The effect of incidental dose to pelvic nodes in bladder-only irradiation in the era of IMRT: a dosimetric study.

PURPOSE: While three-dimensional radiotherapy (RT) causes high incidental nodal doses in bladder-only irradiation for muscle-invasive bladder cancer (MIBC), the impact on pelvic lymphatics is unclear in the era of intensity-modulated RT (IMRT). This study evaluates incidental doses to pelvic lymphatics in MIBC patients treated with IMRT. METHODS: The data of 40 MIBC patients treated with bladder-only IMRT and concurrent chemotherapy were retrospectively evaluated. The pelvic lymphatics were contoured on initial simulation images and incidental nodal doses were evaluated. The Statistical Package for the Social Sciences (SPSS) version 23.0 (IBM, Armonk, NY, USA) was used for statistics. RESULTS: Median RT dose to the bladder was 60 Gy in 30 fractions. In dosimetric analysis, median values of mean dose (Dmean) of the obturator, presacral, external iliac, internal iliac, and distal common iliac lymphatics were 33 Gy (range 4-50 Gy), 3 Gy (range 1-28 Gy), 9.5 Gy (range 3-41 Gy), 7.5 Gy (range 2-14 Gy), and 1 Gy (range 0-15 Gy), respectively. The Dmean of the obturator lymphatics was significantly higher (p < 0.001) and the Dmean of the distal common iliac lymphatics was significantly lower (p < 0.001) than all remaining lymphatic stations. The Dmean of the external iliac lymphatics was significantly higher than that of the presacral lymphatics (p < 0.001), but the difference with the internal iliac lymphatics was not statistically significant (p = 0.563). CONCLUSION: The incidental nodal doses with bladder-only IMRT are heterogeneous and remain below the generally accepted doses for microscopic disease eradication for bladder cancer.

Stereotactic body radiotherapy and tyrosine kinase inhibitors in patients with oligometastatic renal cell carcinoma: a multi-institutional study.

PURPOSE: Few studies have determined the viability of stereotactic body radiotherapy (SBRT) and tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell carcinoma (mRCC). We examined the results of RCC patients who had five or fewer lesions and were treated with TKI and SBRT. METHODS: The clinical data of 42 patients with 96 metastases treated between 2011 and 2020 were retrospectively evaluated. The prognostic factors predicting overall survival (OS) and progression-free survival (PFS) were assessed in uni- and multivariable analyses. RESULTS: Median follow-up and time between TKI therapy and SBRT were 62.3 and 3.7 months, respectively. The 2­year OS and PFS rates were 58.0% and 51.3%, respectively, and 2­year local control rate was 94.1% per SBRT-treated lesion. In univariable analysis, the time between TKI therapy and SBRT and treatment response were significant prognostic factors for OS and PFS. In multivariable analysis, a time between TKI therapy and SBRT of less than 3 months and complete response were significant predictors of better OS and PFS. Only 12 patients (28.6%) had a systemic treatment change at a median of 18.2 months after SBRT, mostly in patients with a non-complete treatment response after this therapy. Two patients (4.8%) experienced grade III toxicity, and all side effects observed during metastasis-directed therapy subsided over time. CONCLUSION: We demonstrated that SBRT in combination with TKIs is an effective and safe treatment option for RCC patients with ≤ 5 metastases. However, distant metastasis was observed in 60% of the patients, indicating that distant disease control still has room for improvement.

Effects of reconstruction methods on dose distribution for lung stereotactic body radiotherapy treatment plans.

The aim of the present study was to investigate the effect of tumour motion on various imaging strategies as well as on treatment plan accuracy for lung stereotactic body radiotherapy treatment (SBRT) cases. The ExacTrac gating phantom and paraffin were used to investigate respiratory motion and represent a lung tumour, respectively. Four-dimensional computed tomography (4DCT) imaging was performed, while the phantom was moving sinusoidally with 4 s cycling time with three different amplitudes of 8, 16, and 24 mm. Reconstructions were done with maximum (MIP) and average intensity projection (AIP) methods. Comparisons of target density and volume were performed using two reconstruction techniques and references values. Volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) were planned based on reconstructed computed tomography (CT) sets, and it was examined how density variations affect the dose-volume histogram (DVH) parameters. 4D cone beam computed tomography (CBCT) was performed with the Elekta Versa HD linac imaging system before irradiation and compared with 3D CBCT. Thus, various combinations of 4DCT reconstruction methods and treatment alignment methods have been investigated. Point measurements as well as 2 and 3D dose measurements were done by optically stimulated luminescence (OSL), gafchromic films, and electronic portal imaging devices (EPIDs), respectively. The mean volume reduction was 7.8% for the AIP and 2.6% for the MIP method. The obtained Hounsfield Unit (HU) values were lower for AIP and higher for MIP when compared with the reference volume density. In DVH analysis, there were no statistical differences for D95%, D98%, and Dmean (p > 0.05). However, D2% was significantly affected by HU changes (p < 0.01). A positional variation was obtained up to 2 mm in moving direction when 4D CBCT was applied after 3D CBCT. Dosimetric measurements showed that the main part of the observed dose deviation was due to movement. In lung SBRT treatment plans, D2% doses differ significantly according to the reconstruction method. Additionally, it has been observed that setups based on 3D imaging can cause a positional error of up to 2 mm compared to setups based on 4D imaging. It is concluded that MIP has advantages over AIP in defining internal target volume (ITV) in lung SBRT applications. In addition, 4D CBCT and 3D EPID dosimetry are recommended for lung SBRT treatments.

Planning and dosimetric evaluation of three total body irradiation techniques: Standard SSD VMAT, Extended SSD VMAT and Extended SSD Field-in-Field.

The aim of this study was to dosimetrically compare three total body irradiation (TBI) techniques which can be delivered by a standard linear accelerator, and to deduce which one is preferable. Specifically, Extended Source to Surface Distance (SSD) Field-in-Field (FiF), Extended SSD Volumetric Modulated Arc Therapy (VMAT), and Standard SSD VMAT TBI techniques were dosimetrically evaluated. Percent depth dose and dose profile measurements were made under treatment conditions for each specified technique. After having generated treatment plans with a treatment planning system (TPS), dose homogeneity and critical organ doses were investigated on a Rando phantom using radiochromic films and optically stimulated luminescence dosimeters (OSLDs). TBI dose of 12 Gy in six fractions was prescribed for each technique. The gamma index (5%/5 mm) was used for the analysis of radiochromic films. Passing rates for Extended SSD FiF, Extended SSD VMAT and Standard SSD VMAT techniques were found to be 90%, 87% and 94%, respectively. OSLD measurements were within ± 5% agreement with TPS calculations for the first two techniques whereas the agreement was found to be within ± 3% for the Standard SSD VMAT technique. TPS calculations demonstrated that mean lung doses in the first two techniques were around 8.5 Gy while it was kept around 7 Gy in Standard SSD VMAT. It is concluded that Standard SSD VMAT is superior in sparing the lung tissue while all three TBI techniques are feasible in clinical practice with acceptable dose homogeneity. In the absence of VMAT-based treatment planning, Extended SSD FiF would be a reasonable choice compared to other conventional techniques.

Treatment Outcomes of Stereotactic Body Radiotherapy in Patients with Synchronous and Metachronous Oligometastatic Renal Cell Carcinoma.

INTRODUCTION: The aim of this study was to investigate the clinical outcomes of metastasis-directed therapy (MDT) using stereotactic body radiotherapy (SBRT) in patients with synchronous or metachronous oligometastatic renal cell carcinoma (RCC). METHODS: The clinical data of 87 patients with 138 lesions who received MDT between February 2008 and January 2019 were retrospectively analyzed. All patients had ≤5 metastasis at diagnosis (synchronous) or during progression (metachronous) and were treated with SBRT for their metastasis. The primary endpoints were local control (LC) and progression-free survival (PFS). The secondary endpoint was overall survival (OS). RESULTS: Median follow-up was 20.4 months for entire cohort and 27.2 months for survivors. Synchronous oligometastatic disease was observed in 35 patients (40.2%), and 52 patients (59.8%) had metachronous disease. Seventy-two patients (82.8%) received systemic treatment synchronously or after MDT, while 15 patients (17.2%) did not receive any systemic treatment. The 1- and 2-year OS rates were 79.4% and 58.1%, respectively, and the 1- and 2-year PFS rates were 58.6% and 15.1%, respectively. The 1- and 2-year LC rates per lesion were 96.6% and 91.4%, respectively. There were no significant differences in survival between patients with synchronous oligometastasis and those with metachronous oligometastasis. All disease progressions were observed at a median time of 31.6 months (range: 1.9-196.9 months) after the completion of SBRT. Patients with solitary oligometastasis had significantly better OS compared to patients with >1 metastasis (p = 0.04). No patients experienced grade 3 or higher acute or late toxicities. CONCLUSION: SBRT is a successful treatment for oligometastatic RCC patients due to its excellent LC and minimal toxicity profile. There were no statistically significant survival differences between patients with synchronous and metachronous oligometastasis. Patients with solitary oligometastasis outlived their counterparts.

The Effect of Video-Based Education on Anxiety of Patients Receiving Stereotactic Radiosurgery and Stereotactic Body Radiation Therapy.

Patients receiving stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) may have an anxiety due to unknown aspects of the treatment. We aimed to reduce patient anxiety by using video-based education. Forty patients were divided into 2 groups, with one-to-one information session (n = 20) and one-to-one information session plus video-based education (n = 20). The patients completed the State-Trait Anxiety Inventory (STAI) and visual facial anxiety scale before and after information sessions and after treatment. The setup time and disruptions during treatment sessions were recorded for patients receiving treatment with Novalis® and Cyberknife®, respectively. The patient characteristics and STAI scores before education were similar between groups. The anxiety level was significantly lower in group 1 after treatment (median 38, interquartile range (IQR) 27-45) compared to before (median 43, IQR 36-47) (p = 0.003) and after information sessions (median 42, IQR 36-47) (p = 0.004); however, any difference was not observed in anxiety levels between before and after information sessions (p = 0.317). The anxiety level was significantly lower in group 2 after video-based education (median 25, IQR 22-33) and after treatment (median 25, IQR 20-30) compared to before video-based education (median 35, IQR 31-42) (p < 0.001 for both), while there was no significant difference in anxiety levels between after video-based education and after the treatment (p = 0.407). The interruptions during treatment were observed in 9 (60%) patients in group 1 and 6 (40%) patients in group 2 (p = 0.038). Video-based educations significantly reduce patient anxiety before SRS/SBRT and increase their compliance with the treatment.

Bone-only oligometastatic renal cell carcinoma patients treated with stereotactic body radiotherapy: a multi-institutional study.

PURPOSE: This study aimed to analyze the prognostic factors associated with overall survival (OS) and progression-free survival (PFS) in patients with bone-only metastatic renal cell carcinoma (RCC) who have five or fewer lesions treated with stereotactic body radiotherapy (SBRT). METHODS: The clinical data of 54 patients with 70 bone metastases undergoing SBRT treated between 2013 and 2020 with a dose of at least 5 Gy per fraction and a biologically effective dose (BED) of at least 90 Gy were retrospectively evaluated. RESULTS: The majority of lesions were located in the spine (57.4%) and had only one metastasis (64.8%). After a median follow-up of 22.4 months, the 1­ and 2­year OS rates were 84.6% and 67.3%, respectively, and median OS was 43.1 months. The 1­ and 2­year PFS rates and median PFS were 63.0%, 38.9%, and 15.3 months, respectively. In SBRT-treated lesions, the 1­year local control (LC) rate was 94.9%. Age, metastasis localization, and number of fractions of SBRT were significant prognostic factors for OS in univariate analysis. In multivariate analysis, patients with spinal metastasis had better OS compared to their counterparts, and patients who received single-fraction SBRT had better PFS than those who did not. No patient experienced acute or late toxicities of grade 3 or greater. CONCLUSION: Despite excellent LC at the oligometastatic site treated with SBRT, disease progression was observed in nearly half of patients 13 months after metastasis-directed local therapy, particularly as distant disease progression other than the treated lesion, necessitating an effective systemic treatment to improve treatment outcomes.

Clinical parameters and nomograms for predicting lymph node metastasis detected with 68 Ga-PSMA-PET/CT in prostate cancer patients candidate to definitive radiotherapy.

BACKGROUND: Defining the extent of disease spread with imaging modalities is crucial for therapeutic decision-making and definition of treatment. This study aimed to investigate whether clinical parameters and nomograms predict prostate-specific membrane antigen (PSMA)-positive lymph nodes in treatment-naïve nonmetastatic prostate cancer (PC) patients. MATERIALS AND METHODS: The clinical data of 443 PC patients (83.3% high-risk and 16.7% intermediate-risk) were retrospectively analyzed. Receiver operating characteristic (ROC) curves with areas under the curve (AUC) were generated to evaluate the accuracy of clinical parameters (prostate-specific antigen [PSA], T stage, Gleason score [GS], International Society of Urological Pathology [ISUP] grade) and nomograms (Roach formula [RF], Yale formula [YF], and a new formula [NF]) in predicting lymph node metastasis. The AUCs of the various parameters and clinical nomograms were compared using ROC and precision-recall (PR) curves. RESULTS: A total of 288 lymph node metastases were identified in 121 patients (27.3%) using 68 Ga-PSMA-11-positron emission tomography (PET)/computed tomography (CT). Most PSMA-avid lymph node metastases occurred in external or internal iliac lymph nodes (142; 49.3%). Clinical T stage, PSA, GS, and ISUP grade were significantly associated with PSMA-positive lymph nodes according to univariate logistic regression analysis. The PSMA-positive lymph nodes were more frequently detected in patients with PSA >20 ng/ml, GS ≥7 or high risk disease compared to their counterparts. The clinical T stage, serum PSA level, GS, and ISUP grade showed similar accuracy in predicting PSMA-positive metastasis, with AUC values ranging from 0.675 to 0.704. The median risks for PSMA-positive lymph nodes according to the RF, YF, and NF were 31.3% (range: 12.3%-100%), 22.3% (range: 4.7%-100%), and 40.5% (range: 12.3%-100%), respectively. The AUC values generated from ROC and PR curve analyses were similar for all clinical nomograms, although the RF and YF had higher accuracy compared to NF. CONCLUSION: The clinical T stage, PSA, GS, and ISUP grade are independent predictors of PSMA-positive lymph nodes. The RF and YF can be used to identify patients who can benefit from 68 Ga-PSMA-11 PET/CT for the detection of lymph node metastasis. Together with nomograms, 68 Ga-PSMA-11 PET/CT images help to localize PSMA-positive lymph node metastases and can thus assist in surgery and radiotherapy planning.

Stereotactic body radiotherapy for oligoprogressive lesions in metastatic castration-resistant prostate cancer patients during abiraterone/enzalutamide treatment.

BACKGROUND: Metastasis-directed therapy (MDT) utilizing stereotactic body radiotherapy (SBRT) for oligoprogressive lesions could provide a delay in next-line systemic treatment (NEST) change while undergoing androgen receptor-targeted agents (ARTA) treatment. We evaluated prognostic factors for prostate cancer-specific survival (PCSS) and progression-free survival (PFS) to characterize patients receiving treatment with ARTA who may benefit from MDT for oligoprogressive lesions. The impact of MDT on delaying NEST and the predictive factors for NEST-free survival (NEST-FS) were also assessed. MATERIALS AND METHODS: The clinical data of 54 metastatic castration-resistant prostate cancer patients with 126 oligoprogressive lesions receiving abiraterone (1 g/day) or enzalutamide (160 mg/day) before or after systemic chemotherapy were analyzed. A median of three lesions (range: 1-5) were treated with MDT. The primary endpoints were PCSS and PFS. The secondary endpoints were time to switch to NEST and NEST-FS. RESULTS: The median follow-up time was 19.1 months. Univariate analysis showed that the number of oligoprogressive lesions treated with SBRT and the time between the start of ARTA treatment and oligoprogression were significant prognostic factors for PCSS, and the timing of ARTA treatment (before or after chemotherapy) and the prostate-specific antigen (PSA) response after MDT were significant prognostic factors for PFS. Multivariate analysis showed that early MDT for oligoprogressive lesions delivered less than 6 months after the beginning of ARTA and higher PSA levels after MDT were significant predictors of worse PCSS and PFS. The median total duration of ARTA treatment was 13.8 months. The median time between the start of ARTA treatment and the start of MDT for oligoprogressive lesions was 5.2 months, and MDT extended the ARTA treatment by 8.6 months on average. Thirty-two (59.3%) patients continued ARTA treatment after MDT. ARTA treatment after chemotherapy, early oligoprogression requiring MDT, and lower radiation doses for MDT were independent predictors of NEST-FS in multivariate analysis. CONCLUSIONS: MDT for oligoprogressive lesions is effective and may provide several benefits compared to switching from ARTA treatment to NEST. Patients with early progression while on ARTAs and inadequate PSA responses after MDT have a greater risk of rapid disease progression and poor survival, which necessitates intensified treatment.

Stereotactic radiotherapy to oligoprogressive lesions detected with 68Ga-PSMA-PET/CT in castration-resistant prostate cancer patients.

PURPOSE: We assessed the outcomes of stereotactic body radiotherapy (SBRT) to treat oligoprogressive castration-resistant prostate cancer (CRPC) patients with ≤5 lesions using gallium prostate-specific membrane antigen-positron emission tomography (68Ga-PSMA-PET/CT). METHODS: The clinical data of 67 CRPC patients with 133 lesions treated with 68Ga-PSMA-PET/CT-based SBRT were retrospectively analyzed. All of the patients had oligoprogressive disease during androgen-deprivation therapy (ADT). The prognostic factors for overall- (OS) and progression-free survival (PFS) and the predictive factors for switching to next-line systemic treatment (NEST) and NEST-free survival (NEST-FS) were analyzed. RESULTS: With a median follow-up of 17.5 months, the 2-year overall survival (OS) and PFS rates were 86.9% and 34.4%, respectively. The PSA response was observed in 49 patients (73.1%). Progression was observed in 37 patients (55.2%) at a median of 11.0 months following SBRT. A total of 45 patients (67.2%) remained on ADT after SBRT, and 22 patients (32.8%) had a NEST change at a median of 16.4 months after metastasis-directed treatment (MDT). Patients with a NEST change had higher post-SBRT PSA values and fewer PSA nadirs after MDT than their counterparts. In multivariate analysis, higher pre-SBRT PSA values were the only significant predictor for worse OS and NEST-FS, and no significant factor was found for PFS. No serious acute or late toxicities were observed. CONCLUSION: This study demonstrated the feasibility of MDT using SBRT to treat oligoprogressive lesions by 68Ga-PSMA-PET/CT in CRPC patients is efficient and well-tolerated, prolonging the effectiveness of ADT by delaying NEST.

Factors affecting post-treatment radiation-induced lung disease in patients receiving stereotactic body radiotherapy to lung.

The aim of the study is to investigate factors that may cause radiation-induced lung disease (RILD) in patients undergoing stereotactic body radiotherapy (SBRT) for lung tumors. Medical records of patients treated between May 2018 and June 2019 with SBRT were retrospectively evaluated. All patients should have a diagnosis of either primary non-small cell lung cancer (NSCLC) or less than three metastases to lung from another primary. The median treatment dose was 50 Gy in 4-5 fractions. Tumor response and RILD were evaluated in thoracic computer tomography (CT) using RECIST criteria. 82 patients with 97 lung lesions were treated. The median age was 68 years (IQR = 62-76). With a median follow-up of 7.2 months (3-18 months), three patients had grade 3 radiation pneumonitis (RP). RILD was observed in 52% of cases. Patients who had RILD had a higher risk of symptomatic RP (p = 0.007). In multivariate analyses older age, previous lung radiotherapy history, and median planning treatment volume (PTV) D95 value of ≥ 48 Gy were associated with RILD. Local recurrence (LR) was observed in 5.1% of cases. There was no difference in overall survival and LR with the presence of RILD. Older age, previous lung radiotherapy history, and median PTV D95 value of ≥ 48 Gy seems to be associated with post-SBRT RILD.

Treatment outcomes of metastasis-directed treatment using 68Ga-PSMA-PET/CT for oligometastatic or oligorecurrent prostate cancer: Turkish Society for Radiation Oncology group study (TROD 09-002).

PURPOSE: The aim of this study was to evaluate the outcomes of 68Ga prostate-specific membrane antigen (68Ga-PSMA) positron-emission tomography (PET)/CT-based metastasis-directed treatment (MDT) for oligometastatic prostate cancer (PC). METHODS: In this multi-institutional study, clinical data of 176 PC patients with 353 lesions receiving MDT between 2014 and 2019 were retrospectively evaluated. All patients had biopsy proven PC with ≤5 metastases detected with 68Ga-PSMA-PET/CT. MDT was delivered with conventional fractionation or stereotactic body radiotherapy (SBRT) techniques. CTCAE v4.0 was used for acute and RTOG/EORTC Late Radiation Morbidity Scoring Schema was used for late toxicity evaluation. RESULTS: At the time of MDT, 59 patients (33.5%) had synchronous and 117 patients (66.5%) had metachronous metastases. Median number of metastases was one and the MDT technique was SBRT in 73.3% patients. The 2­year overall survival (OS) and progression-free survival (PFS) rates were 87.6% and 63.1%, respectively. With a median follow-up of 22.9 months, 9 patients had local recurrence at the irradiated site. The 2­year local control rate at the treated oligometastatic site per patient was 93.2%. In multivariate analysis, an increased number of oligometastases and untreated primary PC were negative predictors for OS; advanced clinical tumor stage, untreated primary PC, BED3 value of ≤108 Gy, and MDT with conventional fractionation were negative predictors for PFS. No patient experienced grade ≥3 acute toxicity, but one patient had a late grade 3 toxicity of compression fracture after spinal SBRT. CONCLUSION: 68Ga-PSMA-PET/CT-based MDT is an efficient and safe treatment for oligometastatic PC patients. Proper patient selection might improve treatment outcomes.

Stereotactic body radiotherapy in patients with early-stage non-small cell lung cancer: Does beam-on time matter?

PURPOSE: Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with early-stage non-small cell lung cancer (NSCLC). In this study, we evaluated the treatment results using two different SBRT techniques and the effect of beam-on time (BOT) on treatment outcomes. METHODS: Between July 2007 and January 2018, 142 patients underwent SBRT for primary NSCLC. We have delivered SBRT using either respiratory tracking system (RTS) or internal-target-volume (ITV)-based motion management techniques. The effect of age, tumor size, pretreatment tumor SUVmax value, presence of tissue diagnosis, histopathological subtype, operability status, tumor location, motion management technique, BED10 value, BOT on overall survival (OS), loco-regional control (LRC), event-free survival (EFS) and primary tumor control (PTC) were evaluated. RESULTS: Median age of the patients was 70 years (range, 39-91 years). Most of the patients were inoperable (90%) at the time of SBRT. Median BED10 value was 112.5 Gy. With a median follow-up of 25 months, PTC was achieved in 91.5% of the patients. Two-year estimated OS, LRC, PTC and EFS rates were 68, 63, 63 and 53%, respectively. For the entire group, OS was associated with BOT (P = 0.027), and EFS was associated with BOT (P = 0.027) and tumor size (P = 0.015). For RTS group, OS was associated with age (P = 0.016), EFS with BOT (P = 0.05) and tumor size (P = 0.024), LRC with BOT (P = 0.008) and PTC with BOT (P = 0.028). The treatment was well tolerated in general. CONCLUSION: SBRT is an effective and safe treatment with high OS, LRC, EFS and PTC rates in patients with primary NSCLC. Protracted BOT might deteriorate SBRT outcomes.

Treatment outcomes of prostate cancer patients with Gleason score 8-10 treated with definitive radiotherapy : TROD 09-001 multi-institutional study.

PURPOSE: To validate the clinical outcomes and prognostic factors in prostate cancer (PCa) patients with Gleason score (GS) 8-10 disease treated with external beam radiotherapy (EBRT) + androgen deprivation therapy (ADT) in the modern era. METHODS: Institutional databases of biopsy proven 641 patients with GS 8-10 PCa treated between 2000 and 2015 were collected from 11 institutions. In this multi-institutional Turkish Radiation Oncology Group study, a standard database sheet was sent to each institution for patient enrollment. The inclusion criteria were, T1-T3N0M0 disease according to AJCC (American Joint Committee on Cancer) 2010 Staging System, no prior diagnosis of malignancy, at least 70 Gy total irradiation dose to prostate ± seminal vesicles delivered with either three-dimensional conformal RT or intensity-modulated RT and patients receiving ADT. RESULTS: The median follow-up time was 5.9 years (range 0.4-18.2 years); 5­year overall survival (OS), biochemical relapse-free survival (BRFS) and distant metastases-free survival (DMFS) rates were 88%, 78%, and 79%, respectively. Higher RT doses (≥78 Gy) and longer ADT duration (≥2 years) were significant predictors for improved DMFS, whereas advanced stage was a negative prognosticator for DMFS in patients with GS 9-10. CONCLUSIONS: Our results validated the fact that oncologic outcomes after radical EBRT significantly differ in men with GS 8 versus those with GS 9-10 prostate cancer. We found that EBRT dose was important predictive factor regardless of ADT period. Patients receiving 'non-optimal treatment' (RT doses <78 Gy and ADT period <2 years) had the worst treatment outcomes.

Assessment of uterus position as a surrogate for high-risk clinical target volume with respect to the applicator position for multiple fractions of brachytherapy in cervical cancer.

AIM: Hybrid magnetic resonance imaging/computerized tomography (MRI/CT) planning for high-dose-rate (HDR) brachytherapy in cervical cancer with MR/CT fusion for the first fraction followed by CT for fraction 2 and 3 is used at our center. The aim of this study is to evaluate the position of applicator intrauterine tube (IU) in relation to uterine serosa with each fraction of intracavitary high-dose-rate brachytherapy. METHODS: Position of the applicator relative to uterus was measured from tip of the applicator (IU) to the top of uterus in the plane of IU and perpendicular to IU in anterior, posterior, left and right directions at the tip of IU, mid-point of the IU and 1 cm from the surface of vaginal ring. The mean absolute difference (±95 % confidence interval) between these positions at fraction 2 and 3 was calculated with fraction one as reference. RESULTS: The mean absolute difference (±95 %) of the applicator relative to uterus was 2.7 ± 0.5 mm at the tip, 1.5 ± 4 mm at mid-point and 1.1 ± 0.3 mm at 1 cm from the surface of the ring. CONCLUSION: This study shows that there is consistency in inter-fraction applicator position relative to uterus apart from at the tip and, therefore, in situations where high-risk clinical target volume (HRCTV) extends towards uterine fundus, MRI should be used for each fraction of brachytherapy planning to accurately define HRCTV.

Evaluation of Treatment Outcomes of Prostate Cancer Patients With Lymph Node Metastasis Treated With Definitive Radiotherapy: Comparative Analysis of PSMA PET/CT and Conventional Imaging.

PURPOSE: We investigated the impact of prostate-specific membrane antigen (PSMA) PET/CT compared with conventional imaging on treatment outcomes for node-positive prostate cancer (PCa) patients who underwent androgen deprivation therapy (ADT) and external radiotherapy (RT). PATIENTS AND METHODS: A multicentric, retrospective study recruited patients with node-positive PCa patients who underwent conventional radiological evaluation or PSMA PET/CT and received ADT and RT at 3 hospitals from 2009 to 2021 were enrolled. Patients underwent prostate and pelvis RT, accompanied by a minimum of 6 months of ADT. The primary endpoints were progression-free survival (PFS) and PCa-specific survival (PCSS). Cox regression analyzed the association of survival with potential prognostic factors, whereas logistic regression identified the predictors of bone and lymph node metastasis. RESULTS: The median follow-up time was 64.0 months. The majority of patients (64.1%) underwent PSMA PET/CT for staging. The 5-year rates of PFS and PCSS were 63.7% and 83.7%, respectively. Disease progression was observed in 90 patients (36.3%). In multivariable analysis, ADT duration of less than 24 months and post-RT prostate-specific antigen (PSA) nadir were prognostic for PFS. Early clinical T stage and PSMA PET/CT predicted better PCSS. Patients staged with PSMA PET/CT had exhibited significantly higher 5-year PCSS rates than compared with those staged with conventional imaging (95.1% vs 76.9%; P = 0.01). Shorter ADT duration and higher PSA levels after RT independently predicted bone metastasis in multivariable logistic regression. Advanced T stage, shorter ADT duration, and higher PSA levels after neoadjuvant ADT predicted nonregional lymph node recurrence. CONCLUSIONS: ADT with pelvis RT is an effective treatment option for node-positive PCa patients. The PSMA PET/CT outperformed conventional imaging in PCSS, emphasizing the importance of precise clinical staging for patients undergoing definitive RT.

A Post-International Gastrointestinal Cancers' Conference (IGICC) Position Statements.

Hepatocellular carcinoma (HCC), the most prevalent liver tumor, is usually linked with chronic liver diseases, particularly cirrhosis. As per the 2020 statistics, this cancer ranks 6th in the list of most common cancers worldwide and is the third primary source of cancer-related deaths. Asia holds the record for the highest occurrence of HCC. HCC is found three times more frequently in men than in women. The primary risk factors for HCC include chronic viral infections, excessive alcohol intake, steatotic liver disease conditions, as well as genetic and family predispositions. Roughly 40-50% of patients are identified in the late stages of the disease. Recently, there have been significant advancements in the treatment methods for advanced HCC. The selection of treatment for HCC hinges on the stage of the disease and the patient's medical status. Factors such as pre-existing liver conditions, etiology, portal hypertension, and portal vein thrombosis need critical evaluation, monitoring, and appropriate treatment. Depending on the patient and the characteristics of the disease, liver resection, ablation, or transplantation may be deemed potentially curative. For inoperable lesions, arterially directed therapy might be an option, or systemic treatment might be deemed more suitable. In specific cases, the recommendation might extend to external beam radiation therapy. For all individuals, a comprehensive, multidisciplinary approach should be adopted when considering HCC treatment options. The main treatment strategies for advanced HCC patients are typically combination treatments such as immunotherapy and anti-VEGFR inhibitor, or a combination of immunotherapy and immunotherapy where appropriate, as a first-line treatment. Furthermore, some TKIs and immune checkpoint inhibitors may be used as single agents in cases where patients are not fit for the combination therapies. As second-line treatments, some treatment agents have been reported and can be considered.

Prostate-Specific Membrane Antigen PET Response Associates with Metastasis-Free Survival After Stereotactic Ablative Radiation in Oligometastatic Prostate Cancer.

Purpose: Emerging data suggest that metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can detect occult metastatic disease, and PSMA response has been proposed as a biomarker for treatment response. Herein, we identify and validate a PSMA-PET biomarker for metastasis-free survival (MFS) following MDT in omCSPC. Methods and Materials: We performed an international multi-institutional retrospective study of patients with omCSPC, defined as ≤3 lesions, treated with metastasis-directed stereotactic ablative radiation who underwent PSMA-PET/computed tomography (CT) before and after (median, 6.2 months; range, 2.4-10.9 months) treatment. Pre- and post-MDT PSMA-PET/CT maximum standardized uptake value (SUVmax) was measured for all lesions, and PSMA response was defined as the percent change in SUVmax of the least responsive lesion. PSMA response was both evaluated as a continuous variable and dichotomized into PSMA responders, with a complete/partial response (at least a 30% reduction in SUVmax), and PSMA nonresponders, with stable/progressive disease (less than a 30% reduction in SUVmax). PSMA response was correlated with conventional imaging-defined metastasis-free survival (MFS) via Kaplan-Meier and Cox regression analysis. Results: A total of 131 patients with 261 treated metastases were included in the analysis, with a median follow-up of 29 months (IQR, 18.5-41.3 months). After stereotactic ablative radiation, 70.2% of patients were classified as PSMA responders. Multivariable analysis demonstrated that PSMA response as a continuous variable was associated with a significantly worse MFS (hazard ratio = 1.003; 95% CI, 1.001-1.006; P = .016). Patients classified as PSMA responders were found to have a significantly improved median MFS of 39.9 versus 12 months (P = .001) compared with PSMA nonresponders. Our study is limited as it is a retrospective review of a heterogenous population. Conclusions: After stereotactic ablative radiation, PSMA-PET response appears to be a radiographic biomarker that correlates with MFS in omCSPC. This approach holds promise for guiding clinical management of omCSPC and should be validated in a prospective setting.

Radiation Oncologists' Approach to Rectosigmoid Junction Tumors in Turkey: The Turkish Society for Radiation Oncology Gastrointestinal Group Survey Study (TROD 02-007).

BACKGROUND/AIMS: The objective was to determine the preferences and perspectives regarding preoperative evaluation and treatment strategies for rectosigmoid junction cancer among radiation oncologists using a questionnaire survey. MATERIALS AND METHODS: Since defining the correct origin of the neoplasm is essential in tailoring the most appropriate treatment scheme in the rectosigmoid junction region, we surveyed Turkish radiation oncologists about clinical decisions in rectosigmoid junction cancer patients via a 20-point questionnaire. RESULTS: Based on responses from 130 radiation oncologists surveyed across the country, 119 (91.5%) used the anterior peritoneal reflection as the landmark, while 111 (85.4%) used the distance from the anal verge to the boundary between the rectum and sigmoid. This indicates that most of the participants decided to consider both pretreatment evaluation methods. Although distance at colonoscopy can be very variable, when the discrepancy was observed between these methods, 66 (50.8%) participants made the final decision according to the distance from the anal verge in our questionnaire. The conclusion from the questionnaire is that there is difficulty in interpreting magnetic resonance imaging findings, and there is a need for anatomic landmarks relevant to the limit between the rectum and sigmoid so that clinicians can confidently facilitate the diagnosis. CONCLUSIONS: There is a wide variation in the diagnosis and decision-making of rectosigmoid junction cancer among radiation oncologists in Turkey, according to our survey, because of several definitions of the rectosigmoid junction boundaries. Considerable attention is required to clarify whether the first preoperative treatment or surgery for rectosigmoid junction cancer.