Conventional 2D (2DRT) and 3D conformal radiotherapy (3DCRT) versus intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer treatment

Purpose

Nasopharyngeal carcinoma represents a distinct entity as compared to other head and neck tumours. Radio-chemotherapy is the treatment of first choice in non-metastatic disease. Intensity-modulated radiation therapy (IMRT) allows the sparing of parotid glands, improving the toxicity profile. The aim of this study was to compare the results obtained with IMRT with those obtained with conventional 2D (2DRT) and 3D conformal radiation therapy (3DCRT) in terms of tumour control, survival, acute and late toxicity.

Materials and methods

We reviewed the clinical records of 52 patients with histologically proven carcinoma of the nasopharynx (stage I–IVB according to the 2002 American Joint Committee on Cancer staging system) treated with curative intent between January 2003 and August 2011: 26 patients were treated with 2D or 3D technique (arm A) and 26 with IMRT technique (arm B) with simultaneous integrated boost. Fifty patients (96 %) received chemotherapy. Local control (LC), locoregional control (LRC), disease-free survival (DFS), overall survival (OS), acute and late toxicity were retrospectively evaluated.

Results

After a median follow-up of 37.6 months (69 months in arm A and 23 months in arm B), 69 % of patients were alive and disease-free, 10 % were alive with disease and 21 % died of disease, with an OS of 81 % at 2 years and 79 % at 5 years, a LC rate of 88 % at 2 years and 78 % at 5 years, a LRC rate of 80 % at 2 years and 73 % at 5 years and a DFS of 74 % at 2 years and 65 % at 5 years, with no statistically significant differences between IMRT and 2DRT/3DCRT. In multivariate analysis, the TNM stage and the volume treated at high dose correlated with DFS. No factor was found to be related to OS. Chronic toxicity was not statistically different in the two study groups and in particular ≥G2 xerostomia rates were 67 and 41 % in arm A and B, respectively (p = 0.10).

Conclusions

The findings of this study confirm that IMRT associated with chemotherapy, even with moderately hypofractionated regimens, allows good disease control with better results in terms of late xerostomia, although without statistically significant differences compared to 2DRT and 3DCRT. The hypothesis of an impact of IMRT on survival has yet to be confirmed.     

Mammographic and ultrasonographic comparison between intraoperative radiotherapy (IORT) and conventional external radiotherapy (RT) in limited-stage breast cancer, conservatively treated

OBJECTIVE: Assess mammographic and echographic modifications in mild cases of breast cancer (suitable for conservative surgery) after intraoperatory radio treatment (IORT) as opposed to conventional post-operative radiotherapy (RT). MATERIALS AND METHODS: We report data from 45 patients in each group (IORT and RT). All patients were examined using the same mammographic and ecographic equipment at 6, 12 and 24 months after treatment. We focused on structural alterations, edema and others, and quantified them using pre-established (unbiased) protocols. Both patient examination and subsequent assessment of the results were performed by radiologists with exepertise in breast cancer evaluation. RESULTS: At 6 months, IORT patients showed slightly more pronounced structural distortions and oedema than RT patients; these differences became more apparent at 12 months, with the addition of fat necrosis and/or calcifications. These alterations were evident and consistent under both mammographic and ecographic examination, and became even more pronounced at 24 months. At this stage, RT patients showed minimal alterations of the tissue (apart from normal post-surgical scarring), whereas IORT patients showed virtually no improvement over the preceding 12-month period. CONCLUSION: We show radiological alterations in post-operative breast cancer are significantly more pronounced in patients treated with IORT as opposed to RT.     

Technical record in radiotherapy (author's transl)

The term "technical record in radiotherapy" is used to describe collected information relative to treatment using radiation. The subject of this session of the chapter of Radiotherapy of the Société Fran?aise de Radiologie was the intrinsic functions of this record and its extrinsic limitations. The extreme diversity of the current state of the record is a known fact. A majority of participants express the desire for uniformisation of the collection of data or even, as a second stage, to have a common record. A library of technical records was set up under the responsibility of the Centre Georges-Fran?ois Leclerc at Dijon (J.C. Horiot). One broad conclusion was seen to emerge: the creation of a minimum common record including essential information to which could be added the more specific data of each radiotherapist and at each time of use. Prior agreement will be necessary with regard to the standardisation of apparatus and the expression of the dose. This session was of necessity merely a reflection of future needs and it is to be hoped that the good will which was obvious during the course of the discussion may produce concrete results in the months to come.     

Single-arc volumetric-modulated arc therapy (sVMAT) as adjuvant treatment for gastric cancer: Dosimetric comparisons with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)

To compare the dosimetric differences between the single-arc volumetric-modulated arc therapy (sVMAT), 3-dimensional conformal radiotherapy (3D-CRT), and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for gastric cancer as adjuvant radiotherapy. Twelve patients were retrospectively analyzed. In each patient's case, the parameters were compared based on the dose-volume histogram (DVH) of the sVMAT, 3D-CRT, and IMRT plans, respectively. Three techniques showed similar target dose coverage. The maximum and mean doses of the target were significantly higher in the sVMAT plans than that in 3D-CRT plans and in the 3D-CRT/IMRT plans, respectively, but these differences were clinically acceptable. The IMRT and sVMAT plans successfully achieved better target dose conformity, reduced the V_20/30, and mean dose of the left kidney, as well as the V_20/30 of the liver, compared with the 3D-CRT plans. And the sVMAT technique reduced the V₂₀ of the liver much significantly. Although the maximum dose of the spinal cord were much higher in the IMRT and sVMAT plans, respectively (mean 36.4 vs 39.5 and 40.6 Gy), these data were still under the constraints. Not much difference was found in the analysis of the parameters of the right kidney, intestine, and heart. The IMRT and sVMAT plans achieved similar dose distribution to the target, but superior to the 3D-CRT plans, in adjuvant radiotherapy for gastric cancer. The sVMAT technique improved the dose sparings of the left kidney and liver, compared with the 3D-CRT technique, but showed few dosimetric advantages over the IMRT technique. Studies are warranted to evaluate the clinical benefits of the VMAT treatment for patients with gastric cancer after surgery in the future.     

SI-units in radiotherapy and radiation protection--an addendum (author's transl)

As an extension of a recent paper, this addendum conversion tables between the new SI-unit Sievert (Sv) for the dose equivalent and the unit Rem (rem) used previously, as well as the relations of the corresponding dose rates.     

Commissioning of mini-multi-leaf-collimator (MMLC) for stereotactic radiosurgery and radiotherapy

Commissioning of a Radionics miniature multi-leaf collimator (MMLC) for stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) is reported. With single isocenter and multi static fields, the MMLC can provide better conformity of dose distributions to the target and/or irregularly shaped target volumes than standard arc (circular) field beams with multiple isocenters. Advantages offered by the MMLC over traditional LINAC based SRS and SRT includes greatly improved dose homogeneity to the target, reduced patient positioning time and reduced treatment time. In this work, the MMLC is attached to a Varian 2300 C/D with Varian 80-leaf multi-leaf collimator. The MMLC has 62 leaves, each measured to a width of 3.53 mm at isocenter, with fields range from 1x1 cm to less than 10 × 12 cm. Beam parameters required by the Radionics treatment planning system (XPlan version 2) for evaluating the dose include tissue maximum ratio (TMR), scatter factors (SF), off-axis ratios (OAR), output factors, penumbra function (P) and transmission factors (TF) are performed in this work. Beam data are acquired with a small stereotactic diode, standard ion chambers and radiographic films. Measured profiles of dose distribution are compared to those calculated by the software and absolute dosimetry is performed.     

Efficacy and toxicity of (chemo)radiotherapy for primary subglottic cancer

Background and purpose

Primary subglottic cancer is a rare malignancy. We investigated the efficacy and toxicity of radiotherapy for subglottic cancer.

Patients and methods

Nineteen patients with primary squamous cell carcinoma of the subglottis received radiotherapy, 14 of whom also underwent chemotherapy. Of the 19 patients, 15 received definitive radiotherapy to the gross tumors with total doses of 70–70.2 Gy in 35–39 fractions, and 4 underwent preoperative radiotherapy with total doses of 37.8–55.8 Gy in 21–31 fractions, followed by total laryngectomy.

Results

Of the 19 patients, 5 developed local progression and 2 developed distant metastasis at the median follow-up period of 5 years. The 5-year local control and disease-free rates were 74 and 63%, respectively. Three patients died of tumor progression, and the 5-year overall and disease-free survival rates were 80 and 63%, respectively. Regarding acute toxicities, transient mucositis and dermatitis of grade 3 or lower were observed in all patients, but there were no late toxicities of grade 3 or higher.

Conclusion

Radiotherapy is a safe and effective treatment for patients with primary squamous cell carcinoma of the subglottis. The use of chemotherapy together with radiotherapy may enhance treatment efficacy and contribute to larynx preservation through good local control.     

Supine magnetic resonance (MR) mammography in radiotherapy planning

Purpose: Radiotherapy of the breast is normally performed in a supine position, so conventional prone magnetic resonance (MR) mammography is unsuitable for radiotherapy planning purposes. No dedicated supine breast coil is yet available, limiting the application of magnetic resonance imaging (MRI) in this area. A technique has been developed on a 0.2T open scanner to produce breast images suitable for radiotherapy planning.Method: The single-sided supine breast technique uses a similar patient position to that for radiotherapy treatment. A small coil is used as a side-on loop over the patient's shoulder that allows the arms to be raised and abducted and a flat tabletop insert imitates the treatment tabletops. The open design of the scanner allows the breast to be positioned in the field centre, increasing the signal to noise ratio (SNR).Twenty patients undergoing routine radiotherapy of the breast were referred for MRI scans in addition to the routine radiotherapy planning. MR markers were placed on the patient's skin over tattoos corresponding to treatment field borders. A high bandwidth T1W sequence was performed in transverse, sagittal and coronal planes. Images were assessed by the clinical oncologist to determine whether all breast tissue was included within the treatment field.Results: Images of good diagnostic quality were produced in reasonable scan times. Glandular breast tissue was well demonstrated, particularly in younger, pre-menopausal women. Surgical cavities and enlarged lymph nodes were also well demonstrated. MR markers allowed accurate delineation of the treatment field.Conclusion: The single-sided supine technique produces high quality breast images contributing valuable infonnation for treatment planning and assessment. MR provides better discrimination between breast and surrounding fatty tissue than fluoroscopy.     

创伤失血性休克患者中心静脉压与尿量关系回顾性分析

探讨创伤失血性休克患者中心静脉压（CVP）和尿量间的临床关系，当CVP逐渐提高到稳定水平、出现多尿症状时，提示内环境趋于稳定、紊乱的血流动力学趋向纠正，心肾功能正在恢复之中，病情开始好转，是判定预后的一个良好指标。而单纯的CVP变化不能评价患者的预后价值。     

Stereotactic body radiotherapy (SBRT) in the management of extracranial oligometastatic (OM) disease

Objective:

A review of stereotactic body radiotherapy (SBRT) for oligometastases defined as three or fewer sites of isolated metastatic disease. The aim was to identify local control, overall survival (OS) and progression-free survival (PFS) of patients receiving SBRT for oligometastatic (OM) disease.

Methods:

Data were analysed for SBRT delivered between 01 September 2010 and 31 March 2014. End points included local control, PFS, OS and toxicity.

Results:

76 patients received SBRT. The median age was 60 years (31–89 years). 44 were male. Median follow-up was 12.3 months (0.2–36.9 months). Major primary tumour sites included colorectal (38%), the breast (18%) and the prostate (12%). The treatment sites included lymph nodes (42%), the bone and spine (29%) and soft tissue (29%). 42% were previously treated with conventional radiotherapy. 45% were disease free after SBRT. 4% had local relapse, 45% had distant relapse, and 6% had local and distant relapse. Local control was 89%. The OS was 84.4% at 1 year and 63.2% at 2 years. PFS was 49.1% at 1 year and 26.2% at 2 years. Toxicities included duodenal ulcer and biliary stricture formation.

Conclusion:

SBRT can achieve durable control of OM lesions and results in minimal radiation-induced morbidity.

Advances in knowledge:

This cohort is one of the largest reported to date and contributes to the field of SBRT in oligometastases that is emerging as an important research area. It is the only study reported from the UK and uses a uniform technique throughout. The efficacy and low toxicity with durable control of local disease with this approach is shown, setting the foundations for future randomized studies.Stereotactic body radiotherapy (SBRT) allows us to deliver ablative doses of radiation to extracranial sites, and this treatment modality can be considered in the setting of oligometastatic (OM) disease. Traditionally, systemic agents have been the mainstay of the management of metastatic disease, however, we have entered an era where in certain settings long-term local control or cure can be achieved. The idea of an OM state (defined as 1–3 isolated metastatic deposits) was first proposed in 1995 by Hellman and Weichselbaum¹ when they suggested that for many cancers, a few metastases exist at first, before the malignant cells acquire widespread metastatic potential. Following this, Niibe and Hayakawa² described the concept of oligorecurrence that whilst similar to oligometastases has control of the primary site of the malignancy allowing local therapies to achieve control of metastatic sites. Radical treatment of oligometastases and/or oligorecurrences may therefore achieve local control or cure in carefully selected cases. Local therapies including surgical resection, irradiation and radiofrequency ablation are radical treatment options to achieve this.^1,2 Local control rates of 80% have been achieved from several non-randomized studies of SBRT for oligometastases, and SBRT has been shown to be safe and effective.³     

Hypofractionated stereotactic radiotherapy (HFSRT) for who grade I anterior clinoid meningiomas (ACM)

Purpose

While microsurgical resection plays a central role in the management of ACMs, extensive surgery may be associated with substantial morbidity particularly for tumors in intimate association with critical structures. In this study, we evaluated the use of HFSRT in the management of ACM.

Materials and methods

A total of 22 patients with ACM were treated using HFSRT. Frameless image guided volumetric modulated arc therapy (VMAT) was performed with a 6 MV linear accelerator (LINAC). The total dose was 25 Gy delivered in five fractions over five consecutive treatment days. Local control (LC) and progression free survival (PFS) rates were calculated using the Kaplan–Meier method. Common Terminology Criteria for Adverse Events, version 4.0 was used in toxicity grading.

Results

Out of the total 22 patients, outcomes of 19 patients with at least 36 months of periodic follow-up were assessed. Median patient age was 40 years old (range 24–77 years old). Median follow-up time was 53 months (range 36–63 months). LC and PFS rates were 100 and 89.4 % at 1 and 3 years, respectively. Only two patients (10.5 %) experienced clinical deterioration during the follow-up period.

Conclusion

LINAC-based HFSRT offers high rates of LC and PFS for patients with ACMs.