Helical tomotherapy in cervical cancer patients: simultaneous integrated boost concept: technique and acute toxicity

Image-guided radiotherapy and -brachytherapy for cervical cancer

Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer.

Dosimetric comparison of MRI-based HDR brachytherapy and stereotactic radiotherapy in patients with advanced cervical cancer: A virtual brachytherapy study

AIM

To evaluate the treatment plans of 3D image-guided brachytherapy (BT) and stereotactic robotic radiotherapy with online image guidance - CyberKnife (CK) in patients with locally advanced cervix cancer.

METHODS AND MATERIALS

Ten pairs of plans for patients with locally advanced inoperable cervical cancer were created using MR based 3D brachytherapy and stereotaxis CK. The dose that covers 98% of the target volume (HR CTV D98) was taken as a reference and other parameters were compared.

RESULTS

Of the ten studied cases, the dose from D100 GTV was comparable for both devices, on average, the BT GTV D90 was 10-20% higher than for CK. The HR CTV D90 was higher for CK with an average difference of 10-20%, but only fifteen percent of HR CTV (the peripheral part) received a higher dose from CK, while 85% of the target volume received higher doses from BT. We found a significant organ-sparing effect of CK compared to brachytherapy (20-30% lower doses in 0.1 cm(3), 1 cm(3), and 2 cm(3)).

CONCLUSION

BT remains to be the best method for dose escalation. Due to the significant organ-sparing effect of CK, patients that are not candidates for BT could benefit from stereotaxis more than from classical external beam radiotherapy.

Helical tomotherapy for cancer treatment: a rapid health technology assessment

OBJECTIVES

Helical tomotherapy (HT) can be applied to treat complex malignant cancer with high-precise radiotherapy, and it can reduce the damage to normal tissues and improve treatment effects. But the procurement of HT must be approved by relevant departments of administration affairs. This study, appointed by the National Health and Family Planning Commission of China and undertook by the National Health Development Research Center and the Chinese Evidence-Based Medicine Centre, was aimed to rapidly assess the effectiveness, safety, costs, and applicability of HT, so as to provide currently available best evidence for decision-makers of health policies.

METHODS

We electronically searched databases including PubMed, EMbase, The Cochrane Library, CNKI, WanFang Data, VIP, CBM, and other professional websites. Two reviewer independently screened literature according to the inclusion and exclusion criteria, extracted data, assessed quality, and then performed descriptive analysis.

RESULTS

(i) We finally included 150 studies, encompassing 5 HTAs, 18 CCTs, and 127 observational studies. (ii) The included HTAs were published during 2006-2009, providing fairly less evidence of low quality and the results of 145 primary studies showed that: HT had been used mainly in the treatments of 14 kinds of cancer, with low total toxicity and high survival rates. Although the quality of the included studies was poor, there was much evidence about prostate cancer, head and neck cancer, nasopharynx cancer, cervical cancer, lung cancer and liver cancer, with enough sample and fairly reliable results in HT efficacy and safety. And (iii) a total of 56 clinical trials were registered in Clinicaltrials.gov, most of which were registered by the occident. Among them, 9 were completed but the results had not been published yet.

CONCLUSIONS

The evidence of this study showed that, HT is safe and effective in clinic. But the abovementioned conclusion needs to be verified by conducting more high-quality studies with long-term follow-up. The costs of HT in procurement, maintenance, and application are high; and the skills, training, and qualification of operators are required. We suggest that the procurement of HT should be reduced; it should be allocated rationally and effectively used after comprehensive assessment in China's cancer epidemiology characteristics, health resource allocation, disease burden, medical service level, etc.; and also high-quality studies with long-term follow-up should be financially supported on the basis of establishing projects, so as to provide local evidence and consistently guide and improve scientific decision-making.

Optimizing image guidance frequency and implications on margins for gynecologic malignancies

Background

To analyze setup deviations using daily megavoltage computed tomography (MVCT) and to evaluate three MVCT frequency reducing protocols for gynecologic cancer patients treated with helical tomotherapy.

Methods

We recorded the setup errors of 56 patients with gynecological cancer observed throughout their whole course by matching their daily MVCT with the planning CT. Systematic and random errors were calculated on a patient and population basis. We defined three different protocols corresponding to MVCTs from the first five fractions (FFF), the first ten fractions (FTF) or from the first and third weeks (505). We compared theoretical. setup errors calculated using these 5 or 10 early MVCT scans with the actual errors found with the remaining fractions to to analyze the residual deviations.

Results

The total systematic (random) deviations had means of −2.0 (3.8)mm, 0.5 (3.4)mm, 0.5 (6.1)mm and −0.5° (0.9°) in vertical (V), longitudinal (LO), lateral (LA), and roll (R) directions, respectively. The proposed three MVCT protocols resulted in minor residual deviations. In all three protocols, 95% of all calculated residual deviations were less than or equal to 5 mm in all 3 directions. When examining the additional minimal CTV-PTV setup margins that were calculated based on these residual deviations, the 505 protocol would have allowed smaller margins than the FFF and FTF protocol, particularly in the V direction.

Conclusions

For patients with gynecologic cancer, the 505-protocol led to the lowest residual deviations and therefore might offer the best approach in reducing the frequency of pre-treatment MVCTs.

Residual tumour volumes and grey zones after external beam radiotherapy (with or without chemotherapy) in cervical cancer patients. A low-field MRI study

BACKGROUND

Grey zones, which are defined as tissue with intermediate signal intensity in the area of primary hyperintense tumour extension, can be seen during radiation with or without chemotherapy on the T2-weighted MRI in patients with cervical cancer. The purpose of this study was to systematically measure the tumour volume at the time of diagnosis and the residual tumour volume at the time of brachytherapy without and with consideration of the grey zones and to estimate tumour regression during external beam radiotherapy (EBRT).

MATERIAL AND METHODS

T2-weighted MRI datasets of 175 patients with locally advanced cervical cancer (FIGO stage IB-IVA), who underwent combined external beam radiotherapy and brachytherapy with or without concomitant chemotherapy were available for this study. The gross tumour volume at the time of diagnosis (GTV(init)) and at the time of first brachytherapy without (GTV(res)) and with (GTV(res)+ GZ) consideration of grey zones were measured for each patient. A descriptive statistical analysis was performed and tumour regression rates without (R) and with consideration of grey zones (R(GZ)) were calculated. Further, the role of prognostic factors on GTV(init), GTV(res), GTV(res)+ GZ and tumour regression rates was investigated.

RESULTS

The median GTV(init), GTV(res), GTV(res)+ GZ in all patients were 44.4 cm(3), 8.2 cm(3), 20.3 cm(3), respectively. The median R was 78.5% and the median R(GZ) was 50.1%. The histology and FIGO staging showed a significant impact on GTV(init), GTV(res) and GTV(res)+ GZ.

CONCLUSION

Grey zones represent a substantial proportion of the residual tumour volume at the time of brachytherapy. Differentiation of high signal intensity mass and surrounding intermediate signal intensity grey zones may be reasonable.

Retrospective feasibility study of simultaneous integrated boost in cervical cancer using Tomotherapy: the impact of organ motion and tumor regression

Background

Whole pelvis intensity modulated radiotherapy (IMRT) is increasingly being used to treat cervical cancer aiming to reduce side effects. Encouraged by this, some groups have proposed the use of simultaneous integrated boost (SIB) to target the tumor, either to get a higher tumoricidal effect or to replace brachytherapy. Nevertheless, physiological organ movement and rapid tumor regression throughout treatment might substantially reduce any benefit of this approach.

Purpose

To evaluate the clinical target volume - simultaneous integrated boost (CTV-SIB) regression and motion during chemo-radiotherapy (CRT) for cervical cancer, and to monitor treatment progress dosimetrically and volumetrically to ensure treatment goals are met.

Methods and materials

Ten patients treated with standard doses of CRT and brachytherapy were retrospectively re-planned using a helical Tomotherapy - SIB technique for the hypothetical scenario of this feasibility study. Target and organs at risk (OAR) were contoured on deformable fused planning-computed tomography and megavoltage computed tomography images. The CTV-SIB volume regression was determined. The center of mass (CM) was used to evaluate the degree of motion. The Dice’s similarity coefficient (DSC) was used to assess the spatial overlap of CTV-SIBs between scans. A cumulative dose-volume histogram modeled estimated delivered doses.

Results

The CTV-SIB relative reduction was between 31 and 70%. The mean maximum CM change was 12.5, 9, and 3 mm in the superior-inferior, antero-posterior, and right-left dimensions, respectively. The CTV-SIB-DSC approached 1 in the first week of treatment, indicating almost perfect overlap. CTV-SIB-DSC regressed linearly during therapy, and by the end of treatment was 0.5, indicating 50% discordance. Two patients received less than 95% of the prescribed dose. Much higher doses to the OAR were observed. A multiple regression analysis showed a significant interaction between CTV-SIB reduction and OAR dose increase.

Conclusions

The CTV-SIB had important regression and motion during CRT, receiving lower therapeutic doses than expected. The OAR had unpredictable shifts and received higher doses. The use of SIB without frequent adaptation of the treatment plan exposes cervical cancer patients to an unpredictable risk of under-dosing the target and/or overdosing adjacent critical structures. In that scenario, brachytherapy continues to be the gold standard approach.

Adjuvant radiochemotherapy in patients with locally advanced high-risk cervical cancer

BACKGROUND AND PURPOSE

The aim of this retrospective study was to analyze the outcome of patients with locally advanced cervical carcinoma treated by adjuvant radiochemotherapy and to determine risk factors for local and distant relapse. Furthermore, acute and late effects of treatment were recorded.

PATIENTS AND METHODS

A total of 72 patients with FIGO stages I-III cervical carcinoma were treated by radical hysterectomy, pelvic lymphadenectomy, and postoperative radiochemotherapy. Only patients with positive pelvic lymph nodes, parametrial involvement, positive margins, or tumor bulk were eligible. Patients were irradiated with a standard pelvic field (50.4 Gy in 28 fractions). The majority of patients received platinum-based chemotherapy.

RESULTS

After a median follow-up of 37 months, estimated 1-, 2-, and 4-year disease-free survival (DFS) and overall survival (OS) rates were 89%, 80%, 68% and 95%, 88%, 76%, respectively. Nine of the 72 patients had pelvic recurrences including only 1 isolated local failure; 23 of the 72 patients presented with distant relapse. The majority of relapses occurred within the first 3 years after adjuvant treatment. The number of positive pelvic lymph nodes (> 1) was the strongest prognostic factor for DFS. Treatment was well tolerated with transient acute hematologic (~30%) and gastrointestinal (~30%) grade 3 toxicity. Small bowel obstruction (~6%) was the only important late sequelae.

CONCLUSION

Adjuvant radiochemotherapy in patients with advanced cervical cancer and several risk factors is highly effective to prevent local relapse. Future efforts to improve outcome should be placed on improvement of systemic control especially in subgroups with high-risk features for distant relapse. Combined treatment was well tolerated with moderate acute and late toxicity.

Intensity-modulated arc therapy with cisplatin as neo-adjuvant treatment for primary irresectable cervical cancer. Toxicity, tumour response and outcome

PURPOSE

The goal of this work was to evaluate the feasibility and outcome of intensity-modulated arc therapy ± cisplatin (IMAT ± C) followed by hysterectomy for locally advanced cervical cancer.

PATIENTS AND METHODS

A total of 30 patients were included in the study. The primary tumour and PET-positive lymph node(s) received a simultaneous integrated boost. Four weeks after IMAT ± C treatment, response was evaluated. Resection consisted of hysterectomy with or without lymphadenectomy. Tumour response, acute and late radiation toxicity, postoperative morbidity and outcome were evaluated.

RESULTS

All hysterectomy specimens were macroscopically tumour-free with negative resection margins; pathological complete response was 40%. In 2 patients, one resected lymph node was positive. There was no excess in postoperative morbidity. Apart from two grade 3 hematologic toxicities, no grade 3 or 4 acute radiation toxicity was observed. No grade 3, 1 grade 4 (4%) intestinal, and 4 grade 3 (14%) urinary late toxicities were observed. The 2-year local and regional control rates were 96% and 100%, respectively. The 2-year distant control rate was 92%. Actuarial 2-year progression free survival rate was 89%. Actuarial 1- and 2-year overall survival rates were 96% and 91%, while 3-year overall survival was 84%.

CONCLUSION

Surgery after IMAT ± C is feasible with low postoperative morbidity and radiation toxicity. Local, regional, distant control and survival rates are promising.

Current therapy of patients with endometrial carcinoma. A critical review

Magnetic resonance imaging (MRI), 18-FDG positron emission tomography ((18)FDG PET-CT), and computed tomography (CT) have demonstrated disappointing detectability of lymph node metastases in endometrial cancer. The treatment of choice in patients with endometrial cancer is hysterectomy and bilateral salpingoophorectomy. Above all, obese patients with comorbidity have benefited the most from laparoscopically assisted approaches. For inoperable patients in FIGO stage I/II, radiation remains an alternative to hysterectomy. The role of pelvic and paraaortic lymphadenectomy is the most controversial issue in endometrial carcinoma treatment. The current spectrum of treatment ranges from no lymphadenectomy, exclusive pelvic or additional inframesentric paraaortic sampling, or complete pelvic to infrarenal paraaortic lymphadenectomy. The sentinel concept in patients with endometrial carcinoma is far from being introduced into routine clinical practice. Without a lymphadenectomy, decision making for adjuvant therapy remains a challenge, because no information is available from lymph node status and the reliability of pathologic grading is poor. For patients after hysterectomy with a low risk of local relapse (stage I/II without additional risk factors), vaginal brachytherapy is sufficient to prevent vaginal relapses. Adjuvant external beam irradiation (EBRT) in stage I/II demonstrated improved local control which impacted overall survival only in patients with high-risk features (higher age, grading myometrial infiltration). Stage IIIC patients seem to benefit from EBRT with regard to overall survival. In patients at high risk of progression (grade 3, MI > 50%, FIGO IIIC, unfavorable histology), multimodal treatment should be considered. The optimal substances and sequences are under investigation.

Whole-brain radiotherapy combined with surgery or stereotactic radiotherapy in patients with brain oligometastases: long-term analysis

OBJECTIVE

To verify whether the treatment of brain oligometastases with whole-brain radiotherapy (WBRT) plus stereotactic radiotherapy (SRT) or surgical resection results in different outcomes.

METHODS

Files of patients affected by brain metastases submitted to surgical resection followed by WBRT (group A) or WBRT + SRT (group B) were retrospectively selected for this study. The two treatment groups were matched for the following potential prognostic factors: WBRT schedule, age, gender, performance status, tumor type, number of brain metastases, extra-cerebral metastases, and recursive partitioning analysis class (RPA). The outcomes of patients in both groups were evaluated in terms of toxicity, local control, and overall survival.

RESULTS

Total of 97 patients were selected (56 male; 42 female) who were respectively submitted to surgical resection followed by WBRT (group A, n = 50 patients) or WBRT + SRT (Group B, n = 47 patients). Median follow-up was 95 months (range, 8-171 months). The 1-year local control rates were 46.0% and 69.0% respectively. No significant difference in local tumor control was observed between group A and B (p = 0.10). Median overall survival was 15 and 19 months in group A and B, respectively. One-year survival was 56.0% and 62%, respectively. No difference was observed in the two groups (p = 0.40).

CONCLUSION

Surgery remains the main therapeutic approach in symptomatic patients; nevertheless, our data support the use of WBRT plus SRT in one or two brain metastases smaller than 3 cm.

Feasibility of tomotherapy for Graves' ophthalmopathy: Dosimetry comparison with conventional radiotherapy

PURPOSE

To compare the dosimetry of tomotherapy and the conventional half-beam technique (HBT) or non-split beam technique (NSBT) for target coverage and radiation dose to the lacrimal glands and lens.

PATIENTS AND METHODS

A retrospective review of 7 patients with Graves' ophthalmopathy who had radiotherapy because of disease progression on high steroid dose is reported: 3 patients were treated with tomotherapy and 4 patients with HBT.

RESULTS

Compared to HBT, tomotherapy may provide better target coverage and significant reduction of radiation dose to the lacrimal glands and a higher dose to the lens. The NSBT improved target coverage but resulted in significantly higher doses to the lens and lacrimal glands.

CONCLUSION

Tomotherapy may provide better coverage of the target volume and may be more effective in reducing severe exophthalmos compared to the conventional radiotherapy technique.