Intraoperative electron beam radiotherapy during radical surgery for locally advanced and recurrent cervical cancer

Feasibility and Safety of Intraoperative Radiotherapy with Low Energy X-ray Photon Therapy for Recurrent Gynecological Cancer: A Case Series

Objectives: To evaluate the feasibility and safety of low energy X-ray photon intraoperative radiotherapy (IORT) as an adjuvant therapy for recurrent gynecological cancer.Methods: Medical records of all recurrence gynecological cancer patients who underwent IORT were reviewed. Results: Between January 2018 and December 2021, five women (including cervical cancer (n = 2), endometrial cancer (n = 2), and uterine leiomyosarcoma (n = 1)), who underwent IORT and surgical resection for recurrent gynecologic cancer were reviewed. A median dose of 15.62 Gy (range, 12 to 20 Gy) was used for IORT. Repeated IORT and surgical resection was performed in two women. Three women experienced local recurrence, and three women died during follow-up. The 1-year local control rate was 60%. The 2-year overall survival rate was 30%. There was no Clavien–Dindo classification grade III–V complication. Conclusion: IORT using low energy X-ray photon therapy seems to be feasible and safe as an adjuvant therapy in women who underwent salvage surgery for recurrent gynecologic cancer. However, large-scale prospective studies are needed to confirm our findings and evaluate its efficacy.

British Gynaecological Cancer Society (BGCS) cervical cancer guidelines: Recommendations for practice

Cervix cancer in many countries is declining and screening programmes and immunisation will reduce the incidence in the next few decades. This guideline attempts to cover management of invasive disease reflecting diagnosis and imaging including new imaging and sentinel lymph node biopsies. Smaller volume disease is usually managed surgically whereas advanced disease is treated with (chemo)- radiation. It also includes discussion of fertility sparing procedures. Practices are changing frequently for all aspects of care usually in attempts to reduce complications and improve quality of life. The management of advanced disease is treated by chemotherapy and the use of newer agents is also discussed. Other sections discuss specialist situations such as cancer in pregnancy, rare cervical tumours, late effects and supportive measures and fertility preserving approaches.

[Radiotherapy for ovarian carcinoma management: Literature review]

Ovarian cancer is the fifth most common cancer in women in France with 4714 new cases in 2017. More than 70% of patients whose disease is initially locally advanced will present locoregional or distant recurrence. Therapeutic options in this situation are not consensual. They are based on chemotherapy possibly associated with an iterative cytoreductive surgery when it is bearable by the patient. The place of radiotherapy in the management of the disease is hidden in the vast majority of national or international standards. We conducted a general review of the literature to clarify the role of irradiation in the global management of ovarian cancers, particularly in recurrence.

PEGylated WS2 nanodrug system with erythrocyte membrane coating for chemo/photothermal therapy of cervical cancer

The side effects of chemical drugs and multi-drug resistance are serious obstacles hindering efficient tumor therapy.

The American Brachytherapy Society consensus statement on intraoperative radiation therapy

PURPOSE

Although radiation therapy has traditionally been delivered with external beam or brachytherapy, intraoperative radiation therapy (IORT) represents an alternative that may shorten the course of therapy, reduce toxicities, and improve patient satisfaction while potentially lowering the cost of care. At this time, there are limited evidence-based guidelines to assist clinicians with patient selection for IORT. As such, the American Brachytherapy Society presents a consensus statement on the use of IORT.

METHODS

Physicians and physicists with expertise in intraoperative radiation created a site-directed guideline for appropriate patient selection and utilization of IORT.

RESULTS

Several IORT techniques exist including radionuclide-based high-dose-rate, low-dose-rate, electron, and low-energy electronic. In breast cancer, IORT as monotherapy should only be used on prospective studies. IORT can be considered in the treatment of sarcomas with close/positive margins or recurrent sarcomas. IORT can be considered in conjunction with external beam radiotherapy for retroperitoneal sarcomas. IORT can be considered for colorectal malignancies with concern for positive margins and in the setting of recurrent gynecologic cancers. For thoracic, head and neck, and central nervous system malignancies, utilization of IORT should be evaluated on a case-by-case basis.

CONCLUSIONS

The present guidelines provide clinicians with a summary of current data regarding IORT by treatment site and guidelines for the appropriate patient selection and safe utilization of the technique. High-dose-rate, low-dose-rate brachytherapy methods are appropriate when IORT is to be delivered as are electron and low-energy based on the clinical scenario.

Intraoperative radiation therapy in uterine cervical cancer: A review

Locally advanced uterine cervical cancer continues to present a high number of pelvic relapses. Intraoperative radiation therapy (IORT) allows a precise therapeutic intensification in the surgical area in cases in which removal of the tumour recurrence is feasible. At the same time, IORT excludes the radiosensitive organs from the field of irradiation. While the first gynecological IORT took place in 1905, procedures have been limited over the years and the series are retrospective, including few patients. At the same, time recurrences are located at different pelvic areas. Both heterogeneity and the long recruiting time make it difficult to correctly interpret the published results. Despite this, we have reviewed the most relevant publications. Some institutions indicated IORT as a boost on the surgical bed of the excised tumor recurrence. In others, IORT permits an extra radiation dose after radical surgery of the primary tumor, usually in stage IIB. Most studies conclude that the addition of IORT increases the local control but probably with little impact on survival. On the other hand, there is a controversy in the indication of IORT in surgically resectable primary tumours. No clear advantage over the usual scheme of chemoradiation and brachytherapy has been detected. Randomized studies that allow a breakthrough in the conclusions are highly unlikely to be performed in this area.

Peripheral dose around a mobile linac for intraoperative radiotherapy: radiation protection aspects

The aim of this work is to analyse the scattered radiation produced by the mobile accelerator Mobetron 1000. To do so, detailed Monte Carlo simulations using two different codes, Penelope2008 and Geant4, were performed. Measurements were also done. To quantify the attenuation due to the internal structures, present in the accelerator head, on the scattered radiation produced, some of the main structural shielding in the Mobetron 1000 has been incorporated into the geometry simulation. Results are compared with measurements. Some discrepancies between the calculated and measured dose values were found. These differences can be traced back to the importance of the radiation component due to low energy scattered electrons. This encouraged us to perform additional calculations to separate the role played by this component. Ambient dose equivalent, H*(10), outside of the operating room (OR) has been evaluated using Geant4. H*(10) has been measured inside and outside the OR, being its values compatible with those reported in the literature once the low energy electron component is removed. With respect to the role played by neutrons, estimations of neutron H*(10) using Geant4 together with H*(10) measurements has been performed for the case of the 12 MeV electron beam. The values obtained agree with the experimental values existing in the literature, being much smaller than those registered in conventional accelerators. This study is a useful tool for the clinical user to investigate the radiation protection issues arising with the use of these accelerators in ORs without structural shielding. These results will also enable to better fix the maximum number of treatments that could be performed while insuring adequate radiological protection of workers and public in the hospital.

Intraoperative radiation therapy for the treatment of recurrent retroperitoneal and pelvic tumors: a single-institution analysis

Background

Patients with recurrent retroperitoneal and pelvic region tumors often require multimodal therapies. Intraoperative radiation therapy (IORT) can deliver high-dose radiation to tumor beds, even if first-line external beam radiation therapy (EBRT) was administered. We evaluated local control (LC) and survival in patients receiving IORT for recurrent tumors.

Methods

We retrospectively analyzed 41 patients with isolated pelvic or retroperitoneal recurrences of colorectal, gynecological, or retroperitoneal primary tumors. Following salvage surgery, all patients underwent tumor bed IORT via electron beam or high dose rate brachytherapy. Isolated IORT (median dose: 15 Gy) was administered to patients who had received first-line EBRT; other patients received IORT (median dose 12 Gy) plus EBRT. Local (LF), regional (RF), and distant failures (DF) were evaluated, and the Kaplan–Meier method and log-rank test were used to evaluate and compare overall survival (OS) from the date of IORT.

Results

Forty-one patients underwent 44 treatments, including 27 (61.3%) isolated IORT and 17 (38.7%) IORT and EBRT combination regimens. The median follow-up was 8.1 years (range: 4.4–11.7 years), and the 2, 5, and 8 year overall LC rates were 87.9, 64.0, and 49.8%, respectively. Regarding resection status, the respective 2, 5, and 8 year LC rates were 90, 76, and 76% for R0 resection and 75, 25, and 0% for R1 resection (p < 0.001). The 2, 5, and 8 year OS rates were 68, 43, and 26%, respectively. OS was better among patients with LC (p < 0.001). Twenty-four patients (58.5%) experienced a DF, and the 5 year OS rates for the patients with and without DF were 36 and 52%, respectively (p = 0.04).

In a multivariate analysis, LF (p = 0,012) and recurrent retroperitoneal sarcoma (p = 0,014) were identified as significant predictors of worse OS. Thirteen patients (31%) developed clinically treatable complications related to IORT.

Conclusions

Many patients achieve long-term OS and LC without significant morbidity after salvage surgery and IORT, especially in case of clear margins.

Pain in Platin-Induced Neuropathies: A Systematic Review and Meta-Analysis

Introduction

Platin-induced peripheral neuropathy (PIPN) is a common cause of PN in cancer patients. The aim of this paper is to systematically review the current literature regarding PIPN, with a particular focus on epidemiological and clinical characteristics of painful PIPN, and to discuss relevant management strategies.

Methods

A systematic computer-based literature search was conducted on the PubMed database.

Results

This search strategy resulted in the identification of 353 articles. After the eligibility assessment, 282 articles were excluded. An additional 24 papers were identified by scanning the reference lists. In total, 95 papers met the inclusion criteria and were used for this review. The prevalence of neuropathic symptoms due to acute toxicity of oxaliplatin was estimated at 84.6%, whereas PN established after chemotherapy with platins was estimated at 74.9%. Specifically regarding pain, the reported prevalence of pain due to acute toxicity of oxaliplatin was estimated at 55.6%, whereas the reported prevalence of chronic peripheral neuropathic pain in PIPN was estimated at 49.2%.

Conclusion

Peripheral neuropathy is a common complication in patients receiving platins and can be particularly painful. There is significant heterogeneity among studies regarding the method for diagnosing peripheral neuropathy. Nerve conduction studies are the gold standard and should be performed in patients receiving platins and complaining of neuropathic symptoms post-treatment.

Re-irradiation of cervical and endometrial cancer

PURPOSE OF REVIEW

Re-irradiation historically has been associated with unacceptable toxicity and limited benefit. Recent advances in radiotherapy can change the treatment paradigm to provide new salvage treatments for recurrences of cervical and endometrial cancer.

RECENT FINDINGS

Image-guided brachytherapy is an effective method for salvaging central pelvic recurrence, although it has resulted in 20-25% severe late toxicity. Pelvic sidewall disease is not accessible to brachytherapy, so a combined modality approach with radical surgery and intraoperative radiotherapy is an alternative approach. Stereotactic body radiotherapy (SBRT) now provides the option of radical re-irradiation with local control rates of 50-80% and a low incidence of severe late complications.

SUMMARY

Initial outcomes using SBRT and image-guided brachytherapy for re-irradiation of gynaecological cancer are encouraging. There has been good local control and acceptable toxicity. Further, large-scale studies are required to define optimal target doses and OAR limits.

Intraoperative radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

Intraoperative radiotherapy in gynaecological and genito-urinary malignancies: focus on endometrial, cervical, renal, bladder and prostate cancers

Intraoperative radiotherapy (IORT) refers to the delivery of a single radiation dose to a limited volume of tissue during a surgical procedure. A literature review was performed to analyze the role of IORT in gynaecological and genito-urinary cancer including endometrial, cervical, renal, bladder and prostate cancers.

Literature search was performed by Pubmed and Scopus, using the words “intraoperative radiotherapy/IORT”, “gynaecological cancer”, “uterine/endometrial cancer”, “cervical/cervix cancer”, “renal/kidney cancer”, “bladder cancer” and “prostate cancer”. Forty-seven articles were selected from the search databases, analyzed and briefly described.

Literature data show that IORT has been used to optimize local control rate in genito-urinary tumours mainly in retrospective studies. The results suggest that IORT could be advantageous in the setting of locally advanced and recurrent disease although further prospective trials are needed to confirm this findings.

Intraoperative radiation therapy (IORT) for gynecologic malignancies

Every year almost 95,000 women are diagnosed with a gynecologic malignancy and over 28,000 women will succumb to their disease. For patients with an isolated locoregional recurrence after primary therapy, surgical resection may sometimes provide a chance of cure. To optimize the chance of local control intraoperative radiation therapy (IORT) has been used. The combination of salvage surgery and IORT has resulted in reasonable control in the IORT field. The addition of external beam radiation to limited volumes seems to result in improved disease control over surgery and IORT alone. Side effects are closely related to radical surgery, although neuropathy is seen more frequently after IORT; especially if doses of >20Gy are prescribed. Margin status remains critical, even with IORT.

Multidisciplinary therapy for patients with locally oligo-recurrent pelvic malignancies

PURPOSE

To analyze prognostic factors and long-term outcomes in patients with locally recurrent pelvic cancer (LRPC) treated with a multidisciplinary approach.

METHODS AND MATERIALS

From January 1995 to December 2011, 81 patients [rectal (47 %); gynecologic (39 %); retroperitoneal sarcoma (14 %)] underwent extended surgery [multiorgan (58 %), bone (35 %), vascular (9 %), soft tissue (63 %)] and intraoperative electron beam radiation therapy (IOERT) to treat recurrent tumors in the pelvic region. Thirty-five patients (43 %) received external beam radiotherapy (EBRT). Survival was estimated using the Kaplan-Meier method, and risk factors were identified using univariate and multivariate analysis.

RESULTS

Median follow-up was 39 months (6-189 months); the 1- 3- and 5-year rates of locoregional control (LRC) were 83, 53, and 41 %, respectively. Univariate Cox proportional hazard analysis revealed worse LRC in patients who did not receive integrated EBRT as rescue treatment of pelvic recurrence (p = 0.003) or underwent non-radical resection (p = 0.01). In the multivariate analysis EBRT, non-radical resection, and tumor fragmentation retained significance (p = 0.002, p = 0.004, and p = 0.05, respectively).

CONCLUSIONS

Radical resection, absence of tumor fragmentation and addition of EBRT for rescue are associated with improved LRC in patients with LRPC. Our results suggest that this group can benefit from EBRT combined with extended surgical resection and IOERT.

Intraoperative Electron Beam Radiotherapy (IOERT) in the management of locally advanced or recurrent cervical cancer

Background

To report outcomes in women with locally recurrent or advanced cervical cancer who received intraoperative electron beam radiotherapy (IOERT) as a component of therapy.

Methods

From 1983 to 2010, 86 patients with locally recurrent (n = 73, 85%) or primary advanced (n = 13, 15%) cervical cancer received IOERT following surgery. Common surgeries included pelvic exenteration (n = 26; 30%) or sidewall resection (n = 22; 26%). The median IOERT dose was 15 Gy (range, 6.25-25 Gy). Sixty-one patients (71%) received perioperative external beam radiotherapy (EBRT; median dose, 45 Gy). Forty-one patients (48%) received perioperative chemotherapy.

Results

Median follow-up was 2.7 years (range, 0.1-25.5 years). Resections were classified as R0 (n = 35, 41%), R1 (n = 30, 35%), or R2 (n = 21, 24%). Cumulative incidences of central (within the IOERT field) and locoregional relapse at 3 years were 23 and 38%, respectively. The 3-year cumulative incidence of distant relapse was 43%. Median survival was 15 months, and 3-year Kaplan-Meier estimates of cause-specific (CSS) and overall survival (OS) were 31 and 25%, respectively. On multivariate analysis, pelvic exenteration (p = 0.02) and perioperative EBRT (p = 0.009) were associated with improved central control in patients with recurrent disease. Recurrence within 6 months of initial therapy was associated with reduced CSS (p = 0.001). Common IOERT-related toxicities included peripheral neuropathy (n = 16), ureteral stenosis (n = 4), and bowel fistula/perforation (n = 4). Eleven of 16 patients with neuropathy required long-term pain medication.

Conclusions

Long-term survival is possible with combined modality therapy including IOERT for advanced cervical cancer. Distant relapse is common, yet a significant number of patients experienced local progression in spite of aggressive treatment. In addition to consideration of disease- and treatment-related morbidity, other factors to be considered when selecting patients for this approach include the time interval from initial therapy to recurrence and whether the patient is able to receive perioperative EBRT and pelvic exenteration in addition to IOERT.

Intraoperative electron beam radiotherapy for primary treatment of stage IIB cervical cancer: a retrospective study

OBJECTIVE

A retrospective study to evaluate intraoperative electron beam radiotherapy (IOERT) as a primary treatment modality for stage IIB cervical squamous cell carcinoma.

METHODS

Patients underwent treatment with IOERT (n = 78) or radical radiotherapy (RT; n = 89). Patients in the IOERT group received 20 Gy external beam radiotherapy (EBRT) in 10 fractions, intracavitary brachytherapy (7-14 Gy, in patients with tumours ≥ 4 cm in diameter) and simple hysterectomy/selective lymphadenectomy with 18 - 20 Gy IOERT. Patients in the RT group received 50 Gy EBRT in 25 fractions followed by intracavitary brachytherapy (35-40 Gy).

RESULTS

Median duration of follow-up was 92 months. IOERT resulted in significantly better 5- and 10-year overall survival, disease-free survival and local control rates, as well as fewer rectal and bladder complications, compared with RT.

CONCLUSION

IOERT is an effective primary treatment for stage IIB cervical squamous cell carcinoma.

Resectability rates of previously irradiated recurrent cervical cancer (PIRCC) treated with pelvic exenteration: is still the clinical involvement of the pelvis wall a real contraindication? a twenty-year experience

OBJECTIVE

(1) To determine the accuracy of a standard clinical and radiological assessment of resectability in patients with previously irradiated recurrent cervical cancer (PIRCC), and (2) to report the outcome and prognostic factors in this high-risk population treated with an exenterative procedure.

METHODS

Forty-eight patients with centrally located (n=20, 41.7%) or lateralized (n=28, 58.3%) PIRCC treated with exenterative procedures were analyzed. All patients underwent standard assessment of resectability with pelvic exam and radiological studies. Patients with centrally located tumors were considered as resectable and lateralized tumors were deemed unresectable.

RESULTS

Complete surgical resection with negative margins (R0) was achieved in 28.6% of the patients with lateral recurrences and in 65.0% of the patients with central recurrences (p<0.019). After a median follow-up of 114.6 months (3.0-244.9 months), the 10-year local control rate for the whole group was 36.3%, 43.1% in the central PIRCC group and 31.5% in the lateral PIRCC group, respectively (p=0.290). Multivariate analysis showed that improved local control was significantly associated with the presence of negative margins (p=0.004). The 10-year distant failure rate was 69%, 56.6% in the central PIRCC group and 83.2% in the lateral PIRCC group (p=0.178), respectively. Multivariate analysis showed that the development of distant metastases was significantly correlated with the absence of local control (p=0.01). The 10-year disease-specific survival (DSS) for central and lateral PIRCC was 27.2% and 14.9%, respectively (p=0.239). Multivariate analysis showed that negative margins (p=0.001), local control (p=0.001) and distant control (p=0.006) were all significantly associated with improved DSS. Location of PIRCC (central vs. lateral) was irrelevant for DSS in completely resected (R0) patients. Overall morbidity rate was 65.0% and 73.3% for central and lateral PIRCC patients, respectively (p=0.528).

CONCLUSION

About one-third of the patients with lateral PIRCC classified as unresectable with non-surgical means may ultimately undergo complete (R0) resections and about one-third of the patients with centrally located PIRCC and judged as resectable will undergo non-curative (R1) resections. A curative (R0) resection significantly impacts local control rates, distant metastases-free rates and DSS.

New developments in the surgical therapy of cervical carcinoma

For almost a century abdominal radical hysterectomy has been the standard surgical treatment of early-stage macroscopic carcinoma of the uterine cervix. The excessive parametrial resection of the original procedures of Wertheim, Okabayashi, and Meigs has later been "tailored" to tumor extent. Systematic pelvic and eventually periaortic lymph node dissection is performed to identify and treat regional disease. Adjuvant (chemo)radiation therapy is liberally added to improve locoregional tumor control when histopathological risk factors are present. The therapeutic index of the current surgical treatment, particularly if combined with radiation, appears to be inferior to that of primary chemoradiation as an oncologically equivalent therapeutic alternative. Several avenues of new conceptual and technical developments have been used since the 1990s with the goal of improving the therapeutic index. These are: surgical staging, including sentinel node biopsy and nodal debulking; minimal access and recently robotic radical hysterectomy; fertility-preserving surgery; nerve-sparing radical hysterectomy; total mesometrial resection based on developmentally defined surgical anatomy; and supraradical hysterectomy. The superiority of these new developments over the standard treatment remains to be demonstrated by controlled prospective trials. Multimodality therapy including surgery for locally advanced disease represents another area of clinical research. Both neoadjuvant chemotherapy followed by radical surgery, with or without adjuvant radiation, and completion surgery after (chemo)radiation are feasible and have to be compared to primary chemoradiation as the new nonsurgical treatment standard. Surgical treatment of postirradiation persisting or recurrent cervical carcinoma has been traditionally limited to pelvic exenteration for central disease. Applying the principle of developmentally derived anatomical compartments increases R0 resectability. The laterally extended endopelvic resection allows even the extirpation of a subset of visceral pelvic side wall tumors with clear margins. Many questions regarding the indication for these "ultraradical" operations, the surgery of irradiated tissues, and the optimal reconstructive procedures are still open and demand multi-institutional controlled trials to be answered.

Long-Term Survivors Using Intraoperative Radiotherapy for Recurrent Gynecologic Malignancies

PURPOSE

To analyze the outcomes of therapy and identify prognostic factors for patients treated with surgery followed by intraoperative radiotherapy (IORT) for gynecologic malignancies at a single institution.

METHODS AND MATERIALS

We performed a retrospective review of 36 consecutive patients treated with IORT to 44 sites with mean follow-up of 50 months. The primary site was the cervix in 47%, endometrium in 31%, vulva in 14%, vagina in 6%, and fallopian tubes in 3%. Previous RT had failed in 72% of patients, and 89% had recurrent disease. Of 38 IORT sessions, 84% included maximal cytoreductive surgery, including 18% exenterations. The mean age was 52 years (range, 30-74), mean tumor size was 5 cm (range, 0.5-12), previous disease-free interval was 32 months (range, 0-177), and mean IORT dose was 1,152 cGy (range, 600-1,750). RT and systemic therapy after IORT were given to 53% and 24% of the cohort, respectively. The outcomes measured were locoregional control (LRC), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and treatment-related complications.

RESULTS

The Kaplan-Meier 5-year LRC, DMFS, and DSS probability for the whole group was 44%, 51%, and 47%, respectively. For cervical cancer patients, the Kaplan-Meier 5-year LRC, DMFS, and DSS estimate was 45%, 60%, and 46%, respectively. The prognostic factors found on multivariate analysis (p <or= 0.05) were the disease-free interval for LRC, tumor size for DMFS, and cervical primary, previous surgery, and locoregional relapse for DSS. Our cohort had 10 Grade 3-4 complications associated with treatment (surgery and IORT) and a Kaplan-Meier 5-year Grade 3-4 complication-free survival rate of 72%.

CONCLUSIONS

Survival for pelvic recurrence of gynecologic cancer is poor (range, 0-25%). IORT after surgery seems to confer long-term local control in carefully selected patients.

Perioperative high-dose-rate brachytherapy in locally advanced and recurrent gynecologic cancer: Initial results of a phase II trial

BACKGROUND

This study was undertaken to determine the feasibility of perioperative high-dose-rate brachytherapy (PHDRB) as an adjunct to salvage surgery in primary advanced or recurrent gynecologic cancer.

METHODS

Twenty-five patients with either locally advanced (n = 4) or recurrent (n = 21) gynecologic cancer suitable for salvage surgery were included. Unirradiated patients were treated with preoperative chemoradiation followed by salvage surgery and PHDRB (R0 and R1 resections receiving 16 or 24 Gy, respectively). Previously irradiated patients were treated with salvage surgery and PHDRB alone with 32 or 40 Gy for R0 or R1 resections, respectively.

RESULTS

Resections were categorized as R0 in 9 patients (36.0%) and R1 in 16 (64.0%). Four previously irradiated patients suffered fatal pelvic bleeding between 8 and 13 months after surgery and PHDRB. After a median follow-up of 20 months (3-55+), the 4-year actuarial local and pelvic controls were 88.1% and 80.8%, respectively. The 4-year distant metastases-free survival was 40.9%. Four-year actuarial overall survival was 34.0%, with a median survival of 27.1 months (95% confidence interval: 17.5-36.8).

CONCLUSIONS

Local and pelvic control results are excellent for this very high-risk-disease population. PHDRB dose in previously irradiated patients has been shifted to the closest lower level due to unacceptable vascular toxicity.

Intraoperative radiation therapy using a mobile electron linear accelerator: field matching for large-field electron irradiation

Intraoperative radiation therapy (IORT) consists of delivering a large, single-fraction dose of radiation to a surgically exposed tumour or tumour bed at the time of surgery. With the availability of a mobile linear accelerator in the OR, IORT procedures have become more feasible for medical centres and more accessible to cancer patients. Often the area requiring irradiation is larger than what the treatment applicators will allow, and therefore, two or more adjoining fields are used. Unfortunately, the divergence and scattering of the electron beams may cause significant dose variations in the region of the field junction. Furthermore, because IORT treatments are delivered in a large single fraction, the effects of underdosing or overdosing could be more critical when compared to fractionated external beam therapy. Proper matching of the fields is therefore an important technical aspect of treatment delivery. We have studied the matching region using the largest flat applicator available for three different possibilities: abutting the fields, leaving a small gap or creating an overlap. Measurements were done using film dosimetry for the available energies of 4, 6, 9 and 12 MeV. Our results show the presence of clinically significant cold spots for the low-energy beams when the fields are either gapped or abutted, suggesting that the fields should be overlapped. No fields should be gapped. The results suggest that an optimal dose distribution may be obtained by overlapping the fields at 4 and 6 MeV and simply abutting the fields at 9 and 12 MeV. However, due to uncertainties in the placement of lead shields during treatment delivery, one may wish to consider overlapping the higher energy fields as well.

intraoperative radiation therapy part 2. Clinical results

Intraoperative radiation therapy (IORT) has been used for over 30 years in Asia, Europe and America as a supplementary activity in the treatment of cancer patients with promising results. Modern IORT is carried out with electron beams (IOERT) produced by a linear accelerator generally used for external beam irradiation (EBRT) or a specialized mobile electron accelerator. HDR brachytherapy (HDR-IORT) has also been applied on selected locations. Retrospective analysis of clinical experiences in cancer sites such as operable pancreatic tumour, locally advanced/recurrent rectal cancer, head and neck carcinomas, sarcomas and cervical cancer are consistent with local tumour control promotion compared to similar clinical experiences without IORT. New emerging indications such as the treatment of breast cancer are presented. The IORT component of the therapeutical approach allows intensification of the total radiation dose without additional exposure of healthy tissues and improves dose-deposit homogeneity and precision. Results of the application of IORT on selected disease sites are presented with an analysis on future possibilities. To improve the methodology, clinical trials are required with multivariate analysis including patient, tumour and treatment characteristics, prospective evaluation of early and late toxicity, patterns of tumour recurrence and overall patient outcome.

Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72

Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT, (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems.

Intraoperative radiotherapy using a mobile electron LINAC: a retroperitoneal sarcoma case

The advent of mobile LINACs for use in intraoperative radiation therapy (IORT) promises to make IORT more accessible than before and easier to deliver to patients undergoing surgery. Although mobile IORT systems have been available since 1999, few treatment centers currently use them. Here, we present the case of a typical patient undergoing IORT for retroperitoneal sarcoma to show how easy these mobile systems are to use and how adaptable they are within the operating room (OR) environment. We also discuss the roles and coordination of multidisciplinary team members during IORT and the feasibility of using mobile LINACs for IORT.

PACS number(s):

Stereotactic boost irradiation for targets in the abdomen and pelvis

Based on the experience of stereotactic irradiation of lung and liver tumors the feasibility of stereotactic boost irradiation to abdominal and pelvic tumors was evaluated. Twenty-one patients with inoperable tumors received a stereotactic boost of 2-3 x 5Gy/PTV-enclosing-100% isodose with normalization to 150% at the isocenter after normofractionated irradiation of 45-50.4Gy. Actuarial local control (16/21 targets) was 96/70% after 12 and 24 months. Treatment was feasible and well tolerated.

Potential of mobile intraoperative radiotherapy technology

Mobile IORT units have the potential to change the way patients who have cancer are treated. The integration of IORT into cancer treatment programs, made possible by the new technologies of mobile linear accelerators that can be used in unshielded operating rooms, makes IORT significantly less time-consuming, less costly, and less risky to administer. It is now practical for IORT to be used in early-stage disease, in addition to advanced disease, and in sites for which patient transportation in the middle of surgery is considered too risky. Preliminary results of trials for early-stage breast and rectal cancer indicate benefits of IORT. Pediatric patients and patients who have lung cancer, previously underserved by IORT therapies, can be offered potential gains when patient transport issues do not limit IORT. Furthermore, because many of these mobile systems require no shielding, it is now practical for mobile units to be shared between hospitals, making this new mobile technology much more widely available.