Comparison of acute toxicities between contemporary forward‐planned 3D conformal radiotherapy and inverse‐planned intensity‐modulated radiotherapy for whole breast radiation

The use of inverse‐planned intensity‐modulated radiation therapy for whole breast radiation treatment has become more prevalent, but this may impose an increased cost on the health system. We hypothesized that when applied with the same treatment planning goals, tangential forward‐planned field‐in‐field 3D conformal radiotherapy and tangential inverse‐planned intensity‐modulated radiotherapy would be associated with comparable toxicities. Women who underwent tangential whole breast irradiation at our institution from 2011 to 2015 planned using either forward‐planned field‐in‐field 3D conformal radiotherapy or intensity‐modulated radiotherapy were retrospectively analyzed. Grade 2+ Radiation dermatitis was the primary endpoint. A total of 201 and 212 women had undergone field‐in‐field 3D conformal radiotherapy and intensity‐modulated radiotherapy, respectively. No differences were observed between the two modalities regarding acute radiation dermatitis, breast pain, or fatigue. In a multivariable logistic regression that incorporated the use of boost, hypofractionation, use of chemotherapy, patient positioning, use of a supraclavicular field, and breast planning target volume, intensity‐modulated radiotherapy was not correlated with different rates of Grade 2+ radiation dermatitis. This study supports the routine first‐line use of field‐in‐field 3D conformal radiotherapy for whole breast radiation instead of tangential intensity‐modulated radiotherapy from the standpoint of equivalence in acute toxicity. Further investigation is needed to assess whether there are subgroups of women who may still benefit from intensity‐modulated radiotherapy.     

Current status of intensity‐modulated radiation therapy for prostate cancer: History,clinical results and future directions

External beam radiotherapy has changed dramatically over several decades with the improvement of computer hardware and software, and machinery developments. Intensity‐modulated radiation therapy is the most sophisticated technique for all cancer treatment with radiation therapy, and is widely disseminated and available for daily use in many countries. Several retrospective and prospective studies have shown that intensity‐modulated radiation therapy reduces the radiation dose in the organs at risk with diminished rates of acute and late toxicity, even with higher doses (>74 Gy). An important technique for the clinical use of intensity‐modulated radiation therapy is image‐guided radiation therapy. The clinical benefit for prostate image‐guided radiation therapy has been assessed by comparing the outcomes of patients with either the image‐guided radiation therapy or non‐image‐guided radiation therapy technique. These studies have shown that image‐guided radiation therapy significantly decreases acute and late rectal and bladder toxicities. Randomized trials and meta‐analysis have shown that higher doses result in better biochemical control. More recently, hypofractionated radiation therapy comparing hypofractionated radiation therapy versus conventional fractionated radiation therapy have shown that hypofractionated radiation therapy produces biochemical control and toxicity rated similar to those produced by conventional fractionated radiation therapy. The clinical use of ultrahypofractionated radiation therapy and simultaneous integrated boost technique is necessary to evaluate its further safety and benefits. Intensity‐modulated radiation therapy is also widely accepted in the field of salvage therapy and for the patients with distant oligometastases. The purpose of the present review is to summarize the history of intensity‐modulated radiation therapy, new techniques for intensity‐modulated radiation therapy, hypofractionation and future directions for prostate cancer.     

间歇内分泌治疗联合调强适形放射治疗局限性前列腺癌的临床研究

目的：探讨间歇性内分泌治疗联合调强适形放射治疗局限性前列腺癌的临床价值。方法：选择局限性前列腺癌患者72例,分为两组,联合治疗组37例,采用间歇内分泌治疗联合调强适形放射治疗;单纯治疗组35例,采用单纯调强适形放射治疗。分析比较两组患者的临床症状缓解率、前列腺体积变化情况、血清前列腺特异抗原（PSA）值改变、肿瘤控制率、放疗不良反应发生率及生存率等方面。结果：随访5～118个月,平均56个月。联合治疗组与单纯治疗组比较,临床症状缓解率差异有统计学意义（x^2=3．280,P=0．036）;前列腺体积差值的差异有统计学意义（t=5．1353,P=0．000）;血清PsA〈0．2μg／L者所占比例差异有统计学意义（x^2=20．182,P=0．000）;1年、3年、5年和8年PSA无进展生存率差异均有统计学意义（P〈0．05）;1年、3年均无死亡病例,差异均无统计学意义;5年生存率差异有统计学意义（x^2=5．168,P=0．023）;8年生存率差异有统计学意义（x^2=5．061,P=0．024）;早期放疗不良反应发生率差异有统计学意义（P〈0．05）。结论：间歇内分泌治疗联合调强适形放射治疗局限性前列腺癌可明显改善患者的临床症状,降低血清PSA水平,提高疾病控制率及患者生存率,降低放疗早期不良反应发生率,疗效优于单纯调强适形放射治疗,是一种安全、有效的治疗措施。     

简单调强技术在胃癌术后放疗中的应用研究

目的研究简单调强放射治疗（sIMRT）技术在胃癌术后放射治疗中的剂量学特点,为临床提供参考。方法选取2012年2—6月间在南京医科大学附属淮安第一医院接受治疗的12例胃癌术后患者,分别设计三维适形放疗（3D-CRT）、5野调强放射治疗（IMRT）计划和5野简单调强放射治疗（sIMRT）计划,其中3D．CRT采用上下分野照射,调强放疗均选取20°、80°、180°、280°和34005个照射野。应用剂量体积直方图（DVH）比较3种计划的适形度指数、不均匀性指数、正常组织受照剂量特点、机器治疗总跳数及治疗总时间。结果sIMRT和IMRT计划适形度优于3D—CRT计划,但不均匀性亦甚于3D．CRT计划,差异有统计学意义（均P〈0．05）。在不同的放疗剂量下,sIMRT计划受照射的肝脏和双肾体积百分比均低于3D．CRT计划（均P〈0．05）,与IMRT计划相近（均P〉0．05）。sIMRT计划的机器总跳数和总治疗时间均少于IMRT计划和3D—CRT计划。结论sIMRT技术和IMRT技术用于胃癌术后放疗,其剂量分布明显优于3D—CRT技术;但sIMRT技术治疗时间最短,在临床应用具有更便捷的优势。     

Matched-cohort analysis of patients with prostate cancer followed with observation or treated with three-dimensional conformal radiation therapy

OBJECTIVES: To compare the outcome of similar patients with prostate cancer treated by either observation or three-dimensional conformal radiation therapy (3-DCRT). PATIENTS AND METHODS: The study included 69 patients with nonmetastatic prostate cancer who were observed only; the indications included indolent disease, significant medical comorbidities and refusal of treatment. Of these, 62 patients had palpable T1-T2a and seven T2b-T3a disease, a median Gleason score of 6 and a median initial prostate-specific antigen (PSA) level of 5.3 ng/mL. A matched-cohort analysis of 69 patients, based on palpation T category, Gleason score and initial PSA, was used to compare the outcome between the observation and 3-DCRT groups. The median radiation dose for latter was 72 Gy. RESULTS: The median follow-up for the observed patients was 49 months. The 5- and 8-year actuarial rates of freedom from distant metastases were 100% and 93%, respectively, and the actuarial overall survival rates 94% and 73%, respectively. Seven observed patients had local disease progression on physical examination. Four patients who initially were observed received radiation therapy later for a rising PSA and/or local disease progression. For the 69 matched 3-DCRT patients, the overall 5-year rate for no biochemically evident disease was 74%. The respective 5- and 8-year actuarial rates of freedom from distant metastases were 95% and 95%, and actuarial overall survival rates 95% and 75%. There were no significant differences in distant metastasis and overall survival rates between the groups, and no deaths from prostate cancer in either group. CONCLUSIONS: Observation is a reasonable alternative to treatment in selected patients. During the 5-year follow-up the progression rates were relatively low, and there was no difference in distant metastasis or overall survival between the groups. As the follow-up was short a longer follow-up is needed to determine whether the outcome of those patients who chose observation will remain comparable to that in those undergoing immediate 3-DCRT.     

Carbon‐ion radiation therapy for prostate cancer

In 1994, carbon‐ion radiotherapy was started at the National Institute of Radiological Sciences using the Heavy‐Ion Medical Accelerator in Chiba. Between June 1995 and March 2000, two phase I/II dose escalation studies (protocols 9402 and 9703) of hypofractionated carbon‐ion radiotherapy for both early‐ and advance‐stage prostate cancer patients had been carried out to establish radiotherapy technique and to determine the optimal radiation dose. To validate the feasibility and efficacy of hypofractionated carbon‐ion radiotherapy, a phase II study (9904) was initiated in April 2000 using the shrinking field technique and the recommended dose fractionation (66 gray equivalents in 20 fractions over 5 weeks) obtained from the phase I/II studies, and was successfully completed in October 2003. The data from 175 patients in the phase II study showed the importance of an appropriate use of androgen deprivation therapy according to tumor risk group. Since November 2003, carbon‐ion radiotherapy for prostate cancer was approved as “Highly Advanced Medical Technology” from the Ministry of Health, Labor, and Welfare, and since then approximately 1100 patients have received carbon‐ion radiotherapy as of July 2011. In this review, we introduce our steps thorough three clinical trials carried out at National Institute of Radiological Sciences, and show the updated data of carbon‐ion radiotherapy obtained from approximately 1000 prostate cancer patients. In addition, our recent challenge and future direction will be also described.     

Transurethral resection of the prostate immediately after high‐intensity focused ultrasound treatment for prostate cancer

Objectives: To evaluate the long‐term outcomes of transurethral resection of the prostate (TURP) immediately after high‐intensity focused ultrasound (HIFU) treatment for prostate cancer (CaP). Methods: The present retrospective study included 65 CaP patients who underwent HIFU alone and 64 patients who underwent TURP immediately after HIFU. HIFU treatment was carried out using a Sonablate‐500 HIFU device (Focus Surgery, Indianapolis, IN, USA). International Prostate Symptom Score (IPSS) and the occurrence of urinary complications, such as urethral stricture during follow‐up, were statistically compared between groups. Results: Clinical stage tended to be lower for the HIFU + TURP group (P = 0.0311), but none of the preoperative parameters differed significantly between groups. Both catheterization time (P < 0.0001) and post‐treatment IPSS (P < 0.0001) at 6, 12, and 24 months after treatment differed significantly between groups. Urethral strictures were noted in 16 (24.6%) of the HIFU‐only patients and seven (10.9%) of the HIFU + TURP patients. Bladder neck contracture was noted in 11 (68.8%) of the patients with urethral stricture in the HIFU‐only group, but in just two (28.6%) of the patients with urethral stricture in the HIFU + TURP group. Multiple logistic regression analyses showed that TURP resection volume (P = 0.0118) was a strong factor for the prevention of urethral stricture. Conclusions: Our results suggest that combining HIFU with an immediately following TURP improves post‐treatment urinary status without causing additional morbidity.     

Significance of prostatic biopsies after radiation therapy for carcinoma of the prostate

The significance of a prostatic biopsy after radiation therapy for prostatic cancer is at present uncertain. Criteria for interpreting residual tumor cells as viable and, more important, determining whether such cells are biologically capable of local growth and/or subsequent dissemination, by histological evaluation, require further clinical correlation and studies designed to better characterize biological behavior and growth potential of neoplastic cells in general and how this may or may not be altered by irradiation. A positive biopsy after radiation therapy must be regarded, however, as ominous simply because its potential significance is yet to be determined. Prostatic biopsies may predict treatment failure in general, but their significance relative to an individual patient requires correlation with 1) tumor stage, grade, size, and site of the original tumor; 2) technique of biopsy, number of cores obtained, and the location relative to the original tumor; 3) time interval of biopsy after treatment and whether biopsy is performed on one or more occasions; 4) circumstances (clinical progression or clinical regression) at the time of biopsy; and 5) treatment artifacts regarding dose delivered and distribution, which is especially important with regard to interstitial irradiation.