Radiation myelopathy: estimates of risk in 1048 patients in three randomized trials of palliative radiotherapy for non-small cell lung cancer. The Medical Research Council Lung Cancer Working Party

Obtaining organ-specific radiobiological parameters from clinical data for radiation therapy planning of head and neck cancers

Objective.Different radiation therapy (RT) strategies, e.g. conventional fractionation RT (CFRT), hypofractionation RT (HFRT), stereotactic body RT (SBRT), adaptive RT, and re-irradiation are often used to treat head and neck (HN) cancers. Combining and/or comparing these strategies requires calculating biological effective dose (BED). The purpose of this study is to develop a practical process to estimate organ-specific radiobiologic model parameters that may be used for BED calculations in individualized RT planning for HN cancers.Approach.Clinical dose constraint data for CFRT, HFRT and SBRT for 5 organs at risk (OARs) namely spinal cord, brainstem, brachial plexus, optic pathway, and esophagus obtained from literature were analyzed. These clinical data correspond to a particular endpoint. The linear-quadratic (LQ) and linear-quadratic-linear (LQ-L) models were used to fit these clinical data and extract relevant model parameters (alpha/beta ratio, gamma/alpha,dTand BED) from the iso-effective curve. The dose constraints in terms of equivalent physical dose in 2 Gy-fraction (EQD2) were calculated using the obtained parameters.Main results.The LQ-L and LQ models fitted clinical data well from the CFRT to SBRT with the LQ-L representing a better fit for most of the OARs. The alpha/beta values for LQ-L (LQ) were found to be 2.72 (2.11) Gy, 0.55 (0.30) Gy, 2.82 (2.90) Gy, 6.57 (3.86) Gy, 5.38 (4.71) Gy, and the dose constraint EQD2 were 55.91 (54.90) Gy, 57.35 (56.79) Gy, 57.54 (56.35) Gy, 60.13 (59.72) Gy and 65.66 (64.50) Gy for spinal cord, optic pathway, brainstem, brachial plexus, and esophagus, respectively. Additional two LQ-L parametersdTwere 5.24 Gy, 5.09 Gy, 7.00 Gy, 5.23 Gy, and 6.16 Gy, and gamma/alpha were 7.91, 34.02, 8.67, 5.62 and 4.95.Significance.A practical process was developed to extract organ-specific radiobiological model parameters from clinical data. The obtained parameters can be used for biologically based radiation planning such as calculating dose constraints of different fractionation regimens.

Feasibility and safety of shortened hypofractionated high-dose palliative lung radiotherapy – A retrospective planning study

OBJECTIVE

Assess the safety and feasibility of shortened hypofractionated high-dose palliative lung radiotherapy in a retrospective planning study.

METHODS

Fifteen late stage (III or IV) NSCLC lung radiotherapy patients previously treated with the standard palliative 36 Gy in 12 fractions (12F) schedule were non-randomly selected to achieve a representative distribution of tumour sizes, volumes, and location. Plans were produced using 30 Gy in 5 fractions (5F) and 6 fractions (6F) using a 6MV FFF co-planar VMAT technique. Plans were optimised to meet dose-constraints for planning target volumes (PTVs) and organs at risk (OARs) with established OAR constraints expressed as biological equivalent doses (BEDs). The potential safety was assessed using these BEDs and also with reductions of 10% (BED-10%) and 20% (BED-20%) to account for a reduction in tolerance doses from the effects of chemotherapy or surgery.

RESULTS

Mandatory BED constraints were met for all fifteen 5F and 6F plans; BED-10% constraints were met by all 6F plans and six 5F plans. BED-20% constraints were met by six 6F and three 5F respectively.

CONCLUSION

It is potentially safe and feasible to deliver high-dose palliative radiotherapy for late stage NSCLC using the 5F or 6F regimes described, when planned to comparable OAR BEDs as standard radical techniques. It appears toxicity from these regimes should be within acceptable limits provided the dose-constraints described are met. A Phase II study is required to fully assess safety and feasibility, the outcomes of which could reduce the number of patient hospital visits for radiotherapy, thereby benefiting patients and optimising resource utilisation.

Radiation myelitis after pembrolizumab administration, with favorable clinical evolution and safe rechallenge: a case report and review of the literature

Background

Neurologic complications as myelitis are very rare but extremely deleterious adverse effects of both immunotherapy and radiotherapy. Many recent studies have focused on the possible synergy of these two treatment modalities due to their potential to enhance each other’s immunomodulatory actions, with promising results and a safe tolerance profile.

Case presentation

We report here the case of a 68-year-old man with metastatic non-small-cell lung cancer (NSCLC) who developed myelitis after T12-L2 vertebral radiotherapy, with motor deficit and sphincter dysfunction, while on treatment with pembrolizumab (an immune checkpoint inhibitor). The spinal abnormalities detected by magnetic resonance imaging (MRI), suggestive of myelitis, faithfully matched the area previously irradiated with 30 Gy in 10 fractions, six and a half months earlier. After immunotherapy discontinuation and steroid treatment, the patient rapidly and completely recovered. On progression, pembrolizumab was rechallenged and, after 8 cycles, the patient is on response and there are no signs of myelitis relapse.

Conclusion

The confinement within the radiation field and the latency of appearance are suggestive of delayed radiation myelopathy. Nevertheless, the relatively low dose of radiation received and the full recovery after pembrolizumab discontinuation and steroid therapy plead for the contribution of both radiotherapy and immunotherapy in the causality of this complication, as an enhanced inflammatory reaction on a focal post-radiation chronic inflammatory state. In the three previously described cases of myelopathy occurring after radiotherapy and immunotherapy, a complete recovery had not been obtained and the immunotherapy was not rechallenged. The occurrence of a radiation recall phenomenon, in this case, can not be excluded, and radiation recall myelitis has already been described with chemotherapy and targeted therapy. Safe rechallenges with the incriminated drug, even immunotherapy, have been reported after radiation recall, but we describe it for the first time after myelitis.

Re-Irradiation of Brain Metastases and Metastatic Spinal Cord Compression: Clinical Practice Suggestions

The recent improvements of therapeutic approaches in oncology have allowed a certain number of patients with advanced disease to survive much longer than in the past. So, the number of cases with brain metastases and metastatic spinal cord compression has increased, as has the possibility of developing a recurrence in areas of the central nervous system already treated with radiotherapy.

Clinicians are reluctant to perform re-irradiation of the brain, because of the risk of severe side effects. The tolerance dose for the brain to a single course of radiotherapy is 50–60 Gy in 2 Gy daily fractions. New metastases appear in 22–73% of the cases after whole brain radiotherapy, but the percentage of re-irradiated patients is 3–10%. An accurate selection must be made before giving an indication to re-irradiation. Patients with Karnofsky performance status >70, age <65 years, controlled primary and no extracranial metastases are those with the best prognosis. The absence of extracranial disease was the most significant factor in conditioning survival, and maximum tumor diameter was the only variable associated with an increased risk of unacceptable acute and/or chronic neurotoxicity. Re-treatment of brain metastases can be done with whole brain radiotherapy, stereotactic radiosurgery or fractionated stereotactic radiotherapy. Most patients had no relevant radiation-induced toxicity after a second course of whole brain radiotherapy or stereotactic radiosurgery. There are few data on fractionated stereotactic radiotherapy in the re-irradiation of brain metastases.

In general, the incidence of an “in-field” recurrence of spinal metastasis varies from 2.5–11% of cases and can occur 2–40 months after the first radiotherapy cycle. Radiation-induced myelopathy can occur months or years (6 months-7 years) after radiotherapy, and the pathogenesis remains obscure. Higher radiotherapy doses, larger doses per fraction, and previous exposure to radiation could be associated with a higher probability of developing radiation-induced myelopathy. Experimental data indicate that also the total dose of the first and second radiotherapy, interval to re-treatment, length of the irradiated spinal cord, and age of the treated animals influence the risk of radiation-induced myelopathy. An α/β ratio of 1.9–3 Gy could be generally the reference value for fractionated radiotherapy. However, when fraction sizes are up to 5 Gy, the linear-quadratic equation become a less valid model. The early diagnosis of relapse is crucial in conditioning response to re-treatment.

Outcomes After Hypofractionated Dose-Escalation using a Simultaneous Integrated Boost Technique for Treatment of Spine Metastases Not Amenable to Stereotactic Radiosurgery

PURPOSE

Spine stereotactic radiosurgery delivers an ablative dose of radiation therapy (RT) with high conformity relative to standard fractionated RT. This technique is suboptimal for extended targets (>3 vertebral levels) owing to treatment alignment concerns or for patients with marked epidural extension. In these patients, we hypothesized that use of hypofractionated intensity modulated RT/volumetric modulated arc therapy to dose escalate the gross tumor volume (GTV) to 40 Gy as a spinal simultaneous integrated boost (SSIB) would allow for durable local control and palliation.

METHODS AND MATERIALS

We retrospectively analyzed 15 separate spinal sites (12 patients) that were treated with the SSIB technique between 2012 and 2016. The GTV and clinical target volume were prescribed at 40 Gy and 30 Gy, respectively, in 10 fractions. The spinal cord was allowed a maximum point dose of 34 Gy. The GTV was defined as gross tumor. The clinical target volume encompassed the GTV in addition to the involved vertebral bodies, at-risk paraspinal space, and spinal canal, followed by a planning target volume expansion of 3 to 5 mm.

RESULTS

The median follow-up for patients in our cohort was 17 months. At 1 year, local control was 93%, and overall survival was 58%, with a median time to death after treatment of 7 months. No grade ≥2 neurologic toxicities were reported for any of the patients. Nine of 12 patients had pain at presentation, of which 7 patients (78%) reported improvement and/or complete resolution of their pain after treatment.

CONCLUSIONS

Our early experience using a dose of 40 Gy to the GTV delivered via an SSIB technique, in lieu of spine stereotactic radiation surgery but more aggressive than conventional palliative doses, provides durable local control and pain relief. This technique may allow for improved local control and palliation in patients with radioresistant disease compared with conventional 3-dimensional conformal fractionated RT.

Exploration and application of phenomenological RBE models for proton therapy

The relative biological effectiveness (RBE) of protons varies with multiple physical and biological factors. Phenomenological RBE models have been developed to include such factors in the estimation of a variable RBE, in contrast to the clinically applied constant RBE of 1.1. In this study, eleven published phenomenological RBE models and two plan-based models were explored and applied to simulated patient cases. All models were analysed with respect to the distribution and range of linear energy transfer (LET) and reference radiation fractionation sensitivity ((α/β) _x ) of their respective experimental databases. Proton therapy plans for a spread-out Bragg peak in water and three patient cases (prostate adenocarcinoma, pituitary adenoma and thoracic sarcoma) were optimised using an RBE of 1.1 in the Eclipse^™ treatment planning system prior to recalculation and modelling in the FLUKA Monte Carlo code. Model estimated dose-volume parameters for the planning target volumes (PTVs) and organs at risk (OAR) were compared. The experimental in vitro databases for the various models differed greatly in the range of (α/β) _x values and dose-averaged LET (LET_d). There were significant variations between the model estimations, which arose from fundamental differences in the database definitions and model assumptions. The greatest variations appeared in organs with low (α/β) _x and high LET_d, e.g. biological doses given to late responding OARs located distal to the target in the treatment field. In general, the variation in maximum dose (D_2%) was larger than the variation in mean dose and other dose metrics, with D_2% of the left optic nerve ((α/β) _x   =  2.1 Gy) in the pituitary adenoma case showing the greatest discrepancies between models: 28-52 Gy(RBE), while D_2% for RBE_1.1 was 30 Gy(RBE). For all patient cases, the estimated mean RBE to the PTV was in the range 1.09-1.29 ((α/β) _x   =  1.5/3.1/10.6 Gy). There were considerable variations between the estimations of RBE and RBE-weighted doses from the different models. These variations were a consequence of fundamental differences in experimental databases, model assumptions and regression techniques. The results from the implementation of RBE models in dose planning studies should be evaluated in light of these deviations.

Comparison of four techniques for spine stereotactic body radiotherapy: Dosimetric and efficiency analysis

PURPOSE

The aim of this study is to compare the dosimetric differences between four techniques for spine stereotactic body radiotherapy (SBRT): CyberKnife (CK), volumetric modulated arc therapy (VMAT), and helical tomotherapy (HT) with dynamic jaws (HT-D) and fixed jaws (HT-F).

MATERIALS/METHODS

Data from 10 patients were utilized. All patients were planned for 24 Gy in two fractions, with the primary objectives being: (a) restricting the maximum dose to the cord to ≤ 17 Gy and/or cauda equina to ≤ 20 Gy, and (b) to maximize the clinical target volume (CTV) to receive the prescribed dose. Treatment plans were generated by separate dosimetrists and then compared using velocity AI. Parameters of comparison include target volume coverage, conformity index (CI), gradient index (GI), homogeneity index (HI), treatment time (TT) per fraction, and monitor units (MU) per fraction.

RESULTS

PTV D2 and D5 were significantly higher for CK compared to VMAT, HT-F, and HT-D (P < 0.001). The average volume of CTV receiving the prescription dose (CTV D95) was significantly less for VMAT compared to CK, HT-F and HT-D (P = 0.036). CI improved for CK (0.69), HT-F (0.66), and HT-D (0.67) compared to VMAT (0.52) (P = 0.013). CK (41.86) had the largest HI compared to VMAT (26.99), HT-F (20.69), and HT-D (21.17) (P < 0.001). GI was significantly less for CK (3.96) compared to VMAT (6.76) (P = 0.001). Likewise, CK (62.4 min, 14059 MU) had the longest treatment time and MU per fraction compared to VMAT (8.5 min, 9764 MU), HT-F (13 min, 10822 MU), and HT-D (13.5 min, 11418 MU) (P < 0.001).

CONCLUSION

Both CK and HT plans achieved conformal target coverage while respecting cord tolerance. Dose heterogeneity was significantly larger in CK. VMAT required the least treatment time and MU output, but had the least steep GI, CI, and target coverage.

Clinical outcomes of multileaf collimator-based CyberKnife for spine stereotactic body radiation therapy

OBJECTIVE

Stereotactic body radiotherapy (SBRT) for spinal metastases is becoming a prevalent therapeutic option. We aimed to evaluate the clinical feasibility and outcomes of the recently developed multileaf collimator (MLC)-based CyberKnife (CK-M) for spine SBRT.

METHODS

We reviewed 119 patients of 144 cases with 229 lesions treated with CK between November 2014 and March 2016. The lesion features, dosimetric parameters and clinical outcomes were compared between fixed cone collimator based CK (CK-F) and CK-M.

RESULTS

Of 144 cases, 78 and 66 were treated with CK-F and CK-M, respectively. CK-M achieved an adequate target volume coverage that was comparable with CK-F (median 92 vs 90%; p = 0.03) even in larger targets (median 64.2 vs 46.7 cm3; p = 0.01), respectively. CK-M showed an improvement in the gradient index (p < 0.001) and no difference in conformity (p = 0.16). With CK-M, the median beam delivery time was significantly reduced by 30% (to 34 vs 48 min; p < 0.001). CK-M showed 1 year local control rates that were comparable to CK-F (77 vs 78%, respectively; p = 0.83).

CONCLUSION

CK-M exhibits dosimetric data and local control that are comparable with CK-F, but with significant treatment time reduction. CK-M could be widely used in spine SBRT. Advances in knowledge: Given the recently developed MLC in CK, we aimed to evaluate the clinical feasibility and outcomes of MLC compared with fixed cone-based CK. MLC showed equivalent plan quality and significant treatment time reduction with comparable radiological control. We report here MLC as an effective and tolerable treatment option in CK.

Normal tissue considerations and dose-volume constraints in the moderately hypofractionated treatment of non-small cell lung cancer

Hypofractionated radiation therapy (RT) regimes in non-small cell lung cancer (NSCLC) have become increasingly popular with a number of international trials currently underway. The majority of the dose-volume-constraints (DVCs) published in the literature refer to conventional 2Gy per fraction deliveries. Here relevant organs-at-risk (OARs) are identified and available dose-volume constraint data discussed and summarised for moderately hypofractionated NSCLC regimes. The OARs examined include lung, brachial plexus, heart, oesophagus, airway and spinal cord. Where available the toxicity rates are also reported with all data summarised tabulated to aid its use in the clinic.

Spinal metastases: From conventional fractionated radiotherapy to single-dose SBRT

AIM

To review the recent evolution of spine SBRT with emphasis on single dose treatments.

BACKGROUND

Radiation treatment of spine metastases represents a challenging problem in clinical oncology, because of the high risk of inflicting damage to the spinal cord. While conventional fractionated radiation therapy still constitutes the most commonly used modality for palliative treatment, notwithstanding its efficacy in terms of palliation of pain, local tumor control has been approximately 60%. This limited effectiveness is due to previous lack of technology to precisely target the tumor while avoiding the radiosensitive spinal cord, which constitutes a dose-limiting barrier to tumor cure.

MATERIALS AND METHODS

A thorough review of the available literature on spine SBRT has been carried out and critically assessed.

RESULTS

Stereotactic body radiotherapy (SBRT) emerges as an alternative, non-invasive high-precision approach, which allows escalation of tumor dose, while effectively sparing adjacent uninvolved organs at risk. Engaging technological advances, such as on-line Cone Beam Computed Tomography (CBCT), coupled with Dynamic Multi-Leaf Collimation (DMLC) and rapid intensity-modulated (IMRT) beam delivery, have promoted an interactive image-guided (IGRT) approach that precisely conforms treatment onto a defined target volume with a rapid dose fall-off to collateral non-target tissues, such as the spinal cord. Recent technological developments allow the use of the high-dose per fraction mode of hypofractionated SBRT for spinal oligometastatic cancer, even if only a few millimeters away from the tumor.

CONCLUSION

Single-dose spine SBRT, now increasingly implemented, yields unprecedented outcomes of local tumor ablation and safety, provided that advanced technology is employed.

Radiation myelitis after hypofractionated radiotherapy with concomitant gefitinib

We describe the case of a 71-year-old Caucasian female with primary disseminated non-small cell cancer of the lung, presented for palliative radiotherapy of metastatic spread to the 9th and 11th thoracic vertebrae without intramedullary growth. Palliative radiotherapy with daily fractions of 3 Gy and a cumulative dose of 36 Gy to thoracic vertebrae 8-12 was performed. The patient received concomitantly 250 mg gefitinib daily. After a latent period of 16 months, the patient developed symptoms of myelitis. Magnetic resonance imaging (MRI) did not reveal any bony or intraspinal tumor progression, but spinal cord signal alteration. No response to steroids was achieved. The neurological symptoms were progressive in August 2013 with the right leg being completely plegic. The left leg was incompletely paralyzed. Deep and superficial sensitivity was also diminished bilaterally. The patient was completely urinary and anally incontinent. Contrary to the clinical findings, a follow-up MRI (July 2013) showed amelioration of the former signal alterations in the spinal cord. The diagnosis of paraneoplastic myelopathy was refuted by a negative test for autologous antibodies. At the last clinical visit in May 2014, the neurological symptoms were stable. The last tumor-specific treatment the patient is receiving is erlotinib 125 mg/d.

We reviewed the literature and found no reported cases of radiation myelopathy after the treatment in such a setting. The calculated probability of such complication after radiotherapy alone is statistically measurable at the level of 0.02%. We suppose that gefitinib could also play a role in the development of this rare complication.

Palliative radiotherapy regimens for patients with thoracic symptoms from non-small cell lung cancer

BACKGROUND

Palliative radiotherapy to the chest is often used in patients with lung cancer, but radiotherapy regimens are more often based on tradition than research results. This is an update of a Cochrane review first published in 2001 and previously updated in 2006.

OBJECTIVES

The two objectives of this review were:1. To assess the effects of different palliative radiotherapy regimens on improving thoracic symptoms in patients with locally advanced or metastatic non-small cell lung cancer who are not suitable for radical RT given with curative intent.2. To assess the effects of radiotherapy dose on overall survival in patients with locally advanced or metastatic non-small cell lung cancer who are not suitable for radical RT given with curative intent.

SEARCH METHODS

The electronic databases MEDLINE (1966 - Jan 2014), EMBASE and the Cochrane Central Register of Controlled Trials, reference lists, handsearching of journals and conference proceedings, and discussion with experts were used to identify potentially eligible trials, published and unpublished.Two authors (FM and RS) independently identified all studies that may be suitable for inclusion in the review.We updated the search up to January 2014.

SELECTION CRITERIA

Randomised controlled clinical trials comparing different regimens of palliative thoracic radiotherapy in patients with non-small cell lung cancer.

DATA COLLECTION AND ANALYSIS

The reviewers assessed search results independently and possible studies were highlighted and the full text obtained. Data were extracted and attempts were made to contact the original authors for missing information.The primary outcome measure was improvement in major thoracic symptoms (degree and duration). Secondary outcome measures were short and long term toxicities, effect on quality of life and overall survival.Patient reported outcomes were reported descriptively. Quantitative data such as survival and toxicity were analysed as dichotomous variables and reported using relative risks (RR).For this update of the review a meta-analysis of the survival data was carried out.

MAIN RESULTS

Fourteen randomised controlled trials (3576 patients) were included, with no new studies added in this update.There were important differences in the doses of radiotherapy investigated, the patient characteristics including disease stage and performance status and the outcome measures.The doses of RT investigated ranged from 10 Gy in 1 fraction (10Gy/1F) to 60 Gy/30F over six weeks, with a total of 19 different dose/ fractionation regimens.Potential biases were identified in some studies. Methods of randomisation, assessment of symptoms and statistical methods used were unclear in some papers. Withdrawal and drop-outs were accounted for in all but one study.All 13 studies that investigated symptoms reported that major thoracic symptoms improved following RT.There is no strong evidence that any regimen gives greater palliation. Higher dose regimens may give more acute toxicity and some regimens are associated with an increased risk of radiation myelitis. Variation in reporting of toxicities, in particular the absence of clear grading, means results of the meta-analysis should be treated with caution.Meta-analysis of overall survival broken down by performance status, a key variable, is included in this update. Further information was sought from all the original authors if stratified data was not included in the original publication. Three published studies contained sufficient data and seven authors were able to provide further information which represented 1992 patients (56% of all patients). The absence of data for nearly half of the patients has affected the quality of evidence.The meta-analysis showed no significant difference in 1-year overall survival between regimens with fewer radiotherapy fractions compared with regimens with more when patients were stratified by performance status. The results of the meta-analysis of 1-year overall survival for patients with good performance status (WHO performance status 0-1) showed moderately high heterogeneity and a summary result was not thought meaningful. The results of 1-year overall survival for patients with poor performance status was RR 0.96 (95% CI 0.91 to 1.02; moderate quality of evidence).

AUTHORS' CONCLUSIONS

Radiotherapy for patients with incurable non-small cell lung cancer can improve thoracic symptoms. Care should be taken with the dose to the spinal cord to reduce the risk of radiation myelopathy. The higher dose, more fractionated palliative radiotherapy regimens do not provide better or more durable palliation and their use to prolong survival is not supported by strong evidence. More research is needed into reducing the acute toxicity of large fraction regimens and into the role of radical compared to high dose palliative radiotherapy. In the future, large trials comparing different RT regimens may be difficult to set up because of the increasing use of systemic chemotherapy. Trials looking at how best to integrate these two modalities, particularly in good PS patients, need to be carried out.

Stereotactic radiosurgery and radiation therapy for spinal tumors

Spinal tumors constitute 15% of all CNS neoplasms. Radiation therapy can be administered for palliation of pain and spinal cord compression. However, the amount of radiation that can be administered is often limited by the tolerance of the spinal cord, especially in cases where prior radiation therapy has been given. Stereotactic radiosurgery and radiotherapy allow the delivery of a higher dose of radiation to spinal lesions, while limiting the spinal cord dose to below the tolerance level. These are technically demanding procedures and should be performed only when proper equipment and expertise are available. Data on spinal stereotactic radiosurgery and radiotherapy have emerged in recent years. This review summarizes the clinical applications of stereotactic radiosurgery and radiotherapy for spinal tumors.

Small cell carcinoma of the head and neck: report of three cases

OBJECTIVE

Small cell carcinoma of the head and neck is rare and has unique histopathological characteristics that make it difficult to diagnose and treat. In this report, the Japanese Lung Cancer Treatment Guidelines were adapted to treat three patients with small cell carcinoma of the head and neck, and outcomes evaluated.

METHODS

There was one case each of stage I small cell carcinoma of the nasal cavity, stage IV-B small cell carcinoma of the ethmoid sinus, and stage IV-A small cell carcinoma of the submandibular gland. All patients underwent chemoradiotherapy and achieved a partial response.

RESULTS

Only case one underwent surgery after chemoradiotherapy; 31 months after treatment, this patient had suffered no recurrence. Case two died three months after treatment due to bone marrow metastasis. Case three had experienced no progression after 12 months of follow up.

CONCLUSION

In this small patient series, short-term results were equivalent to or better than usual treatment outcomes for small cell carcinoma of the lung.

Single-fraction radiotherapy versus multifraction radiotherapy for palliation of painful vertebral bone metastases-equivalent efficacy, less toxicity, more convenient: a subset analysis of Radiation Therapy Oncology Group trial 97-14

BACKGROUND

The Radiation Therapy Oncology Group (RTOG) trial 97-14 revealed no difference between radiation delivered for painful bone metastases at a dose of 8 gray (Gy) in 1 fraction (single-fraction radiotherapy [SFRT]) and 30 Gy in 10 fractions (multifraction radiotherapy [MFRT]) in pain relief or narcotic use 3 months after randomization. SFRT for painful vertebral bone metastases (PVBM) has not been well accepted, possibly because of concerns about efficacy and toxicity. In the current study, the authors evaluated the subset of patients that was treated specifically for patients with PVBM.

METHODS

PVBM included the cervical, thoracic, and/or lumbar spine regions. Among patients with PVBM, differences in retreatment rates and in pain relief, narcotic use, and toxicity 3 months after randomization were evaluated.

RESULTS

Of 909 eligible patients, 235 (26%) had PVBM. Patients with and without PVBM differed in terms of the percentage of men (55% vs 47%, respectively; P = .03) and the proportion of patients with multiple painful sites (57% vs 38%, respectively; P < .01). Among those with PVBM, more patients who received MFRT had multiple sites treated (65% vs 49% for MFRT vs SFRT, respectively; P = .02). There were no statistically significant treatment differences in terms of pain relief (62% vs 70% for MFRT vs SFRT, respectively; P = .59) or freedom from narcotic use (24% vs 27%, respectively; P = .76) at 3 months. Significant differences in acute grade 2 through 4 toxicity (20% vs 10% for MFRT vs SFRT, respectively; P = .01) and acute grade 2 through 4 gastrointestinal toxicity (14% vs 6%, respectively; P = .01) were observed at 3 months, with lower toxicities seen in the patients treated with SFRT. Late toxicity was rare. No myelopathy was recorded. SFRT produced higher 3-year retreatment rates (5% vs 15%; P = .01).

CONCLUSIONS

Results for the subset of patients with PVBM in the RTOG 94-17 randomized controlled trial were comparable to those for the entire population. SFRT produced less acute toxicity and a higher rate of retreatment than MFRT. SFRT and MFRT resulted in comparable pain relief and narcotic use at 3 months.

Probabilities of radiation myelopathy specific to stereotactic body radiation therapy to guide safe practice

PURPOSE

Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients without RM.

METHODS AND MATERIALS

DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an α/β = 2 Gy (units = Gy(2/2)). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume.

RESULTS

Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions.

CONCLUSION

We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.

Local tumor control after retreatment of spinal metastasis using stereotactic body radiotherapy; comparison with initial treatment group

BACKGROUND

The aim of this study is to evaluate local control rates after stereotactic body radiotherapy (SBRT) in recurrent spinal metastasis after external beam radiotherapy (EBRT) and new spinal metastatic lesions.

MATERIAL AND METHODS

Retrospective review of medical records and radiological data was performed on 54 retreatment and 131 initial SBRT patients. To compare various fractionation schedules, the biologically effective dose (BED) was applied. SBRT dose was calculated with linear-quadratic model and normalized to a 2-Gy equivalent dose (nBED, α/β =2 Gy for spinal cord, α/β =10 Gy for tumor). Doses to a point within the spinal cord that received the maximum dose (Pmax) were checked. Local control failure was defined as progression by imaging study. Overall survival, progression free survival, delivered radiation dose to tumor and spinal cord, and spinal cord Pmax nBED were compared in two groups.

RESULTS

The mean delivered radiation doses to tumor margin during SBRT were 51.1 Gy2/10 (retreatment) and 50.7 Gy2/10 (initial treatment). Mean survival was 29.6 months (overall)/20.7 months (retreatment)/ 32.4 months (initial treatment). Mean progression free period was 23.9 months (overall)/18.0 months (retreatment)/ 26.0 months (initial treatment). Radiological control rates of retreatment and initial treatment group were 96%/95% at six months, 81%/89% at 12 months and 79%/90% at 24 months. Among 54 retreatment lesions, 13 lesions showed local control failure during follow-up. With regard to spinal cord radiation dose during SBRT, Spinal cord Pmax nBED was 46.2 Gy2/2 (retreatment) and 48.7 Gy2/2 (initial treatment). In retreatment group, total nBED to spinal cord was a mean of 83.4 Gy2/2. There was no case of radiation myelopathy detected.

CONCLUSIONS

Retreatment of spinal metastases using SBRT provided effective local control without neurological complications.

Proton therapy with concurrent chemotherapy for non-small-cell lung cancer: technique and early results

BACKGROUND

Proton therapy can deliver a more conformal dose distribution than photon radiation and may allow safe dose escalation in stage III lung cancer. Early outcomes are presented here for patients who received proton therapy with concurrent chemotherapy for non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Nineteen patients with regionally advanced NSCLC were treated with concurrent chemotherapy (carboplatin and paclitaxel [n = 18]) and proton therapy from August 2008 to April 2010 either with (n = 7) or without (n = 12) induction chemotherapy. Eighteen patients had stage III NSCLC, and 1 patient had stage IIB disease. The median proton therapy dose was 74 cobalt gray equivalent (CGE) in 2 CGE fractions with 18 patients who received ≥70 CGE. Twelve patients also received selective nodal proton therapy to the adjacent uninvolved nodal regions, with a median dose of 40 CGE (range, 40-46 CGE). The patients were routinely evaluated for treatment-related toxicity and disease progression every 3 months, with a history, physical, and computed tomography or positron emission tomography-computed tomography.

RESULTS

The median follow-ups for living patients were 15 and 16 months (range, 7-26 months), respectively. Nonhematologic and hematologic acute grade 3+ toxicity (<90 days) developed in 1 and 4 patients, respectively. Two of 16 patients assessable for late toxicity (≥90 days) developed a significant grade 3+ nonhematologic late toxicity, whereas 1 patient developed a grade 3+ hematologic late toxicity. Local progression was the site of first relapse in one patient.

CONCLUSION

Mediastinal proton therapy with concomitant chemotherapy was associated with acceptable toxicity. Although encouraging, longer follow-up with more patients is needed to confirm the long-term efficacy of this treatment.

Stereotactic body radiosurgery for spinal metastatic disease: an evidence-based review

Spinal metastasis is a problem that afflicts many cancer patients. Traditionally, conventional fractionated radiation therapy and/or surgery have been the most common approaches for managing such patients. Through technical advances in radiotherapy, high dose radiation with extremely steep drop off can now be delivered to a limited target volume along the spine under image-guidance with very high precision. This procedure, known as stereotactic body radiosurgery, provides a technique to rapidly treat selected spinal metastasis patients with single- or limited-fraction treatments that have similar to superior efficacies compared with more established approaches. This review describes current treatment systems in use to deliver stereotactic body radiosurgery as well as results of some of the larger case series from a number of institutions that report outcomes of patients treated for spinal metastatic disease. These series include nearly 1400 patients and report a cumulative local control rate of 90% with myelopathy risk that is significantly less than 1%. Based on this comprehensive review of the literature, we believe that stereotactic body radiosurgery is an established treatment modality for patients with spinal metastatic disease that is both safe and highly effective.

Spinal cord tolerance in the age of spinal radiosurgery: lessons from preclinical studies

Clinical implementation of spinal radiosurgery has increased rapidly in recent years, but little is known regarding human spinal cord tolerance to single-fraction irradiation. In contrast, preclinical studies in single-fraction spinal cord tolerance have been ongoing since the 1970s. The influences of field length, dose rate, inhomogeneous dose distributions, and reirradiation have all been investigated. This review summarizes literature regarding single-fraction spinal cord tolerance in preclinical models with an emphasis on practical clinical significance. The outcomes of studies that incorporate uniform irradiation are surprisingly consistent among multiple small- and large-animal models. Extensive investigation of inhomogeneous dose distributions in the rat has demonstrated a significant dose-volume effect while preliminary results from one pig study are contradictory. Preclinical spinal cord dose-volume studies indicate that dose distribution is more critical than the volume irradiated suggesting that neither dose-volume histogram analysis nor absolute volume constraints are effective in predicting complications. Reirradiation data are sparse, but results from guinea pig, rat, and pig studies are consistent with the hypothesis that the spinal cord possesses a large capacity for repair. The mechanisms behind the phenomena observed in spinal cord studies are not readily explained and the ability of dose response models to predict outcomes is variable underscoring the need for further investigation. Animal studies provide insight into the phenomena and mechanisms of radiosensitivity but the true significance of animal studies can only be discovered through clinical trials.

Total en bloc spondylectomy for spinal metastases in thyroid carcinoma

OBJECT

Thyroid carcinoma generally has a favorable prognosis, and patients rarely present with distant metastases. Authors of several studies have proposed piecemeal resection for spinal metastases in thyroid carcinoma; however, few have analyzed the impact of local curative surgery such as total en bloc spondylectomy (TES) for thyroid carcinoma. The purposes of the present study are to determine the strategy of surgical treatment for spinal metastases of thyroid carcinoma and to evaluate the surgical results of and the prognosis associated with TES.

METHODS

Twenty-four cases of spinal metastases were retrospectively reviewed. The patients included 16 women and 8 men, with a mean age of 60.7 years. Histological examination showed follicular carcinoma in 15 cases, papillary carcinoma in 8, and medullary carcinoma in 1. Total en bloc spondylectomy was performed in 10 cases; debulking surgery, such as piecemeal excision or eggshell curettage, was performed in 14. The average follow-up time was 55 months (12-180 months).

RESULTS

Four patients had no evidence of disease, 8 were alive with the disease, and 12 had died of the disease. The overall survival rate from the time of surgery was 74% at 5 years. Patients with visceral metastases had a significant, higher risk of death. The survival rate of patients following TES was 90% at 5 years, which was higher than the rate in patients who underwent debulking surgery (63%). However, no significant difference was observed between the 2 types of surgery. There was a local recurrence after debulking surgery in 8 (57%) of 14 cases. Because of the recurrences, reoperation was required after a mean of 41 months. In contrast, there was a local recurrence after TES in only 1 (10%) of 10 cases. The difference between debulking surgery and TES regarding local recurrence was statistically significant.

CONCLUSIONS

Total en bloc spondylectomy with enough of a margin provided favorable local control of spinal metastases of thyroid carcinoma during a patient's lifetime.

Radiation myelopathy after 36 Gy in 12 fractions palliative chest radiotherapy for squamous cell cancer of the lung: case report and review of published studies

A 55 year old man was treated with 36 Gy in 12 fractions palliative chest irradiation for squamous cell carcinoma of the lung. This was followed by 3 cycles of cisplatin and gemcitabine. Five months later he developed clinical and imaging findings consistent with radiation myelopathy. The maximum spinal cord dose was 38.9 Gy. The possible contributions of portal imaging and gemcitabine are discussed and the literature reviewed.

Phase I clinical trial of the anti-EGFR monoclonal antibody nimotuzumab with concurrent external thoracic radiotherapy in Canadian patients diagnosed with stage IIb, III or IV non-small cell lung cancer unsuitable for radical therapy

PURPOSE

Many patients with non-small cell lung cancer (NSCLC) are eligible only for palliative radiation (RT) at presentation. This study was designed to assess the feasibility of adding the anti-EGFR monoclonal antibody nimotuzumab to palliative thoracic RT.

METHODS

Patients with stage IIB, III or IV NSCLC considered unsuitable for radical radiation or chemo-radiation received nimotuzumab weekly 8× (100, 200 or 400 mg) with radiation (30 or 36 Gy in 3 Gy fractions). If response or disease stability was observed, nimotuzumab was continued every other week starting from week 10 until progression or toxicity.

RESULTS

Eighteen patients were enrolled: 6 at 100 mg, 7 at 200 mg, 5 at 400 mg nimotuzumab. Patient characteristics included median age 69 years, 11 males, 17 smokers, 17 Caucasians, stage IIIA/IIIB/IV 2/7/9, 5 Eastern Cooperative Oncology Group performance status (PS) 2; 9 adenocarcinoma. The most commonly reported adverse events were fatigue, anorexia, chills, pain and hypophosphatemia (grades 1 to 2 in most patients). No severe skin or allergic toxicity was noted. No dose-limiting toxicity was encountered. Objective response rate and disease control rate inside the radiation field were 66 and 94.0%, respectively.

CONCLUSION

Nimotuzumab administered concurrently with palliative thoracic radiation is well tolerated at each of the three doses investigated in NSCLC patients unsuitable for radical treatment. The low toxicity and absence of rash make this combination therapeutically attractive for frail patients with other co-morbidities and poor performance status. These results support further testing of this regimen in the phase II setting.

Radiobiological basis and clinical results of the simultaneous integrated boost (SIB) in intensity modulated radiotherapy (IMRT) for head and neck cancer: A review

The simultaneous integrated boost (SIB)-IMRT technique allows the simultaneous delivery of different dose levels to different target volumes within a single treatment fraction. The most significant aspect associated with SIB-IMRT is related to the fractionation strategy, concerning two time-dose parameters: (1) the shortening of the overall treatment time (OTT); (2) the increase of fraction size (FS) to the boost volume. The SIB-IMRT technique represents, therefore, a new way to investigate the accelerated fractionation in definitive treatment of head and neck (H&N) cancers. The aims of this paper are the following: (1) to briefly review the influence of OTT and FS on H&N tumors and on acutely and late responding normal tissues; (2) to review the results of clinical studies of accelerated radiotherapy not employing IMRT in H&N cancer; (3) to review the clinical experiences of the SIB-IMRT technique and to compare the different SIB regimes in terms of radiobiological efficacy.

The radiation dose-response of the human spinal cord

PURPOSE

To characterize the radiation dose-response of the human spinal cord.

METHODS AND MATERIALS

Because no single institution has sufficient data to establish a dose-response function for the human spinal cord, published reports were combined. Requisite data were dose and fractionation, number of patients at risk, number of myelopathy cases, and survival experience of the population. Eight data points for cervical myelopathy were obtained from five reports. Using maximum likelihood estimation correcting for the survival experience of the population, estimates were obtained for the median tolerance dose, slope parameter, and alpha/beta ratio in a logistic dose-response function. An adequate fit to thoracic data was not possible. Hyperbaric oxygen treatments involving the cervical cord were also analyzed.

RESULTS

The estimate of the median tolerance dose (cervical cord) was 69.4 Gy (95% confidence interval, 66.4-72.6). The alpha/beta = 0.87 Gy. At 45 Gy, the (extrapolated) probability of myelopathy is 0.03%; and at 50 Gy, 0.2%. The dose for a 5% myelopathy rate is 59.3 Gy. Graphical analysis indicates that the sensitivity of the thoracic cord is less than that of the cervical cord. There appears to be a sensitizing effect from hyperbaric oxygen treatment.

CONCLUSIONS

The estimate of alpha/beta is smaller than usually quoted, but values this small were found in some studies. Using alpha/beta = 0.87 Gy, one would expect a considerable advantage by decreasing the dose/fraction to less than 2 Gy. These results were obtained from only single fractions/day and should not be applied uncritically to hyperfractionation.

Treatment of non-small cell lung cancer, stage IIIB: ACCP evidence-based clinical practice guidelines (2nd edition)

OBJECTIVE

To develop evidence-based guidelines on best available treatment options for patients with stage IIIB non-small cell lung cancer (NSCLC).

METHODS

A review was conducted of published English-language (abstract or full text) phase II or phase III trials and guidelines from other organizations that address management of the various categories of stage IIIB disease. The literature search was provided by the Duke University Center for Clinical Health Policy Research and supplemented by any additional studies known by the authors.

RESULTS

Surgery may be indicated for carefully selected patients with T4N0-1M0. Patients with N3 nodal involvement are not considered to be surgical candidates. For individuals with unresectable disease, good performance score, and minimal weight loss, treatment with combined chemoradiotherapy results in better survival than radiotherapy (RT) alone. Concurrent chemoradiotherapy seems to be associated with improved survival compared with sequential chemoradiotherapy. Multiple daily fractions of RT when combined with chemotherapy have not been shown to result in improved survival compared with standard once-daily RT combined with chemotherapy. The optimal chemotherapy agents and the number of cycles of treatment to combine with RT are uncertain.

CONCLUSION

Prospective trials are needed to answer important questions, such as the role of induction therapy in patients with potentially resectable stage IIIB disease. Future trials are needed to answer the questions of optimal chemotherapy agents and radiation fractionation schedule. The role of targeted novel agents in combination with chemoradiotherapy is just starting to be investigated.

Physical models and simpler dosimetric descriptors of radiation late toxicity

Predicting radiation damage to specific organs is becoming ever more challenging with the use of intensity-modulated beams, nonuniform dose distributions, partial organ irradiation, and interpatient and even intraorgan variations in radiation sensitivity. Data-based physical models can be of use in summarizing complicated dose-volume data to help describe clinical outcomes and ultimately aid in the prediction of clinical toxicity. This article attempts to provide a brief overview of the use of normal tissue complication probability (NTCP) models and other simple dose/volume metrics to describe a few clinically significant complications (either frequent or serious) associated with radiation therapy of the head and neck, thorax, and abdominal-pelvic regions. Specifically, it reviews the application of these methods for late toxicities of the parotid, lung, heart, spinal cord, liver, and rectum. It focuses on organ-specific NTCP parameters as well as simple dosimetric descriptors that might be used to help treatment plan evaluation in clinical practice.

Partial volume tolerance of the spinal cord and complications of single-dose radiosurgery

BACKGROUND

Spine radiosurgery causes a rapid dose fall-off within the spinal cord. The tolerance of partial volume of the spinal cord may determine the extent of clinical application. The study analyzed the partial volume tolerance of the human spinal cord to single fraction radiosurgery.

METHODS

A total of 230 lesions with spine metastases in 177 patients were treated with radiosurgery with single fraction of 8 to 18 Gy, prescribed to the 90% isodose line that encompassed the target volume. Spinal cord volume was defined as 6 mm above and below the radiosurgery target volume. Spinal cord dose was calculated from the radiation dose/spinal cord volume histogram and correlated with clinical/neurological status and radiographic studies. Median follow-up was 6.4 months (range, 0.5-49 months). The 1-year survival rate was 49%.

RESULTS

The average spinal cord volume defined at the treated spinal segment was 5.9 +/- 2.2 mL. The average dose to the 10% spinal cord volume was 9.8 +/- 1.5 Gy, calculated from the dose-volume histogram in the group of 18 Gy prescribed dose. The spinal cord volume that received higher than 80% of the prescribed dose was 0.07 +/- 0.10 mL, which represented 1.3 +/- 1.8% of the cord volume. Among the 86 patients who survived longer than 1 year there was 1 case of radiation-induced cord injury after 13 months of radiosurgery. There were no other cases of spinal cord sequelae.

CONCLUSIONS

Whereas the maximum spinal cord tolerance to single-dose radiation is not known, partial volume tolerance of the human spinal cord is at least 10 Gy to 10% of the spinal cord volume defined as 6 mm above and below the radiosurgery target.

Palliative radiotherapy regimens for non-small cell lung cancer

BACKGROUND

Palliative radiotherapy to the chest is often used in patients with lung cancer, but radiotherapy regimens are more often based on tradition than research results.

OBJECTIVES

To discover the most effective and least toxic regimens of palliative radiotherapy for non-small cell lung cancer, and whether higher doses increase survival.

SEARCH STRATEGY

The electronic databases MEDLINE, EMBASE, Cancerlit and the Cochrane Central Register of Controlled Trials, reference lists, handsearching of journals and conference proceedings, and discussion with experts were used to identify potentially eligible trials, published and unpublished.

SELECTION CRITERIA

Randomised controlled clinical trials comparing different regimens of palliative radiotherapy in patients with non-small cell lung cancer.

DATA COLLECTION AND ANALYSIS

Fourteen randomised trials were reviewed. There were important differences in the doses of radiotherapy investigated, the patient characteristics and the outcome measures. Because of this heterogeneity no meta-analysis was attempted.

MAIN RESULTS

There is no strong evidence that any regimen gives greater palliation. Higher dose regimens give more acute toxicity, especially oesophagitis. There is evidence for a modest increase in survival (5% at 1 year and 3% at 2 years) in patients with better performance status (PS) given higher dose radiotherapy. Some regimens are associated with an increased risk of radiation myelitis.

AUTHORS' CONCLUSIONS

The majority of patients should be treated with short courses of palliative radiotherapy, of 1 or 2 fractions. Care should be taken with the dose to the spinal cord. The use of high dose palliative regimens should be considered for and discussed with selected patients with good performance status. More research is needed into reducing the acute toxicity of large fraction regimens and into the role of radical compared to high dose palliative radiotherapy. In the future, large trials comparing different RT regimens may be difficult to set up because of the increasing use of systemic chemotherapy. Trials looking at how best to integrate these two modalities, particularly in good PS patients, need to be carried out.

Hypofractionated Stereotactic Radiation Therapy for Skull Base and Upper Cervical Chordoma and Chondrosarcoma: Preliminary Results

INTRODUCTION

Chordoma and chondrosarcoma are rare tumors of the base of the skull and are difficult candidates for surgical treatment. They are also usually resistant to conventional radiation therapy. We report preliminary results of hypofractionated stereotactic radiation therapy (SRT) using the Cyberknife system (Accuray Inc., Sunnyvale, Calif., USA) for primary and recurrent chordomas and chondrosarcomas of the skull base and upper cervical region.

MATERIAL AND METHODS

Nine pathologically proven chordoma/chondrosarcoma patients underwent Cyberknife treatment, and in 4 patients Cyberknife was performed as a primary adjuvant treatment after operation. Remainder of the patients had previously received conventional radiotherapy except 1 who had received Gamma Knife treatment. The prescribed tumor dose ranged from 21 to 43.6 Gy in three to five fractions. The dosimetric characteristics were evaluated for conformity and coverage indices. Dose volume histograms of both the tumor and the critical structure were obtained, and the dose delivered to a specific volume (25, 50 and 100%) of the critical structure was calculated in each case. Mass response was measured on follow-up MRI scans. Total tumor doses of different fractionation numbers were converted into single session equivalent doses and linear quadratic equivalent doses of conventional radiation for comparison among patient groups.

RESULT

No significant complications were observed during the treatment and early follow-up periods except one instance of transient esophagitis and one instance of otitis. All treatment plans met the criteria for standard protocol of radiosurgery suggested by the Radiation Therapy Oncology Group, specifically in terms of conformity index, which ranged from 1.01 to 1.83. Three plans had a coverage index that was rated as a minor acceptable deviation. All patients were followed from 11 to 30 (median 24) months following the treatment with regular magnetic resonance images, and 4 patients showed mass reduction. Disease progression was not noted in any patient during the above follow-up period except 1 patient who showed asymptomatic recurrence on 27-month follow-up MRI. Dose volume histograms revealed that the relative dose to volume percent of critical structure, measured at 25, 50 and 100%, was apparently lower in the pretreatment surgical decompression group than in the nondecompression group. Two patients developed radiation-induced myelopathy. The delivered radiation dose to the critical structure calculated using the linear-quadratic formula was within the acceptable range in one case and exceeded 70 Gy at 50% volume of the spinal cord in the other.

CONCLUSION

The hypofractionated Cyberknife SRT is effective in generating therapeutic response in these radioresistant tumors, with minimal toxicity during the procedure and early follow-up period. Repeated radiosurgical treatment may also be feasible for tumor recurrences but deserves great caution with respect to the biological effects of the accumulated dose on the adjacent critical structures. Cyberknife SRT may be a potentially valuable treatment option once the long-term results and appropriate dose calculators are optimally defined.

Fatal radiation myelopathy after high-dose busulfan and melphalan chemotherapy and radiotherapy for Ewing's sarcoma: a review of the literature and implications for practice

Radiation myelopathy is a rare, devastating, late effect of radiotherapy to the spinal cord. Spinal cord tolerance is currently accepted as about 50 Gy in 1.8-2 Gy fractions. However, the effect of chemotherapy on cord tolerance is unclear. This issue is important, given the increasing use of chemotherapy in combination with radiotherapy. We describe the case of a 17-year-old boy with a right apical paraspinal Ewing's tumour in the neck treated with induction chemotherapy, high-dose chemotherapy (busulfan and melphalan) with peripheral stem-cell rescue and, 4 months later, radiotherapy to the primary tumour site (cervical cord received 50 Gy in 30 fractions). After a latent period of 4 months, he developed a progressive, severe and ultimately fatal radiation myelopathy, which we suggest was due to a synergistic interaction between the high-dose chemotherapy and the radiotherapy. The use of such chemotherapy regimens in Ewing's tumours should be carefully considered, particularly when radiotherapy encompassing the spinal cord is an essential component of management.

Symptom control and quality of life in people with lung cancer: a randomised trial of two palliative radiotherapy fractionation schedules

AIMS

To determine whether palliation of chest symptoms from a 10 Gy single fraction (regimen 1) was equivalent to that from 30 Gy in 10 fractions (regimen 2).

MATERIALS AND METHODS

Patients with cytologically proven, symptomatic lung cancer not amenable to curative therapy, with performance status 0-3, were randomised to receive either 30 Gy in 10 fractions or a 10 Gy single fraction. Local symptoms were scored on a physician-assessed, five-point categorical scale and summed to produce a total symptom score (TSS). This, performance status, Hospital Anxiety and Depression (HAD) score and Spitzer's quality-of-life index were noted before treatment, at 1 month after treatment and every 2 months thereafter. Palliation was defined as an improvement of one point or more in the categorical scale. Equivalence was defined as less than 20% difference in the number achieving an improvement in the TSS.

RESULTS

We randomised 149 patients and analysed 74 in each arm. According to the design criteria, palliation was equivalent between the two arms. TSS improved in 49 patients (77%) on regimen 1, and in 57 (92%) patients on regimen 2, a difference of 15% (95% confidence interval [CI] 3-28) in the proportion improving between the two regimens. A complete resolution of all symptoms was achieved in three (5%) on regimen 1, and in 14 (23%) patients on regimen 2 (P < 0.001), a difference in the proportion between the two regimens of 21% (95% CI 10-33). A significantly higher proportion of patients experienced palliation and complete resolution of chest pain and dyspnoea with regimen 2. No differences were observed in toxicity. The median survival was 22.7 weeks for regimen 1 and 28.3 weeks for regimen 2 (P = 0.197).

CONCLUSIONS

Although this trial met the pre-determined criteria for equivalence between the two palliative regimens, significantly more patients achieved complete resolution of symptoms and palliation of chest pain and dyspnoea with the fractionated regimen.