ABSTRACT
Objective:To compare the outcomes of watch&wait (W&W) strategy in patients with locally advanced rectal cancer who achieved complete clinical response (cCR) after neoadjuvant therapy, with those who obtained pathological complete response (pCR) after total mesorectal excision (TME).Methods:This is a retrospective cohort analysis study. Patients histologically proven with locally advanced rectal adenocarcinoma (stage Ⅱ-Ⅲ) who had received neoadjuvant chemotherapy were eligible between January 2014 and December 2019. In whom we included patients who had cCR offered management with W&W strategy after completing neoadjuvant therapy and follow-up ≥1 year (W&W group), and patients who did not have cCR but pCR after TME (pCR group). The primary endpoints were 3-year and 5-year overall survival (OS), colostomy-free survival (CFS), disease-free survival (DFS), non-local regrowth disease-free survival (NR-DFS), and organ preservation rate. Kaplan-Meier analysis was used for survival analysis and log-rank test was performed. For comparative analysis, we also derived one-to-one paired cohorts of W&W versus pCR using propensity-score matching (PSM).Results:A total of 118 patients were enrolled, 49 of whom had cCR and managed by W&W, 69 had pCR, with a median follow-up period of 49.5 months (12.1-79.9 months). No difference was observed in the 3-year OS (97.1% vs. 96.7%) and 5-year OS (93.8% vs. 90.9%, P=0.696) between the W&W and pCR groups. Patients managed by W&W had significantly better 3-year and 5-year CFS (89.1% vs. 43.5%, P<0.001), better 3-year DFS (83.6% vs. 97.0%) and 5-year DFS (83.6% vs. 91.2%, P=0.047) compared with those achieving pCR. The 3-year NR-DFS (95.9% vs. 97.0%) and 5-year NR-DFS (92.8% vs. 97.0%, P=0.407) did not significantly differ between the W&W and pCR groups. Local regeneration occurred in six cases, and 87.7% of patients had successful rectum preservation in the W&W group. In the PSM analysis (34 patients in each group), absolutely better CFS (90.1% vs. 26.5%, P<0.001) was noted in the W&W group. A median interval of 17.5 weeks was observed for achieving cCR, while only 23.9% of patients achieved cCR within 5 to 12 weeks from radiation completion. Patients with short-course sequential chemoradiotherapy achieved cCR significantly later when compared with those with long-course concurrent chemoradiotherapy (19.0 vs. 9.8 weeks, P<0.001). Conclusions:The oncological outcomes of W&W strategy in patients with locally advanced rectal cancer are safe and effective, significantly improving the quality of life. Longer interval for cCR evaluation may improve rectal organ preservation rate.
ABSTRACT
With aligned MR registration, the MR-Linac provides superior soft tissue resolution for prostate cancer. No fiducial markers or electromagnetic transponders insertion is needed to guarantee high-precision radiotherapy. The highly-recommended Adapt-To-Shape (ATS) workflow can resolve all the problems encountered during prostate cancer radiotherapy, including prostate volume changes and adjacent organs motion, both inter-fractionally and intra-fractionally. With all the above advantages, MR-Linac performs outstandingly than conventional linac in prostate cancer RT delivery, and probably helps us to reduce the CTV-PTV margin safely in the near future. Nevertheless, it is difficult to implement the ATS workflow in clinical practice. In this article, the standard ATS workflow for prostate cancer was summarized based on our own experience.
ABSTRACT
Objective:To describe a prospective study of pre-operative tumor-bed boost performed at the 1.5 T MR-Linac in combination with adjuvant whole breast irradiation, and a first case, with an accentuation on clinical feasibility and safety.Methods:A phase II, single arm study recruiting early stage patients follows a paradigm that first boosts the tumor bed and then undergoes breast conservative surgery in 2 weeks, and last irradiates the whole breast in 6 weeks. The primary endpoint is ≥ grade 2 acute breast toxicity. A 43 years old patient affected by a breast carcinoma, not special type of the right-sided lateral quadrant, staged cT 2N 0M 0, was planned and treated. The dose, 8 Gy for one time, was calculated by Monaco on CT simulation images. Both the air electron stream effect (ESE) and the electron return effect (ERE) at the presence of 1.5 T magnetic field were evaluated. During the pre-treatment evaluation, we carried out adaptation-to-position adjustment. Results:The normal organ dosimetry is within toleration. The Dmax to the skin, the chin and the right upper arm was 8.44 Gy, 28.5 cGy and 17.8 cGy, respectively. There was no increased toxicity from ERE and ESE, and the treatment was well tolerated without > grade 1 acute toxicity. The patient received breast conservative surgery on day 7 without delayed wound healing.Conclusions:This is the first case successfully treated within a clinical trial by pre-operative tumor-bed boost under 1.5 T MR-Linac in our institution. More participants are needed to validate and optimize the paradigm.
ABSTRACT
Objective:To investigate the workflow, efficacy and safety of MR-Linac in liver malignancies.Methods:Clinical data of 15 patients with hepatocellular carcinomas (HCC) or liver metastases treated with MR-Linac between November 2019 and July 2021 were retrospectively analyzed. The workflow of MR-Linac was investigated and image identification rate was analyzed. Patients were followed up for response and toxicity assessment.Results:Fifteen patients (6 HCC, 8 liver metastases from colorectal cancer, 1 liver metastasis from breast cancer) were enrolled. A total of 21 lesions were treated, consisting of 10 patients with single lesion, 4 patients with double lesions and 1 patient with triple lesions. The median tumor size was 2.4 cm (0.8-9.8 cm). The identification rate for gross tumor volume (GTV) in MR-Linac was 13/15. Although GTV of two patients were unclearly displayed in MR-Linac images, the presence of adjacent blood vessel and bile duct assisted the precise registration. All the patients were treated with stereotactic body radiation therapy (SBRT). For HCC, the median fraction dose for GTV or planning gross tumor volume (PGTV) was 6 Gy (5-10 Gy) and the median number of fractions was 9(5-10). The median total dose was 52 Gy (50-54 Gy) and the median equivalent dose in 2 Gy fraction (EQD 2Gy) at α/ β= 10 was 72 Gy (62.5-83.3 Gy). For liver metastases, the median fraction dose for GTV or PGTV was 5 Gy (5-10 Gy) and the median number of fractions was 10(5-10). The median total dose was 50 Gy (40-50 Gy) and the median EQD 2Gy at α/ β=5 was 71.4 Gy (71.4-107.1 Gy). At 1 month after SBRT, the in-field objective response rate (ORR) was 8/13 and the disease control rate was 13/13. At 3-6 months after SBRT, the in-filed ORR was increased to 6/6. During the median follow-up of 4.0 months (0.3-11.6), 4-month local progression-free survival, progression-free survival and overall survival were 15/15, 11/15 and 15/15, respectively. Toxicities were mild and no grade 3 or higher toxicities were observed. Conclusions:MR-Linac provides a platform with high identification rates of liver lesions. Besides, the presence of adjacent blood vessel and bile duct also assists the precise registration. It is especially suitable for liver malignancies with promising local control and well tolerance.
ABSTRACT
Objective:To explore the impacts of comprehensive geriatric assessment (CGA) on setup errors during the radiotherapy of elderly patients with rectal cancer.Methods:A total of 45 patients over 70 years of age and receiving radiotherapy were enrolled in the study. A comprehensive geriatric assessment was conducted before the radiotherapy. The enrolled patients had a median age of 77 years, including 28 male and 17 female cases. Meanwhile, 31 patients were determined to be in a good CGA status and 14 were determined to be in a poor CGA status, and 35 patients received radiotherapy in the prone position and 10 in the supine position. Cone beam CT (CBCT) was used for setup correction during radiotherapy. CBCT was performed daily in the first week and once a week from the second week. By fusing and aligning the CBCT images with simulation CT images according to the lumbar vertebra, setup errors in the left-right ( x axis), cranio-caudal ( y axis), and anterior-posterior ( z axis) directions were obtained. A total of 338 CBCT images were obtained. A generalized linear model was used to evaluate the effects of multiple factors on the setup errors. Results:During the radiotherapy, setup errors of all patients were (0.24±0.19) cm in the left-right direction, (0.33±0.25) cm in the cranio-caudal direction, and (0.19±0.15) cm in the anterior-posterior direction. The setup error in the cranio-caudal direction was more than that in the left-right direction and that in the anterior-posterior direction ( Z=-4.86, -7.72, P< 0.001). The setup error in the left-right direction was greater than that in the anterior-posterior direction ( Z=-2.79, P=0.005). The mean setup errors of the good and poor status groups in the left-right direction were (0.21 ± 0.17) and (0.30 ± 0.22) cm, respectively ( Z=2.16, P=0.031). There was no statistically significant difference in the setup errors between cranio-caudal direction and anterior-posterior direction ( P>0.05). The setup errors in the anterior-posterior direction were (0.17 ± 0.13) and (0.27 ± 0.19) cm, respectively for the prone and supine positions during the radiotherapy ( Z=2.85, P=0.004). There was no statistically significant difference in the setup errors between the left-right direction and the cranio-caudal direction ( P>0.05). Conclusion:The status of CGA elderly patients with rectal cancer affects the setup error in the left-right direction. It may be necessary to clinically adjust the PTV margin.
ABSTRACT
Objective:To explore the motion and influencing factors of implanted gold markers in guiding liver stereotactic body radiation therapy (SBRT) using abdominal compression.Methods:Twenty patients with oligometastatic colorectal cancer or primary hepatocellular carcinoma from January 2016 to December 2019 were included. All patients were treated with SBRT under abdominal compression, with 1-3 gold markers were implanted within 2 cm from the lesion before positioning. Four-dimensional computed tomography (4DCT) scan was used for treatment planning. The respiratory cycle was divided into 0-90% respiratory phase images based on the respiratory signal, which were reconstructed by the system (Pinnacle 3 version 9.1; Philips Medical System, Madison, WI, USA), and cone beam CT validation images before radiation exposure were obtained. The liver volume was divided into 3 parts: within 2 cm from the main hepatic portal vein, 2-5 cm from the main hepatic portal vein, and>5 cm from the main hepatic portal vein. The motion of different tumor locations was evaluated. Results:The average intrafractional motion amplitude was (2.63±2.81) mm in the cranial-caudal (CC) direction, (1.35±1.23) mm in the anterior-posterior (AP) direction, and (0.76±0.88) mm in the left-right (LR) direction, respectively. The average interfractional motion amplitude was (3.45±3.06) mm, (2.64±2.60) mm, and (2.23±2.07) mm, respectively. Both the intra-or inter-fractional motion amplitudes in the CC direction were the highest, followed by those in the AP and LR direction (all P<0.001). The motion varied at different tumor locations. The longer distance from the main hepatic portal vein, the larger the intrafractional motion (all P<0.05). To cover the 95% population-based confidence interval, the internal target volume (ITV) was suggested to include the expansion of 3.9 mm, 5.2 mm and 7.9 mm in the LR, AP and CC direction. The expansion of 4.3 mm, 4.4 mm and 6.1 mm was delivered within 2 cm from the main hepatic portal vein, and 3.5 mm, 7.3 mm and 9.7 mm>5 cm from the main hepatic portal vein, respectively. The expansion varied significantly depending on the tumor location, whereas the motion in the CC direction was the largest regardless of the tumor location. The longer distance of the tumor from the main portal vein, the larger expansion in the CC direction. The expansion of tumor > 5 cm from the main portal vein in the AP direction was larger than that of inner parts. Conclusion:Liver tumors at different locations require individual external expansion of ITV.
ABSTRACT
Objective:To investigate the dosimetric characteristics, acute toxicity and short-term efficacy of postmastectomy hypofractionated internal mammary (IM) chain irradiation with electrons in patients with high-risk breast cancer.Methods:A total of 155 patients with breast cancer who underwent modified mastectomy between November 2018 and January 2020 were selected. Among them, 137(88.4%) patients were classified as stage Ⅲ and 18(11.6%) as stage Ⅱ. All patients received standard chemotherapy, endocrine therapy and anti-Her2 targeted therapy. CTV im was divided into three subregions: CTV im1, CTV im2 and CTV im3, which represented the first, second and third intercostal IM, respectively. The planning target volume of subraclavicular region (PTV sc) was delineated. CTV cw and CTV im were irradiated with 6-15 MeV electron at 43.5 Gy in 15 fractions over 3 weeks. Moreover, PTV sc was irradiated with 6 MV X-ray at 43.5 Gy in 15 fractions over 3 weeks using two-dimensional radiotherapy (2DRT) or three-dimensional radiotherapy (3DRT). The dosimetric characteristics of CTV im, PTV sc, lung, heart, left anterior descending coronary artery (LAD) and right coronary artery (RA) were evaluated, and the acute toxicity and short-term efficacy were analyzed. Results:The mean dose (D mean) of CTV im was (43.3±2.6) Gy, D 95% was (30.5±8.3) Gy, V 90% was (85.0±10.5)% and V 80% was (91.0±7.4)%, respectively. The corresponding parameters of CTV im1 were significantly lower than those of CTV im2 and CTV im3(all P<0.001). Body mass index exerted no significant effect on IM dose ( P>0.05). Compared with 2DRT, 3DRT for SC significantly increased theD mean of CTV im[(43.4±2.6) Gy vs.(41.4±2.3) Gy, P=0.021], and the hot spot within PTV sc[V 110%: (26.7±17.5) cm 3vs.(12.5±8.4) cm 3, P=0.018; V 120%: (6.1±5.3) cm 3vs.(2.0±2.6) cm 3, P=0.023]. TheD mean of the ipsilateral lung was (9.8±1.9) Gy, and V 20Gy was (19.7±4.7)%. TheD mean of heart was (3.3±1.7) Gy in the whole group, (4.7±1.4) Gy for the left-sided breast cancer and (2.6±1.2) Gy for the right-sided breast cancer, respectively. TheD mean of LAD for the left-sided breast cancer was (13.9±4.9) Gy. TheD mean of RA for the right-sided breast cancer was (7.5±3.7) Gy. The incidence rates of ≥ grade 2 acute radiation dermatitis, esophagitis and pneumonitis were 19.3%, 4.5% and 2.6%, respectively. With a median follow-up time of 20.5 months (range: 9.9-41.8 months), 2 cases of chest wall recurrence, 2 regional lymph node recurrence, 6 distant metastases and 1 death were reported. Conclusions:When hypofractionated internal mammary chain is irradiated by electrons after mastectomy, the doses to the lung, heart and coronary artery are low, and the acute toxicities are mild. However, the dose to CTV im1 is inadequate. Although short-term efficacy is high, long-term follow-up is warranted.
ABSTRACT
Objective:To analyze the prognosis of patients with isolated regional recurrence (RR) after mastectomy, and evaluate the efficacy of radiotherapy and identify the optimal radiation target volumes.Methods:Clinical data of 144 patients with first isolated RR after mastectomy between 2001 and 2018 were retrospectively analyzed. All patients had not received post-mastectomy radiotherapy. The primary endpoints consisted of the subsequent locoregional recurrence (sLRR), distant metastasis (DM), progression-free survival (PFS) and overall survival (OS).Results:With a median follow-up of 82.5 months after RR, the 5-year sLRR, DM, PFS and OS rates for the entire group were 42.1%, 71.9%, 22.9% and 62.6%, respectively. Local plus systemic therapy was an independent favorable prognostic factor for sLRR ( P<0.001) and PFS ( P=0.013). The sLRR rate in the surgery plus radiotherapy group was the lowest ( P<0.001). Surgery plus radiotherapy significantly reduced the 5-year risk of recurrence within the initially involved nodal regions ( P<0.001). Patients with chest wall irradiation obtained the 5-year subsequent chest wall recurrence rate of 12.1% compared to 14.8%( P=0.873) for those without chest wall irradiation. The subsequent supraclavicular recurrence rate was lower in patients with prophylactic supraclavicular irradiation than that without prophylactic supraclavicular irradiation (9.9% vs. 23.8%, P=0.206). The incidence rates of initially uninvolved axillary and internal mammary nodal recurrence were below 10% regardless of prophylactic irradiation or not. Conclusions:Patients with RR alone have an optimistic 5-year OS in the contemporary era. Comprehensive locoregional treatment including surgery and radiotherapy combined with systemic therapy is recommended. The chest wall, axillary and internal mammary nodal prophylactic irradiation should not be routinely performed for all patients with RR. The value of supraclavicular prophylactic irradiation remains to be evaluated.
ABSTRACT
Objective:To evaluate the safety and preliminary efficacy of total neoadjuvant therapy (TNT) model of" neoadjuvant chemoradiotherapy plus consolidation neoadjuvant chemotherapy (CNCT) followed by surgery" for locally advanced gastric cancer.Methods:From 2018 to 2020, 28 patients clinically diagnosed with locally advanced gastric adenocarcinoma or Siewert Ⅱ/Ⅲ adenocarcinoma gastroesophageal junction cancer were prospectively enrolled. The neoadjuvant chemoradiotherapy (NCRT) was delivered with a total dose of 45 Gy, 1.8 Gy/f. Concurrent chemotherapy was S-1 at a dose of 40-60 mg twice daily. Then, patients received four to six cycles of CNCT of SOX regimen at three weeks after neoadjuvant chemoradiotherapy. D 2 lymphadenectomy was performed at 4-6 weeks after CNCT. Results:A total of 28 patients completed the whole therapy. Grade 3 or above adverse events occurred in 3 cases (11%) during CCRT, including thrombocytopenia, leukopenia and anorexia; 2 cases (7%) developed leukopenia and 3 cases (11%) of thrombocytopenia during CNCT. Twenty patients (71%) completed the surgery. The proportion of patients with pathological complete remission (pCR) was 50%. Three patients experienced surgical complications including anastomotic leak, anastomotic stenosis and intra-abdominal sepsis. All were recovered after symptomatic treatment.Conclusion:Interim analysis results demonstrate that TNT can yield significant down-staging for patients with locally advanced gastric cancer, which causes tolerable adverse events and postoperative complications.
ABSTRACT
Objective:To investigate the radiation field and dose selection of patients with isolated chest wall recurrence (ICWR) after modified radical mastectomy, and analyze the prognostic factors related to subsequent chest wall recurrence.Methods:Clinical data of 201 patients with ICWR after mastectomy admitted to the Fifth Medical Center, Chinese PLA General Hospital from 1998 to 2018 were retrospectively analyzed. None of the patients received postoperative adjuvant radiotherapy. After ICWR, 48 patients (73.6%) underwent surgery and 155 patients (77.1%) received radiotherapy. Kaplan-Meier method was used to calculate the post-recurrence progression-free survival (PFS) rates and the difference was compared by log-rank test. Multivariate analysis was performed using Cox regression model. Competing risk model was adopted to estimate the subsequent local recurrence (sLR) rates after ICWR and the difference was compared with Gray test. Multivariate analysis was conducted using F&G analysis. Results:With a median follow up of 92.8 months after ICWR, the 5-year PFS rate was 23.2%, and the 5-year sLR rate was 35.7%. Multivariate analysis showed that patients with surgery plus radiotherapy and recurrence interval o F>12 months had a lower sLR rate. Patients with recurrence interval o F>48 months, local plus systemic treatment and surgery plus radiotherapy had a higher PFS rate. Among the 155 patients who received chest wall radiotherapy after ICWR, total chest wall irradiation plus local boost could improve the 5-year PFS rate compared with total chest wall irradiation alone (34.0% vs. 15.4%, P=0.004). Chest wall radiation dose (≤60 Gy vs.>60 Gy) exerted no significant effect upon the sLR and PFS rates (both P>0.05). In the 53 patients without surgery, the 5-year PFS rates were 9.1% and 20.5%( P=0.061) with tumor bed dose ≤60 Gy and>60 Gy, respectively. Conclusions:Local radiotherapy is recommended for patients with ICWR after modified radical mastectomy of breast cancer, including total chest wall radiation plus local boost. The radiation dose for recurrence should be increased to 60 Gy, and it should be above 60 Gy for those who have not undergone surgical resection. In addition, patients with ICWR still have a high risk of sLR, and more effective treatments need to be explored.
ABSTRACT
Objective:To investigate the relationship between gastric filling status and intra-or inter-fractional tumor displacement in patients with adenocarcinoma of the esophagogastric junction (AEG) undergoing preoperative radiotherapy.Methods:From October 2018 to June 2019, 10 patients with locally advanced AEG who received totally neoadjuvant therapy were enrolled in this prospective study. Patients received two markers implanted at the cranial and caudal borders of the tumors under gastroscope and a total of 20 fiducial markers were implanted finally. All patients underwent 4DCT scan under the gastric fasting and filling status. Ten images of 0% to 90% respiratory phase were automatically reconstructed by the system (Pinnacle 3, version 9.1, Philips Medical Systems, Eindhoven, The Netherland). Each patient obtained one hundred sets of images. Results:In the tumors proximal to the chest, gastric filling did not significantly affect intrafractional or interfractional tumor displacements. Nevertheless, in the tumors distal to the chest, the interfractional displacement in the cranio-caudal (CC) direction under the gastric fasting status was significantly larger compared with that under the gastric filling status (6.22±4.67 mm vs. 4.13±3.68 mm, P=0.013). To ensure 95% of the prescribed dose irradiated to at least 90% of the tumor volume during the radiotherapy, the margins of tumors proximal to the chest in the left-right (LR), antero-posterior (AP) and CC directions were 9 mm, 8.5 mm, 12.1 mm under gastric filling status with 300 ml semi-fluid. Six patients diagnosed with gastric cancer with proximal thoracic fiducial markers treated by preoperative radiotherapy were included in the validation group, revealing that the fiducial markers of 93% patients were covered in this margin. Conclusion:During the preoperative radiotherapy in AEG patient, the approach of quantitative gastric filling can be considered.
ABSTRACT
Objective:To evaluate the clinical efficacy of radiotherapy in the treatment of extracranial metastatic breast cancer, and to investigate the significance and prognostic factors of whole-lesion radiotherapy (WLRT).Methods:Clinical data of 85 patients with extracranial metastatic breast cancer treated with radiotherapy between 2014 and 2019 were retrospectively analyzed. Thirty-six patients were assigned into the WLRT group and 49 in the non-WLRT group. The local control (LC), progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan- Meier method, log-rank test and univariate prognostic analysis. Cox proportional hazards model was used for multivariate prognostic analysis. Results:The median follow-up time was 26.7 months. The 2-year LC, PFS, OS rates were 77%, 26%, 77%, respectively. The 2-year LC (91% vs. 67%, P=0.001), PFS (47% vs. 8%, P<0.001), OS rates (84% vs. 71%, P=0.010) in the WLRT group were significantly higher than those in the non-WLRT group, respectively. Multivariate analysis demonstrated that WLRT was an independent favorable prognostic factor for the LC, PFS and OS. Furthermore, bone metastasis alone was associated with improved LC and positive hormone receptor status was correlated with improved OS. Conclusions:WLRT has the potential to prolong the survival of patients with extracranial metastatic breast cancer. The patients with bone metastases alone obtain better LC, whereas those with negative hormone receptor status has worse OS.
ABSTRACT
Objective:To evaluate the prognostic significance of neoadjuvant rectal (NAR) score and downstaging depth score (DDS) after neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC).Methods:Retrospective analysis was performed for 200 patients with LARC (T 3-T 4 and/or N 1-N 2, M 0), who were initially treated in the Cancer Hospital of Chinese Academy of Medical Sciences from 2015 to 2018. All patients had baseline MRI data and received preoperative nCRT and radical resection. All patients received preoperative radiotherapy with a dose of 45-50Gy combined with concurrent capecitabine. The effect of NAR and DDS scores on clinical prognosis was statistically compared. The 3-year disease-free survival (DFS) was calculated using the Kaplan- Meier method and compared by the log- rank test. Cox proportional hazards model was used to perform multivariate survival analysis. The predictive performance for 3-year DFS was calculated using the receiver operating characteristic (ROC) curve. Results:The median follow-up time was 30.5(10.6-54.0) months. In terms of DDS, the 3-year DFS rate was 56.4% in the DDS ≤0 group, significantly lower than 83.0% in the DDS >0 group ( P=0.002). In terms of NAR score, the 3-year DFS rates were 90.1%, 73.8% and 53.6% in NAR score ≤8, 8-16 and>16 groups, respectively ( P<0.001). In the whole cohort, the area under the ROC curve (AUC) of DDS and NAR scores for predicting 3-year DFS were 0.683 and 0.756( P=0.037). In yp0-I stage patients ( n=72), the AUC of DDS and NAR scores for predicting 3-year DFS were 0.762 and 0.569( P=0.032). Conclusions:High DDS and low NAR scores after nCRT indicate good prognosis for patients with LARC. NAR score yields better accuracy than DDS in predicting clinical prognosis, but DDS is significantly better than NAR score in yp0-I stage population.
ABSTRACT
Objective:To compare magnetic resonance imaging (MRI)-based and computed tomography (CT)-based target volume delineation and dose coverage in partial breast irradiation (PBI) for patients with breast cancer, aiming to explore the application value of MRI localization in PBI after breast-conserving surgery.Methods:Twenty-nine patients with early breast cancer underwent simulating CT and MRI scans in a supine position. The cavity visualization score (CVS) of tumor bed (TB) was evaluated. The TB, clinical target volume (CTV), planning target volume (PTV) were delineated on CT and MRI images, and then statistically compared. Conformity indices (CI) between CT- and MRI-defined target volumes were calculated. PBI treatment plan of 40 Gy in 10 fractions was designed based on PTV-CT, and the dose coverage for PTV-MRI was evaluated.Results:The CVS on CT and MRI images was 2.97±1.40 vs. 3.10±1.40( P=0.408). The volumes of TB, CTV, PTV on MRI were significantly larger than those on CT, (24.48±16.60) cm 3vs. (38.00±19.77) cm 3, (126.76±56.81) cm 3vs. (168.42±70.54) cm 3, (216.63±81.99) cm 3vs. (279.24±101.55) cm 3, respectively, whereas the increasing percentage of CTV and PTV were significantly smaller than those of TB. The CI between CT-based and MRI-based TB, CTV, PTV were 0.43±0.13, 0.66±0.11, 0.70±0.09( P<0.001), respectively. The median percentage of PTV-MRI receiving 40 Gy dose was 81.9%(62.3% to 92.4%), significantly lower than 95.6%(95.0%~97.5%) of PTV-CT. Conclusions:The CVS between CT and MRI is not significantly different, but the MRI-based TB, CTV, PTV are significantly larger than CT-based values. The PTV-MRI is of underdose if PBI treatment plan is designed for PTV-CT. As a supplement of CT scan, MRI can enhance the accuracy of TB delineation after breast-onserving surgery.
ABSTRACT
Objective:To investigate the efficacy and prognosis of hypofractionated intensity-modulated radiation therapy combined with hormonal therapy in the treatment of pelvic lymph node metastatic prostate cancer.Methods:Clinical data of 42 IV A prostate cancer patients who received hypofractionated intensity-modulated radiation therapy combined with hormonal therapy in Cancer Hospital of Chinese Academy of Medical Sciences between 2006 and 2018 were retrospectively analyzed. The total irradiation doses to the prostate and seminal vesicles were 67.5 Gy/25f, 2.7 Gy/f. The prophylactic irradiation doses to the pelvic lymph nodes were 45-50 Gy with a daily fraction dose of 1.8-2.0 Gy. Thirty-three patients with residual lymph nodes were boosted to 60.0-67.5 Gy for the residual area, 2.4-2.7 Gy/f. Androgen deprivation therapy included surgical castration or luteinizing hormone-releasing hormone agonists combined with antiandrogens. Survival rate was calculated using Kaplan- Meier method. The differences between two groups were analyzed by log-rank test. Prognostic factors were identified by univariate and multivariate analyses. Results:The median follow-up was 65.5 months (range, 5 to 150 months). The 5-year and 10-year failure-free survival (FFS) rates in the whole group were 67% and 45%, respectively. No clinical recurrence was observed in the irradiation field. The 5-year and 10-year prostate cancer-specific survival/overall survival (PCSS/OS) rates were 85% and 60%, respectively. Gleason score (≥8 and<8) and duration of hormonal therapy impacted the FFS (both P<0.05). The duration of hormonal therapy was an independent prognostic factor for PCSS/OS ( P=0.003). Conclusions:Hypofractionated intensity-modulated radiotherapy combined with hormonal therapy yields optimistic clinical efficacy in the treatment of pelvic lymph node metastatic prostate cancer. Gleason score (≥8 and <8) and duration of hormonal therapy are critical prognostic factors.
ABSTRACT
Objective:To evaluate the toxicities and clinical efficacy of postoperative radiotherapy for children with nephroblastoma (Wilms’ tumor).Methods:In total, 116 WT Children (≤14-year-old) treated with radiotherapy (RT) in our center from 2005 to 2018 were recruited in this retrospective analysis. RT-induced toxicities and clinical efficacy were analyzed. RT was performed guided by Children′s Oncology Group (COG) protocol. The overall survival (OS), flank-field control (LC), abdominal control (AC), and distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method. pathologically proved.Results:From January, 2005 to August, 2018, 116 pathologically proved WT patients were enrolled. Most of them were diagnosed with favorable WT (94.8%) and stage Ⅲ WT (87.1%). With a median follow-up time of 30.4(0.7-185.7) months, the 3-year OS, LC, AC and DMFS were 83.9%, 78.2%, 75.2% and 82.8%, respectively. Sixty-four (55.2%) patients suffered from Grade I to Ⅱ gastrointestinal toxicities and Grade I to IV hematological toxicities. Only 5 patients (4.3%) had Grade Ⅱ late toxicities. For 96 patients who received adjuvant RT, the median surgery-RT interval time was 1.2(0.5 to 7.1) months. The 3-year OS, LC, AC and DMFS were 88.1%, 96.7%, 92.7% and 86.9%, respectively. Patients with tumor rupture without whole abdomen irradiation (WAI) tended to have lower AC, DMFS and OS. Twenty children received salvage RT when they had disease relapse. The 3-year OS and DMFS of patients with salvage RT were significantly worse than those receiving adjuvant RT (OS: 68.2% vs. 88%, P=0.012; DMFS: 64.3% vs. 86.9%, P=0.032). Conclusions:Tumor bed irradiation for WT patients as per COG protocol can be well tolerated and achieve high efficacy. Salvage RT yields poor efficacy for tumor bed recurrence. Furthermore, tumor rupture without WAI possibly increases the abdominal and distant recurrence and the risk of death.
ABSTRACT
Objective:To compare the setup errors between deep inspiration breath hold (DIBH) and free breathing (FB) for breast cancer patients who were treated with whole breast irradiation (WBI) after breast conserving surgery (BCS).Methods:In this retrospective analysis, 30 breast cancer patients receiving WBI following BCS using DIBH in National Cancer Center/ Chinese Academy of Medical Sciences, an 30 patients treated with WBI using FB were enrolled as comparator.The kilovoltage cone-beam computed tomography (CBCT) was performed to evaluate and reduce setup errors. The optimal margins from clinical target volume (CTV) to planning target volume (PTV) for DIBH were estimated. The differences of setup errors between two techniques were compared using independent two-sample t-test. Results:A total of 318 sets of CBCT images were acquired, with (5.1±1.1) sets per patient on average. The setup errors along the three translational directions (laternal, longitudinal and vertical) were (2.1±1.6) mm, (2.6±1.7) mm and (2.5±2.1) mm for DIBH, and (2.2±1.7) mm, (3.1±2.5) mm and (3.3±2.3) mm for FB, respectively. Compared with FB, DIBH significantly reduced setup errors in the longitudinal ( P=0.015) and vertical ( P=0.004) directions, whereas the setup errors in the lateral direction did not significantly differ ( P=0.294). The optimal margins from CTV to PTV using DIBH were 6.2 mm, 7.3 mm and 7.8 mm, respectively. In the DIBH group, treatment fractions at the beginning and higher body mass index (BMI) did not associate with larger set-up deviation. Conclusions:DIBH technique yields less setup errors than FB for breast cancer patients treated with WBI after BCS. The CTV-PTV margins of 6-8 mm are recommended for DIBH.
ABSTRACT
Objective:To investigate the relationship between MRI parameters and clinical prognosis before and after chemoradiotherapy in patients with locally advanced rectal cancer.Methods:Clinical and follow-up data of 96 patients with locally advanced rectal cancer who were initially treated in the Cancer Hospital of Chinese Academy of Medical Sciences from 2015 to 2017 were retrospectively analyzed. All patients received preoperative chemoradiotherapy, followed by delayed radical surgery at 6-13 weeks after radiotherapy. MRI assessment was performed twice around radiotherapy which were within 4 weeks before the treatment and 4-8 weeks after it. Correlation analysis was utilized to determine the association between MRI assessment and 3-year disease-free survival (DFS).Results:Of the all patients, 80 (83%) had T 3 stage, 16(17%) had T 4 stage, 14 (15%) had N 0 stage, and 82 (86%) had N 1-2 stage. Among them, 69(72%) and 58(60%) patients were positive for MRF and EMVI. The median dose of radiotherapy was 50 Gy, and all patients were sensitized by simultaneous capecitabine. After chemoradiotherapy, T-downstage rate of the whole group was 24%, and 50% for the N-downstage rate. The MRF-and EMVI-positive rates were significantly decreased to 37% and 27% after chemoradiotherapy (both P<0.001). Univariate and multivariate analyses showed that N staging and EMVI status change were significantly correlated with the 3-year DFS. Conclusion:MRI after concurrent chemoradiotherapy reveals that positive EMVI throughout the treatment and N 1-N 2 staing are poor prognostic factors of DFS, suggesting the need for improving the treatment.
ABSTRACT
Objective:To evaluate the effectiveness of deep learning (DL)-based radiomic features extracted from pre-treatment diffusion-weighted magnetic resonance images (DWI) for predicting neoadjuvant chemoradiation treatment (nCRT) response in patients with locally advanced rectal cancer (LARC).Methods:Forty-three patients receiving nCRT from 2016 to 2017 were included. All patients received DWI before nCRT and total mesorectal excision surgery 6-12 weeks after completion of nCRT. The patient-cohort was split into the responder group ( n=22) and the non-responder group ( n=21) based on the post-nCRT response assessed by postoperative pathology, MRI or colonoscopy. DL-based radiomic features were extracted from the apparent diffusion coefficient map of the DWI using a pre-trained convolution neural network, respectively. Least absolute shrinkage and selection operator-Logistic regression models were constructed using extracted radiomic features for predicting treatment response. The model performance was evaluated with repeated 20 times stratified 4-fold cross-validation using receiver operating characteristic (ROC) curves. Results:The model established with DL-based radiomic features achieved the mean area under the ROC curve of 0.73(SE, 0.58-0.80).Conclusion:DL-based radiomic features extracted from pre-treatment DWI achieve high accuracy for predicting nCRT response in patients with LARC.
ABSTRACT
Objective:To analyze the efficacy of chest wall boost radiotherapy in stage T 4 breast cancer patients after modified radical mastectomy. Methods:A retrospective analysis was performed on the data of 148 stage T 4 breast cancer patients who were admitted from 2000 to 2016 and received radiotherapy after modified radical mastectomy. There were 57 cases in the chest wall boost radiotherapy group and 91 cases in the conventional dose group. Radiotherapy was performed by conventional+ chest wall electron beam, three-dimensional conformal+ chest wall electron beam, intensity modulated radiotherapy+ chest wall electron beam irradiation. EQD 2 at the boost group was >50Gy. All patients received neoadjuvant chemotherapy. Kaplan-Meier method was used to analyze survival; Logrank was used to test differences; and Cox model was used to do multivariate prognostic analysis. Results:The median follow-up time was 67.2 months. The 5-year rates of chest wall recurrence (CWR), locoregional recurrence (LRR), disease-free survival (DFS), and overall survival (OS) were 9.9%, 16.2%, 58.0%, and 71.4%, respectively. The 5-year rates of CWR, LRR, DFS, and OS with and without chest wall boost radiotherapy were 14% vs. 7%, 18% vs. 15%, 57% vs. 58%, 82% vs. 65%( P>0.05), respectively. Multivariate analysis showed that chest wall boost radiotherapy had no significant effect on prognosis ( P>0.05). Among 45 patients in the recurrent high-risk group, boost radiotherapy seemed to have higher OS rate ( P=0.058), DFS rate ( P=0.084), and lower LRR rate ( P=0.059). Conclusions:Stage T 4 breast cancer patients had strong heterogeneity. Chest wall boost radiotherapy did not apparently benefit all patients. For patients with 2-3 high risk factors including positive vascular tumor embolus, pN 2-N 3, and hormone receptor negative, chest wall boost radiotherapy showed a trend of improving efficacy.