Acute toxicity in patients with high-risk prostate cancer treated with stereotactic body radiation, with irradiation to the prostate and pelvic nodes

PURPOSE

Stereotactic body radiation therapy has been used for prostate cancer. However, the bulk of published studies on stereotactic body radiation therapy for prostate cancer has involved the irradiation of the prostate alone, without irradiation of the pelvic lymph nodes. We report our preliminary experience with this approach.

MATERIAL AND METHODS

The files of patients with biopsy-proven prostate cancer treated with stereotactic body radiation therapy in our institution were reviewed. Stereotactic body radiation was delivered with intensity modulated-volumetric arctherapy with daily image-guidance. The prostate planning target volume included the prostate plus a margin of 5mm in all directions. The pelvic planning target volume included pelvic nodes plus an expansion of 6 to 7mm in all directions. The prostate planning target volume received a total dose of 36.25Gy delivered in five fractions on alternate days. The nodal planning target volume received a dose of 25Gy in the same five fractions. Patients were followed during treatment, after 1, and 3 months and every 6 months thereafter. Gastrointestinal and genitourinary toxicity was prospectively graded according to Common Terminology Criteria for Adverse Events.

RESULTS

Among the 188 patients, 80 received stereotactic body radiation to the prostate and the pelvic nodes, while 108 received stereotactic body radiation to the prostate target only. Grade 2 acute gastrointestinal toxicity was 4% in both groups, and grade 2 acute genitourinary toxicity was 27% and 20% (P=0.9) for prostate only versus prostate and pelvis respectively. There was no grade 3 or higher acute gastrointestinal or genitourinary toxicity.

CONCLUSION

Stereotactic body radiation therapy in five fractions including the prostate and pelvic nodes, in patients with high-risk prostate cancer, has been feasible and safe in terms of acute toxicity.

Biochemical Failure in Intermediate Risk Prostate Cancer: Then What? Long-Term Data from a Phase III Trial

PURPOSE/OBJECTIVE(S)

Aiming to determine long-term outcomes post biochemical failure (BF) in patients (pts) treated for intermediate-risk prostate cancer, we analyzed data from our prospective randomized trial (PCS III).

MATERIALS/METHODS

From December 2000 to September 2010, 600 pts with intermediate risk prostate cancer (IRPC) received prostate radiotherapy (RT) with or without short-term (6 months) androgen deprivation therapy (ADT) on a Phase III trial. We report death rate from prostate cancer, rate and timing of BF plus the final clinical outcome of patients, alive or dead, with BF. Chi-squared test was used to compare BF and prostate cancer progression (PCP) rates between patient with or without ADT.

RESULTS

Median age at randomization was 71 years (IQR 66-74). With a median follow-up (FU) of 13.5 years (IQR 11.2-17.0), 74.5% (447/600) were free from BF at last FU. Of these, 211 died, 79 stopped FU after 10 years, 9 were lost to FU, 6 withdrew from the study and 142 are still on FU, at a median follow-up of 13.2 years (IQR = 10.9 - 16.2). A total of 153 pts (25.5%) developed BF at a median time of 6.5 years post-randomization. Among BF pts, 82/153 died: we documented 32 deaths from prostate cancer (DPC) at a median time of 6 years post-BF and 50/153 pts died from other causes at a median time of 4.7 years from BF. 48/153 BF pts continue on FU: 34 show no clinical evidence of cancer, 9 developed a second cancer and 5 show clinical evidence of PCP. 20/153 pts stopped FU after 10 years: 3 of them with PCP. 3/153 pts were lost to FU: 1 after 3 years with prostate bone metastasis and 2 after 13 years of FU. In the first 5 years post-randomization, 47 pts (7.8%) presented BF with 1 (0.2%) DPC; between 6 and 10 years, there were another 84 (14%) BFs and 11 (1.8%) DPC. Finally, after 10 years and beyond, we recorded an additional 22 (3.7%) BFs and 20 (3.3%) DPC. The rate of patients who received ADT was significantly lower in patients with BF (74/153 = 48.4%) compared to patients without BF (324/447 = 72.5%), p<0.001. The rate of patients who received ADT was also significantly lower in patients with PCP (19/48 = 39.6%) compared to patients without PCP (379/552 = 68.7%), p<0.001.

CONCLUSION

In our trial for intermediate-risk prostate cancer, a quarter of the pts developed BF. Most of the BFs occurred between 5- and 10- year post-randomization. Deaths due to prostate cancer post-BF occurred at a median time of 6 years, justifying the need for long-term FU. BF and PCP were significantly higher in patients not receiving ADT.

Patient Reported Outcomes in High-Risk Prostate Cancer Patients with or without Testosterone Recovery after Androgen Deprivation Therapy

PURPOSE/OBJECTIVE(S)

In a previous report from a randomized trial of 630 patients (pts), we showed that 18 months of androgen deprivation therapy (18m ADT) appears to be equally effective as 36 months (36m ADT) in high-risk prostate cancer (HRPC) pts. We performed the current analysis to evaluate quality of life (QOL) using the 25 items of EORTC PR25 validated tool in pts with or without testosterone (T) recovery after ADT.

MATERIALS/METHODS

We selectedpts with no biochemical failure to avoid subsequent T variations due to reintroduction of ADT for recurrence. Patients receiving exactly 18 or 36m of ADT, survived more than one year (y) post randomization, had T measured at baseline and during follow-up and who completed QOL questionnaire entered this review. The 25 items were regrouped into 5 scales. All items and scales scores were linearly transformed to a 0-100 points scale. Serum T was measured at baseline then at each visit. We defined unrecovered testosterone as measured below the normal level. All items and scales scores were analyzed with general linear model and repeated measures to evaluate changes between pts with or without T recovery over time. T recovery was adjusted in a multivariable model including age, initial normal/unrecovered T and ADT (18 or 36m). P-value < 0.01 was considered statistically significant and a difference in mean scores of ≥10 points was considered clinically relevant. Patient-reported outcomes were filled out before treatments, every 6m during ADT, 4m after ADT and then once a year for 5y.

RESULTS

Two hundred sixty nine of 630 pts met the eligibility criteria and were retained for the analysis. At a median follow-up of 14 years, 140/269 (52.0%) pts recovered T to normal level: 94/166 (56.6%) in 18m ADT and 46/103 (44.7%) in 36m ADT, p = 0.056. The median time to recovered T was significantly lower in 18m vs. 36m ADT (3.04 vs. 5.06 y, p<0.001). The global adherence to QOL questionnaires was 83.9% (2649/3156) and was similar between arms. Pts recovering T compared to those who did not, had a better QOL. 6/20 items [difficult to get enough sleep: get up frequently at night to urinate, blood in stool, hot flushes, feel less man, interested in sex, sexually active (with or without intercourse)] and 2/4 scales (treatment and sexual activity) were statistically significant (all p<0.01). 2 items were also clinically relevant: hot flushes and interested in sex. Hot flushes were clinically relevant (more than 10 point of difference) between 3.5 to 5y inclusively with maximum difference of 19.4 point. Interest in sex was clinically relevant with 13.1 point of difference at 3 years.

CONCLUSION

T recoverypost long-term ADT is associated with a significantly improved QOL in patients with HRPC. Considering similar prostate cancer clinical outcomes and faster T recovery, our results suggest that 18m ADT may be the most appropriate ADT treatment duration for these patients.

Prognostic Significance of Pretreatment Immune Cell Infiltration in Muscle Invasive Bladder Cancer Treated with Definitive Chemoradiation: Analysis of NRG RTOG 0524 and 0712

PURPOSE/OBJECTIVE(S)

Chemoradiation therapy (CRT) is an organ conserving approach in the treatment of locally advanced bladder cancer. Chemoradiation is thought to potentially result in immunogenic stimulation, and bladder cancer is often a tumor with high immune cell infiltration. Thus, we aimed to profile the tumor immune microenvironment of bladder cancer and identify prognostic immune biomarkers for CRT response by profiling tumor samples from NRG/RTOG 0524 and 0712, two prospective trials of CRT in muscle invasive bladder cancer (MIBC).

MATERIALS/METHODS

Pretreatment tissue samples from both trials were profiled using Cofactor Genomics ImmunoPrism, an RNA sequencing assay that uses gene expression profiles to quantify immune cell populations in the tumor microenvironment (TME). Differential gene expression was estimated for different immune cell type proportions across samples. Kaplan-Meier survival analysis and log rank tests were performed to evaluate differences in overall survival (OS) stratified by genes influenced by immune cell proportions or genes associated with immune response signatures.

RESULTS

A total of 70 samples (43 from RTOG 0524 and 27 from RTOG 0712) underwent analysis using the ImmunoPrism assay. Immune cell proportions were as follows: CD8 T cells: median 1.2%, CD4 T cells: median 0.8%, Treg cells: median 9.2%, CD19 B cells: median 5.1%, M2 macrophages: median 0.8%, M1 macrophages: median 0%. Unbiased clustering based on gene expression profiles driven by immune cell proportions demonstrated two groups: cluster 1 with a low percentage of immune cells and shorter OS (median 31 months) and cluster 2 with a high percentage of immune cells and longer OS (median 101 months, p = 0.036). Higher expression of genes associated with T cell infiltration (CD8A and ICOS) was associated with improved OS (104 vs 35 months, p = 0.028, HR = 0.48 (0.25 - 0.94), p = 0.031) as was higher expression of IDO1, which is associated with the interferon gamma pathway (104 vs 35 months, p = 0.042, HR = 0.49 (0.24 - 0.99), p = 0.046).

CONCLUSION

Bladder tumors have a wide range of immune cell infiltration in the TME. Increased immune cell proportions are prognostic for OS following CRT, as well as a higher expression of genes associated with T cell infiltration interferon gamma signaling. These findings have implications for the integration of immunotherapy in the definitive management of MIBC; and can be explored further in the ongoing NRG/SWOG 1806 trial.

Reduction of inter-observer contouring variability in daily clinical practice through a retrospective, evidence-based intervention

BACKGROUND

Inter-observer variations (IOVs) arising during contouring can potentially impact plan quality and patient outcomes. Regular assessment of contouring IOV is not commonly performed in clinical practice due to the large time commitment required of clinicians from conventional methods. This work uses retrospective information from past treatment plans to facilitate a time-efficient, evidence-based intervention to reduce contouring IOV.

METHODS

The contours of 492 prostate cancer treatment plans created by four radiation oncologists were analyzed in this study. Structure volumes, lengths, and DVHs were extracted from the treatment planning system and stratified based on primary oncologist and inclusion of a pelvic lymph node (PLN) target. Inter-observer variations and their dosimetric consequences were assessed using Student's t-tests. Results of this analysis were presented at an intervention meeting, where new consensus contour definitions were agreed upon. The impact of the intervention was assessed one-year later by repeating the analysis on 152 new plans.

RESULTS

Significant IOV in prostate and PLN target delineation existed pre-intervention between oncologists, impacting dose to nearby OARs. IOV was also present for rectum and penile-bulb structures. Post-intervention, IOV decreased for all previously discordant structures. Dosimetric variations were also reduced. Although target contouring concordance increased significantly, some variations still persisted for PLN structures, highlighting remaining areas for improvement.

CONCLUSION

We detected significant contouring IOV in routine practice using easily accessible retrospective data and successfully decreased IOV in our clinic through a reflective intervention. Continued application of this approach may aid improvements in practice standardization and enhance quality of care.

Thoracic irradiation in 3weeks for limited-stage small cell lung cancer: Is twice a day fractionation really needed?

PURPOSE

Many Canadian institutions treat limited-disease small cell lung cancer with 40Gy in 15 fractions delivered once-a-day in 3weeks concomitantly with chemotherapy. This regimen is convenient and seems to be effective. Here, we report and compare with a literature review the outcomes of patients with limited-stage small cell lung cancer treated in our institution with this hypofractionated regimen.

PATIENTS AND METHODS

From January 2004 to December 2012, patients with limited-stage small cell lung cancer treated curatively with platinum-based chemotherapy and concurrent thoracic radiotherapy at a dose of 40Gy in 16 fractions once-a-day were eligible for this review.

RESULTS

Sixty-eight patients fit the analysis criteria, including ten patients with small pleural effusion. The median age was 66years old. After a median follow-up of 77months for those alive, the median survival was 28months. At 3 and 5years respectively, the locoregional control rates were 67 and 64%, while the overall survival rates were 40 and 35%. Prophylaxis cranial irradiation was delivered to 68% of the patients. Grade 2 and 3 acute esophagitis occurred in respectively 49 and 9% of the patients. There was no grade 4 radiation-induced toxicity. All patients, except for one, completed their thoracic irradiation course without interruption.

CONCLUSION

Once-a-day hypofractionated radiation with concurrent chemotherapy followed by prophylactic cranial irradiation is a practical regimen. Based on our experience and the published literature, it appears to be similarly effective as regimens using twice-daily fractionation in 3weeks, or once-daily in 6 to 7weeks with higher radiotherapy doses. Further prospective comparisons of hypofractionation with the current recommendations are needed.