Francesco Moretto

Efficacy and Safety of Tadalafil 20 mg on Demand vs. Tadalafil 5 mg Once-a-Day in the Treatment of Post-Radiotherapy Erectile Dysfunction in Prostate Cancer Men: A Randomized Phase II Trial

INTRODUCTION The role of phosphodiesterase type 5 inhibitors in the treatment of post-radiotherapy erectile dysfunction (ED) has not been extensively investigated. AIM To compare the efficacy and safety of on-demand 20-mg tadalafil (arm A) with the newly released tadalafil 5-mg once-a-day dosing (arm B) in patients with ED following radiotherapy for prostate cancer (PC). METHODS Randomized study to receive on-demand 20-mg or once-a-day 5-mg tadalafil for 12 weeks. Main Outcome Measures.  Changes in the International Index of Erectile Function (IIEF) domain scores and Sexual Encounter Profile (SEP) question 2 and 3 positive response rates. RESULTS Fifty-two out of 86 screened patients were randomized. Forty-four patients were evaluable for efficacy. A significant improvement in all domains of the IIEF was observed in both arms (P = 0.0001) with mean erectile function domain scores values of 25 and 27.1 for the 20-mg and 5-mg tadalafil, respectively (P = 0.19). SEP 2 and 3 positive response rates increased from 0% in both arms at baseline to 81% and 70% in the 20-mg arm and 90% and 73% in the 5-mg arm, respectively, at the end of treatment (P = 0.27). End of treatment global efficacy question positive answers were 86% in the 20-mg arm and 95% in the 5-mg arm (P = 0.27). Higher treatment compliance was shown in arm B (100%) as compared with arm A (86%). There was a nonstatistically significant trend toward fewer side effects in favor of the 5-mg daily dose arm. CONCLUSIONS In the study population, both tadalafil formulations generated significantly high response rates according to the outcome measures and were well tolerated. The once-a-day 5-mg dosing showed higher compliance and marginally reduced side effects, thus making it an attractive alternative to on-demand therapy for ED in post-radiotherapy PC patients.

Sepsis in head and neck cancer patients treated with chemotherapy and radiation: Literature review and consensus.

The reporting of infection/sepsis in chemo/radiation-treated head and neck cancer patients is sparse and the problem is underestimated. A multidisciplinary group of head and neck cancer specialists from Italy met with the aim of reaching a consensus on a clinical definition and management of infections and sepsis. The Delphi appropriateness method was used for this consensus. External expert reviewers then evaluated the conclusions carefully according to their area of expertise. The paper contains seven clusters of statements about the clinical definition and management of infections and sepsis in head and neck cancer patients, which had a consensus. Furthermore, it offers a review of recent literature in these topics.

Tracking target position variability using intraprostatic fiducial markers and electronic portal imaging in prostate cancer radiotherapy

PurposeModern radiotherapy has achieved substantial improvement in tumour control and toxicity rates by escalating the total dose to the target volume while sparing surrounding normal tissues. It has therefore become necessary to precisely track tumour position in order to minimise geometrical uncertainties due to setup errors and organ motion. We conducted this prospective evaluation of prostate cancer patients treated with image-guided conformal radiation therapy at our institution. We implanted three fiducial markers (gold seeds) within the prostatic gland in order to quantify daily target displacements and to generate specific margins around the clinical target volume (CTV) to create an appropriate planned target volume (PTV).Materials and methodsBetween April and December 2009, ten patients affected with localised prostate cancer were transrectally implanted with three radio-opaque markers. Each patient underwent a computed tomography (CT) scan for planning purposes following proper bladder and rectum preparation. During treatment two orthogonal images were acquired daily and compared with previously generated digitally reconstructed radiographs. After manual localisation, comparison between the position of the gold seeds on the portal and reference images was carried out, and a set of extrapolated lateral-lateral (LL), anterior-posterior (AP) and cranial-caudal (CC) shift corrections was calculated and recorded. Couch corrections were applied with a threshold of 3 mm displacement.ResultsSystematic and random errors for each direction were calculated either as measured according to displacement of the gold seeds prior to any couch movement and after couch position correction according to the radio-opaque markers. For skin marks, mean systematic and random errors were 0.12+2.94 mm for LL, 1.04+3.37 mm for AP, −1.14+2.71 mm for CC, whereas for seed markers, mean and systematic errors were 0.6+1.5 mm for LL, 0.51+2.45 mm for AP and −0.25+2.51 mm for CC. A scatter plot generated on all measurements after couch repositioning according to gold-seed displacement suggested a confidence range of shift distributions within 5 mm for LL, 8 mm for CC, and 7 mm for AP. The total systematic and random components were then used to calculate proper PTV in patients receiving conventional treatment (7 mm for LL and 9 mm for both AP and CC).ConclusionsProstate positional variability during a course of radiation treatment is strongly influenced by setup and organ motion. Organ tracking through fiducial markers and electronic portal imaging is able to reduce the spread of displacements, significantly contributing to improve the ballistic precision of radiation delivery.RiassuntoObiettivoLa moderna radioterapia ha raggiunto traguardi considerevoli in termini di controllo tumorale e riduzione dei tassi di tossicità associati al trattamento, con la possibilità di erogare dosi importanti al volume bersaglio, risparmiando contemporaneamente i tessuti sani. Risulta, pertanto, focale la caratterizzazione precisa della posizione della lesione neoplastica per minimizzare le incertezze geometriche dovute agli errori di posizionamento ed al movimento d’organo. Abbiamo intrapreso una valutazione prospettica dei pazienti trattati mediante radioterapia conformazionale guidata dalle immagini per carcinoma prostatico, utilizzando tre reperi fiduciali (semi d’oro) impiantati all’interno della prostata per quantificare gli scostamenti giornalieri del volume bersaglio e generare margini specifici attorno al volume bersaglio clinico (CTV) creando un appropriato volume bersaglio di pianificazione (PTV).Materiali e metodiTra aprile e dicembre 2009, 10 pazienti affetti da adenocarcinoma prostatico organo-confinato sono stati sottoposti ad impianto trans-rettale sotto guida ecografica di 3 reperi fiduciali radio-opachi. Ogni paziente è stato sottoposto a tomografia computerizzata (CT) di pianificazione con una adeguata preparazione vescicale e rettale; ad ogni seduta di trattamento, sono state acquisite 2 immagini ortogonali e poi confrontate con immagini radiografiche a ricostruzione digitale. è stata effettuata una localizzazione manuale confrontando la posizione dei reperi fiduciali nelle immagini portali con quella nelle immagini di riferimento. Sono stati estrapolati e registrati gli scostamenti nelle direzioni latero-laterale (LL), anteroposteriore (AP) e cranio-caudale (CC). La correzione della posizione del lettino di trattamento è stata effettuata con una soglia di 3 mm.RisultatiSono stati calcolati l’errore standard e sistematico per ogni direzione, misurando gli scostamenti dei semi d’oro prima del movimento del lettino di trattamento e dopo aver applicato gli spostamenti secondo i reperi fiduciali. Per i reperi cutanei, l’errore sistematico e casuale medio sono stati 0,12±2,94 mm per la direzione LL, 1,04±3,37 mm per la direzione AP e −1,14±2,71 mm per la direzione CC; per i reperi fiduciali, l’errore sistematico e casuale medio sono stati 0,6±1,5 mm per la direzione LL, 0,51±2,45 mm per la direzione AP e −0,25±2,51 mm per la direzione CC. è stato creato un diagramma di distribuzione di tutte le misure ottenute dopo il riposizionamento del lettino in funzione degli scostamenti registrati mediante i reperi fiduciali; l’ambito di confidenza della distribuzione degli spostamenti si trova entro i 5 mm per la direzione LL, entro i 6 mm per la direzione CC ed entro i 7 mm per la direzione AP. L’errore sistematico e l’errore casuale totale sono stati utilizzati per generare margini per ottenere il PTV nei pazienti trattati convenzionalmente (7 mm per la direzione LL; 9 mm sia per la direzione AP che per la direzione CC).ConclusioniLa variabilità della posizione della ghiandola prostatica durante un trattamento radiante è influenzata in modo importante dal posizionamento e dal movimento d’organo. Il monitoraggio della posizione della prostata mediante reperi fiduciali ed immagini portali è in grado di ridurre la dispersione degli scostamenti rispetto all’atteso, contribuendo in maniera significativa al miglioramento della precisione balistica della radioterapia.

Pulmonary function and quality of life after VMAT-based stereotactic ablative radiotherapy for early stage inoperable NSCLC: a prospective study

OBJECTIVES To analyze changes in pulmonary function and quality of life (QoL) at different time points after Stereotactic Ablative Radiotherapy (SABR) for early stage inoperable lung cancer, and potential correlations between radiation dose-volume parameters and pulmonary toxicity or changes in pulmonary function tests (PFT) and QoL. MATERIALS AND METHODS From July 2012 to October 2013, 30 patients were enrolled in this prospective observational study. Complete PFT were performed and Lung Cancer Symptoms Scale (LCSS) questionnaire administered prior to SABR; all patients then underwent Computed Tomography (CT) scan and PFT at 45, 135, 225 and 315 days after SABR, together with LCSS questionnaire. Clinical lung toxicity and radiological toxicity (acute and late) were prospectively recorded by using the Radiation Therapy Oncology Group (RTOG) scoring system. RESULTS A decline in Slow Vital Capacity (SVC), Forced Expiratory Volume in 1s (FEV1), Single-breath lung diffusing capacity (DLCO) and blood partial pressure of oxygen (PaO2) was seen at 135 days post-SABR. PaO2 values rescued to normal levels at 315 days. None of the baseline PFT parameters resulted to be associated with the occurrence of pulmonary toxicity or with late radiological changes. Mean V5, V10, and V20 and MLD2Gy were higher in patients who developed radiation pneumonitis, even if not significantly associated at Cox regression analysis. LCSS QoL showed a significant worsening of the single item fatigue at 135 days after SABR. CONCLUSIONS A small (mean 10%) but significant decline in lung volumes and DLCO was recorded after SABR, with clinical impact of such change difficult to estimate in individual patients. Global QoL was not significantly impaired. Dose-volume parameters did not emerge as significantly predictive of any clinical, radiological or functional toxicity.

Hypericum perforatum and neem oil for the management of acute skin toxicity in head and neck cancer patients undergoing radiation or chemo-radiation: a single-arm prospective observational study.

BackgroundRadiation dermatitis is common in patients treated with combined radiotherapy and chemotherapy for head and neck malignancies. Its timely and adequate management is of uttermost importance for both oncological outcomes and global quality of life. We prospectively evaluated the role of hypericum perforatum and neem oil (Holoil®; RIMOS srl, Mirandola, Italy) in the treatment of acute skin toxicity for patients undergoing radiotherapy or chemo-radiotherapy for head and neck cancer.MethodsA consecutive series of 28 head and neck cancer patients submitted to radiotherapy (RT) was enrolled onto this mono-institutional single-arm prospective observational study. Patients undergoing both definitive or post-operative radiotherapy were allowed, either as exclusive modality or combined with (concomitant or induction) chemotherapy. We started Holoil treatment whenever bright erythema, moderate oedema or patchy moist desquamation were observed. Holoil® was used during all RT course and during follow up time, until acute skin toxicity recovery.ResultsThe maximum detected acute skin toxicity was Grade 1 in 7% of patients, Grade 2 in 68%, Grade 3 in 25%, while at the end of RT was Grade 0 in 3.5%, Grade 1 in 32%, Grade 2 in 61%, Grade 3 in 3.5%. For patients having G2 acute skin toxicity, it mainly started at weeks 4-5; for those having G3, it began during weeks 5-6. Median times spent with G2 or G3 toxicity were 17.5 and 11 days. Patients having G2 acute skin toxicity had a dermatitis worsening in 27% of case (median occurrence time: 7 days). G3 events were reconverted to a G2 profile in all patients (median time: 7 days). Those experiencing a G2 skin event were converted to a G1 score in 23% of cases (median time: 14 days). Time between maximum acute skin toxicity and complete skin recovery after RT was 27 days.ConclusionsHoloil® proved to be a safe and active option in the management of acute skin toxicity in head and neck cancer patients submitted to RT or chemo-radiotherapy. A prophylactic effect in the prevention of moist desquamation may be hypothesized for hypericum and neem oil and need to be tested within a prospective controlled study.

Three-Dimensional Ultrasound-Based Image-Guided Hypofractionated Radiotherapy for Intermediate-Risk Prostate Cancer: Results of a Consecutive Case Series

External beam radiotherapy (EBRT) is a standard of care in the treatment of prostate cancer. Hypofractionation is a valid option either radiobiologically and logistically in this context. Image-guidance procedures are strongly needed to provide ballistic precision to radiation delivery. The Clarity platform allows for the acquisition of three-dimensional ultrasound scans (3D-US) to perform image-guided radiotherapy. We treated a consecutive series of intermediate-risk prostate cancer patients (according to NCCN stratification) with a hypofractionated schedule (70.2 Gy/26 fractions at 2.7 Gy/daily to the prostate gland excluding the seminal vesicles at 62.1 Gy) under 3D-US guidance with the Clarity platform. The 3-year biochemical-relapse-free survival, distant-metastases-free, cancer-specific and overall survival were 98.6% (CI: 91.1–99.6%), 98.6% (CI: 91.1–99.6%), 97.5% (CI: 94.5–99.1%), and 94.3% (CI: 90.4–96.7%), respectively. Maximum detected acute GU toxicity was G0 in 22 patients (29.7%), G1 in 30 (22.7%), G2 in 19 (25.6%), G3 in 3 (4%). Maximum detected acute GI toxicity at the end of EBRT was G0 in 42 patients (56.8%), G1 in 22 (29.7%), G2 in 9 (12.1%), G3 in 1 (1.4%). The 3-year actuarial rates of ≥ G2 late toxicities were 6.1% for genito-urinary and 8.9% for gastrointestinal. The whole image-guidance workflow resulted in being robust and reliable. EBRT delivered employing a hypofractionated schedule under 3D-US-based image guidance proved to be a safe and effective treatment approach with consistent biochemical control and a mild toxicity profile. Hence, it has been transferred into daily clinical practice in our Department.

Salvage External Beam Radiotherapy for Recurrent Prostate Adenocarcinoma after High-Intensity Focused Ultrasound as Primary Treatment

Introduction: The main objective was to evaluate feasibility, toxicity and biochemical control rates of salvage external beam radiotherapy (EBRT) in recurrent localized prostate cancer after high-intensity focused ultrasound (HIFU) as primary therapy. Patients and Methods: A total of 24 patients who underwent salvage EBRT after 1 or 2 HIFU sessions and with a minimum post-treatment follow-up of 24 months were retrospectively evaluated. Primary endpoints were toxicity and biochemical disease-free survival (bDFS, defined according to the ASTRO Phoenix definition). Results: Median follow-up was 40.3 months. Gastrointestinal toxicity was low. Acute genitourinary (GU) toxicity grade ≤II rate was 45.8%, with only few patients presenting grade III (8.3%) and grade IV (4.2%) toxicity. Late grade ≥III GU toxicity was registered in 16.7% of patients. The 3-year bDFS rate was 77.8%. Patients achieving a nadir prostate-specific antigen (nPSA) of ≤0.35 ng/ml after EBRT had significantly higher bDFS (3-year bDFS: 87.7 vs. 50%, respectively; p = 0.001). Achieving nPSA ≤0.35 ng/ml was the only factor independently associated to long-term bDFS both on univariate (p = 0.01) and multivariate analysis (HR 7.06, p = 0.039). Conclusions: Salvage EBRT after HIFU failure is feasible and allows to obtain satisfactory biochemical control rates, especially in patients attaining a nPSA ≤0.35 ng/ml after EBRT.

Variabilità della posizione del volume bersaglio utilizzando reperi fiduciali intra-prostatici ed immagini portali nella radioterapia del tumore della prostata

PurposeModern radiotherapy has achieved substantial improvement in tumour control and toxicity rates by escalating the total dose to the target volume while sparing surrounding normal tissues. It has therefore become necessary to precisely track tumour position in order to minimise geometrical uncertainties due to setup errors and organ motion. We conducted this prospective evaluation of prostate cancer patients treated with image-guided conformal radiation therapy at our institution. We implanted three fiducial markers (gold seeds) within the prostatic gland in order to quantify daily target displacements and to generate specific margins around the clinical target volume (CTV) to create an appropriate planned target volume (PTV).Materials and methodsBetween April and December 2009, ten patients affected with localised prostate cancer were transrectally implanted with three radio-opaque markers. Each patient underwent a computed tomography (CT) scan for planning purposes following proper bladder and rectum preparation. During treatment two orthogonal images were acquired daily and compared with previously generated digitally reconstructed radiographs. After manual localisation, comparison between the position of the gold seeds on the portal and reference images was carried out, and a set of extrapolated lateral-lateral (LL), anterior-posterior (AP) and cranial-caudal (CC) shift corrections was calculated and recorded. Couch corrections were applied with a threshold of 3 mm displacement.ResultsSystematic and random errors for each direction were calculated either as measured according to displacement of the gold seeds prior to any couch movement and after couch position correction according to the radio-opaque markers. For skin marks, mean systematic and random errors were 0.12+2.94 mm for LL, 1.04+3.37 mm for AP, −1.14+2.71 mm for CC, whereas for seed markers, mean and systematic errors were 0.6+1.5 mm for LL, 0.51+2.45 mm for AP and −0.25+2.51 mm for CC. A scatter plot generated on all measurements after couch repositioning according to gold-seed displacement suggested a confidence range of shift distributions within 5 mm for LL, 8 mm for CC, and 7 mm for AP. The total systematic and random components were then used to calculate proper PTV in patients receiving conventional treatment (7 mm for LL and 9 mm for both AP and CC).ConclusionsProstate positional variability during a course of radiation treatment is strongly influenced by setup and organ motion. Organ tracking through fiducial markers and electronic portal imaging is able to reduce the spread of displacements, significantly contributing to improve the ballistic precision of radiation delivery.RiassuntoObiettivoLa moderna radioterapia ha raggiunto traguardi considerevoli in termini di controllo tumorale e riduzione dei tassi di tossicità associati al trattamento, con la possibilità di erogare dosi importanti al volume bersaglio, risparmiando contemporaneamente i tessuti sani. Risulta, pertanto, focale la caratterizzazione precisa della posizione della lesione neoplastica per minimizzare le incertezze geometriche dovute agli errori di posizionamento ed al movimento d’organo. Abbiamo intrapreso una valutazione prospettica dei pazienti trattati mediante radioterapia conformazionale guidata dalle immagini per carcinoma prostatico, utilizzando tre reperi fiduciali (semi d’oro) impiantati all’interno della prostata per quantificare gli scostamenti giornalieri del volume bersaglio e generare margini specifici attorno al volume bersaglio clinico (CTV) creando un appropriato volume bersaglio di pianificazione (PTV).Materiali e metodiTra aprile e dicembre 2009, 10 pazienti affetti da adenocarcinoma prostatico organo-confinato sono stati sottoposti ad impianto trans-rettale sotto guida ecografica di 3 reperi fiduciali radio-opachi. Ogni paziente è stato sottoposto a tomografia computerizzata (CT) di pianificazione con una adeguata preparazione vescicale e rettale; ad ogni seduta di trattamento, sono state acquisite 2 immagini ortogonali e poi confrontate con immagini radiografiche a ricostruzione digitale. è stata effettuata una localizzazione manuale confrontando la posizione dei reperi fiduciali nelle immagini portali con quella nelle immagini di riferimento. Sono stati estrapolati e registrati gli scostamenti nelle direzioni latero-laterale (LL), anteroposteriore (AP) e cranio-caudale (CC). La correzione della posizione del lettino di trattamento è stata effettuata con una soglia di 3 mm.RisultatiSono stati calcolati l’errore standard e sistematico per ogni direzione, misurando gli scostamenti dei semi d’oro prima del movimento del lettino di trattamento e dopo aver applicato gli spostamenti secondo i reperi fiduciali. Per i reperi cutanei, l’errore sistematico e casuale medio sono stati 0,12±2,94 mm per la direzione LL, 1,04±3,37 mm per la direzione AP e −1,14±2,71 mm per la direzione CC; per i reperi fiduciali, l’errore sistematico e casuale medio sono stati 0,6±1,5 mm per la direzione LL, 0,51±2,45 mm per la direzione AP e −0,25±2,51 mm per la direzione CC. è stato creato un diagramma di distribuzione di tutte le misure ottenute dopo il riposizionamento del lettino in funzione degli scostamenti registrati mediante i reperi fiduciali; l’ambito di confidenza della distribuzione degli spostamenti si trova entro i 5 mm per la direzione LL, entro i 6 mm per la direzione CC ed entro i 7 mm per la direzione AP. L’errore sistematico e l’errore casuale totale sono stati utilizzati per generare margini per ottenere il PTV nei pazienti trattati convenzionalmente (7 mm per la direzione LL; 9 mm sia per la direzione AP che per la direzione CC).ConclusioniLa variabilità della posizione della ghiandola prostatica durante un trattamento radiante è influenzata in modo importante dal posizionamento e dal movimento d’organo. Il monitoraggio della posizione della prostata mediante reperi fiduciali ed immagini portali è in grado di ridurre la dispersione degli scostamenti rispetto all’atteso, contribuendo in maniera significativa al miglioramento della precisione balistica della radioterapia.

Tracking target position variability using intraprostatic fiducial markers and electronic portal imaging in prostate cancer radiotherapy@@@Variabilità della posizione del volume bersaglio utilizzando reperi fiduciali intra-prostatici ed immagini portali nella radioterapia del tumore della prostata

PurposeModern radiotherapy has achieved substantial improvement in tumour control and toxicity rates by escalating the total dose to the target volume while sparing surrounding normal tissues. It has therefore become necessary to precisely track tumour position in order to minimise geometrical uncertainties due to setup errors and organ motion. We conducted this prospective evaluation of prostate cancer patients treated with image-guided conformal radiation therapy at our institution. We implanted three fiducial markers (gold seeds) within the prostatic gland in order to quantify daily target displacements and to generate specific margins around the clinical target volume (CTV) to create an appropriate planned target volume (PTV).Materials and methodsBetween April and December 2009, ten patients affected with localised prostate cancer were transrectally implanted with three radio-opaque markers. Each patient underwent a computed tomography (CT) scan for planning purposes following proper bladder and rectum preparation. During treatment two orthogonal images were acquired daily and compared with previously generated digitally reconstructed radiographs. After manual localisation, comparison between the position of the gold seeds on the portal and reference images was carried out, and a set of extrapolated lateral-lateral (LL), anterior-posterior (AP) and cranial-caudal (CC) shift corrections was calculated and recorded. Couch corrections were applied with a threshold of 3 mm displacement.ResultsSystematic and random errors for each direction were calculated either as measured according to displacement of the gold seeds prior to any couch movement and after couch position correction according to the radio-opaque markers. For skin marks, mean systematic and random errors were 0.12+2.94 mm for LL, 1.04+3.37 mm for AP, −1.14+2.71 mm for CC, whereas for seed markers, mean and systematic errors were 0.6+1.5 mm for LL, 0.51+2.45 mm for AP and −0.25+2.51 mm for CC. A scatter plot generated on all measurements after couch repositioning according to gold-seed displacement suggested a confidence range of shift distributions within 5 mm for LL, 8 mm for CC, and 7 mm for AP. The total systematic and random components were then used to calculate proper PTV in patients receiving conventional treatment (7 mm for LL and 9 mm for both AP and CC).ConclusionsProstate positional variability during a course of radiation treatment is strongly influenced by setup and organ motion. Organ tracking through fiducial markers and electronic portal imaging is able to reduce the spread of displacements, significantly contributing to improve the ballistic precision of radiation delivery.RiassuntoObiettivoLa moderna radioterapia ha raggiunto traguardi considerevoli in termini di controllo tumorale e riduzione dei tassi di tossicità associati al trattamento, con la possibilità di erogare dosi importanti al volume bersaglio, risparmiando contemporaneamente i tessuti sani. Risulta, pertanto, focale la caratterizzazione precisa della posizione della lesione neoplastica per minimizzare le incertezze geometriche dovute agli errori di posizionamento ed al movimento d’organo. Abbiamo intrapreso una valutazione prospettica dei pazienti trattati mediante radioterapia conformazionale guidata dalle immagini per carcinoma prostatico, utilizzando tre reperi fiduciali (semi d’oro) impiantati all’interno della prostata per quantificare gli scostamenti giornalieri del volume bersaglio e generare margini specifici attorno al volume bersaglio clinico (CTV) creando un appropriato volume bersaglio di pianificazione (PTV).Materiali e metodiTra aprile e dicembre 2009, 10 pazienti affetti da adenocarcinoma prostatico organo-confinato sono stati sottoposti ad impianto trans-rettale sotto guida ecografica di 3 reperi fiduciali radio-opachi. Ogni paziente è stato sottoposto a tomografia computerizzata (CT) di pianificazione con una adeguata preparazione vescicale e rettale; ad ogni seduta di trattamento, sono state acquisite 2 immagini ortogonali e poi confrontate con immagini radiografiche a ricostruzione digitale. è stata effettuata una localizzazione manuale confrontando la posizione dei reperi fiduciali nelle immagini portali con quella nelle immagini di riferimento. Sono stati estrapolati e registrati gli scostamenti nelle direzioni latero-laterale (LL), anteroposteriore (AP) e cranio-caudale (CC). La correzione della posizione del lettino di trattamento è stata effettuata con una soglia di 3 mm.RisultatiSono stati calcolati l’errore standard e sistematico per ogni direzione, misurando gli scostamenti dei semi d’oro prima del movimento del lettino di trattamento e dopo aver applicato gli spostamenti secondo i reperi fiduciali. Per i reperi cutanei, l’errore sistematico e casuale medio sono stati 0,12±2,94 mm per la direzione LL, 1,04±3,37 mm per la direzione AP e −1,14±2,71 mm per la direzione CC; per i reperi fiduciali, l’errore sistematico e casuale medio sono stati 0,6±1,5 mm per la direzione LL, 0,51±2,45 mm per la direzione AP e −0,25±2,51 mm per la direzione CC. è stato creato un diagramma di distribuzione di tutte le misure ottenute dopo il riposizionamento del lettino in funzione degli scostamenti registrati mediante i reperi fiduciali; l’ambito di confidenza della distribuzione degli spostamenti si trova entro i 5 mm per la direzione LL, entro i 6 mm per la direzione CC ed entro i 7 mm per la direzione AP. L’errore sistematico e l’errore casuale totale sono stati utilizzati per generare margini per ottenere il PTV nei pazienti trattati convenzionalmente (7 mm per la direzione LL; 9 mm sia per la direzione AP che per la direzione CC).ConclusioniLa variabilità della posizione della ghiandola prostatica durante un trattamento radiante è influenzata in modo importante dal posizionamento e dal movimento d’organo. Il monitoraggio della posizione della prostata mediante reperi fiduciali ed immagini portali è in grado di ridurre la dispersione degli scostamenti rispetto all’atteso, contribuendo in maniera significativa al miglioramento della precisione balistica della radioterapia.