Dose-Intensified Postoperative Radiation Therapy for Prostate Cancer: Long-Term Results From the PKUFH Randomized Phase 3 Trial.

PURPOSE: In the randomized, single-center, PKUFH phase 3 trial, dose-intensified (72 Gy) radiation therapy was compared with conventional (66 Gy) radiation therapy. In a previous study, we found no significant difference in biochemical progression-free survival (bPFS) between the 2 cohorts at 4 years. In the current analysis, we provide 7-year outcomes. METHODS AND MATERIALS: Patients with stage pT3-4, positive surgical margins, or a prostate-specific antigen increase ≥0.2 ng/mL after radical prostatectomy were randomly assigned 1:1 to receive either 72 Gy in 36 fractions or 66 Gy in 33 fractions. All the patients underwent image guided intensity modulated radiation therapy. The primary endpoint was bPFS. Secondary endpoints were distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS) as estimated using the Kaplan-Meier method. RESULTS: Between September 2011 and November 2016, 144 patients were enrolled with 73 and 71 in the 72- and 66-Gy cohorts, respectively. At a median follow-up of 89.5 months (range, 73-97 months), there was no difference in 7-year bPFS between the 72- and 66-Gy cohorts (70.3% vs 61.2%; hazard ratio [HR], 0.73; 95% CI, 0.41-1.29; P = .274). However, in patients with a higher Gleason score (8-10), the 72-Gy cohort had statistically significant improvement in 7-year bPFS compared with the 66-Gy cohort (66.5% vs 30.2%; HR, 0.37; 95% CI, 0.17-0.82; P = .012). In addition, in patients with multiple positive surgical margins, the 72-Gy cohort had statistically significant improvement in 7-year bPFS compared with single positive surgical margin (82.5% vs 57.5%; HR, 0.36; 95% CI, 0.13-0.99; P = .037). The 7-year DMFS (88.4% vs 84.9%; HR, 0.93; 95% CI, 0.39-2.23; P = .867), CSS (94.1% vs 95.5%; HR, 1.19; 95% CI, 0.42-3.39; P = .745), and OS (92.8% vs 94.1%; HR, 1.29; 95% CI, 0.51-3.24; P = .594) had no statistical differences between the 72- and 66-Gy cohorts. CONCLUSIONS: The current 7-year bPFS results confirmed our previous findings that dose escalation (72 Gy) demonstrated no improvement in 7-year bPFS, DMFS, CSS, or OS compared with the 66-Gy regimen. However, patients with a higher Gleason score (8-10) or multiple positive surgical margins might benefit from the 72-Gy regimen, but this requires further prospective research.

Treatment-related neuroendocrine prostate cancer managed with partial stereotactic ablative radiotherapy (P-SABR) for long-term survival: a case series.

Background: The amount of treatment-related neuroendocrine prostate cancer (t-NEPC) increases after hormonal therapy, especially novel androgen receptor pathway inhibitors (ARPIs). T-NEPC is considered a hormone refractory [androgen receptor (AR)-negative] subtype of prostate cancer. Although tumors are initially responsive to platinum-based chemotherapy, the drugs are only effective for a short time. Therefore, whether or not local treatment can prolong survival is of great concern. Case Description: In this case series, we discuss 4 t-NEPC cases who were treated with partial stereotactic ablative radiotherapy (P-SABR) for bulky tumors. P-SABR is a radiotherapy regimen that is used in a SABR boost [such as 6 Gy × 4 fractions (f), 8 Gy × 3 f] prior to conventional radiotherapy to enhance the tumor biological effective dose (BED) without increasing the dose to organs at risk. All patients achieved good local control after P-SABR. For patient 1, P-SABR was used for the prostate tumor. After radiotherapy, pathological complete remission (pCR) was achieved, and the prostate lesion remained stable thus far. As of this writing, the patient has been in remission for 3 years after initial t-NEPC diagnosis. Conclusions: We describe 4 cases and indicate that P-SABR is safe and effective in the treatment of a large prostate mass and may prolong the survival of these patients.

Contouring lumbosacral plexus nerves with MR neurography and MR/CT deformable registration technique.

Purpose: It is difficult to contour nerve structures with the naked eye due to poor differentiation between the nerve structures with other soft tissues on CT images. Magnetic resonance neurography (MRN) has the advantage in nerve visualization. The purpose of this study is to identify one MRN sequence to better assist the delineation of the lumbosacral plexus (LSP) nerves to assess the radiation dose to the LSP using the magnetic resonance (MR)/CT deformable coregistration technique. Methods: A total of 18 cases of patients with prostate cancer and one volunteer with radiation-induced lumbosacral plexopathy (RILSP) were enrolled. The data of simulation CT images and original treatment plans were collected. Two MRN sequences (Lr_NerveVIEW sequence and Cs_NerveVIEW sequence) were optimized from a published MRN sequence (3D NerveVIEW sequence). The nerve visualization ability of the Lr_NerveVIEW sequence and the Cs_NerveVIEW sequence was evaluated via a four-point nerve visualization score (NVS) scale in the first 10 patients enrolled to determine the better MRN sequence for assisting nerve contouring. Deformable registration was applied to the selected MRN sequence and simulation CT images to get fused MR/CT images, on which the LSP was delineated. The contouring of the LSP did not alter treatment planning. The dosimetric data of the LSP nerve were collected from the dose-volume histogram in the original treatment plans. The data of the maximal dose (Dmax) and the location of the maximal radiation point received by the LSP structures were collected. Results: The Cs_NerveVIEW sequence gained lower NVS scores than the Lr_NerveVIEW sequence (Z=-2.887, p=0.004). The LSP structures were successfully created in 18 patients and one volunteer with MRN (Lr_NerveVIEW)/CT deformable registration techniques, and the LSP structures conformed with the anatomic distribution. In the patient cohort, the percentage of the LSP receiving doses exceeding 50, 55, and 60 Gy was 68% (12/18), 33% (6/18), and 17% (3/18), respectively. For the volunteer with RILSP, the maximum irradiation dose to his LSP nerves was 69 Gy. Conclusion: The Lr_NerveVIEW MRN sequence performed better than the Cs_NerveVIEW sequence in nerve visualization. The dose in the LSP needs to be measured to understand the potential impact on treatment-induced neuropathy.

Radiation therapy for nonmetastatic medically inoperable upper-tract urothelial carcinoma.

BACKGROUND: The standard management for upper urinary tract urothelial carcinoma (UTUC) is radical nephroureterectomy (RNU). However, some patients cannot undergo this procedure for several reasons, such as unresectable disease, old age, and multiple comorbidities. Our study explored the potential safety and effectiveness of radiotherapy as a curative treatment for UTUC patients unfit for surgery. METHODS: The data of patients treated with radiotherapy between December 2017 and November 2019 were retrospectively reviewed. For the literature review, computerized PubMed Medline, Index Medicus, and Web of Science databases and reference lists from the identified publications of interest were used. And "upper-tract urothelial carcinoma" and "radiotherapy" were used as key words in the search. RESULTS: We describe 8 patients with UTUC who were treated with radiotherapy. The median follow-up time was 13.5 months (range, 8.6-30.9 months). Local tumor control was achieved in all patients. However, distant metastases were observed in 2 patients with T3-4/N+ status. One patient had T4 status and the other had N2+ status. The patients died of tumor progression at 15.0 and 17.7 months. In addition, the other 6 patients who were still alive had relatively early-stage tumors without nodal involvement. Regarding acute toxicity, according to the CTCAE v5.0, mild side effects were noted, including grade 1 nausea and diarrhea. Four patients developed mild anemia, generally of grade 1-2. One patient experienced grade 3 anemia, but it was manageable and improved with symptomatic support. In addition, no grade 4 acute or late toxicities were observed. No significant long-term impairment of renal function occurred. CONCLUSIONS: For patients with nonmetastatic UTUC who are not suitable for surgery, radiotherapy is a safe treatment and can achieve good local tumor control.

Dosimetric feasibility of stereotactic ablative radiotherapy in pulmonary vein isolation for atrial fibrillation using intensity-modulated proton therapy.

PURPOSE: To evaluate dosimetric properties of intensity-modulated proton therapy (IMPT) for simulated treatment planning in patients with atrial fibrillation (AF) targeting left atrial-pulmonary vein junction (LA-PVJ), in comparison with volumetric-modulated arc therapy (VMAT) and helical tomotherapy (TOMO). METHODS: Ten thoracic 4D-CT scans with respiratory motion and one with cardiac motion were used for the study. Ten respiratory 4D-CTs were planned with VMAT, TOMO, and IMPT for simulated AF. Targets at the LA-PVJ were defined as wide-area circumferential ablation line. A single fraction of 25 Gy was prescribed to all plans. The interplay effects from cardiac motion were evaluated based on the cardiac 4D-CT scan. Dose-volume histograms (DVHs) of the ITV and normal tissues were compared. Statistical analysis was evaluated via one-way Repeated-Measures ANOVA and Friedman's test with Bonferroni's multiple comparisons test. RESULTS: The median volume of ITV was 8.72cc. All plans had adequate target coverage (V23.75Gy  ≥ 99%). Compared with VMAT and TOMO, IMPT resulted in significantly lower dose of most normal tissues. For VMAT, TOMO, and IMPT plans, Dmean of the whole heart was 5.52 ± 0.90 Gy, 5.89 ± 0.78 Gy, and 3.01 ± 0.57 Gy (P < 0.001), mean dose of pericardium was 4.74 ± 0.76 Gy, 4.98 ± 0.62 Gy, and 2.59 ± 0.44 Gy (P < 0.001), and D0.03cc of left circumflex artery (LCX) was 13.96 ± 5.45 Gy, 14.34 ± 5.91 Gy, and 8.43 ± 7.24 Gy (P < 0.001), respectively. However, no significant advantage for one technique over the others was observed when examining the D0.03cc of esophagus and main bronchi. CONCLUSIONS: IMPT targeting LA-PVJ for patients with AF has high potential to reduce dose to surrounding tissues compared to VMAT or TOMO. Motion mitigation techniques are critical for a particle-therapy approach.

Toxicity and Biochemical Outcomes of Dose-Intensified Postoperative Radiation Therapy for Prostate Cancer: Results of a Randomized Phase III Trial.

PURPOSE: Our purpose was to compare toxicity and biochemical control in postprostatectomy patients treated with conventional (66 Gy) or dose-intensified (72 Gy) radiation therapy. METHODS AND MATERIALS: Patients who had stage pT3-4, positive surgical margins, or rising prostate-specific antigen ≥ 0.2 ng/mL after radical prostatectomy were randomly assigned to receive either 66 Gy in 33 fractions or 72 Gy in 36 fractions. A primary endpoint was to assess the difference in biochemical progression-free survival (bPFS) between these 2 cohorts, and secondary endpoints were to assess differences in genitourinary (GU), gastrointestinal (GI), and hematologic toxicities between these 2 cohorts. bPFS was estimated by the Kaplan-Meier method and toxicities were compared using the χ2 test. RESULTS: Between September 2011 and November 2016, 144 patients were enrolled: 71 patients to the 66 Gy cohort and 73 patients to the 72 Gy cohort. The median follow-up time was 48.5 months (range, 14-79 months). There was no difference in 4-year bPFS between the 66 Gy and 72 Gy cohorts (75.9% vs 82.6%; P = .299). However, in patients with a higher Gleason score (8-10), the 72 Gy cohort had statistically significant improvement in bPFS compared with the 66 Gy cohort (79.7% vs 55.7%; P = .049). Toxicity analysis showed no difference in ≥2 acute or late GI or GU toxicities between these 2 cohorts. A total of 48 patients were scored as urinary incontinence before radiation therapy, of which 39 (81.3%) reported incontinence recovery or stable at 1-year follow-up, and only 9 (18.8%) patients reported worsening. There was no difference between the 2 cohorts in urinary incontinence either at baseline or at 1-year follow-up. CONCLUSIONS: Dose escalation (72 Gy) demonstrated no improvement in 4-year bPFS compared with the 66 Gy regimen. However, the dose escalation was not associated with greater acute or late GU or GI toxicities and did not increase urinary incontinence.

Intra-rectal use of epinephrine in radiotherapy of prostate cancer.

Purpose: The aim of the study was to evaluate the feasibility and toxicity of intra-rectal epinephrine during prostatic radiotherapy. Materials and methods: A total of 34 patients with prostate cancer were randomized to receive daily intra-rectal epinephrine (4 mg in 40 mL, n=16) or placebo (40 mL normal saline, n=18) 5 min before daily radiotherapy. Physical examination including systolic blood pressure (SBP) and heart rate (HR) was performed before, 5 min after, and 20 min after intra-rectal use. Toxicities were graded using the Radiation Therapy Oncology Group standard. A two-sided Fisher's exact test was used to compare proportions between groups. A mixed-effects model was used to analyze multiple measurements of SBP and HR. Survival curves were calculated using the Kaplan-Meier method and compared between groups using the log-rank test. Results: All patients completed the protocol treatment and reported no cardiovascular symptoms after intra-rectal administration. There were no differences in SBP and HR between these two groups at any time point (before, 5 min after, and 20 min after epinephrine). At 5 weeks after the start of radiotherapy, the incidence of rectal toxicity≥grade 2 was 27.8% (5/18) for the control group versus 12.5% (2/16) for the epinephrine group, but was not statistically significant (p=0.4). There was no rectal toxicity≥grade 2 in these two groups beyond 2-year follow-up. The 5-year biochemical relapse-free survival was 75.0% and 72.2% for the epinephrine and control group, respectively. Conclusion: Results of this pilot randomized trial have demonstrated that intra-rectal administration of epinephrine is feasible and safe in prostatic radiotherapy. Its radio-protective effect warrants further investigation.

Partial stereotactic ablative boost radiotherapy in bulky non-small cell lung cancer: a retrospective study.

PURPOSE: Bulky non-small cell lung cancer (NSCLC) is difficult to achieve effective local control by conventionally fractionated radiotherapy (CRT). The present work aims to evaluate the safety and efficacy of partial stereotactic ablative boost radiotherapy (P-SABR) in bulky NSCLC. PATIENTS AND METHODS: From December 2012 through August 2017, 30 patients with bulky NSCLC treated with P-SABR technique were analyzed. The P-SABR plan consisted of one partial SABR plan (5-9 Gy/f, 3-6 fractions) to gross tumor boost (GTVb), followed by one CRT plan to the planning target volume (PTV). GTVb was the max volume receiving SABR to guarantee the dose of organs-at-risks (OARs) falloff to about 3 Gy/f. The total dose of PTV margin was planned to above 60 Gy. The simply CRT plans were created using the same planning parameters as the original plan, with the goal to achieve comparable OARs doses and PTV margin dose to the P-SABR plan. Dosimetric variables were acquired in both P-SABR and compared CRT plans. Toxicity, local control, and survival were also evaluated. RESULTS: Median follow-up in survivors was 10.3 months (range=2.3-39.4 months). Eleven patients (36.7%) had partial response (PR) and ten patients (33.3%) had stable disease (SD). Two-year overall survival was 55.6%. Two-year local control rate was 85.7%. No severe acute side effects >CTCAE Grade III were observed. Compared to the simply CRT plan, P-SABR plans achieved similar doses to the OARs and Dmin, but increased dose at the isocenter, Dmean, Dmax, and biological equivalent dose (BED) significantly (P<0.05). BED in the tumor center could reach 107.3 Gy (93.2-132 Gy). Patients with B90≥65% achieved a higher local control rate than those with B90<65% (P=0.010). CONCLUSION: This retrospective study suggests that P-SABR is feasible and well tolerated in bulky NSCLC. Local control rate is encouraging, especially for the B90≥65% group, which may due to the ability of P-SABR to optimize BED with equivalent toxicity.