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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.
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Objective:To analyze and compare the dosimetric differences based on volumetric-modulated arc therapy (VMAT), fixed field intensity-modulated radiotherapy (F_IMRT), and electron irradiation combined with VMAT (E&VMAT) in radiotherapy for breast cancer after modified mastectomy, aiming to provide reference for clinical selection of treatment plan.Methods:Ten patients with the left breast cancer who received radiotherapy after modified mastectomy were randomly selected. The target areas included chest wall and supraclavicular region, and the prescribed dose was 43.5 Gy in 15 fractions (2.9 Gy/F). Based on the Pinnacle 3 planning system, the VMAT, F_IMRT and E&VMAT plans (electron beam for chest wall, VMAT for supraclavicular area) were designed for each patient. The conformity and homogeneity of the target areas, the dose of organs at risk and treatment time were compared. Results:The VMAT plan could improve the dose distribution of the target areas. The conformity index and homogeneity index of the target dose were significantly better than those of the F_IMRT and E&VMAT plans (all P<0.05). The average dose, V 30Gy, V 20Gy, V 10Gy of the left lung in the VMAT plan were significantly better than those in the F_IMRT and E&VMAT plans (all P<0.05). The V 5Gy of the left lung in the VMAT plan was significantly better than that in the F_IMRT plan ( P<0.05). There was no statistical difference in the V 5Gy of the left lung between the VMAT and E&VMAT plans ( P>0.05). The heart, right breast and right lung of the VMAT plan could meet the clinical dose limit requirements. The treatment time of the VMAT, F_IMRT and E&VMAT plans was (326±27) s, (1 082±169) s, and (562±48) s, respectively. Conclusions:Compared with the F_IMRT and E&VMAT plans, the VMAT plan has better quality and shorter treatment time. VMAT plan has higher value in clinical application compared with the F_IMRT and E&VMAT plans.
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PURPOSE: We aimed to evaluate clinical outcomes including progression-free survival (PFS), overall survival (OS), partial response, and complete response in patients who underwent radiation therapy (RT) for mycosis fungoides (MF). Also, we sought to find prognostic factors for clinical outcomes. MATERIALS AND METHODS: Total 19 patients confirmed with MF between 1999–2015 were retrospectively reviewed. Clinical and treatment characteristics, clinical outcomes, and and toxicities were analyzed. RESULTS: Eleven patients were treated with total skin electron beam radiotherapy (TSEBT) and 8 patients with involved field radiation therapy (IFRT) with median dose of 30 Gy, respectively. The median time interval from diagnosis to RT was 2.6 months (range, 0.4 to 87.3 months). The overall response rate was 100%; 11 patients (57.9%) had a complete response and 8 patients (42.1%) a partial response. The presence of positive lymph node at the time of consultation of RT was associated with lower OS (p = 0.043). In multivariate analysis, PFS was significantly lower for patients with increased previous therapies experienced following RT (p = 0.019) and for patients showing PR during RT (p = 0.044). There were no reported grade 3 or more skin toxicities related with RT. CONCLUSION: Both IFRT and TSEBT are effective treatment for MF patients. Patients with short disease course before RT or complete response during RT are expected to have longer PFS. Positive lymph node status at the initiation of RT was associated woth poor OS, suggesting other treatment modalities such as low-dose RT for patients with low life-expectancy.
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Humans , Diagnosis , Disease-Free Survival , Lymph Nodes , Lymphoma, T-Cell, Cutaneous , Multivariate Analysis , Mycosis Fungoides , Radiotherapy , Retrospective Studies , SkinABSTRACT
Objective To report the total skin electron irradiation(TSEI) to treat the mycosis fungoides and the related acute toxicity,short-term efficacy and long-term results.Methods Five patients with pathologically confirmed mycosis fungoides were enrolled from 1990 to 2011,including 4 males and 1 female.Median age was 51 years old(range 14-56 years old).Dose homegeneity within the field were ± 10％ of the prescribed dose with a skin surface dose of about 90％ of the prescribed dose.Four cases received a total dose of about 30 Gy in 30-32 fractions in 8 weeks,and the other case received an electron boost of 5 Gy to the residual tumor after irradiation with 31 Gy within 31 fractions in 8 weeks,who had received 6 cycles chemotherapy before TSEI.Results 4 cases with a follow-up time of more than 15 years achieved complete response 6 months after radiotherapy.For the recently treated case,a great partial response was achieved after radiotherapy.Acute toxicities for all patients were acceptable.Two patients survived after a follow-up of more than 15 years while the other two cases died of visceral involvement at 1 and 3 years later,respectively.The case treated recently survived 2 months later.Conclusions A total TSEI dose of about 30 Gy within 30-32 fractions during 8 weeks could be proved to be very effective and safe in skin lesion control.Visceral involvement is the main failure type.
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Objective To study the sequence of learning and memory loss in the rat after hemispheric irradiation. Methods After Sprague Dawly(SD) female rats were anaesthetized with chloral hydrate, their cerebral hemispheres were irradiated with a single dose of 5,15 or 30?Gy by 4?MeV electron. On D3,D7,D30 and D60, the learning and memorizing ability was measured with the Y maze test. Results On D3 and D7, the learning ability of SD rats was impaired most but partly restored in 1 to 2 months. In observation of memory loss, the intensity of cerebral function damage was in direct proportion to the increase of radiation dose.Conclusion The learning and memorizing ability of rats can be damage by hemispheric irradiation with the severity of impairment and possibility of recruitment depending on the dose.