High-Dose Robotic Stereotactic Body Radiotherapy in the Treatment of Patients With Prostate Cancer: Preliminary Results in 26 Patients

Photon vs proton hypofractionation in prostate cancer: A systematic review and meta-analysis

BACKGROUND

High-level evidence on hypofractionated proton therapy (PT) for localized and locally advanced prostate cancer (PCa) patients is currently missing. The aim of this study is to provide a systematic literature review to compare the toxicity and effectiveness of curative radiotherapy with photon therapy (XRT) or PT in PCa.

METHODS

PubMed, Embase, and the Cochrane Library databases were systematically searched up to April 2022. Men with a diagnosis of PCa who underwent curative hypofractionated RT treatment (PT or XRT) were included. Risk of grade (G) ≥ 2 acute and late genitourinary (GU) OR gastrointestinal (GI) toxicity were the primary outcomes of interest. Secondary outcomes were five-year biochemical relapse-free survival (b-RFS), clinical relapse-free, distant metastasis-free, and prostate cancer-specific survival. Heterogeneity between study-specific estimates was assessed using Chi-square statistics and measured with the I2 index (heterogeneity measure across studies).

RESULTS

A total of 230 studies matched inclusion criteria and, due to overlapped populations, 160 were included in the present analysis. Significant lower rates of G ≥ 2 acute GI incidence (2 % vs 7 %) and improved 5-year biochemical relapse-free survival (95 % vs 91 %) were observed in the PT arm compared to XRT. PT benefits in 5-year biochemical relapse-free survival were maintained for the moderate hypofractionated arm (p-value 0.0122) and among patients in intermediate and low-risk classes (p-values < 0.0001 and 0.0368, respectively). No statistically relevant differences were found for the other considered outcomes.

CONCLUSION

The present study supports that PT is safe and effective for localized PCa treatment, however, more data from RCTs are needed to draw solid evidence in this setting and further effort must be made to identify the patient subgroups that could benefit the most from PT.

The march toward single-fraction stereotactic body radiotherapy for localized prostate cancer-Quo Vadimus?

PURPOSE

Stereotactic body radiotherapy (SBRT) is an emerging treatment option for localized prostate cancer. There is increasing interest to reduce the number of fractions for prostate SBRT.

METHODS

We provide a narrative review and summary of prospective trials of different fractionation schedules for prostate SBRT, focusing on efficacy, toxicities, and quality of life outcomes.

RESULTS

There are two randomized phase 3 trials comparing standard external beam radiotherapy with ultra-hypofractionated radiotherapy. HYPO-RT-PC compared 78 Gy in 39 fractions vs 42.7 Gy in 7 fractions (3D-CRT or IMRT) showing non-inferiority in 5-year biochemical recurrence-free survival and equivalent tolerability. PACE-B trial compared 78 Gy in 39-fraction or 62 Gy in 20-fraction vs 36.25 Gy in 5-fraction prostate SBRT, with no significant differences in toxicity outcomes at 2 years. Five-year efficacy data for PACE-B are expected in 2024. Five-fraction prostate SBRT is currently the most common and well-established fractionation schedule with multiple prospective phase 2 trials published to date. There is more limited data on 1-4 fraction prostate SBRT. All fractionation schedules had acceptable toxicity outcomes. Experience from a high-dose-rate brachytherapy randomized trial showed inferior efficacy with single-fraction compared to two-fraction brachytherapy. Hence, caution should be applied in adopting single-fraction prostate SBRT.

CONCLUSION

Two-fraction SBRT is likely the shortest fractionation schedule that maintains the therapeutic ratio. Several randomized trials currently recruiting will likely provide us with more definite answers about whether two-fraction prostate SBRT should become a standard-of-care option. Enrollment of eligible patients into these trials should be encouraged.

Hypofractionated Radiotherapy in Localized, Low-Intermediate-Risk Prostate Cancer: Current and Future Prospectives

At the time of diagnosis, the vast majority of prostate carcinoma patients have a clinically localized form of the disease, with most of them presenting with low- or intermediate-risk prostate cancer. In this setting, various curative-intent alternatives are available, including surgery, external beam radiotherapy and brachytherapy. Randomized clinical trials have demonstrated that moderate hypofractionated radiotherapy can be considered as a valid alternative strategy for localized prostate cancer. High-dose-rate brachytherapy can be administered according to different schedules. Proton beam radiotherapy represents a promising strategy, but further studies are needed to make it more affordable and accessible. At the moment, new technologies such as MRI-guided radiotherapy remain in early stages, but their potential abilities are very promising.

Virtual HDR Boost for Prostate Cancer: Rebooting a Classic Treatment Using Modern Tech

Prostate cancer (PC) is the most common malignancy in men. Internal radiotherapy (brachytherapy) has been used to treat PC successfully for over a century. In particular, there is level-one evidence of the benefits of using brachytherapy to escalate the dose of radiotherapy compared with standard external beam radiotherapy approaches. However, the use of PC brachytherapy is declining, despite strong evidence for its improved cancer outcomes. A method using external beam radiotherapy known as virtual high-dose-rate brachytherapy boost (vHDRB) aims to noninvasively mimic a brachytherapy boost radiation dose plan. In this review, we consider the evidence supporting brachytherapy boosts for PC and the continuing evolution of vHDRB approaches, culminating in the current generation of clinical trials, which will help define the role of this emerging modality.

Ultrahypofractionated Radiotherapy for Localised Prostate Cancer: How Far Can We Go?

Following adoption of moderately hypofractionated radiotherapy as a standard for localised prostate cancer, ultrahypofractioned radiotherapy delivered in five to seven fractions is rapidly being embraced by clinical practice and international guidelines. However, the question remains: how low can we go? Can radiotherapy for prostate cancer be delivered in fewer than five fractions? The current review summarises the evidence that radiotherapy for localised prostate cancer can be safely and effectively delivered in fewer than five fractions using high dose rate brachytherapy or stereotactic body radiotherapy. We also discuss important lessons learned from the single-fraction high dose rate brachytherapy experience.

Stereotactic Body Radiotherapy for High-Risk Prostate Cancer: A Systematic Review

BACKGROUND

Radiotherapy (RT) is an established, potentially curative treatment option for all risk constellations of localized prostate cancer (PCA). Androgen deprivation therapy (ADT) and dose-escalated RT can further improve outcome in high-risk (HR) PCA. In recent years, shorter RT schedules based on hypofractionated RT have shown equal outcome. Stereotactic body radiotherapy (SBRT) is a highly conformal RT technique enabling ultra-hypofractionation which has been shown to be safe and efficient in patients with low- and intermediate-risk PCA. There is a paucity of data on the role of SBRT in HR PCA. In particular, the need for pelvic elective nodal irradiation (ENI) needs to be addressed. Therefore, we conducted a systematic review to analyze the available data on observed toxicities, ADT prescription practice, and oncological outcome to shed more light on the value of SBRT in HR PCA.

METHODS

We searched the PubMed and Embase electronic databases for the terms "prostate cancer" AND "stereotactic" AND "radiotherapy" in June 2020. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations.

RESULTS

After a rigorous selection process, we identified 18 individual studies meeting all selection criteria for further analyses. Five additional studies were included because their content was judged as relevant. Three trials have reported on prostate SBRT including pelvic nodes; 2 with ENI and 1 with positive pelvic nodes only. The remaining studies investigated SBRT of the prostate only. Grade 2+ acute genitourinary (GU) toxicity was between 12% and 46.7% in the studies investigating pelvic nodes irradiation and ranged from 0% to 89% in the prostate only studies. Grade 2+ chronic GU toxicity was between 7% and 60% vs. 2% and 56.7%. Acute gastrointestinal (GI) grade 2+ toxicity was between 0% to 4% and 0% to 18% for studies with and without pelvic nodes irradiation, respectively. Chronic GI grade 2+ toxicity rates were between 4% and 50.1% vs. 0% and 40%. SBRT of prostate and positive pelvic nodes only showed similar toxicity rates as SBRT for the prostate only. Among the trials that reported on ADT use, the majority of HR PCA patients underwent ADT for at least 2 months; mostly neoadjuvant and concurrent. Biochemical control rates ranged from 82% to 100% after 2 years and 56% to 100% after 3 years. Only a few studies reported longer follow-up data.

CONCLUSION

At this point, SBRT with or without pelvic ENI cannot be considered the standard of care in HR PCA, due to missing level 1 evidence. Treatment may be offered to selected patients at specialized centers with access to high-precision RT. While concomitant ADT is the current standard of care, the necessary duration of ADT in combination with SBRT remains unclear. Ideally, all eligible patients should be enrolled in clinical trials.

Short fractionation radiotherapy for early prostate cancer in the time of COVID-19: long-term excellent outcomes from a multicenter Italian trial suggest a larger adoption in clinical practice

INTRODUCTION

To evaluate stereotactic body radiotherapy (SBRT) in low-risk Prostate Cancer patients as preferred treatment option in emergency health conditions.

MATERIALS AND METHODS

From April 2013 to September 2015, 28 patients with low-risk prostate cancer were prospectively enrolled. The SBRT prescribed dose was 36.25 Gy in 5 fractions, twice a week. Primary endpoints were acute and late toxicity. Secondary endpoints were biochemical recurrence free survival (bRFS) and overall survival.

RESULTS

Median follow-up was 65.5 months (range 52-81). No acute G3 or G4 toxicity was recorded. Acute G1 or G2 genitourinary (GU) toxicity occurred in 43% and acute G1-G2 gastrointestinal (GI) toxicity in 14%. Late G1 and G3 GU toxicity in 18% and 3.5%, respectively. The G3 toxicity was not directly attributable to radiotherapy. Late G1 GI toxicity occurred in 18%. 5yy bRFS was 96.5% (95% CI 82.3-99.4%).

CONCLUSIONS

Stereotactic body radiotherapy for early prostate cancer reported safe toxicity profile and a good clinical outcome at the median follow-up of 5 years. It may be an useful option if radiotherapy is required in emergency medical conditions.

Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost in Patients With Spinal Metastases

Stereotactic body radiation therapy in patients with spine metastases maximizes local tumor control and preserves neurologic function. A novel approach could be the use of stereotactic body radiation therapy with simultaneous integrated boost delivering modality. The aim of the present study is to report our experience in the treatment of spine metastases using a frameless radiosurgery system delivering stereotactic body radiation therapy–simultaneous integrated boost technique. The primary endpoints were the pain control and the time to local progression; the secondary ones were the overall survival and toxicity. A total of 20 patients with spine metastases and 22 metastatic sites were treated in our center with stereotactic body radiation therapy–simultaneous integrated boost between December 2007 and July 2018. Stereotactic body radiation therapy–simultaneous integrated boost treatments were delivered doses of 8 to 10 Gy in 1 fraction to isodose line of 50%. The median follow-up was 35 months (range: 12-110). The median time to local progression for all patients was not reached and the actuarial 1-, 2-, and 3-years local free progression rate was 86.36%. In 17 of 20 patients, a complete pain remission was observed and 3 of 20 patients had a partial pain remission (complete pain remission + partial pain remission: 100%). The median overall survival was 38 months (range 12-83). None of the patients experienced neither radiation adverse events (grade 1-4) nor reported pain flair reaction. None of the patients included in our series experienced vertebral compression fracture. Spine radiosurgery with stereotactic body radiation therapy–simultaneous integrated boost is safe. The use of this modality in spine metastases patients provides an excellent local control.

A treatment planning study comparing IMRT techniques and cyber knife for stereotactic body radiotherapy of low-risk prostate carcinoma

Purpose

Comparing radiation treatment plans by using the same safety margins and dose objectives for all techniques, to ascertain the optimal radiation technique for the stereotactic body radiotherapy (SBRT) of low-risk prostate cancer.

Material and methods

Treatment plans for 27 randomly selected patients were compared using intensity-modulated (IMRT) techniques as Sliding Window (SW), volumetric modulated arc therapy (VMAT), and helical tomotherapy (HT), as well as Cyber Knife (CK) system. The target dose was calculated to 36.25 Gy delivered in five fractions over 1 week. Dosimetric indices for target volume and organs at risk (OAR) as well as normal tissue complication probability (NTCP) of late rectal and urinary bladder toxicities were analyzed.

Results

The CK provided lower homogeneity in the target volume, but higher values for most of the conformity indices compared to the IMRT approaches. The SW demonstrated superior rectum sparing at medium-to-high dose range (V18 Gy - V32.6 Gy) compared to other techniques (p < 0.05). The whole urinary bladder experienced the best shielding by SW and VMAT at the medium dose (V18 Gy, p < 0.05 versus CK), however we obtained no relevant differences between techniques at the high dose. Generally, the CK demonstrated significantly superior rectum and bladder exposure at V18 Gy as compared to HT, SW, and VMAT. For the rectum, mean NTCP values were significantly superior for HT (NTCP = 2.3%, p < 0.05), and for urinary bladder, the NTCP showed no significant advantages for any technique.

Conclusion

No absolute dosimetric advantage was revealed to choose between CK or IMRT techniques for the SBRT of low-grade prostate cancer. Using the same safety margins and dose objectives, IMRT techniques demonstrated superior sparing of the rectum and bladder at a medium dose compared to CK. Comparing different IMRT approaches SW displayed superior rectum sparing at a medium-to-high dose range, whereas both SW and RA revealed superior bladder sparing compared to HT. HT demonstrated a significantly lower NTCP outcome compared to CK or IMRT techniques regarding the rectum. Radiation plans can be optimized further by an individual modification of dose objectives independent of the treatment plan strategy.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1353-6) contains supplementary material, which is available to authorized users.

Stereotactic Body Radiation Therapy for Localized Prostate Cancer: A Systematic Review and Meta-Analysis of Over 6,000 Patients Treated On Prospective Studies

PURPOSE

Utilization of stereotactic body radiation therapy (SBRT) for treatment of localized prostate cancer is increasing. Guidelines and payers variably support the use of prostate SBRT. We therefore sought to systematically analyze biochemical recurrence-free survival (bRFS), physician-reported toxicity, and patient-reported outcomes after prostate SBRT.

METHODS AND MATERIALS

A systematic search leveraging Medline via PubMed and EMBASE for original articles published between January 1990 and January 2018 was performed. This was supplemented by abstracts with sufficient extractable data from January 2013 to March 2018. All prospective series assessing curative-intent prostate SBRT for localized prostate cancer reporting bRFS, physician-reported toxicity, and patient-reported quality of life with a minimum of 1-year follow-up were included. The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Meta-analyses were performed with random-effect modeling. Extent of heterogeneity between studies was determined by the I2 and Cochran's Q tests. Meta-regression was performed using Hartung-Knapp methods.

RESULTS

Thirty-eight unique prospective series were identified comprising 6116 patients. Median follow-up was 39 months across all patients (range, 12-115 months). Ninety-two percent, 78%, and 38% of studies included low, intermediate, and high-risk patients. Overall, 5- and 7-year bRFS rates were 95.3% (95% confidence interval [CI], 91.3%-97.5%) and 93.7% (95% CI, 91.4%-95.5%), respectively. Estimated late grade ≥3 genitourinary and gastrointestinal toxicity rates were 2.0% (95% CI, 1.4%-2.8%) and 1.1% (95% CI, 0.6%-2.0%), respectively. By 2 years post-SBRT, Expanded Prostate Cancer Index Composite urinary and bowel domain scores returned to baseline. Increasing dose of SBRT was associated with improved biochemical control (P = .018) but worse late grade ≥3 GU toxicity (P = .014).

CONCLUSIONS

Prostate SBRT has substantial prospective evidence supporting its use, with favorable tumor control, patient-reported quality of life, and levels of toxicity demonstrated. SBRT has sufficient evidence to be supported as a standard treatment option for localized prostate cancer while ongoing trials assess its potential superiority.

Rectal/urinary toxicity after hypofractionated vs conventional radiotherapy in low/intermediate risk localized prostate cancer: systematic review and meta analysis

Purpose

The aim of this review was to compare radiation toxicity in Localized Prostate Cancer (LPC) patients who underwent conventional fractionation (CV), hypofractionated (HYPO) or extreme hypofractionated (eHYPO) radiotherapy. We analyzed the impact of technological innovation on the management of prostate cancer, attempting to make a meta-analysis of randomized trials.

Methods

PubMed database has been explored for studies concerning acute and late urinary/gastrointestinal toxicity in low/intermediate risk LPC patients after receiving radiotherapy. Studies were then gathered into 5 groups: detected acute and chronic toxicity data from phase II non randomized trials were analyzed and Odds Ratio (OR) was calculated by comparing the number of patients with G0-1 toxicity and those with toxicity > G2 in the studied groups. A meta-analysis of prospective randomized trials was also carried out.

Results

The initial search yielded 575 results, but only 32 manuscripts met all eligibility requirements: in terms of radiation-induced side effects, such as gastrointestinal and genitourinary acute and late toxicity, hypofractionated 3DCRT seemed to be more advantageous than 3DCRT with conventional fractionation as well as IMRT with conventional fractionation compared to 3DCRT with conventional fractionation; furthermore, IMRT hypofractionated technique appeared more advantageous than IMRT with conventional fractionation in late toxicities. Randomized trials meta-analysis disclosed an advantage in terms of acute gastrointestinal and late genitourinary toxicity for Hypofractionated schemes.

Conclusions

Although our analysis pointed out a more favorable toxicity profile in terms of gastrointestinal acute side effects of conventional radiotherapy schemes compared to hypofractionated ones, prospective randomized trials are needed to better understand the real incidence of rectal and urinary toxicity in patients receiving radiotherapy for localized prostate cancer.

Cyberknife Radioablation of Prostate Cancer – Preliminary Results for 400 Patients

Objectives: To evaluate the tolerance and effectiveness of stereotactic ablative radiotherapy (SABR) applied in the treatment of low and intermediate risk (LR & IR) prostate cancer patients (PCP) and provide an evaluation of the level of risk group impact on treatment results. In addition, androgen deprivation therapy (ADT) usage and prostatic specific antigen (PSA) decline after SABR were assessed. Material and Methods: A total of 400 PCP (213 LR and 187 IR, including T2c) were irradiated with a CyberKnife using fd 7.25 Gy to TD 36.25 Gy. At the start of treatment, 60.3% of patients were undergoing ADT and this gradually decreased to 0% after 38 months. Follow-up was for a median of 15.0 months. Patients were monitored on SABR completion and 1, 4, 8 months later and then subsequently every 6 months. GI (Gastro-Intestinal) and GU (Genito-Urinary) acute and late adverse effects, PSA and ADT usage were evaluated. Results: Failure was noted in 9 patients (2.25%) (5 in LR and 4 in IR groups) - 4 relapses and 5 nodal metastases. No G3/4 late adverse effects (EORTC/RTOG) were observed. Some 0.5% of G3 GU and 0.3% of G3 GI acute reactions were noted respectively on the SABR completion day and one month later. The median of PSA declined 1.5 ng/ml during the first month and 0.6 ng/ml during the next three months. No impact of risk groups on treatment results was found. An impact of ADT on PSA decline was only confirmed for time point interactions. Conclusions: SABR for LR and IR PCP is a safe and effective treatment. The inclusion of T2c patients and the low percentage of IR patient failure permit us the assumption that this procedure could be utilized in the treatment of more advanced cases. The results do not allow clear definition of the impact of ADT on radioablation results in LR and IR+ T2c cases.

Stereotactic Body Radiotherapy for Localized Ureter Transitional Cell Carcinoma: Three Case Reports

The gold standard management for ureter transitional cell carcinoma (UTCC) is radical nephroureterectomy with excision of the bladder cuff. However, some patients cannot undergo this procedure for several reasons. In the case reports described herein, we performed stereotactic body radiotherapy (SBRT) on three patients with inoperable or surgery-rejected localized UTCC. Two out of the three patients did not develop local recurrence or distant metastasis during the observation period. However, recurrence was detected in the bladder of one patient 22 months after the treatment. No acute or late adverse events occurred in any of the three patients. SBRT may become one of the treatment options for inoperable or surgery-rejected UTCC patients.

A case report of a patient with squamous cell carcinoma of the face irradiated using a stereotactic technique

External beam radiotherapy can be used to treat cutaneous squamous cell carcinomas (SCC). Acute skin toxicity is the most common adverse event. In this case study we report on an elderly patient with nasal root cutaneous SCC treated with stereotactic technique using a dedicated linear accelerator (CyberKnife system). Grade 3 skin toxicity was observed but it was resolved after 6 weeks. The use of stereotactic radiotherapy permitted a clinical remission of SCC with good cosmetic results.