities were assessed according to RTOG criteria. RESULTS: Overall intestinal toxicity was lower in TOMOSIB group than 3DCRT group (p=0.008). When it was divided into rectum and non-rectum intestine (NRI), TOMOSIB showed borderline superiority only in NRI toxicity (p=0.047). For the urinary toxicity, there was no significant difference between two groups (p=0.796). On dosimetric analysis for the rectum and bladder, dose delivered to 80% (p<0.001) and volume receiving 25-40 Gy (p<0.001) were remarkably higher in 3DCRT. For the NRI, only maximum dose showed significant results between two groups (p<0.001). CONCLUSION: Intestinal toxicity should be verified with more detailed anatomic categorization such as rectum and NRI. TOMOSIB could not reduce urinary toxicity because of inevitably high dose exposure to the prostatic urethra. Current dosimetry system did not properly reflect intestinal/urinary toxicity, and suitable dosimetric guidelines are needed in TOMOSIB.
Adenocarcinoma/pathology/*radiotherapy ; Aged ; Humans ; Intestine, Small/*radiation effects ; Male ; Middle Aged ; Pelvis/*radiation effects ; Prostatic Neoplasms/pathology/*radiotherapy ; Radiation Injuries ; Radiotherapy Dosage ; Radiotherapy, Intensity-Modulated/*adverse effects/methods ; Rectum/radiation effects ; Retrospective Studies ; Urinary Bladder/*radiation effects

PURPOSE: The validity of tomotherapy-based simultaneous integrated boost (TOMOSIB) was assessed in terms of acute intestinal/urinary toxicity by comparing with 3-dimensional conformal radiotherapy (3DCRT) in cases of whole-pelvis radiation therapy (WPRT) for prostate cancer. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent curative WPRT were retrospectively reviewed. Twenty six (68.4%) received 3DCRT and the others (31.6%) were treated with TOMOSIB. A local boost to the prostate circumferential area was added to WPRT sequentially for 3DCRT and concomitantly for TOMOSIB. The total median prostate or prostatic bed dose was 64.8 Gy including median 45.0 Gy of WPRT. Acute toxicities were assessed according to RTOG criteria. RESULTS: Overall intestinal toxicity was lower in TOMOSIB group than 3DCRT group (p=0.008). When it was divided into rectum and non-rectum intestine (NRI), TOMOSIB showed borderline superiority only in NRI toxicity (p=0.047). For the urinary toxicity, there was no significant difference between two groups (p=0.796). On dosimetric analysis for the rectum and bladder, dose delivered to 80% (p<0.001) and volume receiving 25-40 Gy (p<0.001) were remarkably higher in 3DCRT. For the NRI, only maximum dose showed significant results between two groups (p<0.001). CONCLUSION: Intestinal toxicity should be verified with more detailed anatomic categorization such as rectum and NRI. TOMOSIB could not reduce urinary toxicity because of inevitably high dose exposure to the prostatic urethra. Current dosimetry system did not properly reflect intestinal/urinary toxicity, and suitable dosimetric guidelines are needed in TOMOSIB.
Adenocarcinoma/pathology/*radiotherapy ; Aged ; Humans ; Intestine, Small/*radiation effects ; Male ; Middle Aged ; Pelvis/*radiation effects ; Prostatic Neoplasms/pathology/*radiotherapy ; Radiation Injuries ; Radiotherapy Dosage ; Radiotherapy, Intensity-Modulated/*adverse effects/methods ; Rectum/radiation effects ; Retrospective Studies ; Urinary Bladder/*radiation effects

OBJECTIVETo evaluate the potential benefit of carbon ion radiotherapy (C-ion RT) through comparison with photon intensity-modulated radiotherapy (IMRT) in dose distribution for prostatic adenocarcinoma.

METHODSIn randomly selected 5 patients, treatment planning of C-ion RT (4 coplanar beams) and IMRT (7 coplanar fields) were worked out by computer working station. In order to make a meaningful comparison, it was defined that the 95% isodose surface had to cover 100% of the PTV in each plan; all dose was given as normalized dose with the definition of the minimum dose of the PTV being equal to 95% of prescribed dose. Dose-volume histograms (DVHs) of the tumor and organ-at-risks (OARs) were calculated. Volume irradiated more than or equal to some specified doses, conformity index ( CI) , and inhomogeneity coefficient (IC) of each treatment plan was compared, respectively.

RESULTSWith C-ion RT, the mean irradiated volumes (in %) of the rectum were significantly smaller than that with IMRT except for 95% dose level, and C-ion RT could provide complete protection to the posterior rectal wall. In addition, C-ion RT could also remarkably reduce the dose to the bladder, femoral heads and non-target normal tissues at each dose level. Dose conformation and homogeneity in the target volume of C-ion RT were better than that in IMRT (mean CI50%, 3.36 vs. 5.04, mean CI95%, 1.20 vs. 1.46, mean IC, 0.03 vs. 0.12).

CONCLUSIONCompared with IMRT, C-ion RT can obtain better dose distribution, and may reduce tumor recurrence and radiation-induced complications in prostatic adenocarcinoma.

Adenocarcinoma ; pathology ; radiotherapy ; Aged ; Carbon Radioisotopes ; therapeutic use ; Femur Head ; radiation effects ; Humans ; Male ; Prostatic Neoplasms ; pathology ; radiotherapy ; Radiotherapy Dosage ; Radiotherapy, Intensity-Modulated ; methods ; Rectum ; radiation effects ; Urinary Bladder ; radiation effects

Active surveillance (AS) is currently accepted as a good management option for men with low-risk prostate cancer (PCa). Moreover, given the grade migration following the 2005 International Society of Urologic Pathology consensus conference, AS may be appropriate for men presenting with favorable intermediate-risk PCa. Three contemporary experiences of AS for men with intermediate-risk features suggest that although these men are at higher risk for radical treatment, most of them are not significantly compromising chances for long-term cure. From the long-term randomized ProtectT trial, 10-year outcomes after active monitoring, surgery, or radiotherapy for localized PCa revealed that PCa specific mortality was low irrespective of the treatment assigned, with no significant difference among treatments. Multiparametric magnetic resonance imaging, molecular biomarkers, and new Gleason grading system could enhance diagnostic accuracy and decrease the demerits of current AS protocols. Particularly, uniform recording of the percentage pattern 4 in Gleason 7 cancers will enable better understanding of prognostic risks and consideration of careful expansion of AS to populations with minimal Gleason pattern 4 disease.
Biomarkers ; Clothing ; Consensus ; Humans ; Magnetic Resonance Imaging ; Male ; Mortality ; Neoplasm Grading ; Passive Cutaneous Anaphylaxis ; Pathology ; Prostate* ; Prostatic Neoplasms* ; Radiotherapy

Recently, the D'Amico classification system is widely used for the risk stratification of prostate cancer (PCa) , although no consensus has been reached for the definition of high-risk PCa. This system defines high-risk PCa as a prostate-specific antigen (PSA) level > 20 ng/ml, a Gleason score of 8-10, or a clinical stage ≥ T2c. Because high-risk PCa is prone to recurrence and metastasis after treatment, a proper initial therapy plays a crucial role. Currently, radical prostatectomy and radiation therapy are considered to be two most important options for the initial treatment of high-risk PCa although it remains controversial which is better.
Humans ; Male ; Neoplasm Grading ; Neoplasm Recurrence, Local ; Prostate-Specific Antigen ; blood ; Prostatectomy ; methods ; Prostatic Neoplasms ; blood ; pathology ; radiotherapy ; surgery ; Risk