Clinical Feasibility of Zero TE Skull MRI in Patients with Head Trauma in Comparison with CT: A Single-Center Study

BACKGROUND AND PURPOSE

Conventional MR imaging techniques cannot produce optimal images of bone structures because bone has little water and a very short T2 life span. The aim of this study was to investigate the clinical feasibility of skull MR imaging using the zero TE sequence in patients with head trauma by assessing its diagnostic image quality and quantitative measurement compared with CT images.

MATERIALS AND METHODS

Thirteen enrolled patients with head trauma were assessed using brain CT and skull MR imaging. Image quality was graded on a 5-point Likert scale to compare the 2 modalities. To evaluate quantitative analyses between the 2 imaging modalities, we measured skull thickness and normalized bone tissue signal. Interobserver reliability was assessed using weighted κ statistics and the intraclass correlation coefficient.

RESULTS

Both imaging techniques clearly depicted skull fractures in all 13 patients. The mean scores for skull MR imaging and CT were 4.65 ± 0.56 and 4.73 ± 0.45 (P = .157), respectively, with substantial interobserver agreement (P < .05). The 2 imaging modalities showed no difference in skull thickness (P = .092) and had good correlation (r ² = 0.997). The mean value of normalized bone tissue signal among the 3 layers of the skull was relatively consistent (P = .401) with high interobserver agreement (P < .001).

CONCLUSIONS

Zero TE skull MR imaging has diagnostic image quality comparable with that of CT images. It also provides consistent results on the quantitative measurement of cortical bone with CT images.

Identification of a new HLA-A*11 allele, A*11:251N

The new allele, A*11:251N, differs from A*11:01:01 by insertion of two nucleotides at position 204-205.

Skin photorejuvenation effects of light-emitting diodes (LEDs): a comparative study of yellow and red LEDs in vitro and in vivo

BACKGROUND

Red-coloured light-emitting diodes (LEDs) can improve skin photorejuvenation and regeneration by increasing cellular metabolic activity.

AIM

To evaluate the effectiveness of visible LEDs with specific wavelengths for skin photorejuvenation in vitro and in vivo.

METHODS

Normal human dermal fibroblasts (HDFs) from neonatal foreskin were cultured and irradiated in vitro by LEDs at different wavelengths (410-850 nm) and doses (0-10 J/cm(2) ). In vivo experiments were performed on the skin of hairless mice. Expression of collagen (COL) and matrix metalloproteinases (MMPs) was evaluated by semi-quantitative reverse transcription PCR (semi-qRT-PCR), western blotting and a procollagen type I C-peptide enzyme immunoassay (EIA). Haematoxylin and eosin and Masson trichrome stains were performed to evaluate histological changes.

RESULTS

In HDFs, COL I was upregulated and MMP-1 was downregulated in response to LED irradiation at 595 ± 2 and 630 ± 8 nm. In the EIA, a peak result was achieved at a dose of 5 J/cm(2) with LED at 595 ± 2 nm. In vivo, COL I synthesis was upregulated in a dose-dependent manner to both 595 and 630 nm LED irradiation, and this effect was prolonged to 21 days after a single irradiation with a dose of 100 J/cm(2) . These histological changes were consistent with the results of semi-qRT-PCR and western blots.

CONCLUSION

Specific LED treatment with 595 ± 2 and 630 ± 8 nm irradiation was able to modulate COL and MMPs in skin, with the effects persisting for at least 21 days after irradiation. These findings suggest that yellow and red LEDs might be useful tools for skin photorejuvenation.

Association Studies of Bone Morphogenetic Protein 2 Gene Polymorphisms With Acute Rejection in Kidney Transplantation Recipients

OBJECTIVE

Bone morphogenetic proteins (BMP) belong to the transforming growth factor beta superfamily of proteins. This study was performed to evaluate the association of BMP gene polymorphisms with acute renal allograft rejection (AR) and graft dysfunction (GD) in Koreans.

METHODS

Three hundred thirty-one patients who had kidney transplantation procedures were recruited. Transplantation outcomes were determined in terms of AR and GD criteria. We selected six single nucleotide polymorphisms (SNPs): rs1979855 (5' near gene), rs1049007 (Ser87Ser), rs235767 (intron), rs1005464 (intron), rs235768 (Arg190Ser), and rs3178250 (3; untranslated region).

RESULTS

Among the six SNPs tested, the rs235767, rs1005464, and rs3178250 SNPs were significantly associated with AR (P < .05). The rs1049007 and rs235768 SNPs also showed an association with GD (P < .05).

CONCLUSIONS

In conclusion, these results suggest that the BMP2 gene polymorphism may be related to the development of AR and GD in kidney transplant recipients.

Acute Basilar Artery Occlusion: Differences in Characteristics and Outcomes after Endovascular Therapy between Patients with and without Underlying Severe Atherosclerotic Stenosis

BACKGROUND AND PURPOSE

Prediction of underlying intracranial atherosclerotic stenosis before endovascular therapy might be helpful for appropriate therapeutic planning in patients with acute ischemic stroke. This study aimed to compare the characteristics and treatment outcomes in patients with acute basilar artery occlusion relative to the existence or nonexistence of underlying intracranial atherosclerotic stenosis.

MATERIALS AND METHODS

Sixty-two patients with acute basilar artery occlusion underwent multimodal endovascular therapy. All patients underwent stent-retriever thrombectomy as a first-line endovascular therapy. Patients with underlying intracranial atherosclerotic stenosis underwent additional intracranial angioplasty and stent placement. The clinical and imaging characteristics and treatment outcomes were retrospectively analyzed and compared between patients with and without intracranial atherosclerotic stenosis.

RESULTS

Underlying intracranial atherosclerotic stenosis was identified at the occlusion site in 15 patients (24.1%). Occlusion in the proximal segment of the basilar artery was more common in patients with intracranial atherosclerotic stenosis (60% versus 6.4%, P < .001), whereas occlusion in the distal segment was more common in those without it (91.5% versus 26.7%, P < .001). Bilateral thalamic infarction on a pretreatment DWI was less common in patients with intracranial atherosclerotic stenosis (0% versus 27.7%, P = .027) compared with those without it. There were no significant differences in the rates of successful revascularization, favorable outcome, symptomatic hemorrhage, and mortality between the 2 groups.

CONCLUSIONS

Underlying intracranial atherosclerotic stenosis was not uncommon in patients with acute basilar artery occlusion. The occlusion segment of the basilar artery and the presence or absence of bilateral thalamic infarction on a pretreatment DWI might be helpful for predicting underlying intracranial atherosclerotic stenosis in patients with acute basilar artery occlusion. Patients with and without underlying intracranial atherosclerotic stenosis who underwent endovascular therapy had similar outcomes.

Effects of interactive metronome training on upper extremity function, ADL and QOL in stroke patients

BACKGROUND

Rhythm and timing training is stimulation that substitutes for a damaged function controls muscular movement or temporal element, which has positive impacts on the neurological aspect and movement of the brain.

OBJECTIVE

This study is to assess the changes caused by rhythm and timing training using an interactive metronome (IM) on upper extremity function, ADL and QOL in stroke patients.

METHODS

In order to assess the effects of IM training, a group experiment was conducted on 30 stroke patients. Twelve sessions of IM training were provided for the experimental group three times a week for four weeks, while the control group was trained with a Bilateral arm Self-Exercise (BSE) for the same period. Both groups were evaluated by pre- and post-tests through MFT, MAL, K-MBI and SS-QOL.

RESULT

There were more statistically significant differences (<0.05) in the total score of MFT and the finger control item in the IM Group than in the BSE Group. With respect to ADL, there were more statistically significant differences (<0.05) in the total score of K-MBI and the dressing item in the IM Group than in the BSE Group.

CONCLUSION

The study proposes that IM training can be applied as an occupational therapy program in patients with various diseases who need to adjust the time for performing movements as well as stroke patients.

Patterns, predictive factors and prognostic impact of multilevel metastasis in N1b papillary thyroid carcinoma

BACKGROUND

The patterns, predictive factors and prognostic impact of multilevel metastasis in patients with N1b papillary thyroid carcinoma (PTC) were investigated.

METHODS

A retrospective review of patients with N1b PTC from a tertiary referral centre in Korea who underwent unilateral modified radical neck dissection was undertaken.

RESULTS

Of 658 patients, multilevel metastasis was found in 73·9 per cent; the most common type was metastasis in two levels. Tumour size per 0·1-cm increment (adjusted odds ratio (OR) 1·33, 95 per cent c.i. 1·08 to 1·64), microscopic extrathyroidal extension (adjusted OR 1·72, 1·10 to 2·71), gross extrathyroidal extension (adjusted OR 2·35, 1·24 to 4·46), unilateral central lymph node metastasis (adjusted OR 2·45, 1·53 to 3·92) and bilateral central lymph node metastasis (adjusted OR 4·06, 2·29 to 7·18) were independent predictors of multilevel metastasis. Only four-level metastasis significantly increased the risk of overall locoregional recurrence (LRR) (adjusted hazard ratio (HR) 7·41, 95 per cent c.i. 2·20 to 24·53) and lateral neck LRR (adjusted HR 7·22, 1·82 to 28·65), compared with one-level metastasis. Two subgroup analyses were conducted, showing that only three-level metastasis including metastasis in level V significantly increased the risk of overall LRR (adjusted HR 5·66, 1·20 to 26·75). In addition, having level V metastasis was an independent predictor of both overall (adjusted HR 3·26, 1·72 to 6·18; P < 0·001) and lateral neck (adjusted HR 3·28, 1·50 to 7·16; P = 0·003) LRR.

CONCLUSION

Level V metastasis rather than multilevel metastasis itself is associated with an increased risk of LRR. Patients with N1b PTC and level V metastasis require risk restratification and meticulous follow-up.

Abstract P1-11-10: Clinical applications of near infra-red imaging system for localization of non-palpable breast lesions in breast conserving surgery

Backgrounds: Localization of non-palpable breast lesions is important for obtaining tumor-free resection margin and achieving better cosmetic outcome. Near infra-red (NIR) imaging system has been introduced for localization in breast surgery. This study aimed to evaluate the feasibility of localization using NIR imaging system in breast conserving surgery (BCS) (ClinicalTrials.gov identifier: NCT 02172989/ NCT02473159).

Materials and Methods: Between June 2014 and October 2015, 20 women with benign neoplasm and 5 patients with early breast cancer were enrolled and underwent BCS using NIR imaging system. Before surgery, Indocyanine green was injected intratumoraly in benign lesions and peritumoraly for resection margins in early breast cancer. Their pathologic results for resection volume and re-excision rate were compared with those of the patients with 99 benign neoplasm and 203 early breast cancer who were treated with BCS by conventional method, respectively.

Results: In the patients with benign lesions, the mean size in sonography was 1.48±0.98 cm in NIR group and 1.32±0.96cm in conventional group (P=0.4). There was no difference of pathologic lesion size and excised specimen size between these groups (1.57±0.78 cm vs 1.42±0.80 cm in pathologic lesion size; P=0.63, 4.28± 0.48 cm vs 4.15±1.37 cm in specimen size; P=0.73). In NIR group, the ratio of excised specimen/lesion was lesser than that of conventional group (3.19 ±1.40 vs 4.31±3.86; P=0.008). In addition, positive margin rate after BCS in early breast cancer patients was 0% in NIG group and 19.7% in conventional group. And re-excision rate was 0% and 4.4%, respectively.

Conclusions: This study showed that localization using NIR image system could be a feasible method to obtain safe resection margins and optimum resection volumes in patients undergoing breast conserving surgery.

This research was supported by National Cancer Center Grant NCC-1410202-1 & NCC-1410202-2 by the National Cancer Center, Republic of Korea.

Citation Format: Jung S-Y, Lee S, Kim SK. Clinical applications of near infra-red imaging system for localization of non-palpable breast lesions in breast conserving surgery [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-11-10.

Association Interleukin-4 and Interleukin-4 Receptor Gene Polymorphism and Acute Rejection and Graft Dysfunction After Kidney Transplantation

BACKGROUND

Cytokine genotypes have previously been studied in patients undergoing solid organ transplantation; certain polymorphisms have been implicated in the development of acute rejection (AR) and graft dysfunction (GD). Allograft outcomes determined, in part, by alloimmune responses is mainly mediated by T-cell responses, activated and driven by cytokines. Interleukin-4 (IL-4) is one such cytokine, which exerts its biological effects through binding to the IL-4 receptor (IL-4R) complex on target cells. In the present study, we investigated whether polymorphisms of the IL-4 and/or IL-4R gene were associated with susceptibility to acute AR and GD after kidney transplantation.

METHODS

We analyzed 2 single nucleotide polymorphism (SNPs) of IL-4 (rs2243250 and rs2070874) and 3 SNPs of IL-4R (rs1801275, rs2107356, and rs1805010) in 344 kidney transplant recipients. These patients included 62 of whom had developed AR and 215 of whom had GD in 1 year after kidney transplantation.

RESULTS

The AR group included 62 patients (45 men and 17 women). There was a statistically significant difference in the male-to-female ratio and the use of tacrolimus in the AR group. The GD group included 215 patients. Patients who developed GD were more likely to be older and have an underlying cause of end-stage renal disease that was unknown compared with patients who did not have GD, the cause of which was typically known. Among the SNPs examined, 1 of the SNPs in the IL-4R gene (ie, rs1801275) showed a statistical association with AR (co-dominant model, P = .061; dominant model, P = .019; and log-addictive model, P = .029). In addition, 1 of the IL-4R SNPs (ie, rs2107356) was statistically associated with GD (dominant model, P = .034). No significant difference in the IL-4 genotype was observed between the AR/GD and non-AR/non-GD subjects.

CONCLUSIONS

One IL-4R gene polymorphism (rs1801275) was associated with AR. In addition, a separate IL-4R SNP (rs2107356) was statistically associated with GD after kidney transplantation.

A randomized controlled clinical and radiological trial about outcomes of navigation-assisted TKA compared to conventional TKA: long-term follow-up

PURPOSE

Well balanced knees with good alignment are essential for a well-functioning TKA with long survival of its implants. This prospective randomized study comparing navigation-assisted TKA and conventional TKA reported the clinical and radiological outcomes at a follow-up of 9 years. The purpose of this study was to compare the clinical and radiological outcomes for patients who underwent navigation-assisted TKA or conventional TKA after long-term follow-up.

METHODS

A total of 80 patients (88 knees) were available for physical and radiological examination 9 years after TKA. Clinical outcomes were evaluated using HSS, WOMAC, and KS function and pain scores. And radiological outcomes of the component loosening and its survivorship during 9-year follow-up were also evaluated.

RESULTS

There were no significant differences in the field of clinical outcomes between the two groups. In terms of radiological outcomes, the navigation group had fewer alignment outliers (7.3 vs 20 %, p = 0.006). Although the clinical outcomes showed no differences between the two groups, the survival rate was slightly better in the navigation group than in the conventional group without statistical significance (best-case scenario 100 vs 95.3 %, n.s., worst-case scenario 95.6 vs 88.4 %, n.s.).

CONCLUSION

Navigation-assisted TKA produced better alignment outcomes and better survival rates than conventional instruments although some of the differences were not statistically significant.

LEVEL OF EVIDENCE

I.

First Observation of the Doubly Cabibbo-Suppressed Decay of a Charmed Baryon: Λ_{c}^{+}→pK^{+}π^{-}

We report the first observation of the decay Λ_{c}^{+}→pK^{+}π^{-} using a 980  fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. This is the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(Λ_{c}^{+}→pK^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})=(2.35±0.27±0.21)×10^{-3}, where the uncertainties are statistical and systematic, respectively.

Incidence and Clinical Significance of Acute Reocclusion after Emergent Angioplasty or Stenting for Underlying Intracranial Stenosis in Patients with Acute Stroke

BACKGROUND AND PURPOSE

A major concern after emergent intracranial angioplasty in cases of acute stroke with underlying intracranial stenosis is the acute reocclusion of the treated arteries. This study reports the incidence and clinical outcomes of acute reocclusion of arteries following emergent intracranial angioplasty with or without stent placement for the management of patients with acute stroke with underlying intracranial atherosclerotic stenosis.

MATERIALS AND METHODS

Forty-six patients with acute stroke received emergent intracranial angioplasty with or without stent placement for intracranial atherosclerotic stenosis and underwent follow-up head CTA. Acute reocclusion was defined as "hypoattenuation" within an arterial segment with discrete discontinuation of the arterial contrast column, both proximal and distal to the hypoattenuated lesion, on CTA performed before discharge. Angioplasty was defined as "suboptimal" if a residual stenosis of ≥50% was detected on the postprocedural angiography. Clinical and radiologic data of patients with and without reocclusion were compared.

RESULTS

Of the 46 patients, 29 and 17 underwent angioplasty with and without stent placement, respectively. Acute reocclusion was observed in 6 patients (13%) and was more frequent among those with suboptimal angioplasty than among those without it (71.4% versus 2.6%, P < .001). The relative risk of acute reocclusion in patients with suboptimal angioplasty was 27.857 (95% confidence interval, 3.806-203.911). Furthermore, a good outcome was significantly less frequent in patients with acute reocclusion than in those without it (16.7% versus 67.5%, P = .028).

CONCLUSIONS

Acute reocclusion of treated arteries was common after emergent intracranial angioplasty with or without stent placement in patients with acute stroke with intracranial atherosclerotic stenosis and was associated with a poor outcome. Suboptimal results of angioplasty appear to be associated with acute reocclusion, irrespective of whether stent placement was performed.

Association between catechol-O-methyl transferase gene polymorphisms and fibromyalgia in a Korean population: A case-control study

BACKGROUND

Although polymorphisms of the catechol-O-methyl transferase (COMT) gene have been implicated in altered pain sensitivity, results concerning the association between COMT gene polymorphisms and fibromyalgia (FM) are equivocal. We assessed the associations between COMT single-nucleotide polymorphisms (SNP) and FM risk and symptom severity.

METHODS

In total, 409 FM patients and 423 controls were enrolled. Alleles and genotypes at five positions [rs6269 (A>G), rs4633 (C>T), rs4818 (C>G), rs4680 (C>G) and rs165599 (A>G)] in the COMT gene were genotyped from peripheral blood DNA.

RESULTS

Alleles and genotypes of the rs4818 COMT gene polymorphism were significantly associated with increased susceptibility to FM. The rs4818 GG genotype was more strongly associated with FM compared to the CC genotype (OR = 1.680, 95% CI: 1.057, 2.672, p = 0.027). Although allele and genotype frequencies did not differ among groups, the rs4633 CT genotype was not associated with the presence of FM following adjustment for age and sex (OR = 0.745; 95% CI: 0.558, 0.995; p = 0.046). However, no association was observed between clinical measures and individual COMT SNPs. In haplotype analysis, there was a significant association between ACG haplotype and FM susceptibility sex (OR = 2.960, 95% CI: 1.447, 6.056, p = 0.003) and the number of tender points (p = 0.046).

CONCLUSIONS

This large-scale study suggests that polymorphisms of the COMT gene may be associated with FM risk and pain sensitivity in Korean FM patients. However, our results differed to those of previous studies, suggesting ethnic variation in COMT gene polymorphisms in FM.

WHAT DOES THIS STUDY ADD

By contrast to Caucasian and Latin-American populations, the COMT gene polymorphisms are associated with FM risk and pain sensitivity in Korean FM patients, suggesting ethnic variation in COMT gene polymorphisms.

Outcomes Are Not Different between Patients with Intermediate and High DWI-ASPECTS after Stent-Retriever Embolectomy for Acute Anterior Circulation Stroke

BACKGROUND AND PURPOSE

Questions remain as to what benefits embolectomy provides to patients presented with considerable early ischemic changes on baseline imaging studies. This study aimed to investigate the impact of the Alberta Stroke Program Early CT Score applied to DWI on treatment outcomes in patients with acute stroke undergoing stent-retriever embolectomy.

MATERIALS AND METHODS

We retrospectively analyzed the clinical and DWI data from 171 patients with acute anterior circulation stroke who were treated with stent-retriever embolectomy within 6 hours of symptom onset. DWI-ASPECTS scores were analyzed with the full scale or were dichotomized (4-6 versus 7-10). Patients with DWI-ASPECTS ≤3 were excluded from the study. Associations between outcome and clinical and radiologic factors were determined with a multivariate logistic regression analysis. A good outcome was defined as a modified Rankin Scale score of 0-2 at 3 months.

RESULTS

The median DWI-ASPECTS was 7 (interquartile range, 6-8). The rates of good outcome, symptomatic hemorrhage, and mortality were not different between high DWI-ASPECTS (scores of 7-10) and intermediate DWI-ASPECTS (scores of 4-6) groups. In patients with an intermediate DWI-ASPECTS, good outcome was achieved in 46.5% (20/43) of patients with successful revascularization, whereas no patients without successful revascularization had a good outcome (P = .016). In multivariate logistic regression analysis, independent predictors of good outcome were age and successful revascularization.

CONCLUSIONS

Our study suggested that there were no differences in outcomes between patients with a high DWI-ASPECTS and those with an intermediate DWI-ASPECTS who underwent stent-retriever embolectomy for acute anterior circulation stroke. Thus, patients with an intermediate DWI-ASPECTS otherwise eligible for endovascular therapy may not be excluded from stent-retriever embolectomy or stroke trials.

Assessment of CASP gene polymorphisms in periodontal disease

Caspases (CASP) are intracellular proteases that play roles as mediators of apoptosis. Activation of caspase 3 is enhanced in chronic periodontitis. Thus, we hypothesized that single nucleotide polymorphisms (SNPs) of CASP genes might be associated with this condition in the Korean population. To investigate whether such polymorphisms might be involved in the development of periodontal disease, 51 patients and 33 control subjects were assessed. A total of 201 CASP gene SNPs were analyzed with genotypes being determined using and Axiom(TM) genome-wide human assay. SNPStats and SPSS 18.0 were used for the analysis of genetic data and logistic regression models were utilized to evaluate odds ratios, 95% confidence intervals, and P values. Of the 201 SNPs, only three (rs12108497, rs4647602, and rs113420705, all in the CASP3 gene) were significantly associated with chronic periodontitis (P < 0.05). The minor allele frequencies of these SNPs were higher in the patient group than in the control group. In addition, the TC and GT haplotypes formed by rs4647602 and rs113420705 were found to be associated with chronic this disease (TC haplotype, P = 0.0039; GT haplotype, P = 0.002). These results suggest that CASP3 gene polymorphisms may be associated with susceptibility to periodontal disease in the Korean population.

Solidification and loss of hydrostaticity in liquid media used for pressure measurements

We carried out a study of the pressure dependence of the solidification temperature in nine pressure transmitting media that are liquid at ambient temperature, under pressures up to 2.3 GPa. These fluids are 1:1 isopentane/n-pentane, 4:6 light mineral oil/n-pentane, 1:1 isoamyl alcohol/n-pentane, 4:1 methanol/ethanol, 1:1 FC72/FC84 (Fluorinert), Daphne 7373, isopentane, and Dow Corning PMX silicone oils 200 and 60,000 cS. We relied on the high sensitivity of the electrical resistivity of Ba(Fe(1-x)Ru(x))2As2 single crystals to the freezing of the pressure media and cross-checked with corresponding anomalies observed in the resistance of the manganin coil that served as the ambient temperature resistive manometer. In addition to establishing the temperature-pressure line separating the liquid (hydrostatic) and frozen (non-hydrostatic) phases, these data permit rough estimates of the freezing pressure of these media at ambient temperature. This pressure establishes the extreme limit for the medium to be considered hydrostatic. For higher applied pressures, the medium has to be treated as non-hydrostatic.

Dosimetric planning study for the prevention of anal complications after post-operative whole pelvic radiotherapy in cervical cancer patients with hemorrhoids

OBJECTIVE

Radiation-induced anal toxicity can be induced by low radiation doses in patients with haemorrhoids. The object of this study was to determine the dosimetric benefits of different whole pelvic radiotherapy (WPRT) techniques in terms of dose delivered to the anal canal in post-operative patients with cervical cancer.

METHODS

The planning CT images of 10 patients with cervical cancer undergoing postoperative radiotherapy were used for comparison of three different plans. All patients had been treated using the conventional box technique WPRT (CV-WPRT), and we tried low-margin-modified WPRT (LM-WPRT), three-dimensional conformal techniques WPRT (CF-WPRT) and intensity-modulated WPRT (IM-WPRT) planning for dosimetric comparison of the anal canal, retrospectively.

RESULTS

Mean anal canal doses of the IM-WPRT were significantly lower (p < 0.05) than those of CV-WPRT, LM-WPRT and CF-WPRT, and V10, V20, V30 and V40 to the anal canal were also significantly lower for IM-WPRT (p < 0.05). The proportion of planning target volumes (PTVs) that received ≥98% of the prescribed dose for all plans was >99%, and the proportion that received ≥108% of the prescribed dose for IM-WPRT was <2%. Volumes of bladders and rectums that received ≥30 or ≥40 Gy were significantly lower for IM-WPRT than for three of the four-field WPRT plans (p = 0.000).

CONCLUSION

IM-WPRT can significantly reduce radiation dose delivered to the anal canal and does not compromise PTV coverage. In patients with haemorrhoids, IM-WPRT may be of value for the prevention of anal complications.

ADVANCES IN KNOWLEDGE

Although tolerance of the anal canal tends to be ignored in patients undergoing post-operative WPRT, patients with haemorrhoids may suffer complications at low radiation doses. The present study shows IM-WPRT can be meaningful in these patients.