Electromagnetic Transmitter-Based Prostate Gating for Dose-Escalated Linac-Based Stereotactic Body Radiation Therapy: An Evaluation of Intrafraction Motion

BACKGROUND

Stereotactic Body Radiotherapy (SBRT) is as a standard treatment for prostate cancer (PCa). Tight margins and high dose gradients are needed, and the precise localization of the target is mandatory. Our retrospective study reports our experience regarding the evaluation of intrafraction prostate motion during LINAC-based SBRT evaluated with a novel electromagnetic (EM) tracking device. This device consists of an integrated Foley catheter with a transmitter connected to a receiver placed on the treatment table.

METHODS

We analyzed 31 patients who received LINAC-based SBRT using flattening filter-free (FFF) volumetric modulated arc therapy (VMAT). The patients were scheduled to be treated for primary (n = 27) or an intraprostatic recurrent PCa (n = 4). A simulation CT scan was conducted while the patients had a filled bladder (100-150 cc) and an empty rectum, and an EM tracking device was used. The same rectal and bladder conditions were employed during the treatment. The patients received 36.25 Gy delivered over five consecutive fractions on the whole prostate and 40 Gy on the nodule(s) visible via MRI, both delivered with a Simultaneous Integrated Boost approach. The CTV-to-PTV margin was 2 mm for both the identified treatment volumes. Patient positioning was verified with XVI ConeBeam-CT (CBCT) matching before each fraction. When the signals exceeded a 2 mm threshold in any of the three spatial directions, the treatment was manually interrupted. A new XVI CBCT was performed if this offset lasted >20 s.

RESULTS

We analyzed data about 155 fractions. The median and mean treatment times, calculated per fraction, were 10 m31 s and 12 m44 s (range: 6 m36 s-65 m28 s), and 95% of the fractions were delivered with a maximum time of 27 m48 s. During treatment delivery, the mean and median number of XVI CBCT operations realized during the treatment were 2 and 1 (range: 0-11). During the treatment, the prostate was outside the CTV-to-PTV margin (2 mm), thus necessitating the stoppage of the delivery +/- a reacquisition of the XVI CBCT for 11.2%, 8.9%, and 3.9% of the delivery time in the vertical, longitudinal, and lateral direction, respectively.

CONCLUSIONS

We easily integrated an EM-transmitter-based gating for prostate LINAC-based SBRT into our normal daily workflow. Using this system, a 2 mm CTV-to-PTV margin could be safely applied. A small number of fractions showed a motion exceeding the predefined 2 mm threshold, which would have otherwise gone undetected without intrafraction motion management.

Extreme hypofractionated stereotactic radiotherapy for elderly prostate cancer patients: side effects preliminary analysis of a phase II trial

PURPOSE

Aim of this study is to evaluate safety and efficacy of SBRT in elderly patients affected by localized prostate cancer (PC).

MATERIAL AND METHODS

Men aged 70 years or older were enrolled and analyzed. The SBRT schedule was 35 Gy in 5 fractions administered in 1-2 weeks. According to risk group, androgen deprivation therapy (ADT) was prescribed. Urinary symptoms were evaluated at baseline using the International Prostate Symptom Score (IPSS). Genitourinary (GU) and gastrointestinal (GI) toxicities were assessed at the end of treatment, 2 weeks after SBRT and during follow-up using the Common Terminology Criteria for Adverse Events (CTCAE). PSA values were recorded before treatment and during follow-up as biochemical response criteria.

RESULTS

Between 07/2019 and 09/2021, 111 patients were enrolled. Median age was 77 years. At the end of treatment, no acute GU/GI toxicities ≥ G2 were observed. At 2-3 weeks after treatment, 3 patients reported G2 GU toxicity, while 14 patients referred G2 GI toxicity. During the last follow up, 26 and 2 patients reported, respectively, G1 and G2 GU toxicity, while 22 and 1 cases described, respectively, G1 and G2 GI toxicity. No late toxicities ≥ G3 were recorded. GU toxicity is related to absence of urethra sparing, increasing PTV volume, Dmax PTV and IPSS; GI toxicity is related to RT schedule (each other day is better than consecutive day), Dmax rectum and IPSS, At a median follow-up of 24 months, excellent biochemical disease control was achieved in all cases with median PSA of 0.5 ng/ml.

CONCLUSION

SBRT in elderly patients affected by PC is feasible and well tolerated with excellent biochemical disease control. Longer follow-up is needed to assess late toxicity profile and long-term clinical outcome.

Acute Toxicity in Hypofractionated/Stereotactic Prostate Radiotherapy of Elderly Patients: Use of the Image-guided Radio Therapy (IGRT) Clarity System

BACKGROUND

The use of intra-fractional monitoring and correction of prostate position with the Image Guided Radio Therapy (IGRT) system can increase the spatial accuracy of dose delivery. Clarity is a system used for intrafraction prostate-motion management, it provides a real-time visualization of prostate with a transperineal ultrasound. The aim of this study was to evaluate the use of Clarity-IGRT on proper intrafraction alignment and monitoring, its impact on Planning Tumor Volume margin and on urinary and rectal toxicity in elderly patients not eligible for surgery.

PATIENTS AND METHODS

Twenty-five elderly prostate cancer patients, median age=75 years (range=75-90 years) were treated with Volumetric Radiotherapy and Clarity-IGRT using 3 different schemes: A) 64.5/72 Gray (Gy) in 30 fractions on prostate and seminal vesicles (6 patients); B) 35 Gy in 5 fractions on prostate and seminal vesicles (12 patients); C): 35 Gy in 5 fractions on prostate (7 patients). Ultrasound identification of the overlapped structures to the detected ones during simulation has been used in each session. A specific software calculates direction and entity of necessary shift to obtain the perfect match. The average misalignment in the three-dimensional space has been determined and shown in a box-plot.

RESULTS

All patients completed treatment with mild-moderate toxicity. During treatment, genitourinary toxicity was 32% Grade 1; 4% Grade 2, rectal was 4% Grade 1. At follow-up of 3 months, genitourinary toxicity was 20% Grade 1; 4% Grade 2, rectal toxicity was 4% Grade 2. At follow-up of 6 months, genitourinary toxicity was 4% Grade 1; 4% Grade 2. Rectal toxicity was 4% Grade 2.

CONCLUSION

Radiotherapy with the Clarity System allows a reduction of PTV margins, the amount of fractions can be reduced increasing the total dose, not exacerbating urinary and rectal toxicity with greater patient's compliance.

Epigenetic mechanisms underlying prostate cancer radioresistance

Radiotherapy (RT) is one of the mainstay treatments for prostate cancer (PCa), a highly prevalent neoplasm among males worldwide. About 30% of newly diagnosed PCa patients receive RT with a curative intent. However, biochemical relapse occurs in 20–40% of advanced PCa treated with RT either alone or in combination with adjuvant-hormonal therapy. Epigenetic alterations, frequently associated with molecular variations in PCa, contribute to the acquisition of a radioresistant phenotype. Increased DNA damage repair and cell cycle deregulation decreases radio-response in PCa patients. Moreover, the interplay between epigenome and cell growth pathways is extensively described in published literature. Importantly, as the clinical pattern of PCa ranges from an indolent tumor to an aggressive disease, discovering specific targetable epigenetic molecules able to overcome and predict PCa radioresistance is urgently needed. Currently, histone-deacetylase and DNA-methyltransferase inhibitors are the most studied classes of chromatin-modifying drugs (so-called ‘epidrugs’) within cancer radiosensitization context. Nonetheless, the lack of reliable validation trials is a foremost drawback. This review summarizes the major epigenetically induced changes in radioresistant-like PCa cells and describes recently reported targeted epigenetic therapies in pre-clinical and clinical settings.

MR-Guided Hypofractionated Radiotherapy: Current Emerging Data and Promising Perspectives for Localized Prostate Cancer

In this review we summarize the currently available evidence about the role of hybrid machines for MR-guided radiotherapy for prostate stereotactic body radiotherapy. Given the novelty of this technology, to date few data are accessible, but they all report very promising results in terms of tolerability and preliminary clinical outcomes. Most of the studies highlight the favorable impact of on-board magnetic resonance imaging as a means to improve target and organs at risk identification with a consequent advantage in terms of dosimetric results, which is expected to relate to a more favorable toxicity pattern. Still, the longer treatment time per session may potentially affect the patient's compliance to the treatment, although first quality of life assessment studies have reported substantial tolerability and no major impact on quality of life. Finally, in this review we hypothesize some future scenarios of further investigation, based on the possibility to explore the superior anatomy visualization and the role of daily adapted treatments provided by hybrid MR-Linacs.

Alexithymia and professional quality of life in radiation oncology: The moderator effect of the professional profile

BACKGROUND AND PURPOSE

Cancer care can be taxing. Alexithymia, a personality construct characterized by difficulties in identifying and describing feeling and emotions, an externally-oriented thinking style and scarcity of imagination and fantasy, is significantly correlated with higher levels of both secondary traumatic stress (STS) and burnout and lower levels of compassion satisfaction in medical professionals in radiation oncology. In this study, we aimed to assess the difference in professional quality of life (QoL) and the association with alexithymia in this multidisciplinary field depending on the specific profession (radiation/clinical oncologist, RO; medical physicist, MP; radiation therapist, RTT).

MATERIAL AND METHODS

The study was conducted via an online questionnaire, receiving 1500 submissions between May and October 2018. Alexithymia was assessed via the Toronto Alexithymia Scale (TAS-20) and professional QoL was evaluated using the Professional Quality of Life Scale (ProQoL) version 5. Comparisons between the RO, RTT, and MP groups were performed by ANOVA or MANOVA, followed by Bonferroni corrected ANOVAs for continuous variables, and Pearson's chi-square test for categorical variables. The effect size was determined by calculating partial eta-squared (η²).

RESULTS

Profession had a moderator role on the correlation between alexithymia and STS, with RO being at a higher risk than MP and RTT. Further, the results of this study demonstrate the relevant point prevalence of decreased well-being at work even for professional categories such as MP despite the more technical profile and reduced interaction with patients.

CONCLUSIONS

This study demonstrates the importance of alexithymia as a factor contributing to decreased professional QoL amongst radiation oncology professionals. Alexithymic ROs are impacted to a higher extent compared to MPs and RTTs by the indirect exposure to patients suffering. It is worth addressing these observations in professional education, aiming to improve QoL for healthcare personnel.

Moderately Hypofractionated Radiotherapy with Simultaneous Integrated Boost in Prostate Cancer: A Comparative Study with Conventionally Fractionated Radiation

Background

To report 5-year clinical outcomes and toxicity in organ-confined prostate cancer (PCa) for low- and intermediate-risk patients treated with a moderately hypofractionated schedule of radiotherapy (RT) delivered with simultaneous integrated boost (SIB) compared to a conventionally fractionated RT regimen.

Methods

Data of 384 patients with PCa treated between August 2006 and June 2017 were retrospectively reviewed. The treatment schedule consisted of hypofractionated RT (HYPO FR) with SIB up to 70 Gy to the prostate gland and 63 Gy to seminal vesicles delivered in 28 fractions or in conventionally fractionated RT (CONV FR) up to a total dose of 80 Gy in 40 fractions. Patient allocation to treatment was based on the time period considered. For intermediate-risk patients, androgen deprivation was given for a median duration of 6 months. The 5-year biochemical relapse-free survival (bRFS), cancer-specific survival (CSS), and overall survival (OS) were assessed. Furthermore, we evaluated gastrointestinal (GI) and genitourinary (GU) toxicities. Uni- and multivariate Cox regression analyses were used to test the impact of clinical variables on both outcome and toxicity.

Results

A total of 198 patients was treated with hypofractionated RT and 186 with the conventional schedule. At a median follow-up of 5 years, no significant differences were observed in terms of GI toxicity and outcome between the two groups. Early GU toxicity was significantly increased in HYPO FR, while late GU toxicity was significantly higher in CONV FR. In HYPO FR, a biochemical relapse occurred in 12 patients (6.1%), and 9 patients (4.5%) reported a clinical relapse (4 local, 2 locoregional, and 3 systemic recurrence). In CONV FR, 15 patients (8.1%) experienced a biochemical relapse and 11 patients (5.9%) showed a clinical relapse (5 local, 4 locoregional, and 3 systemic recurrences). Early grades 1-2 GU and GI toxicities were observed in 60 (30.3%) and 37 (18.7%) patients, respectively, in the hypofractionated group and in 33 (17.7%) and 27 (14.5%) patients, respectively, in the conventionally fractionated RT group. Late GU and GI toxicities occurred in 1 (0.51%) and 8 (4.1%) patients, respectively, in HYPO FR. In CONV FR, 5 (2.7%) and 6 (3.2%) patients experienced late GU and GI toxicities, respectively. The 5-year OS, bRFS, and CSS were 98.9%, 94.1%, and 99.5%, respectively, in HYPO FR, and 94.5%, 92.1%, and 99.0%, respectively, in CONV FR.

Conclusions

Results obtained in this study showed that moderately hypofractionated RT employing SIB can be an effective approach providing valuable clinical outcomes with an acceptable toxicity profile.

Dosimetric comparison among cyberknife, helical tomotherapy and VMAT for hypofractionated treatment in localized prostate cancer

Hypofractionation for localized prostate cancer treatment is rapidly spreading in the medical community and it is supported by radiobiological evidences (lower α/β ratio compared with surrounding tissues). Stereotactic body radiation therapy (SBRT) is a technique to administer high doses with great precision, which is commonly performed with CyberKnife (CK) in prostate cancer treatment. Since the CyberKnife (CK) is not available at all radiotherapy center, alternative SBRT techniques are available such as Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT). The aim of the present study was to compare the dosimetric differences between the CK, VMAT, and HT plans for localized prostate cancer treatment.Seventeenpatients have been recruited and replanned using VMAT and HT to this purpose: they received the treatment using the CK with a prescription of 36.25 Gy in 5 fractions; bladder, rectum and penis bulb were considered as organs at risk (OAR). In order to compare the techniques, we considered DVHs, PTV coverage, Conformity Index and new Conformity Index, Homogeneity Index, beam-on time and OARs received dose.The 3 treatments methods showed a comparable coverage of the lesion (PTV 95%: 99.8 ± 0.4% CK; 98.5 ± 0.8% VMAT; 99.4 ± 0.5% HT. P < .05) and good sparing of OARs. Nevertheless, the beam-on time showed a significant difference (37 ± 9 m CK; 7.1 ± 0.3 m VMAT; 17 ± 2 m HT. P < .05).Our results showed that, although CK is the best SBRT technique for prostate cancer treatment, in case this technology is not available, it can be replaced by a similar treatment delivered by VMAT technique. VMAT can be administrated only if it has an appropriate Image Guided Radiation Therapy (IGRT) tracking system.

Impact of hydrogel peri-rectal spacer insertion on prostate gland intra-fraction motion during 1.5 T MR-guided stereotactic body radiotherapy

Background

The assessment of organ motion is a crucial feature for prostate stereotactic body radiotherapy (SBRT). Rectal spacer may represent a helpful device in order to outdistance rectal wall from clinical target, but its impact on organ motion is still a matter of debate. MRI-Linac is a new frontier in radiation oncology as it allows a superior visualization of the real-time anatomy of the patient and the current highest level of adaptive radiotherapy.

Methods

We present data regarding a total of 100 fractions in 20 patients who underwent MRI-guided prostate SBRT for low-to-intermediate risk prostate cancer with or without spacer. Translational and rotational shifts were computed on the pre- and post-treatment MRI acquisitions referring to the delivery position for antero-posterior, latero-lateral and cranio-caudal direction, and assessed using the Mann-Whitney U-Test.

Results

All patients were treated with a five sessions schedule (35 Gy/5fx) using MRI-Linac for a median fraction treatment time of 50 min (range, 46–65). In the entire study sample, median rotational displacement was 0.1° in cranio-caudal, − 0.002° in latero-lateral and 0.01° in antero-posterior direction; median translational shift was 0.11 mm in cranio-caudal, − 0.24 mm in latero-lateral and − 0.22 mm in antero-posterior. A significant difference between spacer and no-spacer patients in terms of rotational shifts in the antero-posterior direction (p = 0.033) was observed; also for translational shifts a positive trend was detected in antero-posterior direction (p = 0.07), although with no statistical significance. We observed statistically significant differences in the pre-treatment planning phase in favor of the spacer cohort for several rectum dose constraints: rectum V32Gy < 5% (p = 0.001), V28 Gy < 10% (p = 0.001) and V18Gy < 35% (p = 0.039). Also for bladder V35 Gy < 1 cc, the use of spacer provided a dosimetric advantage compared to the no-spacer subpopulation (p = 0.04). Furthermore, PTV V33.2Gy > 95% was higher in the spacer cohort compared to the no-spacer one (p = 0.036).

Conclusion

In our experience, the application of rectal hydrogel spacer for prostate SBRT resulted in a significant impact on rotational antero-posterior shifts contributing to limit prostate intra-fraction motion. Further studies with larger sample size and longer follow-up are required to confirm this ideally favorable effect and to assess any potential impact on clinical outcomes.

Moderate hypofractionated helical tomotherapy for prostate cancer in a cohort of older patients: a mono-institutional report of toxicity and clinical outcomes

PURPOSE OR OBJECTIVE

To evaluate toxicity and outcomes of moderately hypofractionated helical tomotherapy for the curative treatment of a cohort of patients aged ≥ 75 years with localized prostate cancer (PC).

MATERIALS AND METHODS

From January 2013 to February 2017, 95 patients with median age 77 years (range 75-88) were treated for PC. 39% were low risk, 33% intermediate risk (IR), 28% high risk (HR). Median iPSA was 9.42 ng/ml (1.6-107). Androgen deprivation was prescribed according to NCCN recommendations. All patients received 70 Gy in 28 fractions to the prostate; 61.6 Gy were delivered to the seminal vesicles for IR; whole pelvis irradiation with a total dose of 50.4 Gy was added in the HR group. Toxicity evaluation was based on CTCAE V4.0 criteria, biochemical failure was defined following Phoenix criteria. Quality of Life was assessed with the EPIC-26 index. Overall survival and biochemical failure-free survival were analysed with Kaplan-Meier method.

RESULTS

With a median follow-up of 36 months (range 24-73), acute and late toxicity were acceptable. No correlation between toxicity patterns and clinical or dosimetric parameter was registered. EPIC-26 showed a negligible difference in urinary and bowel function post-treatment that did not reach statistical significance. The 2- and 3-years OS were 93% and 87% with cancer specific survival of 97.9% and 96.2%.

CONCLUSION

Moderate hypofractionated RT reported excellent outcomes in our cohort of older patients. Shorter schedules may be proposed regardless of chronological age facilitating the treatment compliance in the older population.

Prostate cancer: more effective use of underutilized postoperative radiation therapy

Introduction: Adverse pathological features at radical prostatectomy such as extracapsular extension, seminal-vesicle involvement, positive surgical margins and/or lymph node invasion define a particular subgroup of patients that might benefit from additional treatment after surgery, in particular radiation therapy.Areas covered: Post-prostatectomy radiation is intended as adjuvant, early-salvage or salvage depending on the timing and PSA levels at the treatment. After providing the most used definitions, the high-level evidence supporting adjuvant radiation is reviewed together with the limitations affecting its utilization. In recent years early-salvage radiation was hypothesized to be a non-inferior alternative based on good-quality retrospective data. Recently, preliminary results of ongoing trials provide additional evidence. In light of the need to identify patients that will truly benefit from adjuvant radiation, clinically based and molecular tools available for this purpose are reviewed.Expert opinion: In order to tailor treatment for the patient after radical prostatectomy, there is a need for a tool that could both improve the oncological outcomes and be cost-effective. To date, genomic testing provides the most promising results that will be reasonably improved in the coming years.

Evaluation of Italian radiotherapy research from 1985 to 2005: preliminary analysis

AIM

The difficulty in conducting meaningful clinical research is a multifactorial issue, involving political, financial and cultural problems, which can lead to unexpected negative long-term consequences, in terms of knowledge advancement and impact on patient care. The aims of the present review were to evaluate the publications of Italian radiotherapy (RT) groups during a 20-year period and to verify whether research is still appealing to young radiation oncologists (ROs) in Italy.

METHODS

PubMed database was searched for English-language articles published by Italian groups from January 1985 to December 2005. Analyzed variables were: publication/year, kind of study, geographical area and age of the first author.

RESULTS

The systematic review identified 3291 articles: 1207 papers fulfilled the inclusion criteria. The number of Italian published papers increased during the examined period. Retrospective analyses, prospective phase I-II trials and literature reviews were 44, 20 and 14.5% of all published manuscripts, respectively. Randomized trials showed a mild increase from 2000 to 2005, but their absolute number remained low respect to other types of studies (4%). Northern Italy produced the very most of Italian research papers (58.7%). The age of the first/second author was evaluated on 716 papers: In more than 50% of cases, the first author was younger than 40.

CONCLUSION

Despite a general gradual improvement, RT clinical research suffers in Italy (as elsewhere) from insufficient funding, with a negative impact on evidence production. It is worth noting that clinical research is still appealing and accessible to junior Italian RO.

Modern intensity-modulated radiotherapy with image guidance allows low toxicity rates and good local control in chemoradiotherapy for anal cancer patients

PURPOSE

To report outcomes of a population of anal cancer patients treated with modern intensity-modulated radiotherapy and daily image-guided radiotherapy techniques.

METHODS

We analyzed data of 155 patients consecutively treated with intensity-modulated radiotherapy +/- chemotherapy in three radiotherapy departments. One hundred twenty-two patients presented a stage II-IIIA disease. Chemotherapy was administered in 138 patients, mainly using mitomycin C and 5-fluorouracil (n = 81). All patients received 36 Gy (1.8 Gy/fraction) on the pelvic and inguinal nodes, on the rectum, on the mesorectum and on the anal canal, and a sequential boost up to a total dose of 59.4 Gy (1.8 Gy/fraction) on the anal canal and on the nodal gross tumor volumes.

RESULTS

Median follow-up was 38 months (interquartile range 12-51). Toxicity data were available for 143 patients: 22% of them presented a G3+ acute toxicity, mainly as moist desquamation (n = 25 patients) or diarrhea (n = 10). Three patients presented a late grade 3 gastrointestinal toxicity (anal incontinence). No grade 4 acute or late toxicity was recorded. Patients treated with fixed-gantry IMRT delivered with a sliding window technique presented a significantly higher risk of acute grade 3 (or more) toxicity compared to those treated with VMAT or helical tomotherapy (38.5 vs 15.3%, p = 0.049). Actuarial 4-year local control rate was 82% (95% CI 76-91%).

CONCLUSIONS

Modern intensity-modulated radiotherapy with daily image-guided radiotherapy is effective and safe in treating anal cancer patients and should be considered the standard of care in this clinical setting.

Volumetric modulated arc therapy (VMAT) to deliver nodal irradiation in breast cancer patients

To evaluate feasibility, safety, toxicity profile and dosimetric results of volumetric modulated arc therapy (VMAT) to deliver regional nodal irradiation (RNI) after either mastectomy or breast conservation (BCS) in high-risk breast cancer patients. Between January 2015 and January 2017, a total of 45 patients were treated with VMAT to deliver RNI together with whole breast or post-mastectomy radiotherapy. The fractionation schedule comprised 50 Gy in 25 fractions given to supraclavicular and axillary apex nodes and to whole breast (after BCS) or chest wall (after mastectomy). Two opposite 50°-60° width arcs were employed for breast ad chest wall irradiation, while a single VMAT arc was used for nodal treatment. Treatment was generally well tolerated. Acute skin toxicity was G2 in 13.3% of patients. Late skin toxicity consisted of G1 induration/fibrosis in six patients (13.3%) and G2 in 1 (2.2%). Dosimetric results were consistent in terms of both target coverage and normal tissue sparing. In conclusion, VMAT proved to be a feasible, safe and effective strategy to deliver RNI in breast cancer patients after either BCS or mastectomy with promising dosimetric results and a mild toxicity profile.

Postoperative radiotherapy for prostate cancer: the sooner the better and potential to reduce toxicity even further

PURPOSE

To evaluate biochemical relapse-free survival (bRFS), overall survival (OS), late rectal and bladder toxicities in a retrospective single institution series, also applying an in-house software for biological dose calculation.

METHODS

258 patients submitted to radiotherapy after prostatectomy were considered. Differences between groups were calculated using the log-rank test and the relevant clinical and therapeutic variables were considered for multivariate analysis. PRODVH is an in-house system able to calculate mean dose-volume histograms (DVHs) of a series of patients, to convert them in biologically effective DVHs (BEDVHs) and allowing to compare them with ANOVA and t Student test.

RESULTS

Adjuvant radiotherapy (ART) and salvage radiotherapy (SRT) were performed in 131 (50.8%) and 127 patients (49.2%). At multivariate analysis advanced T stage, androgen deprivation total (ADT) and SRT resulted as independent variables related to a worst bRFS (p = 0.019, 0.001 and 0.02), while GS > 7 and SRT affected negatively OS (p 0.047 and 0.039). High grade toxicity events occurred mainly in patients treated with 3-dimensional conformal radiotherapy (3DCRT) (proctitis p = 0.006; cystitis: p = 0.041). A significantly more favorable mean rectum BEDVH for patients with G0 or G1 rectal toxicity was shown (p < 0.001). Mean BEDVH for both bladder (p < 0.01) and rectum (p < 0.05) were also significantly better for volumetric modulated arc therapy-image guided radiotherapy (VMAT-IGRT) plans than for 3DCRT plans.

CONCLUSION

ART is better than SRT in terms of bRFS and OS, particularly for more aggressive cases, advanced T stage and higher Gleason Score. Postoperative prostate cancer radiotherapy should be applied as soon as possible after surgery. The use of modern techniques such as VMAT-IGRT significantly reduces toxicity.

Extreme hypofractionation for early prostate cancer: Biology meets technology

The aim of this review is to present the available radiobiological, technical and clinical data about extreme hypofractionation in primary prostate cancer radiotherapy. The interest in this technique is based on the favourable radiobiological characteristics of prostate cancer and supported by advantageous logistic aspects deriving from short overall treatment time. The clinical validity of short-term treatment schedule is proven by a body of non-randomised studies, using both isocentric (LINAC-based) or non-isocentric (CyberKnife^®-based) stereotactic body irradiation techniques. Twenty clinical studies, each enrolling more than 40 patients for a total of 1874 treated patients, were revised in terms of technological setting, toxicity, outcome and quality of life assessment. The implemented strategies for the tracking of the prostate and the sparing of the rectal wall have been investigated with particular attention. The urinary toxicity after prostate stereotactic body irradiation seems slightly more pronounced as compared to rectal adverse events, and this is more evident for late occurring events, but no worse as respect to conventional fractionation schemes. As far as the rate of severe acute toxicity is concerned, in all the available studies the treatment was globally well tolerated. While awaiting long-term data on efficacy and toxicity, the analysed studies suggest that the outcome profile of this approach, alongside the patient convenience and reduced costs, is promising. Forty-eight ongoing clinical trials are also presented as a preview of the expectation from the near future.

Efficacy and safety of helical tomotherapy with daily image guidance in anal canal cancer patients

Background and purpose Intensity-modulated radiotherapy (IMRT), also using volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) techniques, has been only recently introduced for treating anal cancer patients. We report efficacy and safety HT, and daily image-guided RT (IGRT) for anal cancer. Materials and methods We retrospectively analyzed efficacy and toxicity of HT with or without chemotherapy for anal cancer patients. Local control (LC) and grade 3 or more toxicity rate (CTC-AE v.4.0) were the primary endpoints. Overall (OS), disease-free (DFS), and colostomy-free survival (CFS) are also reported. Results Between October 2007 and May 2014, 78 patients were treated. Fifty patients presented a stage II or stage IIIA (UICC 2002), and 33 presented a N1-3 disease. Radiotherapy consisted of 36 Gy (1.8 Gy/fraction) delivered on the pelvis and on the anal canal, with a sequential boost up to 59.4 Gy (1.8 Gy/fraction) delivered to the anal and to nodal gross tumor volumes. Concomitant chemotherapy was delivered in 73 patients, mainly using mitomycin C and 5-fluorouracil (n = 30) or mitomycin C and capecitabine combination (n = 37). After a median follow-up period of 47 months (range 3-75), the five-year LC rate was 83.8% (95% CI 76.2-91.4%). Seven patients underwent a colostomy because of local recurrence (n = 5) or pretreatment dysfunction (n = 2). Overall incidence of grade 3 acute toxicity was 24%, mainly as erythema (n = 15/19) or diarrhea (n = 7/19). Two patients presented a late grade 3 gastrointestinal toxicity (anal incontinence). No grade 4 acute or late toxicity was recorded. Conclusions HT with daily IGRT is efficacious and safe in the treatment of anal canal cancer patients, and is considered in our department standard of care in this clinical setting.

Three-Dimensional Ultrasound-Based Target Volume Delineation and Consequent Dose Calculation in Prostate Cancer Patients with Bilateral Hip Replacement: A Report of 4 Cases

Aim

To investigate the role of 3D ultrasound (3D-US) in target volume delineation in prostate cancer radiotherapy.

Methods

Four patients with intermediate risk prostate cancer and metal artifacts on planning computed tomography (CT) due to previous bilateral hip replacement underwent 3D-US with the Clarity platform (Clarity System, Elekta, Stockholm, Sweden) to allow for image-guided procedures. Ultrasound and CT images were coregistered to allow for better delineation of the prostate gland and organs at risk (OAR). Electron density override (EDO) and standard electron density (EDS) methods were compared for appropriate dose calculation.

Results

3D-US and planning CT minimized image artifacts, providing better evidence of patient anatomy, particularly regarding soft tissue visualization. Prostate gland and seminal vesicles were better delineated, particularly in the posterior aspect. Anterior rectal wall and bladder neck were more visible. No difference was found in terms of average planning target volume dose, D15%, or D25% for rectum or D15%, D25%, or D35% of bladder between EDO and EDS.

Conclusions

3D-US proved to be a viable tool for target volume and OAR visualization in patients with prostate cancer with hip prostheses.

"Hit the primary": A paradigm shift in the treatment of metastatic prostate cancer?

Patients with metastatic prostate cancer (PC) represent a heterogeneous group with survival rates varying between 13 and 75 months. The current standard treatment in this setting is hormonal therapy, with or without docetaxel-based chemotherapy. In the era of individualized medicine, however, maximizing treatment options, especially in long-term surviving patients with limited disease burden, is of capital importance. Emerging data, mainly from retrospective surgical series, show survival benefits in men diagnosed with metastatic PC following definitive therapy for the prostate. Whether the irradiation of primary tumor in a metastatic disease might improve the therapeutic ratio in association with systemic treatments remains investigational. In this scenario, modern radiation therapy (RT) can play a significant role owing to its intrinsic capability to act as a more general immune response modifier, as well as to the potentially better toxicity profile compared to surgery. Preclinical data, clinical experience, and challenges in local treatment in de novo metastatic PC are reviewed and discussed.

Available evidence on re-irradiation with stereotactic ablative radiotherapy following high-dose previous thoracic radiotherapy for lung malignancies

Patients affected with intra-thoracic recurrences of primary or secondary lung malignancies after a first course of definitive radiotherapy have limited therapeutic options, and they are often treated with a palliative intent. Re-irradiation with stereotactic ablative radiotherapy (SABR) represents an appealing approach, due to the optimized dose distribution that allows for high-dose delivery with better sparing of organs at risk. This strategy has the goal of long-term control and even cure. Aim of this review is to report and discuss published data on re-irradiation with SABR in terms of efficacy and toxicity. Results indicate that thoracic re-irradiation may offer satisfactory disease control, however the data on outcome and toxicity are derived from low quality retrospective studies, and results should be cautiously interpreted. As SABR may be associated with serious toxicity, attention should be paid for an accurate patients' selection.

SBRT and extreme hypofractionation: A new era in prostate cancer treatments?

AIM

Radiation therapy (RT) is a standard therapeutic option for prostate cancer (PC). In the last decades, several innovative technology applications have been introduced. 3-Dimensional conformal RT, volumetric/rotational intensity modulated RT associated or not with image-guided RT, are becoming largely diffused in the treatment of PC.

BACKGROUND

Considering that PC could have a low α/β ratio, similar to late-reacting normal tissues, it could also be highly responsive to fraction size. Thus, the reduction of the number of fractions and the increase of the dose/fraction seem to be reasonable choices in the treatment of this cancer. This review reported the technology evolution, the radiobiological and the clinical data about the role of extreme hypofractionated RT in the treatment approach of PC patients.

MATERIALS AND METHODS

Medline search and analysis of published studies containing key words: prostate cancer, radiotherapy, stereotactic radiotherapy.

RESULTS

Recent technological developments, combined with an improved knowledge of the radiobiological models in favor of a high sensitivity of PC to larger fraction sizes are opening a new scenario in its treatment, reporting favorable efficacy and acceptable toxicity, despite short follow-up.

CONCLUSION

Thus, thanks to technological improvement and the recent radiobiological data, "extreme hypofractionated RT" has been strongly introduced in the last years as a potential solid treatment option for PC.