Extended-field Intensity-modulated Radiation Therapy Research Articles

Adaptive extended-field intensity-modulated radiation therapy with simultaneously integrated boost for locally advanced cervical cancer with lymph node metastases

Performing external beam radiotherapy alone without chemotherapy or brachytherapy for locally advanced cervical cancer with multiple lymph node metastases is challenging. The purpose of this case report is to present the efficacy of high-dose adaptive extended-field intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) in treating locally advanced cervical cancer with multiple lymph node metastases. A 67-year-old woman with locally advanced squamous cell carcinoma of the uterine cervix was treated by external beam radiotherapy alone due to the refusal of chemotherapy and intracavitary brachytherapy. In order to maximize the efficacy of treatment, extended-field radiotherapy that includes the paraaortic lymph nodes as well as an adaptive IMRT-SIB plan, was applied. The treatment was successful, resulting in complete tumor disappearance without severe adverse events. In conclusion, high-dose adaptive IMRT-SIB may be an alternative treatment option for locally advanced cervical cancer with multiple lymph node metastases.

Clinical Observation of Prophylactic Extended-Field Intensity-Modulated Radiation Therapy with Synchronous Chemotherapy in Locally Advanced Cervical Cancer.

BackgroundWe aimed to evaluate the value of prophylactic extended-field intensity-modulated radiation therapy (IMRT) in the treatment of locally advanced cervical cancer with multiple pelvic lymph node metastases (≥2) and negative common iliac and paraaortic lymph nodes.Material/MethodsThirty-four patient with newly diagnosed cervical cancer (IB1-IVA) and multiple pelvic lymph node metastases (≥2) confirmed by computed tomography and magnetic resonance imaging were randomly divided into an extended-field group (17 patients) and a pelvic-field group (17 patients). In the extended-field group, we added the drainage area of paraaortic lymph nodes on the pelvic field. The pelvic field was administered Dt 45.0 to 50.4 Gy, while the drainage area of paraaortic lymph nodes was administered Dt 40.0 to 45.0 Gy. Both groups were given IrI92 intracavitary radiotherapy after 3 weeks of external irradiation. The total dose of point A was 25.0 to 30.0 Gy, fractional 6.0 to 7.0 Gy. All patients had concurrent platinum-based chemotherapy once weekly until the end of radiotherapy.ResultsNo paraaortic lymph node metastasis was found in the extended-field group (P=0.0184), and disease-free survival (DFS) was prolonged (P=0.0286). Adverse effects in patients with III–IV degree myelosuppression were increased in the extended-field group (P=0.0324). However, all patients recovered after symptomatic treatment.ConclusionsProphylactic extended-field IMRT with chemotherapy reduced the metastasis rate of paraaortic lymph nodes and prolonged the DFS in patients with locally advanced cervical cancer and multiple pelvic lymph node metastases (≥2), while the toxic adverse effects were tolerated.

Dosimetric predictors of nephrotoxicity in patients receiving extended-field radiation therapy for gynecologic cancer

PurposeWe sought dosimetric predictors of a decreasing estimated glomerular filtration rate (eGFR) in gynecological oncology patients receiving extended-field radiation therapy (EFRT).Materials and methodsBetween July 2012 and April 2020, 98 consecutive cervical or endometrial cancer patients underwent EFRT or whole-pelvis radiation therapy (WPRT) with concurrent cisplatin chemotherapy in our institution. To explore the effect of concurrent cisplatin chemotherapy on renal function, the renal function of the WPRT patients was examined. Of the 98 patients, 34 cervical or endometrial cancer patients underwent EFRT including extended-field intensity-modulated radiation therapy (EF-IMRT) and 64 cervical cancer patients underwent WPRT with cisplatin. Of the 34 EFRT patients, 32 underwent concurrent cisplatin chemotherapy. Excluding patients exhibiting recurrences within 6 months, 31 EFRT patients were analyzed in terms of the dose-volume kidney histograms (the percentages of kidney volumes receiving 12, 16, 20, and 24 Gy) and the post- to pre-treatment eGFR ratios. We calculated Pearson correlation coefficients between the renal dose volume and the percentage eGFR reductions of the 31 EFRT patients, and those treated via EF-IMRT. Renal dose constraint significance was evaluated using the Mann–Whitney U test.ResultsThe eGFR value after WPRT with cisplatin remained largely unchanged for 12 months, unlike that after EFRT. In EFRT patients, a strong correlation was evident between the KV20Gy dose and the post- to pre-treatment eGFR ratio (correlation coefficients − 0.80 for all patients and − 0.74 for EF-IMRT patients). In EF-IMRT patients, the kidney volume receiving 20 Gy tended to correlate negatively with the eGFR reduction. The Mann–Whitney U test showed that patients with KV20Gy values < 10% retained significantly better renal function than did patients with KV20Gy values > 10% (P = 0.002).ConclusionsImposition of a severe kidney dose constraint during EF-IMRT may reduce nephrotic toxicity. Future prospective investigations of kidney-sparing EF-IMRT are required.

Early clinical experience with varian halcyon V2 linear accelerator: Dual-isocenter IMRT planning and delivery with portal dosimetry for gynecological cancer treatments.

PurposeVarian Halcyon linear accelerator version 2 (The Halcyon 2.0) was recently released with new upgraded features. The aim of this study was to report our clinical experience with Halcyon 2.0 for a dual‐isocenter intensity‐modulated radiation therapy (IMRT) planning and delivery for gynecological cancer patients and examine the feasibility of in vivo portal dosimetry.MethodsTwelve gynecological cancer patients were treated with extended‐field IMRT technique using two isocenters on Halcyon 2.0 to treat pelvis and pelvic/or para‐aortic nodes region. The prescription dose was 45 Gy in 25 fractions (fxs) with simultaneous integrated boost (SIB) dose of 55 or 57.5 Gy in 25 fxs to involved nodes. All treatment plans, pretreatment patient‐specific QA and treatment delivery records including daily in vivo portal dosimetry were retrospectively reviewed. For in vivo daily portal dosimetry analysis, each fraction was compared to the reference baseline (1st fraction) using gamma analysis criteria of 4 %/4 mm with 90% of total pixels in the portal image planar dose.ResultsAll 12 extended‐field IMRT plans met the planning criteria and delivered as planned (a total of 300 fractions). Conformity Index (CI) for the primary target was achieved with the range of 0.99–1.14. For organs at risks, most were well within the dose volume criteria. Treatment delivery time was from 5.0 to 6.5 min. Interfractional in vivo dose variation exceeded gamma analysis threshold for 8 fractions out of total 300 (2.7%). These eight fractions were found to have a relatively large difference in small bowel filling and SSD change at the isocenter compared to the baseline.ConclusionHalcyon 2.0 is effective to create complex extended‐field IMRT plans using two isocenters with efficient delivery. Also Halcyon in vivo dosimetry is feasible for daily treatment monitoring for organ motion, internal or external anatomy, and body weight which could further lead to adaptive radiation therapy.

Extended-field intensity-modulated radiation therapy combined with concurrent chemotherapy for cervical cancer with para-aortic lymph nodes metastasis.

This study was conducted to evaluate the efficacy and toxicity of extended-field intensity-modulated radiation therapy combined with concurrent chemotherapy in patients with cervical cancer with positive para-aortic lymph nodes (PALN). From September 2007 to December 2014, a total of 59 patients who had cervical cancer with para-aortic lymph node metastasis were treated with concurrent chemoradiotherapy at our institution. A dose of 45-50.4 Gy in 25-28 fractions with extended-field intensity-modulated radiation therapy was prescribed to planning target volume, and a dose of 30-36 Gy in 5-6 fractions was prescribed to Point A with high-dose-rate brachytherapy. A concurrent first-line cisplatin-based chemotherapy regimen was used. The median duration of follow-up was 32.1 months (range, 3.2-103.7 months). The 2- and 3-year overall survival, disease-free survival and local control rates were 69.0 and 52.8%, 45.0 and 41.3% and 83.4 and 81.0%, respectively. Distant metastasis was the major pattern of treatment failure, which occurred in 26 patients (44.1%). The incidence of Grade 3 or greater acute hematologic, gastrointestinal and genitourinary toxicity was 50.9, 1.7 and 3.4%, respectively. Only one patient had both Grade 3 late gastrointestinal and genitourinary toxicity. The study found that extended-field intensity-modulated radiation therapy combined with concurrent chemotherapy was safe and effective in patients who had cervical cancer with positive PALN.

Extended-Field Intensity Modulated Radiation Therapy (EF-IMRT)and Intra-Cavitary Brachytherapy Combined with Chemotherapy in Cervical Cancer: A Multicenter-Clinical Trial

Extended-Field Intensity Modulated Radiation Therapy (EF-IMRT)and Intra-Cavitary Brachytherapy Combined with Chemotherapy in Cervical Cancer: A Multicenter-Clinical Trial

Prognostic analysis of extended field intensity-modulated radiation therapy for cervical cancer

In recent decades, accurate radiotherapy has developed rapidly, and the application of intensity-modulated radiation therapy (IMRT) in gynecologic malignancies has increased gradually in the past ten years. Many studies have shown a high rate of occult abdominal aortic lymph node metastasis in patients with advanced cervical cancer, while pelvic and abdominal aortic lymph node status are important prognostic factors in cervical cancer patients. Conventional prophylactic extended field radiotherapy has the characteristics of severe gastrointestinal side effects, and synchronic chemotherapy is also controversial. The optimal dose of radiation therapy for metastatic pelvic and abdominal aortic lymph nodes is still controversial. This paper mainly analyzed the effect of prophylactic extended conformal radiotherapy with concurrent chemotherapy on the prognosis of cervical cancer and the dose-effect relationship of lymph node positive region. Key words: Cervical neoplasm/intensity modulated radiation therapy; Extended field radiotherapy; Concurrent chemotherapy; Lymph node; Survival rate

Kidney-Sparing Methods for Extended-Field Intensity-Modulated Radiotherapy (EF-IMRT) in Cervical Carcinoma Treatment.

Coplanar extended-field intensity-modulated radiation therapy (EF-IMRT) targeting the whole-pelvic and para-aortic lymph nodes in patients with advanced cervical cancer results in impaired creatinine clearance. An improvement in renal function cannot be expected unless low-dose (approximately 10 Gy) kidney exposure is reduced. The dosimetric method should be considered during EF-IMRT planning to further reduce low-dose exposure to the kidneys. To assess the usefulness of non-coplanar EF-IMRT with kidney-avoiding beams to spare the kidneys during cervical carcinoma treatment in dosimetric analysis between non-coplanar and coplanar EF-IMRT, we compared the doses of the target organ and organs at risk, including the kidney, in 10 consecutive patients. To estimate the influence of EFRT on renal dysfunction, creatinine clearance values after treatment were also examined in 18 consecutive patients. Of these 18 patients, 10 patients who were included in the dosimetric analysis underwent extended field radiation therapy (EFRT) with concurrent chemotherapy, and eight patients underwent whole-pelvis radiation therapy with concurrent chemotherapy to treat cervical carcinoma between April 2012 and March 2015 at our institution. In the dosimetric analysis, non-coplanar EF-IMRT was effective at reducing low-dose (approximately 10 Gy) exposure to the kidneys, thus maintaining target coverage and sparing other organs at risk, such as the small bowel, rectum, and bladder, compared with coplanar EF-IMRT. Renal function in all 10 patients who underwent EFRT, including coplanar EF-IMRT (with kidney irradiation), was low after treatment, and differed significantly from that of the eight patients who underwent WPRT (no kidney irradiation) 6 months after the first day of treatment (P = 0.005). In conclusion, non-coplanar EF-IMRT should be considered in patients with advanced cervical cancer, particularly in patients with a long life expectancy or with pre-existing renal dysfunction.

Split-field vs extended-field intensity-modulated radiation therapy plans for oropharyngeal cancer: Which spares the larynx? Which spares the thyroid?

Radiation of the low neck can be accomplished using split-field intensity-modulated radiation therapy (sf-IMRT) or extended-field intensity-modulated radiation therapy (ef-IMRT). We evaluated the effect of these treatment choices on target coverage and thyroid and larynx doses. Using data from 14 patients with cancers of the oropharynx, we compared the following 3 strategies for radiating the low neck: (1) extended-field IMRT, (2) traditional split-field IMRT with an initial cord-junction block to 40Gy, followed by a full-cord block to 50Gy, and (3) split-field IMRT with a full-cord block to 50Gy. Patients were planned using each of these 3 techniques. To facilitate comparison, extended-field plans were normalized to deliver 50Gy to 95% of the neck volume. Target coverage was assessed using the dose to 95% of the neck volume (D95). Mean thyroid and larynx doses were computed. Extended-field IMRT was used as the reference arm; the mean larynx dose was 25.7 ± 7.4Gy, and the mean thyroid dose was 28.6 ± 2.4Gy. Split-field IMRT with 2-step blocking reduced laryngeal dose (mean larynx dose 15.2 ± 5.1Gy) at the cost of a moderate reduction in target coverage (D95 41.4 ± 14Gy) and much higher thyroid dose (mean thyroid dose 44.7 ± 3.7Gy). Split-field IMRT with initial full-cord block resulted in greater laryngeal sparing (mean larynx dose 14.2 ± 5.1Gy) and only a moderately higher thyroid dose (mean thyroid dose 31 ± 8Gy) but resulted in a significant reduction in target coverage (D95 34.4 ± 15Gy). Extended-field IMRT comprehensively covers the low neck and achieves acceptable thyroid and laryngeal sparing. Split-field IMRT with a full-cord block reduces laryngeal doses to less than 20Gy and spares the thyroid, at the cost of substantially reduced coverage of the low neck. Traditional 2-step split-field IMRT similarly reduces the laryngeal dose but also reduces low-neck coverage and delivers very high doses to the thyroid.

Extended field intensity modulated radiation therapy for gynecologic cancers: Is the risk of duodenal toxicity high?

PurposeThere have been conflicting reports regarding the incidence of duodenal toxicity in patients receiving intensity modulated radiation therapy (IMRT) with an extended field covering the para-aortic (PA) lymph nodes for gynecologic cancers. We reviewed our experiences and rates of duodenal toxicity in patients treated with extended field IMRT. Methods and materialsPatients with either cervical or endometrial cancer who were treated with IMRT to the PA nodes for involved lymph nodes or for prophylactic intent between 2005 and 2013 were included. For prophylactic intent, the radiation dose to the PA nodes was 45 Gy in 25 fractions. For involved lymph nodes, a boost was delivered to the gross disease with a 0.7-cm expansion, with editing for critical structures. The entire duodenum was retrospectively contoured on all patients from the gastric outlet to the jejunal transition. ResultsWe identified 76 eligible patients with endometrial and cervical cancer. The PA region was treated prophylactically in 46.1% (n = 35) and for involved PA lymph nodes in 53.9% (n = 41). The duodenum was contoured on all patients with a median volume of 83.2 cm3 (range, 21.2-174.9 cm3). The mean volume of duodenum receiving 55 Gy (V55) for those treated prophylactically and for involved PA nodes was 0 cm3 and 0.8 cm3 (range, 0-10.6 cm3), respectively (P = .014). Specifically, no patient had a V55 >15 cm3. The mean V40 was 28.3 cm3 (range, 0-77.3 cm3) and 41.4 (range, 0-90.0 cm3), respectively (P = .016). The mean dose delivered to 2 cm3 of the duodenum was 34.9 Gy (range, 0-52.3 Gy) and 50.1 Gy (range, 31.3 - 58.3 Gy), respectively. Grade 3 acute gastrointestinal toxicity was recorded in 3.9% (n = 3) of patients. ConclusionsIn our experience, the treatment of PA lymph nodes using an IMRT technique is associated with a low duodenal toxicity profile and there has been no high-grade late duodenal toxicity.

Extended Field Intensity Modulated Radiation Therapy With Concomitant Boost for Lymph Node–Positive Cervical Cancer: Analysis of Regional Control and Recurrence Patterns in the Positron Emission Tomography/Computed Tomography Era

Positron emission tomography/computed tomography (PET/CT) is commonly used for nodal staging in locally advanced cervical cancer; however the false negative rate for para-aortic disease are 20% to 25% in PET-positive pelvic nodal disease. Unless surgically staged, pelvis-only treatment may undertreat para-aortic disease. We have treated patients with PET-positive nodes with extended field intensity modulated radiation therapy (IMRT) to address the para-aortic region prophylactically with concomitant boost to involved nodes. The purpose of this study was to assess regional control rates and recurrence patterns. Sixty-one patients with cervical cancer (stage IBI-IVA) diagnosed from 2003 to 2012 with PET-avid pelvic nodes treated with extended field IMRT (45 Gy in 25 fractions with concomitant boost to involved nodes to a median of 55 Gy in 25 fractions) with concurrent cisplatin and brachytherapy were retrospectively analyzed. The nodal location was pelvis-only in 41 patients (67%) and pelvis + para-aortic in 20 patients (33%). There were a total of 179 nodes, with a median number of positive nodes of 2 (range, 1-16 nodes) per patient and a median nodal size of 1.8 cm (range, 0.7-4.5 cm). Response was assessed by PET/CT at 12 to 16 weeks. Complete clinical and imaging response at the first follow-up visit was seen in 77% of patients. At a mean follow-up time of 29 months (range, 3-116 months), 8 patients experienced recurrence. The sites of persistent/recurrent disease were as follows: cervix 10 (16.3%), regional nodes 3 (4.9%), and distant 14 (23%). The rate of para-aortic failure in patients with pelvic-only nodes was 2.5%. There were no significant differences in recurrence patterns by the number/location of nodes, largest node size, or maximum node standardized uptake value. The rate of late grade 3+ adverse events was 4%. Extended field IMRT was well tolerated and resulted in low regional recurrence in node-positive cervical cancer. The dose of 55 Gy in 25 fractions was effective in eradicating disease in involved nodes, with acceptable late adverse events. Distant metastasis is the predominant mode of failure, and the OUTBACK trial may challenge the presented paradigms.

High-Dose and Extended-Field Intensity Modulated Radiation Therapy for Early-Stage NK/T-Cell Lymphoma of Waldeyer's Ring: Dosimetric Analysis and Clinical Outcome

To assess the dosimetric benefit, treatment outcome, and toxicity of high-dose and extended-field intensity modulated radiation therapy (IMRT) in patients with early-stage NK/T-cell lymphoma of Waldeyer's ring (WR-NKTCL). Thirty patients with early-stage WR-NKTCL who received extended-field IMRT were retrospectively reviewed. The prescribed dose was 50 Gy to the primary involved regions and positive cervical lymph nodes (planning target volume requiring radical irradiation [PTV50]) and 40 Gy to the negative cervical nodes (PTV40). Dosimetric parameters for the target volume and critical normal structures were evaluated. Locoregional control (LRC), overall survival (OS), and progression-free survival (PFS) were calculated using the Kaplan-Meier method. The median mean doses to the PTV50 and PTV40 were 53.2 Gy and 43.0 Gy, respectively. Only 1.4% of the PTV50 and 0.9% of the PTV40 received less than 95% of the prescribed dose, indicating excellent target coverage. The average mean doses to the left and right parotid glands were 27.7 and 28.4 Gy, respectively. The 2-year OS, PFS, and LRC rates were 71.2%, 57.4%, and 87.8%. Most acute toxicities were grade 1 to 2, except for grade ≥3 dysphagia and mucositis. The most common late toxicity was grade 1-2 xerostomia, and no patient developed any ≥grade 3 late toxicities. A correlation between the mean dose to the parotid glands and the degree of late xerostomia was observed. IMRT achieves excellent target coverage and dose conformity, as well as favorable survival and locoregional control rates with acceptable toxicities in patients with WR-NKTCL.

Extended-field intensity modulated radiation therapy and intra-cavitary brachytherapy combined with chemotherapy for stage Ib1-IVa cervical cancer with positive para-aortic lymph nodes

To investigate the treatment effects and toxicities of extended-field intensity modulated radiation therapy (EF-IMRT) and intra-cavitary brachytherapy combined with chemotherapy for stageIb1-IVa cervical cancer with positive para-aortic lymph nodes. A total of 46 stage Ib1-IVa cervical cancer patients with positive para-aortic lymph nodes treated at Fudan University Shanghai Cancer Center between 2009 and 2011 were reviewed. Neoadjuvant, concomitant and adjuvant chemotherapy with paclitaxel and carboplatin were administrated for one cycle before radiation therapy, two cycles during radiation therapy or three cycles after radiation therapy. All patients received EF-IMRT and intra-cavitary brachytherapy. The positive lymph nodes received an additional boost dose. All patients received EF-IMRT to 50.4 Gy (1.8 Gy per fraction). Twenty-six patients was treated with boost dose of 6.0-8.0 Gy in 2.0 Gy per fraction to positive para-aortic lymph nodes. Thirty-seven patients received a positive para-aortic lymph nodes boost or (and) parametrial boost. All patient also received a high-dose-rate intra-cavitary brachytherapy at the point "A" dose of 20.0-30.0 Gy in 5.0 Gy per fraction. Total chemotherapy cycles were 189, and the average patient received 4.1 courses. Two cases (4%, 2/46) experienced grade III gastrointestinal toxicities, no patients suffered grade IV gastrointestinal toxicities. Fifteen cases (33%, 15/46) experienced grade III hematological toxicities, and 3(7%, 3/46) experienced grade IV hematological toxicities.Late grade III-IV toxicity was seen in 3 cases (7%, 3/46). The 3 year progression- free survival rate was 46.2%, and the 3 years overall survival rate was 61.2%. EF-IMRT and intra-cavitary brachytherapy combined with chemotherapy is safe and effective for stageIb1-IVa cervical cancer with positive para-aortic lymph nodes.

Outcomes for Patients With Cervical Cancer Treated With Extended-Field Intensity-Modulated Radiation Therapy and Concurrent Cisplatin

To evaluate disease outcomes and toxicity in patients with cervical cancer treated with extended-field intensity-modulated radiotherapy. We included all patients treated with extended-field intensity-modulated radiotherapy and concurrent weekly cisplatin from 2003 to 2010 at 2 institutions. Overall survival and disease-free survival were estimated using Kaplan-Meier method. Locoregional failure (LRF), distant failure, and competing mortality were calculated using cumulative incidence functions. Acute and late toxicity were graded using Common Terminology Criteria for Adverse Events (CTCAE) and Radiation Therapy Oncology Group late radiation morbidity scoring criteria, respectively. The study included 21 patients, 14 and 20 of which had positive para-aortic and pelvic nodes, respectively. The median follow-up was 22 months. Eighteen-month overall survival and disease-free survival were 59.7% (95% confidence interval [CI], 41.2%-86.4%) and 42.9% (95% CI, 26.2%-70.2%). Eighteen-month cumulative incidences of LRF, distant failure, and competing mortality were 9.5% (95% CI, 1.5-26.8%), 42.9% (95% CI, 21.3-62.9%), and 4.8% (95% CI, 0.3-20.2%), respectively. Eighteen-month cumulative incidences of late grade 3 or higher-grade genitourinary and gastrointestinal toxicity were 4.8% (95% CI, 0.2%-20.3%) and 0%, respectively. Intensity-modulated extended-field radiotherapy was associated with low rates of late toxicity and LRF. High rates of distant failure indicate that this group of patients could benefit from intensified systemic therapy.

Duodenal and Other Gastrointestinal Toxicity in Cervical and Endometrial Cancer Treated With Extended-Field Intensity Modulated Radiation Therapy to Paraaortic Lymph Nodes

To characterize the rates of acute and late duodenal and other gastrointestinal (GI) toxicities among patients treated for cervical and endometrial cancers with extended-field intensity modulated radiation therapy (EF-IMRT) to the paraaortic nodes and to analyze dose-volume relationships of GI toxicities. Fifty-three patients with endometrial or cervical cancer underwent EF-IMRT to the paraaortic nodes, of whom 46 met the inclusion criteria for GI toxicity and 45 for duodenal toxicity analysis. The median prescribed dose to the paraaortic nodes was 54 Gy (range, 41.4-65 Gy). The 4 duodenal segments, whole duodenum, small bowel loops, peritoneum, and peritoneum plus retroperitoneal segments of colon were contoured retrospectively, and dosimetric analysis was performed to identify dose-volume relationships to grade ≥3 acute (<90 day) and late (≥90 day) GI toxicity. Only 3/46 patients (6.5%) experienced acute grade ≥3 GI toxicity and 3/46 patients (6.5%) experienced late grade ≥3 GI toxicity. The median dose administered to these 6 patients was 50.4 Gy. One of 12 patients who received 63 to 65 Gy at the level of the renal hilum experienced grade 3 GI toxicity. Dosimetric analysis of patients with and without toxicity revealed no differences between the mean absolute or fractional volumes at any 5-Gy interval between 5 Gy and the maximum dose. None of the patients experienced duodenal toxicity. Treatment of paraaortic nodes with IMRT is associated with low rates of GI toxicities and no duodenal-specific toxicity, including patients treated with concurrent chemotherapy. This technique may allow sufficient dose sparing of the bowel to enable safe dose escalation to at least 65 Gy.

Correlation between Bone Marrow Dose and Acute Hematologic Toxicity in Cervical Cancer Patients Treated with Chemoradiotherapy: Implications for Extended-Field Intensity Modulated Radiation Therapy

Previous studies have found associations between acute hematologic toxicity (HT) and the volume of pelvic bone marrow (BM) receiving > = 10 and 20 Gy (V10 and V20) in patients undergoing pelvic intensity modulated radiation therapy (IMRT). However, BM dosimetric guidelines for extended-field IMRT (EF-IMRT) are lacking. The purpose of this study was to determine if dosimetric parameters of the extended BM volume, including all lumbar vertebrae, are correlated with HT.

Phase I study of extended field intensity modulated radiation therapy (EF-IMRT) and docetaxel in patients with node-positive prostate cancer

e16154 Background: Treatment for patients with node positive prostate cancer remains challenging. With hormonal ablation therapy (HAT), conventional radiation doses to the lymph nodes produces few cures or long-term remissions, likely due to suboptimal doses and/or fields of radiation. Docetaxel has radiosensitizing properties. We conducted a phase I study combining HAT with EF-IMRT and concurrent docetaxel in men with biopsy-proven node positive prostate cancer. Methods: Eligible patients had biopsy proven N1M0 disease and adequate hematologic and hepatic function. All subjects received neoadjuvant HAT (bicalutamide 50 mg/d with an LHRH agonist) for at least 2 months but less than 13 months prior to EF-IMRT and continued for 2 years after completion of radiation (bicalutamide discontinued at the end of radiation). EF-IMRT target doses: prostate 81.0 Gy/45 fractions; intraprostatic target 81.0 - 84.6 Gy/45 fractions; pathologically involved lymph node 72 Gy/43 fractions; pelvic lymph nodes 54.0 Gy to 70.2 Gy/43 fractions. Ultrasound targeting and a water filled rectal catheter balloon were used daily to minimize movement and locate the prostate. Weekly docetaxel was administered during radiation at 5, 10 or 17 mg/m2. The primary endpoint was determining grade III/IV toxicity. Results: Nine patients have been treated. No grade III/IV toxicities occurred within the defined observation period. All subjects received their prescribed radiation and chemotherapy doses. One patient developed an anal fissure and one patient had tachyarrhythmias about 6 months after radiation. Seven of 9 patients are now beyond the 2 year post-radiation period; 4 patients remain in remission; one patient developed primary lung cancer; another was lost to follow up at 1 year post-radiation and 3 had relapsed disease within the 2 year post-radiation window. Conclusions: The addition of weekly docetaxel to EF-IMRT along with HAT is well tolerated in patients with node positive prostate cancer. Phase II studies are warranted based on these results. [Table: see text]

Preliminary outcome and toxicity report of extended-field, intensity-modulated radiation therapy for gynecologic malignancies

The aim of this article is to report a preliminary analysis of our initial clinical experience with extended-field intensity-modulated radiotherapy for gynecologic malignancies. Between November 2002 and May 2005, 13 women with gynecologic malignancies were treated with extended-field radiation therapy. Of the women, 7 had endometrial cancer, 4 cervical cancer, 1 recurrent endometrial cancer, and 1 suspected cervical cancer. All women underwent computed tomography planning, with the upper vagina, parametria, and uterus (if present) contoured within the CTV. In addition, the clinical target volume contained the pelvic and presacral lymph nodes as well as the para-aortic lymph nodes. All acute toxicity was scored according to the Common Terminology Criteria for Adverse Events (CTCAE v 3.0). All late toxicity was scored using the Radiation Therapy Oncology Group late toxicity score. The median follow-up was 11 months. Extended-field intensity-modulated radiation therapy (IMRT) for gynecologic malignancies was well tolerated. Two patients experienced Grade 3 or higher toxicity. Both patients were treated with concurrent cisplatin based chemotherapy. Neither patient was planned with bone marrow sparing. Eleven patients had no evidence of late toxicity. One patient with multiple previous surgeries experienced a bowel obstruction. One patient with bilateral grossly involved and unresectable common iliac nodes experienced bilateral lymphedema. Extended-field-IMRT achieved good local control with only 1 patient, who was metastatic at presentation, and 1 patient not able to complete treatment, experiencing in-field failure. Extended-field IMRT is safe and effective with a low incidence of acute toxicity. Longer follow-up is needed to assess chronic toxicity, although early results are promising.

Evaluation of dose to the brachial plexus using intensity modulated radiation therapy for treatment of head and neck cancer

At our institution, intensity modulated radiation therapy (IMRT) is used to treat many patients receiving radiation therapy for head and neck cancer. In order to avoid inherent problems with matching fields, we currently treat with an extended field IMRT technique encompassing the primary tumor, neck, and supraclavicular fossa. Although this approach improves target coverage, dose imhomongeneities may increase the dose to unidentified normal structures such as the brachial plexus. The purpose of this study is to retrospectively analyze the radiation dose to the brachial plexus using this extended field IMRT technique. Sixteen patients treated definitively with IMRT for head and neck cancer from 2000–2004 were selected for this retrospective study. Primary sites included oropharynx (8), nasopharynx (7), and paranasal sinus (1). Nodal involvement was bilateral in 6 cases, unilateral in 7, and absent in 3. All patients were treated with prescription doses of 70 Gy to the GTV and 59.4 Gy to the CTV1 in 33 fractions with a planning goal of 95% target coverage with the prescription dose. A commercial IMRT treatment planning system (CORVUS, NOMOS) was used to generate each plan. The brachial plexus volumes were not delineated during the initial planning, and the dose to the brachial plexus was not calculated. The brachial plexus volume of each patient was contoured for this study, and a dose volume histogram of the brachial plexus was generated based the dose distribution of the original treatment plan. The median prescription isodose line was 86% (range 81–89, mean 86). The median percent of the GTV receiving greater than 77 Gy was 17% (range 2–50, mean 16), and the median percent of the CTV1 receiving greater than 70 Gy was 24% (range 14–41, mean 25). Maximum point doses to the plexus ranged from 61.7 to 78.5 Gy (median 68.5, mean 69.6). Median volume of the brachial plexus receiving greater than 60 Gy was 1.71 cc (range 0.22–9.45, mean 2.38). No difference in dose was seen based on location of the primary tumor. The median maximum point dose was higher when the plexus was adjacent to grossly positive nodes, 71.9 Gy, than when it was adjacent to node negative regions, 65.7 Gy. The median volumes receiving greater than 60 Gy were 2.95 cc and 0.84 cc, respectively. No cases of brachial plexopathy have been documented to date in these patients. The use of extended field IMRT for definitive treatment of head and neck cancer can result in high point doses to the brachial plexus if this structure is not outlined as a restricted volume during planning. The dose to the brachial plexus is highest ipsilateral to positive neck nodes, reflecting the close proximity of nodal regions to the brachial plexus. Attention should be paid to the location of the brachial plexus when drawing treatment volumes to minimize dose to this structure

Methods of reducing skin toxicity due to extended-field intensity-modulated radiation therapy (EF-IMRT) for the treatment of head and neck cancers

Methods of reducing skin toxicity due to extended-field intensity-modulated radiation therapy (EF-IMRT) for the treatment of head and neck cancers