Objective To compare the efficacy and toxicities between preoperative concomitant boost intensity-modulated radiotherapy (IMRT) and 3-dimensional conformal RT (3-DCRT) for locally advanced rectal cancer.Methods A prospective study from May 2010 to May 2015.A total of 130 patients with histologically confirmed,newly diagnosed,locally advanced rectal adenocarcinoma (cT3-T4 and/or cN +) located within 10 cm from the anal verge were included in this study.The patients were divided into IMRT and 3D-CRT groups by random number table method.Sixty-six patients were treated with IMRT,and the other sixty-four patients were treated with 3-DCRT.In the IMRT group,the prescription dose was 1.8 Gy/fraction to 45 Gy to the pelvis and 2.2 Gy/fraction to 55 Gy to the gross tumor volume simultaneously.The 3D-CRT prescription was 45 Gy in 25 fractions to the pelvis.Capecitabine (1 650 mg· m 2 · d-1) was given twice daily from days 1 to 14 and days 22 to 35 during RT in both arms.Total mesorectal excision (TME) was scheduled 6-8 weeks after the completion of chemoradiation.Results There were no significant differences in age,gender,tumor location,pathological differentiation degree and clinical stage between the two groups.Two patients withdrew from the study:one for grade 3 radiation dermatitis in IMRT group and the other for grade 3 fatigue in 3D-CRT.There was no significant difference in hematologic or nonhematologic toxicities between the two groups.No grade 4 or 5 toxicity was observed in either group.Compared with conformal radiotherapy,IMRT did not increase the difficulty of surgery.No significant difference was found in type of surgery or postoperative complications between the two groups.The rate of tumor regression grade (TRG) 4 (pathologic complete response,pCR) was 22.7％ for IMRT and 15.6％ for 3D-CRT,respectively(P ＞ 0.05).The rate of both TRG4 and 3 was 42.4％ for IMRT and 25.0％ for 3D-CRT,respectively (x2 =4.406,P=0.036).Conclusions Neoadjuvant concomitant boost IMRT is feasible and has a higher histopathological regression for patients with locally advanced rectal cancer.Trial registration Chinese clinical trial registry,ChiCTR-IN R-16008004.

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting. Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these dis-eases. Therefore, many selective optical detection probes and small molecular inhibitors have been developed, and have made significant contributions to the basic and clinical research on these diseases. In this paper, the detection and inhibition of tyrosinase and their application in whitening products are reviewed, with special emphasis on development of fluorescent probes and inhibitors. Hopefully, this review will help design more efficient and sensitive tyrosinase probes and inhibitors, as well as shed light on novel treatment of diseases such as melanoma.

Objective:To evaluate the efficacy and safety of simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) for rectal cancer with lateral lymph node metastasis (LLNM).Methods:From January 2016 to December 2022, 103 rectal cancer patients with LLNM were enrolled. The patients were divided into SIB-IMRT group (52 cases) and conventional chemoradiotherapy (CRT) group (51 cases) using the random number table method. The dose was 50 Gy for the pelvis with 60 Gy of SIB-IMRT for the LLNM in the SIB-IMRT group. The dose was 50 Gy for the pelvis in the CRT group. The primary endpoint was the lateral recurrence rate. The efficacy and adverse reactions of the two groups were compared.Results:The adverse reactions and surgical complications after neoadjuvant radiotherapy were comparable between the two groups. The response rates of LLNM treatment were 76.9% and 56.9%, respectively, in the two groups ( χ2=4.69, P=0.03). The SIB-IMRT group and CRT group had a local recurrence rate of 7.7% and 25.5% ( χ2=5.92, P=0.015), respectively, and a lateral recurrence rate of 3.8% and 23.5% ( χ2=8.49, P=0.004), respectively. Univariate analysis showed that the SIB-IMRT, short axis of lateral lymph nodes <5 mm after radiotherapy, and negative result in the postoperative lymph node pathological examination were factors associated with lateral recurrence. Multivariable regression analysis demonstrated that the SIB-IMRT ( HR=6.42, 95% CI: 1.40-29.49) and short axis of lateral lymph nodes <5 mm after radiotherapy ( HR=0.17, 95% CI: 0.04-0.66) were independent factors associated with lateral recurrence. The two groups had a 3-year disease-free survival of 73.25% and 62.6% ( P>0.05), respectively, and a 3-year overall survival of 87% and 82.5% ( P>0.05), respectively. Conclusions:The SIB-IMRT is safe and effective for rectal cancer with LLNM. The short axis of lateral lymph nodes <5 mm after neoadjuvant radiotherapy and SIB-IMRT is an independent risk factor for lateral recurrence.

As a powerful tool to advance drug discovery, molecular imaging may provide new insights into the process of drug effect and therapy at cellular and molecular levels. When compared with other detection methods, fluorescence-based strategies are highly attractive and can be used to illuminate pathways of drugs' transport, with multi-color capacity, high specificity and good sensitivity. The conjugates of fluorescent molecules and therapeutic agents create exciting avenues for real-time monitoring of drug delivery and distribution, both in vitro and in vivo. In this short review, we discuss recent developments of small molecule-based fluorophore-drug conjugates, including non-cleavable and cleavable ones, that are capable of visualizing drug delivery.